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dmaengine: assorted patches and Freescale SDMA support

RFC In review Sascha Hauer 11 participants 41 messages Aug 16, 2010 – Sep 24, 2010

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Sascha Hauer

author maintainer
#0 lore raw

Hi all,

This is the first attempt to implement the Freescale i.MX SDMA engine as part of the dmaengine API.

The first patch adds support for cyclic transfers usable for audio. There is a similar approach implemented for the dw_dmac, this patch instead adds the cyclic transfers to the dmaengine API.

Other patches not posted here are necessary to actually make use of the SDMA engine. Please pull the following branch if you want to test these patches. The branch includes mxcmmc support for the i.MX31 based on SDMA and i.MX35-3stack audio support (sgtl5000 codec):

http://git.pengutronix.de/git/imx/linux-2.6.git sdma-sdmaengine

For generating firmware images for the SDMA engine look at

http://git.pengutronix.de/git/imx/sdma-firmware.git

Sascha

author maintainer
#1 lore raw

PATCH 1/3 dmaengine: add possibility for cyclic transfers

Cyclic transfers are useful for audio where a single buffer divided in periods has to be transfered endlessly until stopped. After being prepared the transfer is started using the dma_async_descriptor->tx_submit function. dma_async_descriptor->callback is called after each period. The transfer is stopped using the DMA_TERMINATE_ALL callback. While being used for cyclic transfers the channel cannot be used for other transfer types.

Cc Haavard Skinnemoen <[email protected]>
---
 drivers/dma/dmaengine.c   |    2 ++
 include/linux/dmaengine.h |    6 +++++-
 2 files changed, 7 insertions(+), 1 deletions(-)
drivers/dma/dmaengine.c +2 -0
index 9d31d5e..e5e79ce 100644
@@ -692,6 +692,8 @@ int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_interrupt);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_prep_slave_sg);
+	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
+		!device->device_prep_dma_cyclic);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_control);
 
include/linux/dmaengine.h +5 -1
index c61d4ca..0df7864 100644
@@ -67,10 +67,11 @@ enum dma_transaction_type {
 	DMA_PRIVATE,
 	DMA_ASYNC_TX,
 	DMA_SLAVE,
+	DMA_CYCLIC,
 };
 
 /* last transaction type for creation of the capabilities mask */
-#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
+#define DMA_TX_TYPE_END (DMA_CYCLIC + 1)
 
 
 /**
@@ -478,6 +479,9 @@ struct dma_device {
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_data_direction direction,
 		unsigned long flags);
+	struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction);
 	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 		unsigned long arg);
 
Signature · 1 line
1.7.1
#2 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

Hi,

Quoted 58 lines · Sascha Hauer

Cyclic transfers are useful for audio where a single buffer divided in periods has to be transfered endlessly until stopped. After being prepared the transfer is started using the dma_async_descriptor->tx_submit function. dma_async_descriptor->callback is called after each period. The transfer is stopped using the DMA_TERMINATE_ALL callback. While being used for cyclic transfers the channel cannot be used for other transfer types.

Cc Haavard Skinnemoen <[email protected]>
---
 drivers/dma/dmaengine.c   |    2 ++
 include/linux/dmaengine.h |    6 +++++-
 2 files changed, 7 insertions(+), 1 deletions(-)
drivers/dma/dmaengine.c +2 -0
index 9d31d5e..e5e79ce 100644
@@ -692,6 +692,8 @@ int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_interrupt);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_prep_slave_sg);
+	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
+		!device->device_prep_dma_cyclic);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_control);
 
include/linux/dmaengine.h +5 -1
index c61d4ca..0df7864 100644
@@ -67,10 +67,11 @@ enum dma_transaction_type {
 	DMA_PRIVATE,
 	DMA_ASYNC_TX,
 	DMA_SLAVE,
+	DMA_CYCLIC,
 };
 
 /* last transaction type for creation of the capabilities mask */
-#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
+#define DMA_TX_TYPE_END (DMA_CYCLIC + 1)
 
 
 /**
@@ -478,6 +479,9 @@ struct dma_device {
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_data_direction direction,
 		unsigned long flags);
+	struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction);
 	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 		unsigned long arg);
 
Signature · 1 line
1.7.1

Why not implement this feature using cyclic SG lists (created with sg_chain())? This would give you endless DMA transfers without any special DMA API extensions.

Lothar Wa?mann

Signature · 9 lines
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___________________________________________________________
#3 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

2010/8/16 Lothar Wa?mann <[email protected]>:

Quoted 3 lines

Why not implement this feature using cyclic SG lists (created with sg_chain())? This would give you endless DMA transfers without any special DMA API extensions.

That would be elegant...

The driver will have to detect that the sglist is chained like an ouroboros to program the DMAC apropriately, is is easy to detect if an sglist is chained onto itself?

Yours,
Linus Walleij

author maintainer
#4 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

In reply to Lothar Waßmann
Quoted 58 lines · Lothar Wa?mann

Hi,

Quoted 55 lines · Sascha Hauer

Cyclic transfers are useful for audio where a single buffer divided in periods has to be transfered endlessly until stopped. After being prepared the transfer is started using the dma_async_descriptor->tx_submit function. dma_async_descriptor->callback is called after each period. The transfer is stopped using the DMA_TERMINATE_ALL callback. While being used for cyclic transfers the channel cannot be used for other transfer types.

Cc Haavard Skinnemoen <[email protected]>
---
 drivers/dma/dmaengine.c   |    2 ++
 include/linux/dmaengine.h |    6 +++++-
 2 files changed, 7 insertions(+), 1 deletions(-)
drivers/dma/dmaengine.c +2 -0
index 9d31d5e..e5e79ce 100644
@@ -692,6 +692,8 @@ int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_interrupt);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_prep_slave_sg);
+	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
+		!device->device_prep_dma_cyclic);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_control);
 
include/linux/dmaengine.h +5 -1
index c61d4ca..0df7864 100644
@@ -67,10 +67,11 @@ enum dma_transaction_type {
 	DMA_PRIVATE,
 	DMA_ASYNC_TX,
 	DMA_SLAVE,
+	DMA_CYCLIC,
 };
 
 /* last transaction type for creation of the capabilities mask */
-#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
+#define DMA_TX_TYPE_END (DMA_CYCLIC + 1)
 
 
 /**
@@ -478,6 +479,9 @@ struct dma_device {
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_data_direction direction,
 		unsigned long flags);
+	struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction);
 	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 		unsigned long arg);
 
Quoted 6 lines
Quoted 3 lines
Signature · 1 line
1.7.1

Why not implement this feature using cyclic SG lists (created with sg_chain())? This would give you endless DMA transfers without any special DMA API extensions.

Been there, done that. In the end it just seemed like adding additional overhead to create the sg list and using the sg for something for which it is not really designed. Still you need extensions to the DMA API to signal that you want to have a callback for every sg entry. Normally you only need a callback on the end of the list.

Sascha

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
Acked-by on v1 1/3
#5 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

In reply to Sascha Hauer

2010/8/16 Sascha Hauer <[email protected]>:

Quoted 10 lines

Cyclic transfers are useful for audio where a single buffer divided in periods has to be transfered endlessly until stopped. After being prepared the transfer is started using the dma_async_descriptor->tx_submit function. dma_async_descriptor->callback is called after each period. The transfer is stopped using the DMA_TERMINATE_ALL callback. While being used for cyclic transfers the channel cannot be used for other transfer types.

Cc Haavard Skinnemoen <[email protected]>

Looks good to me.

Yours,
Linus Walleij

author maintainer
#6 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

In reply to Sascha Hauer

Hi Dan,

Any comment to this patch?

Sascha

Quoted 59 lines · Sascha Hauer

Cyclic transfers are useful for audio where a single buffer divided in periods has to be transfered endlessly until stopped. After being prepared the transfer is started using the dma_async_descriptor->tx_submit function. dma_async_descriptor->callback is called after each period. The transfer is stopped using the DMA_TERMINATE_ALL callback. While being used for cyclic transfers the channel cannot be used for other transfer types.

Cc Haavard Skinnemoen <[email protected]>
---
 drivers/dma/dmaengine.c   |    2 ++
 include/linux/dmaengine.h |    6 +++++-
 2 files changed, 7 insertions(+), 1 deletions(-)
drivers/dma/dmaengine.c +2 -0
index 9d31d5e..e5e79ce 100644
@@ -692,6 +692,8 @@ int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_interrupt);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_prep_slave_sg);
+	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
+		!device->device_prep_dma_cyclic);
 	BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
 		!device->device_control);
 
include/linux/dmaengine.h +5 -1
index c61d4ca..0df7864 100644
@@ -67,10 +67,11 @@ enum dma_transaction_type {
 	DMA_PRIVATE,
 	DMA_ASYNC_TX,
 	DMA_SLAVE,
+	DMA_CYCLIC,
 };
 
 /* last transaction type for creation of the capabilities mask */
-#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
+#define DMA_TX_TYPE_END (DMA_CYCLIC + 1)
 
 
 /**
@@ -478,6 +479,9 @@ struct dma_device {
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_data_direction direction,
 		unsigned long flags);
+	struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction);
 	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 		unsigned long arg);
 
Signature · 1 line
1.7.1
Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#7 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

Quoted 3 lines · Sascha Hauer

Hi Dan,

Any comment to this patch?

Looks good to me especially given the unique implications for callbacks. Although, I'd like to put a description of the prep_dma_cyclic semantics in the source code. Can you respin this with a description added to the kernel-doc for struct dma_device?

--
Dan

author maintainer
#8 lore raw

Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers

Quoted 9 lines · Dan Williams
Quoted 3 lines · Sascha Hauer

Hi Dan,

Any comment to this patch?

Looks good to me especially given the unique implications for callbacks. Although, I'd like to put a description of the prep_dma_cyclic semantics in the source code. Can you respin this with a description added to the kernel-doc for struct dma_device?

Sure, will do.

Sascha

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
author maintainer
#9 lore raw

PATCH 2/3 dmaengine: add wrapper functions for dmaengine

In reply to Sascha Hauer

Currently dmaengine users have to explicitely dereference function pointers in struct dma_device. For the convenience of drivers and to be more flexible when changing the dmaengine later add static inline wrapper functions for the dma commands.

This patch is not complete yet. If there's consensus on this patch I'll provide an updated patch with the missing functions.

---
 include/linux/dmaengine.h |   41 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 41 insertions(+), 0 deletions(-)
include/linux/dmaengine.h +41 -0
index 0df7864..635c60b 100644
@@ -491,6 +491,47 @@ struct dma_device {
 	void (*device_issue_pending)(struct dma_chan *chan);
 };
 
+static inline int dmaengine_device_control(struct dma_chan *chan,
+					   enum dma_ctrl_cmd cmd,
+					   unsigned long arg)
+{
+	return chan->device->device_control(chan, cmd, arg);
+}
+
+static inline int dmaengine_slave_config(struct dma_chan *chan,
+					  struct dma_slave_config *config)
+{
+	return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
+			(unsigned long)config);
+}
+
+static inline int dmaengine_terminate_all(struct dma_chan *chan)
+{
+	return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_data_direction direction,
+		unsigned long flags)
+{
+	return chan->device->device_prep_slave_sg(chan, sgl, sg_len, direction,
+			flags);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_cyclic(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction)
+{
+	return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
+			period_len, direction);
+}
+
+static inline int dmaengine_tx_submit(struct dma_async_tx_descriptor *desc)
+{
+	return desc->tx_submit(desc);
+}
+
 static inline bool dmaengine_check_align(u8 align, size_t off1, size_t off2, size_t len)
 {
 	size_t mask;
Signature · 1 line
1.7.1
author maintainer
#10 lore raw

Re: [PATCH 2/3] dmaengine: add wrapper functions for dmaengine

Quoted 7 lines · Sascha Hauer

Currently dmaengine users have to explicitely dereference function pointers in struct dma_device. For the convenience of drivers and to be more flexible when changing the dmaengine later add static inline wrapper functions for the dma commands.

This patch is not complete yet. If there's consensus on this patch I'll provide an updated patch with the missing functions.

Dan,

Any comment on this one?

Sascha

Quoted 67 lines
---
 include/linux/dmaengine.h |   41 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 41 insertions(+), 0 deletions(-)
include/linux/dmaengine.h +41 -0
index 0df7864..635c60b 100644
@@ -491,6 +491,47 @@ struct dma_device {
 	void (*device_issue_pending)(struct dma_chan *chan);
 };
 
+static inline int dmaengine_device_control(struct dma_chan *chan,
+					   enum dma_ctrl_cmd cmd,
+					   unsigned long arg)
+{
+	return chan->device->device_control(chan, cmd, arg);
+}
+
+static inline int dmaengine_slave_config(struct dma_chan *chan,
+					  struct dma_slave_config *config)
+{
+	return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
+			(unsigned long)config);
+}
+
+static inline int dmaengine_terminate_all(struct dma_chan *chan)
+{
+	return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_data_direction direction,
+		unsigned long flags)
+{
+	return chan->device->device_prep_slave_sg(chan, sgl, sg_len, direction,
+			flags);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_cyclic(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction)
+{
+	return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
+			period_len, direction);
+}
+
+static inline int dmaengine_tx_submit(struct dma_async_tx_descriptor *desc)
+{
+	return desc->tx_submit(desc);
+}
+
 static inline bool dmaengine_check_align(u8 align, size_t off1, size_t off2, size_t len)
 {
 	size_t mask;
Signature · 7 lines
1.7.1


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Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
author maintainer
#11 lore raw

Re: [PATCH 2/3] dmaengine: add wrapper functions for dmaengine

In reply to Sascha Hauer

Hi Dan,

Any comment?

Sascha

Quoted 69 lines · Sascha Hauer

Currently dmaengine users have to explicitely dereference function pointers in struct dma_device. For the convenience of drivers and to be more flexible when changing the dmaengine later add static inline wrapper functions for the dma commands.

This patch is not complete yet. If there's consensus on this patch I'll provide an updated patch with the missing functions.

---
 include/linux/dmaengine.h |   41 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 41 insertions(+), 0 deletions(-)
include/linux/dmaengine.h +41 -0
index 0df7864..635c60b 100644
@@ -491,6 +491,47 @@ struct dma_device {
 	void (*device_issue_pending)(struct dma_chan *chan);
 };
 
+static inline int dmaengine_device_control(struct dma_chan *chan,
+					   enum dma_ctrl_cmd cmd,
+					   unsigned long arg)
+{
+	return chan->device->device_control(chan, cmd, arg);
+}
+
+static inline int dmaengine_slave_config(struct dma_chan *chan,
+					  struct dma_slave_config *config)
+{
+	return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
+			(unsigned long)config);
+}
+
+static inline int dmaengine_terminate_all(struct dma_chan *chan)
+{
+	return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_data_direction direction,
+		unsigned long flags)
+{
+	return chan->device->device_prep_slave_sg(chan, sgl, sg_len, direction,
+			flags);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_cyclic(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction)
+{
+	return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
+			period_len, direction);
+}
+
+static inline int dmaengine_tx_submit(struct dma_async_tx_descriptor *desc)
+{
+	return desc->tx_submit(desc);
+}
+
 static inline bool dmaengine_check_align(u8 align, size_t off1, size_t off2, size_t len)
 {
 	size_t mask;
Signature · 1 line
1.7.1
Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#12 lore raw

Re: [PATCH 2/3] dmaengine: add wrapper functions for dmaengine

In reply to Sascha Hauer
Quoted 47 lines · Sascha Hauer

Currently dmaengine users have to explicitely dereference function pointers in struct dma_device. For the convenience of drivers and to be more flexible when changing the dmaengine later add static inline wrapper functions for the dma commands.

This patch is not complete yet. If there's consensus on this patch I'll provide an updated patch with the missing functions.

---
?include/linux/dmaengine.h | ? 41 +++++++++++++++++++++++++++++++++++++++++ ?1 files changed, 41 insertions(+), 0 deletions(-)

include/linux/dmaengine.h +26 -0
index 0df7864..635c60b 100644
@@ -491,6 +491,47 @@ struct dma_device {
 ? ? ? ?void (*device_issue_pending)(struct dma_chan *chan);
 ?};
 
+static inline int dmaengine_device_control(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?enum dma_ctrl_cmd cmd,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?unsigned long arg)
+{
+ ? ? ? return chan->device->device_control(chan, cmd, arg);
+}
+
+static inline int dmaengine_slave_config(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct dma_slave_config *config)
+{
+ ? ? ? return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
+ ? ? ? ? ? ? ? ? ? ? ? (unsigned long)config);
+}
+
+static inline int dmaengine_terminate_all(struct dma_chan *chan)
+{
+ ? ? ? return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
+ ? ? ? ? ? ? ? struct dma_chan *chan, struct scatterlist *sgl,
+ ? ? ? ? ? ? ? unsigned int sg_len, enum dma_data_direction direction,
+ ? ? ? ? ? ? ? unsigned long flags)
+{
+ ? ? ? return chan->device->device_prep_slave_sg(chan, sgl, sg_len, direction,
+ ? ? ? ? ? ? ? ? ? ? ? flags);

include/linux/dmaengine.h struct dma_device { · line 529

Quoted 10 lines
include/linux/dmaengine.h +10 -0
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_cyclic(
+ ? ? ? ? ? ? ? struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ ? ? ? ? ? ? ? size_t period_len, enum dma_data_direction direction)
+{
+ ? ? ? return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
+ ? ? ? ? ? ? ? ? ? ? ? period_len, direction);
+}
+

No strong disagreements on the above, the type safety of dmaengine_slave_config() is nice.

include/linux/dmaengine.h struct dma_device { · line 533

Quoted 4 lines
include/linux/dmaengine.h +4 -0
+static inline int dmaengine_tx_submit(struct dma_async_tx_descriptor *desc)
+{
+ ? ? ? return desc->tx_submit(desc);
+}

This one can drop the tx.

--
Dan

author maintainer
#13 lore raw

Re: [PATCH 2/3] dmaengine: add wrapper functions for dmaengine

Hi Dan,

Quoted 39 lines · Dan Williams
Quoted 39 lines
include/linux/dmaengine.h +31 -0
index 0df7864..635c60b 100644
@@ -491,6 +491,47 @@ struct dma_device {
 ? ? ? ?void (*device_issue_pending)(struct dma_chan *chan);
 ?};
 
+static inline int dmaengine_device_control(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?enum dma_ctrl_cmd cmd,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?unsigned long arg)
+{
+ ? ? ? return chan->device->device_control(chan, cmd, arg);
+}
+
+static inline int dmaengine_slave_config(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct dma_slave_config *config)
+{
+ ? ? ? return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
+ ? ? ? ? ? ? ? ? ? ? ? (unsigned long)config);
+}
+
+static inline int dmaengine_terminate_all(struct dma_chan *chan)
+{
+ ? ? ? return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
+ ? ? ? ? ? ? ? struct dma_chan *chan, struct scatterlist *sgl,
+ ? ? ? ? ? ? ? unsigned int sg_len, enum dma_data_direction direction,
+ ? ? ? ? ? ? ? unsigned long flags)
+{
+ ? ? ? return chan->device->device_prep_slave_sg(chan, sgl, sg_len, direction,
+ ? ? ? ? ? ? ? ? ? ? ? flags);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_cyclic(
+ ? ? ? ? ? ? ? struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ ? ? ? ? ? ? ? size_t period_len, enum dma_data_direction direction)
Quoted 8 lines

include/linux/dmaengine.h struct dma_device { · line 500

Quoted 5 lines
include/linux/dmaengine.h +5 -0
+{
+ ? ? ? return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
+ ? ? ? ? ? ? ? ? ? ? ? period_len, direction);
+}
+

No strong disagreements on the above, the type safety of dmaengine_slave_config() is nice.

So you have only small disagreements? ;) I can drop the dmaengine_prep_* functions and only keep the device_control functions if like it better.

Quoted 7 lines

include/linux/dmaengine.h struct dma_device { · line 533

Quoted 5 lines
include/linux/dmaengine.h +4 -0
+static inline int dmaengine_tx_submit(struct dma_async_tx_descriptor *desc)
+{
+ ? ? ? return desc->tx_submit(desc);
+}

This one can drop the tx.

You mean the function should be named dmaengine_submit?

Sascha

Signature · 4 lines
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Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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#14 lore raw

Re: [PATCH 2/3] dmaengine: add wrapper functions for dmaengine

Quoted 51 lines · Sascha Hauer

Hi Dan,

Quoted 39 lines · Dan Williams
Quoted 39 lines
include/linux/dmaengine.h +31 -0
index 0df7864..635c60b 100644
@@ -491,6 +491,47 @@ struct dma_device {
 ? ? ? ?void (*device_issue_pending)(struct dma_chan *chan);
 ?};
 
+static inline int dmaengine_device_control(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?enum dma_ctrl_cmd cmd,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?unsigned long arg)
+{
+ ? ? ? return chan->device->device_control(chan, cmd, arg);
+}
+
+static inline int dmaengine_slave_config(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct dma_slave_config *config)
+{
+ ? ? ? return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
+ ? ? ? ? ? ? ? ? ? ? ? (unsigned long)config);
+}
+
+static inline int dmaengine_terminate_all(struct dma_chan *chan)
+{
+ ? ? ? return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
+ ? ? ? ? ? ? ? struct dma_chan *chan, struct scatterlist *sgl,
+ ? ? ? ? ? ? ? unsigned int sg_len, enum dma_data_direction direction,
+ ? ? ? ? ? ? ? unsigned long flags)
+{
+ ? ? ? return chan->device->device_prep_slave_sg(chan, sgl, sg_len, direction,
+ ? ? ? ? ? ? ? ? ? ? ? flags);
+}
+
+static inline struct dma_async_tx_descriptor *dmaengine_prep_cyclic(
+ ? ? ? ? ? ? ? struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ ? ? ? ? ? ? ? size_t period_len, enum dma_data_direction direction)
Quoted 8 lines

include/linux/dmaengine.h struct dma_device { · line 500

Quoted 5 lines
include/linux/dmaengine.h +5 -0
+{
+ ? ? ? return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
+ ? ? ? ? ? ? ? ? ? ? ? period_len, direction);
+}
+

No strong disagreements on the above, the type safety of dmaengine_slave_config() is nice.

Quoted 3 lines

So you have only small disagreements? ;) I can drop the dmaengine_prep_* functions and only keep the device_control functions if like it better.

The prep versions may just be code churn, unless there is another advantage for having a helper... debug/tracing perhaps?

Quoted 9 lines
Quoted 7 lines

include/linux/dmaengine.h struct dma_device { · line 533

Quoted 5 lines
include/linux/dmaengine.h +4 -0
+static inline int dmaengine_tx_submit(struct dma_async_tx_descriptor *desc)
+{
+ ? ? ? return desc->tx_submit(desc);
+}

This one can drop the tx.

You mean the function should be named dmaengine_submit?

Yes, the "tx" is often mistaken, understandably, for "transmit". Linus proposed renaming ->tx_submit() to just ->submit(). This helper would be a softer way to introduce that rename.

--
Dan

author maintainer
#15 lore raw

PATCH 3/3 dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.
The original Freescale code also supports support for transfering data to the internal SRAM which needs different entry points to the firmware. Support for this is currently not implemented. Also, support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

---
 arch/arm/mach-imx/include/mach/dma-v1.h |    8 +-
 arch/arm/mach-mx3/Kconfig               |    2 +
 arch/arm/plat-mxc/Kconfig               |   10 +
 arch/arm/plat-mxc/include/mach/dma.h    |   64 ++
 arch/arm/plat-mxc/include/mach/sdma.h   |    8 +
 drivers/dma/Kconfig                     |    8 +
 drivers/dma/Makefile                    |    1 +
 drivers/dma/imx-sdma.c                  | 1383 +++++++++++++++++++++++++++++++
 8 files changed, 1478 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/plat-mxc/include/mach/dma.h
 create mode 100644 arch/arm/plat-mxc/include/mach/sdma.h
 create mode 100644 drivers/dma/imx-sdma.c
arch/arm/mach-imx/include/mach/dma-v1.h +2 -6
index 287431c..ac6fd71 100644
@@ -27,6 +27,8 @@
 
 #define imx_has_dma_v1()	(cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
 
+#include <mach/dma.h>
+
 #define IMX_DMA_CHANNELS  16
 
 #define DMA_MODE_READ		0
@@ -96,12 +98,6 @@ int imx_dma_request(int channel, const char *name);
 
 void imx_dma_free(int channel);
 
-enum imx_dma_prio {
-	DMA_PRIO_HIGH = 0,
-	DMA_PRIO_MEDIUM = 1,
-	DMA_PRIO_LOW = 2
-};
-
 int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio);
 
 #endif	/* __MACH_DMA_V1_H__ */
arch/arm/mach-mx3/Kconfig +2 -0
index 85beece..301375c 100644
@@ -3,12 +3,14 @@ if ARCH_MX3
 config ARCH_MX31
 	select ARCH_HAS_RNGA
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 	bool
 
 config ARCH_MX35
 	bool
 	select ARCH_MXC_IOMUX_V3
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 
 comment "MX3 platforms:"
 
arch/arm/plat-mxc/Kconfig +10 -0
index 0527e65..6741625 100644
@@ -109,4 +109,14 @@ config ARCH_MXC_AUDMUX_V1
 config ARCH_MXC_AUDMUX_V2
 	bool
 
+config IMX_HAVE_SDMA
+	bool
+
+config IMX_SDMA
+	depends on IMX_HAVE_SDMA
+	tristate "Enable SDMA support"
+	help
+	  Include support for the SDMA engine. The SDMA engine needs additional
+	  firmware support. SDMA can be compiled as a module to support loading
+	  the firmware when a rootfs is present.
 endif
arch/arm/plat-mxc/include/mach/dma.h new file +64 -0

64 lines not on this page · raw message

arch/arm/plat-mxc/include/mach/sdma.h new file +8 -0
new file mode 100644
index 0000000..5d542b8
@@ -0,0 +1,8 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__
+
+struct sdma_platform_data {
+	int sdma_version;
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +8 -0
index 9520cf0..f76bda9 100644
@@ -195,6 +195,14 @@ config PCH_DMA
 	help
 	  Enable support for the Topcliff PCH DMA engine.
 
+config IMX_SDMA
+	tristate "Atmel AHB DMA support"
+	depends on ARCH_MXC
+	select DMA_ENGINE
+	help
+	  Support the i.MX SDMA engine. This engine is integrated into
+	  Freescale i.MX25/31/35/51 chips.
+
 config DMA_ENGINE
 	bool
 
drivers/dma/Makefile +1 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +1383 -0

1,383 lines not on this page · raw message

Signature · 1 line
1.7.1
#16 lore raw

Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support

2010/8/16 Sascha Hauer <[email protected]>:

Quoted 1 line

This patch adds support for the Freescale i.MX SDMA engine.

I like it!

Quoted 7 lines

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.

Quite fun, if the spec for the microcode is open this opens up for dynamic firmware generation for specific DMA jobs does it not?

Quoted 5 lines

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

If you want to add memcpy() capability later you're gonna need this I think, but you can take that when that need arise.

Quoted 10 lines

(...)
+++ b/arch/arm/plat-mxc/include/mach/dma.h

arch/arm/plat-mxc/include/mach/dma.h new file +7 -0
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */

arch/arm/plat-mxc/include/mach/dma.h line 17

Quoted 10 lines
arch/arm/plat-mxc/include/mach/dma.h new file +10 -0
+
+#ifndef __ASM_ARCH_MXC_DMA_H__
+#define __ASM_ARCH_MXC_DMA_H__
+
+#include <linux/scatterlist.h>
+
+/*
+ * This enumerates peripheral types. Used for SDMA.
+ */
+typedef enum {

The kernel is not really happy about typedefs, can't this be a regular enum?

Quoted 22 lines
(quoted diff) +22 -0
+ ? ? ? IMX_DMATYPE_SSI, ? ? ? ?/* MCU domain SSI */
+ ? ? ? IMX_DMATYPE_SSI_SP, ? ? /* Shared SSI */
+ ? ? ? IMX_DMATYPE_MMC, ? ? ? ?/* MMC */
+ ? ? ? IMX_DMATYPE_SDHC, ? ? ? /* SDHC */
+ ? ? ? IMX_DMATYPE_UART, ? ? ? /* MCU domain UART */
+ ? ? ? IMX_DMATYPE_UART_SP, ? ?/* Shared UART */
+ ? ? ? IMX_DMATYPE_FIRI, ? ? ? /* FIRI */
+ ? ? ? IMX_DMATYPE_CSPI, ? ? ? /* MCU domain CSPI */
+ ? ? ? IMX_DMATYPE_CSPI_SP, ? ?/* Shared CSPI */
+ ? ? ? IMX_DMATYPE_SIM, ? ? ? ?/* SIM */
+ ? ? ? IMX_DMATYPE_ATA, ? ? ? ?/* ATA */
+ ? ? ? IMX_DMATYPE_CCM, ? ? ? ?/* CCM */
+ ? ? ? IMX_DMATYPE_EXT, ? ? ? ?/* External peripheral */
+ ? ? ? IMX_DMATYPE_MSHC, ? ? ? /* Memory Stick Host Controller */
+ ? ? ? IMX_DMATYPE_MSHC_SP, ? ?/* Shared Memory Stick Host Controller */
+ ? ? ? IMX_DMATYPE_DSP, ? ? ? ?/* DSP */
+ ? ? ? IMX_DMATYPE_MEMORY, ? ? /* Memory */
+ ? ? ? IMX_DMATYPE_FIFO_MEMORY,/* FIFO type Memory */
+ ? ? ? IMX_DMATYPE_SPDIF, ? ? ?/* SPDIF */
+ ? ? ? IMX_DMATYPE_IPU_MEMORY, /* IPU Memory */
+ ? ? ? IMX_DMATYPE_ASRC, ? ? ? /* ASRC */
+ ? ? ? IMX_DMATYPE_ESAI, ? ? ? /* ESAI */

Review line 49

Quoted 10 lines
(quoted diff) +10 -0
+} sdma_peripheral_type;
+
+enum imx_dma_prio {
+ ? ? ? DMA_PRIO_HIGH = 0,
+ ? ? ? DMA_PRIO_MEDIUM = 1,
+ ? ? ? DMA_PRIO_LOW = 2
+};
+
+struct imx_dma_data {
+ ? ? ? int dma_request; /* DMA request line */

Can this be negative and what is the range? I would suspect something like u8 or u16 would surely be more apropriate...

Review line 51

Quoted 2 lines
(quoted diff) +2 -0
+ ? ? ? sdma_peripheral_type peripheral_type;
+ ? ? ? int priority;

Isn't this an enum imx_dma_prio?

Quoted 19 lines
arch/arm/plat-mxc/include/mach/dma.h new file +13 -0
+};
+
+static inline int imx_dma_is_ipu(struct dma_chan *chan)
+{
+ ? ? ? return !strcmp(dev_name(chan->device->dev), "ipu-core");
+}
+
+static inline int imx_dma_is_general_purpose(struct dma_chan *chan)
+{
+ ? ? ? return !strcmp(dev_name(chan->device->dev), "imx-sdma");
+}
+
+#endif
arch/arm/plat-mxc/include/mach/sdma.h new file +0 -0
new file mode 100644
index 0000000..5d542b8

arch/arm/plat-mxc/include/mach/sdma.h line 5

Quoted 5 lines
arch/arm/plat-mxc/include/mach/sdma.h new file +5 -0
@@ -0,0 +1,8 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__
+
+struct sdma_platform_data {
+ ? ? ? int sdma_version;

Do you have negative versions or can it be unsigned?

Quoted 93 lines
arch/arm/plat-mxc/include/mach/sdma.h new file +3 -0
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +0 -0
index 9520cf0..f76bda9 100644
@@ -195,6 +195,14 @@ config PCH_DMA

? ? ? ?help
? ? ? ? ?Enable support for the Topcliff PCH DMA engine.

drivers/dma/Kconfig +8 -0
+config IMX_SDMA
+ ? ? ? tristate "Atmel AHB DMA support"
+ ? ? ? depends on ARCH_MXC
+ ? ? ? select DMA_ENGINE
+ ? ? ? help
+ ? ? ? ? Support the i.MX SDMA engine. This engine is integrated into
+ ? ? ? ? Freescale i.MX25/31/35/51 chips.
+

?config DMA_ENGINE
? ? ? ?bool

drivers/dma/Makefile +0 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o

?obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o ?obj-$(CONFIG_PL330_DMA) += pl330.o ?obj-$(CONFIG_PCH_DMA) += pch_dma.o

drivers/dma/Makefile +1 -0
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +56 -0
new file mode 100644
index 0000000..3ba7905
@@ -0,0 +1,1383 @@
+/*
+ * drivers/dma/imx-sdma.c
+ *
+ * This file contains a driver for the Freescale Smart DMA engine
+ *
+ * Copyright 2010 Sascha Hauer, Pengutronix <[email protected]>
+ *
+ * Based on code from Freescale:
+ *
+ * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/firmware.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+
+#include <asm/irq.h>
+#include <mach/sdma.h>
+#include <mach/dma.h>
+#include <mach/hardware.h>
+
+/* SDMA registers */
+#define SDMA_H_C0PTR ? ? ? ? ? (sdma_base + 0x000)
+#define SDMA_H_INTR ? ? ? ? ? ?(sdma_base + 0x004)
+#define SDMA_H_STATSTOP ? ? ? ? ? ? ? ?(sdma_base + 0x008)
+#define SDMA_H_START ? ? ? ? ? (sdma_base + 0x00c)
+#define SDMA_H_EVTOVR ? ? ? ? ?(sdma_base + 0x010)
+#define SDMA_H_DSPOVR ? ? ? ? ?(sdma_base + 0x014)
+#define SDMA_H_HOSTOVR ? ? ? ? (sdma_base + 0x018)
+#define SDMA_H_EVTPEND ? ? ? ? (sdma_base + 0x01c)
+#define SDMA_H_DSPENBL ? ? ? ? (sdma_base + 0x020)
+#define SDMA_H_RESET ? ? ? ? ? (sdma_base + 0x024)
+#define SDMA_H_EVTERR ? ? ? ? ?(sdma_base + 0x028)
+#define SDMA_H_INTRMSK ? ? ? ? (sdma_base + 0x02c)
+#define SDMA_H_PSW ? ? ? ? ? ? (sdma_base + 0x030)
+#define SDMA_H_EVTERRDBG ? ? ? (sdma_base + 0x034)
+#define SDMA_H_CONFIG ? ? ? ? ?(sdma_base + 0x038)
+#define SDMA_ONCE_ENB ? ? ? ? ?(sdma_base + 0x040)
+#define SDMA_ONCE_DATA ? ? ? ? (sdma_base + 0x044)
+#define SDMA_ONCE_INSTR ? ? ? ? ? ? ? ?(sdma_base + 0x048)

drivers/dma/imx-sdma.c line 66

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+#define SDMA_ONCE_STAT ? ? ? ? (sdma_base + 0x04c)
+#define SDMA_ONCE_CMD ? ? ? ? ?(sdma_base + 0x050)
+#define SDMA_EVT_MIRROR ? ? ? ? ? ? ? ?(sdma_base + 0x054)
+#define SDMA_ILLINSTADDR ? ? ? (sdma_base + 0x058)
+#define SDMA_CHN0ADDR ? ? ? ? ?(sdma_base + 0x05c)
+#define SDMA_ONCE_RTB ? ? ? ? ?(sdma_base + 0x060)
+#define SDMA_XTRIG_CONF1 ? ? ? (sdma_base + 0x070)
+#define SDMA_XTRIG_CONF2 ? ? ? (sdma_base + 0x074)
+#define SDMA_CHNENBL_0 ? ? ? ? (sdma_base + (sdma_version == 2 ? 0x200 : 0x80))
+#define SDMA_CHNPRI_0 ? ? ? ? ?(sdma_base + 0x100)

All these rely on a fixed sdma_base which makes the driver a singleton. This is not so good if you imagine the situation with a platform with two SDMA engines on different addresses.

Can't you create a runtime allocated stateholder to hold the base and access relative to the offset?

Quoted 45 lines
drivers/dma/imx-sdma.c new file +45 -0
+
+/*
+ * Buffer descriptor status values.
+ */
+#define BD_DONE ?0x01
+#define BD_WRAP ?0x02
+#define BD_CONT ?0x04
+#define BD_INTR ?0x08
+#define BD_RROR ?0x10
+#define BD_LAST ?0x20
+#define BD_EXTD ?0x80
+
+/*
+ * Data Node descriptor status values.
+ */
+#define DND_END_OF_FRAME ?0x80
+#define DND_END_OF_XFER ? 0x40
+#define DND_DONE ? ? ? ? ?0x20
+#define DND_UNUSED ? ? ? ?0x01
+
+/*
+ * IPCV2 descriptor status values.
+ */
+#define BD_IPCV2_END_OF_FRAME ?0x40
+
+#define IPCV2_MAX_NODES ? ? ? ?50
+/*
+ * Error bit set in the CCB status field by the SDMA,
+ * in setbd routine, in case of a transfer error
+ */
+#define DATA_ERROR ?0x10000000
+
+/*
+ * Buffer descriptor commands.
+ */
+#define C0_ADDR ? ? ? ? ? ? 0x01
+#define C0_LOAD ? ? ? ? ? ? 0x02
+#define C0_DUMP ? ? ? ? ? ? 0x03
+#define C0_SETCTX ? ? ? ? ? 0x07
+#define C0_GETCTX ? ? ? ? ? 0x03
+#define C0_SETDM ? ? ? ? ? ?0x01
+#define C0_SETPM ? ? ? ? ? ?0x04
+#define C0_GETDM ? ? ? ? ? ?0x02
+#define C0_GETPM ? ? ? ? ? ?0x08
+/*

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ * Change endianness indicator in the BD command field
+ */
+#define CHANGE_ENDIANNESS ? 0x80
+
+/*
+ * Mode/Count of data node descriptors - IPCv2
+ */
+#ifdef __BIG_ENDIAN
+struct sdma_mode_count {
+ ? ? ? u32 command : ?8; /* command mostlky used for channel 0 */

There are a lot of inline commented struct members, please use kerneldoc, that's simple. (Applies all over the patch...) Documentation/kernel-doc-nano-HOWTO

drivers/dma/imx-sdma.c line 131

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? u32 status ?: ?8; /* E,R,I,C,W,D status bits stored here */
+ ? ? ? u32 count ? : 16; /* size of the buffer pointed by this BD */
+};
+#else
+struct sdma_mode_count {
+ ? ? ? u32 count ? : 16; /* size of the buffer pointed by this BD */
+ ? ? ? u32 status ?: ?8; /* E,R,I,C,W,D status bits stored here */
+ ? ? ? u32 command : ?8; /* command mostlky used for channel 0 */
+};
+#endif

This use of #ifdef is odd to me but others are probably more experienced. Anyway, the way it is used with different :n suffixes makes me believe that you need a packed compiler directive for this layout to be explicitly coherent.

Atleast add some comment on what this #ifdef construction does so guys like me can understand what's going on.

drivers/dma/imx-sdma.c

Quoted 8 lines
drivers/dma/imx-sdma.c new file +8 -0
+
+/*
+ * Buffer descriptor
+ */
+struct sdma_buffer_descriptor {
+ ? ? ? struct sdma_mode_count ?mode;
+ ? ? ? u32 buffer_addr; ? ?/* address of the buffer described */
+ ? ? ? u32 ext_buffer_addr; /* extended buffer address */

Shouldn't these be dma_addr_t? OK that's probably u32 anyway but just to make a marker...

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+};
+
+/*
+ * Channel control Block
+ */
+struct sdma_channel_control {
+ ? ? ? u32 current_bd_ptr; /* current buffer descriptor processed */
+ ? ? ? u32 base_bd_ptr; ? ?/* first element of buffer descriptor array */
+ ? ? ? void *unused;
+ ? ? ? void *unused1;

Hm, can you comment on what these unused things are for...?

Quoted 24 lines
drivers/dma/imx-sdma.c new file +24 -0
+};
+
+/**
+ * Context structure.
+ */
+#ifdef __BIG_ENDIAN
+struct sdma_state_registers {
+ ? ? ? u32 sf ? ? : 1; /* source fault while loading data */
+ ? ? ? u32 unused0: 1;
+ ? ? ? u32 rpc ? ?:14; /* return program counter */
+ ? ? ? u32 t ? ? ?: 1; /* test bit:status of arithmetic & test instruction*/
+ ? ? ? u32 unused1: 1;
+ ? ? ? u32 pc ? ? :14; /* program counter */
+ ? ? ? u32 lm ? ? : 2; /* loop mode */
+ ? ? ? u32 epc ? ?:14; /* loop end program counter */
+ ? ? ? u32 df ? ? : 1; /* destination fault while storing data */
+ ? ? ? u32 unused2: 1;
+ ? ? ? u32 spc ? ?:14; /* loop start program counter */
+};
+#else
+struct sdma_state_registers {
+ ? ? ? u32 pc ? ? :14; /* program counter */
+ ? ? ? u32 unused1: 1;
+ ? ? ? u32 t ? ? ?: 1; /* test bit: status of arithmetic & test instruction*/

drivers/dma/imx-sdma.c line 183

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? u32 rpc ? ?:14; /* return program counter */
+ ? ? ? u32 unused0: 1;
+ ? ? ? u32 sf ? ? : 1; /* source fault while loading data */
+ ? ? ? u32 spc ? ?:14; /* loop start program counter */
+ ? ? ? u32 unused2: 1;
+ ? ? ? u32 df ? ? : 1; /* destination fault while storing data */
+ ? ? ? u32 epc ? ?:14; /* loop end program counter */
+ ? ? ? u32 lm ? ? : 2; /* loop mode */
+};
+#endif

Again this is odd to me...

Quoted 21 lines
drivers/dma/imx-sdma.c new file +21 -0
+
+struct sdma_context_data {
+ ? ? ? struct sdma_state_registers ?channel_state; /* channel state bits */
+ ? ? ? u32 ?gReg[8]; /* general registers */
+ ? ? ? u32 ?mda; /* burst dma destination address register */
+ ? ? ? u32 ?msa; /* burst dma source address register */
+ ? ? ? u32 ?ms; ?/* burst dma status ?register */
+ ? ? ? u32 ?md; ?/* burst dma data ? ?register */
+ ? ? ? u32 ?pda; /* peripheral dma destination address register */
+ ? ? ? u32 ?psa; /* peripheral dma source address register */
+ ? ? ? u32 ?ps; ?/* peripheral dma ?status ?register */
+ ? ? ? u32 ?pd; ?/* peripheral dma ?data ? ?register */
+ ? ? ? u32 ?ca; ?/* CRC polynomial ?register */
+ ? ? ? u32 ?cs; ?/* CRC accumulator register */
+ ? ? ? u32 ?dda; /* dedicated core destination address register */
+ ? ? ? u32 ?dsa; /* dedicated core source address register */
+ ? ? ? u32 ?ds; ?/* dedicated core status ?register */
+ ? ? ? u32 ?dd; ?/* dedicated core data ? ?register */
+ ? ? ? u32 ?scratch0;
+ ? ? ? u32 ?scratch1;
+ ? ? ? u32 ?scratch2;

drivers/dma/imx-sdma.c line 214

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? u32 ?scratch3;
+ ? ? ? u32 ?scratch4;
+ ? ? ? u32 ?scratch5;
+ ? ? ? u32 ?scratch6;
+ ? ? ? u32 ?scratch7;
+};
+
+struct sdma_channel {
+ ? ? ? /* Channel number */
+ ? ? ? int channel;

Unsigned?

drivers/dma/imx-sdma.c line 220

Quoted 6 lines
drivers/dma/imx-sdma.c new file +6 -0
+ ? ? ? /* Transfer type. Needed for setting SDMA script */
+ ? ? ? enum dma_data_direction direction;
+ ? ? ? /* Peripheral type. Needed for setting SDMA script */
+ ? ? ? sdma_peripheral_type peripheral_type;
+ ? ? ? /* Peripheral event id */
+ ? ? ? int event_id;

Unsigned?

drivers/dma/imx-sdma.c line 222

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+ ? ? ? /* Peripheral event id2 (for channels that use 2 events) */
+ ? ? ? int event_id2;

Unsigned?

drivers/dma/imx-sdma.c line 224

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+ ? ? ? /* SDMA data access word size */
+ ? ? ? unsigned long word_size;

Is this in bits, bytes etc? Isn't e.g. an u8 enough to hold this, and further, isn't it possible to recycle enum dma_slave_buswidth from dmaengine.h instead?

drivers/dma/imx-sdma.c line 231

Quoted 7 lines
drivers/dma/imx-sdma.c new file +7 -0
+
+ ? ? ? /* ID of the buffer that was processed */
+ ? ? ? unsigned int buf_tail;
+
+ ? ? ? wait_queue_head_t waitq; ? ? ? ?/* channel completion waitqeue */
+
+ ? ? ? int num_bd;

Unsigned? Range?

drivers/dma/imx-sdma.c line 236

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+
+ ? ? ? struct sdma_buffer_descriptor *bd;
+ ? ? ? dma_addr_t ? ? ?bd_phys;
+
+ ? ? ? int pc_from_device, pc_to_device;

Unsigned?

drivers/dma/imx-sdma.c line 238

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+
+ ? ? ? unsigned long flags;

Is this an u32?

drivers/dma/imx-sdma.c line 251

Quoted 13 lines
drivers/dma/imx-sdma.c new file +13 -0
+ ? ? ? dma_addr_t per_address;
+
+ ? ? ? uint32_t event_mask1, event_mask2;
+ ? ? ? uint32_t watermark_level;
+ ? ? ? uint32_t shp_addr, per_addr;
+
+ ? ? ? /* DMA-Engine Channel */
+ ? ? ? struct dma_chan chan;
+
+ ? ? ? spinlock_t ? ? ? ? ? ? ?lock;
+ ? ? ? struct dma_async_tx_descriptor desc;
+ ? ? ? dma_cookie_t ? ? ? ? ? ?last_completed;
+ ? ? ? int busy;

Shouldn't this be a bool?

drivers/dma/imx-sdma.c line 264

Quoted 13 lines
drivers/dma/imx-sdma.c new file +13 -0
+};
+
+#define IMX_DMA_SG_LOOP ? ? ? ? ? ? ? ?(1 << 0)
+
+#define MAX_DMA_CHANNELS 32
+#define MXC_SDMA_DEFAULT_PRIORITY 1
+#define MXC_SDMA_MIN_PRIORITY 1
+#define MXC_SDMA_MAX_PRIORITY 7
+
+/*
+ * This enumerates transfer types
+ */
+typedef enum {

Again a typedef, please plain enum is fine.

Quoted 64 lines
drivers/dma/imx-sdma.c new file +64 -0
+ ? ? ? emi_2_per = 0, ? ? ? ? ?/* EMI memory to peripheral */
+ ? ? ? emi_2_int, ? ? ? ? ? ? ?/* EMI memory to internal RAM */
+ ? ? ? emi_2_emi, ? ? ? ? ? ? ?/* EMI memory to EMI memory */
+ ? ? ? emi_2_dsp, ? ? ? ? ? ? ?/* EMI memory to DSP memory */
+ ? ? ? per_2_int, ? ? ? ? ? ? ?/* Peripheral to internal RAM */
+ ? ? ? per_2_emi, ? ? ? ? ? ? ?/* Peripheral to internal EMI memory */
+ ? ? ? per_2_dsp, ? ? ? ? ? ? ?/* Peripheral to DSP memory */
+ ? ? ? per_2_per, ? ? ? ? ? ? ?/* Peripheral to Peripheral */
+ ? ? ? int_2_per, ? ? ? ? ? ? ?/* Internal RAM to peripheral */
+ ? ? ? int_2_int, ? ? ? ? ? ? ?/* Internal RAM to Internal RAM */
+ ? ? ? int_2_emi, ? ? ? ? ? ? ?/* Internal RAM to EMI memory */
+ ? ? ? int_2_dsp, ? ? ? ? ? ? ?/* Internal RAM to DSP memory */
+ ? ? ? dsp_2_per, ? ? ? ? ? ? ?/* DSP memory to peripheral */
+ ? ? ? dsp_2_int, ? ? ? ? ? ? ?/* DSP memory to internal RAM */
+ ? ? ? dsp_2_emi, ? ? ? ? ? ? ?/* DSP memory to EMI memory */
+ ? ? ? dsp_2_dsp, ? ? ? ? ? ? ?/* DSP memory to DSP memory */
+ ? ? ? emi_2_dsp_loop, ? ? ? ? /* EMI memory to DSP memory loopback */
+ ? ? ? dsp_2_emi_loop, ? ? ? ? /* DSP memory to EMI memory loopback */
+ ? ? ? dvfs_pll, ? ? ? ? ? ? ? /* DVFS script with PLL change ? ? ? */
+ ? ? ? dvfs_pdr ? ? ? ? ? ? ? ?/* DVFS script without PLL change ? ?*/
+} sdma_transfer_type;
+
+/*
+ * Structure containing sdma request ?parameters.
+ */
+struct sdma_script_start_addrs {
+ ? ? ? int ap_2_ap_addr;
+ ? ? ? int ap_2_bp_addr;
+ ? ? ? int ap_2_ap_fixed_addr;
+ ? ? ? int bp_2_ap_addr;
+ ? ? ? int loopback_on_dsp_side_addr;
+ ? ? ? int mcu_interrupt_only_addr;
+
+ ? ? ? int firi_2_per_addr;
+ ? ? ? int firi_2_mcu_addr;
+ ? ? ? int per_2_firi_addr;
+ ? ? ? int mcu_2_firi_addr;
+
+ ? ? ? int uart_2_per_addr;
+ ? ? ? int uart_2_mcu_addr;
+ ? ? ? int per_2_app_addr;
+ ? ? ? int mcu_2_app_addr;
+ ? ? ? int per_2_per_addr;
+
+ ? ? ? int uartsh_2_per_addr;
+ ? ? ? int uartsh_2_mcu_addr;
+ ? ? ? int per_2_shp_addr;
+ ? ? ? int mcu_2_shp_addr;
+
+ ? ? ? int ata_2_mcu_addr;
+ ? ? ? int mcu_2_ata_addr;
+
+ ? ? ? int app_2_per_addr;
+ ? ? ? int app_2_mcu_addr;
+ ? ? ? int shp_2_per_addr;
+ ? ? ? int shp_2_mcu_addr;
+
+ ? ? ? int mshc_2_mcu_addr;
+ ? ? ? int mcu_2_mshc_addr;
+
+ ? ? ? int spdif_2_mcu_addr;
+ ? ? ? int mcu_2_spdif_addr;
+
+ ? ? ? int asrc_2_mcu_addr;

drivers/dma/imx-sdma.c line 338

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+
+ ? ? ? int ext_mem_2_ipu_addr;
+
+ ? ? ? int descrambler_addr;
+
+ ? ? ? int dptc_dvfs_addr;
+
+ ? ? ? int utra_addr;
+
+ ? ? ? int ram_code_start_addr;

All these addresses, are they really integers with valid negative values... Aren't they dma_addr_t or atleast u32?

drivers/dma/imx-sdma.c line 350

Quoted 12 lines
drivers/dma/imx-sdma.c new file +12 -0
+};
+
+#define SDMA_FIRMWARE_MAGIC 0x414d4453
+
+struct sdma_firmware_header {
+ ? ? ? uint32_t ? ? ? ?magic; /* "SDMA" */
+ ? ? ? uint32_t ? ? ? ?version_major; ?/* increased whenever layout of struct sdma_script_start_addrs changes */
+ ? ? ? uint32_t ? ? ? ?version_minor; ?/* firmware version */
+ ? ? ? uint32_t ? ? ? ?script_addrs_start; /* offset of struct sdma_script_start_addrs in this image */
+ ? ? ? uint32_t ? ? ? ?num_script_addrs; /* Number of script addresses in this image */
+ ? ? ? uint32_t ? ? ? ?ram_code_start; /* offset of SDMA ram image in this firmware image */
+ ? ? ? uint32_t ? ? ? ?ram_code_size; /* size of SDMA ram image */

Please use u32. uint32_t is not the preferred kernel type. (Still I've seen people use it in some cases so I might be wrong, feel welcome to bit back on this.)

drivers/dma/imx-sdma.c line 356

Quoted 6 lines
drivers/dma/imx-sdma.c new file +6 -0
+};
+
+static struct sdma_channel sdma_data[MAX_DMA_CHANNELS];
+static struct sdma_channel_control *channel_control;
+static void __iomem *sdma_base;
+static int sdma_version;

Unsigned?

drivers/dma/imx-sdma.c line 357

Quoted 1 line
drivers/dma/imx-sdma.c new file +1 -0
+static int sdma_num_events;

Unsigned?

drivers/dma/imx-sdma.c line 361

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+static struct sdma_context_data *sdma_context;
+dma_addr_t sdma_context_phys;
+static struct dma_device __sdma_dma_device;
+static struct dma_device *sdma_dma_device = &__sdma_dma_device;

This is what I suspected: local variables making the entire driver a singleton, which means you can never have more than one SDMA. Atleast collect all of these in a struct, call it "struct sdma" simply (if you ask me) and use as a stateholder. This makes it easier to kzalloc() that struct later if you want to support non-singletons.

I know this require some work but I've done it to several drivers (always asked on mailinglists to do this) and I don't regret a single rewrite. Last time was for the PL18x DMAengine driver actually.

Quoted 42 lines
drivers/dma/imx-sdma.c new file +42 -0
+
+#define SDMA_H_CONFIG_DSPDMA ? (1 << 12) /* indicates if the DSPDMA is used */
+#define SDMA_H_CONFIG_RTD_PINS (1 << 11) /* indicates if Real-Time Debug pins are enabled */
+#define SDMA_H_CONFIG_ACR ? ? ?(1 << 4) ?/* indicates if AHB freq /core freq = 2 or 1 */
+#define SDMA_H_CONFIG_CSM ? ? ?(3) ? ? ? /* indicates which context switch mode is selected*/
+
+static int sdma_config_ownership(int channel, int event_override,
+ ? ? ? ? ? ? ? ? ?int mcu_verride, int dsp_override)
+{
+ ? ? ? u32 evt, mcu, dsp;
+
+ ? ? ? if (event_override && mcu_verride && dsp_override)
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? evt = readl(SDMA_H_EVTOVR);
+ ? ? ? mcu = readl(SDMA_H_HOSTOVR);
+ ? ? ? dsp = readl(SDMA_H_DSPOVR);
+
+ ? ? ? if (dsp_override)
+ ? ? ? ? ? ? ? dsp &= ~(1 << channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? dsp |= (1 << channel);
+
+ ? ? ? if (event_override)
+ ? ? ? ? ? ? ? evt &= ~(1 << channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? evt |= (1 << channel);
+
+ ? ? ? if (mcu_verride)
+ ? ? ? ? ? ? ? mcu &= ~(1 << channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? mcu |= (1 << channel);
+
+ ? ? ? writel(evt, SDMA_H_EVTOVR);
+ ? ? ? writel(mcu, SDMA_H_HOSTOVR);
+ ? ? ? writel(dsp, SDMA_H_DSPOVR);
+
+ ? ? ? return 0;
+}
+
+/*
+ * sdma_run_channel - run a channel and wait till it's done

drivers/dma/imx-sdma.c line 413

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ */
+static int sdma_run_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int ret;
+
+ ? ? ? writel(1 << channel, SDMA_H_START);
+
+ ? ? ? ret = wait_event_interruptible(sdma->waitq,
+ ? ? ? ? ? ? ? ? ? ? ? !(readl(SDMA_H_STATSTOP) & (1 << channel)));

OK not the biggest thing in the world, but can't you use a completion for this? (I'm not so clever with waitqueues so forgive me if this is malinformed.)

Quoted 26 lines
drivers/dma/imx-sdma.c new file +26 -0
+ ? ? ? return ret;
+}
+
+static int sdma_load_script(void *buf, int size, u32 address)
+{
+ ? ? ? struct sdma_buffer_descriptor *bd0 = sdma_data[0].bd;
+ ? ? ? void *buf_virt;
+ ? ? ? dma_addr_t buf_phys;
+ ? ? ? int ret;
+
+ ? ? ? buf_virt = dma_alloc_coherent(NULL,
+ ? ? ? ? ? ? ? ? ? ? ? size,
+ ? ? ? ? ? ? ? ? ? ? ? &buf_phys, GFP_KERNEL);
+ ? ? ? if (!buf_virt)
+ ? ? ? ? ? ? ? return -ENOMEM;
+
+ ? ? ? bd0->mode.command = C0_SETPM;
+ ? ? ? bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
+ ? ? ? bd0->mode.count = size / 2;
+ ? ? ? bd0->buffer_addr = buf_phys;
+ ? ? ? bd0->ext_buffer_addr = address;
+
+ ? ? ? memcpy(buf_virt, buf, size);
+
+ ? ? ? ret = sdma_run_channel(0);
+

drivers/dma/imx-sdma.c line 449

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? dma_free_coherent(NULL, size, buf_virt, buf_phys);
+
+ ? ? ? return ret;
+}
+
+static void sdma_event_enable(int channel, int event)
+{
+ ? ? ? u32 val;
+
+ ? ? ? val = readl(SDMA_CHNENBL_0 + event * 4);

This use indicates that event should probably be unsigned, and probably not greater than u16 atleast. I suspect it is never more than an u8 really.

drivers/dma/imx-sdma.c line 460

Quoted 11 lines
drivers/dma/imx-sdma.c new file +11 -0
+ ? ? ? val |= (1 << channel);
+ ? ? ? writel(val, SDMA_CHNENBL_0 + event * 4);
+}
+
+static void sdma_event_disable(int channel, int event)
+{
+ ? ? ? u32 val;
+
+ ? ? ? val = readl(SDMA_CHNENBL_0 + event * 4);
+ ? ? ? val &= ~(1 << channel);
+ ? ? ? writel(val, SDMA_CHNENBL_0 + event * 4);

Same comment here.

drivers/dma/imx-sdma.c

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+}
+
+static void mxc_sdma_handle_channel_loop(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];

This indicates that channel should be unsigned.

drivers/dma/imx-sdma.c line 467

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+ ? ? ? struct sdma_buffer_descriptor *bd;
+ ? ? ? int error = 0;

Unused variable?

Quoted 35 lines
drivers/dma/imx-sdma.c new file +35 -0
+
+ ? ? ? /*
+ ? ? ? ?* loop mode. Iterate over descriptors, re-setup them and
+ ? ? ? ?* call callback function.
+ ? ? ? ?*/
+ ? ? ? while (1) {
+ ? ? ? ? ? ? ? bd = &sdma->bd[sdma->buf_tail];
+
+ ? ? ? ? ? ? ? if (bd->mode.status & BD_DONE)
+ ? ? ? ? ? ? ? ? ? ? ? break;
+
+ ? ? ? ? ? ? ? if (bd->mode.status & BD_RROR)
+ ? ? ? ? ? ? ? ? ? ? ? error = -EIO;
+
+ ? ? ? ? ? ? ? bd->mode.status |= BD_DONE;
+ ? ? ? ? ? ? ? sdma->buf_tail++;
+ ? ? ? ? ? ? ? sdma->buf_tail %= sdma->num_bd;
+
+ ? ? ? ? ? ? ? if (sdma->desc.callback)
+ ? ? ? ? ? ? ? ? ? ? ? sdma->desc.callback(sdma->desc.callback_param);
+ ? ? ? }
+}
+
+static void mxc_sdma_handle_channel_normal(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? struct sdma_buffer_descriptor *bd;
+ ? ? ? int i, error = 0;
+
+ ? ? ? /*
+ ? ? ? ?* non loop mode. Iterate over all descriptors, collect
+ ? ? ? ?* errors and call callback function
+ ? ? ? ?*/
+ ? ? ? for (i = 0; i < sdma->num_bd; i++) {
+ ? ? ? ? ? ? ? bd = &sdma->bd[i];

drivers/dma/imx-sdma.c line 512

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+
+ ? ? ? ? ? ? ? ?if (bd->mode.status & (BD_DONE | BD_RROR))
+ ? ? ? ? ? ? ? ? ? ? ? error = -EIO;
+ ? ? ? }
+
+ ? ? ? if (sdma->desc.callback)
+ ? ? ? ? ? ? ? sdma->desc.callback(sdma->desc.callback_param);
+ ? ? ? sdma->last_completed = sdma->desc.cookie;
+
+ ? ? ? sdma->busy = 0;

= true if you switch this to bool..

Quoted 47 lines
drivers/dma/imx-sdma.c new file +47 -0
+}
+
+static void mxc_sdma_handle_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+
+ ? ? ? wake_up_interruptible(&sdma->waitq);
+
+ ? ? ? /* not interested in channel 0 interrupts */
+ ? ? ? if (!channel)
+ ? ? ? ? ? ? ? return;
+
+ ? ? ? if (sdma->flags & IMX_DMA_SG_LOOP)
+ ? ? ? ? ? ? ? mxc_sdma_handle_channel_loop(channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? mxc_sdma_handle_channel_normal(channel);
+}
+
+static irqreturn_t sdma_int_handler(int irq, void *dev_id)
+{
+ ? ? ? u32 stat;
+
+ ? ? ? stat = readl(SDMA_H_INTR);
+ ? ? ? writel(stat, SDMA_H_INTR);
+
+ ? ? ? while (stat) {
+ ? ? ? ? ? ? ? int channel = fls(stat) - 1;
+
+ ? ? ? ? ? ? ? mxc_sdma_handle_channel(channel);
+
+ ? ? ? ? ? ? ? stat &= ~(1 << channel);
+ ? ? ? }
+
+ ? ? ? return IRQ_HANDLED;
+}
+
+static struct clk *sdma_clk;
+
+/*
+ * Stores the start address of the SDMA scripts
+ */
+static struct sdma_script_start_addrs __sdma_script_addrs;
+static struct sdma_script_start_addrs *sdma_script_addrs = &__sdma_script_addrs;
+
+/*
+ * sets the pc of SDMA script according to the peripheral type
+ */

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+static void sdma_get_pc(struct sdma_channel *sdma,
+ ? ? ? ? ? ? ? sdma_peripheral_type peripheral_type)
+{
+ ? ? ? int res = 0;
+ ? ? ? int per_2_emi = 0, emi_2_per = 0;
+ ? ? ? int per_2_int = 0, int_2_per = 0;
+ ? ? ? int per_2_per = 0, emi_2_emi = 0;
+
+ ? ? ? sdma->pc_from_device = 0;
+ ? ? ? sdma->pc_to_device = 0;

There are a *lot* of local variables here, and only two of them are used eventually, at the end of the function. I cannot quite follow this, what is going on?

Some like emi_2_emi seem to be totally unused.

The types here look like some kind of enum or other similar construction is really what's being asked for here.

Quoted 54 lines
drivers/dma/imx-sdma.c new file +54 -0
+
+ ? ? ? switch (peripheral_type) {
+ ? ? ? case IMX_DMATYPE_MEMORY:
+ ? ? ? ? ? ? ? emi_2_emi = sdma_script_addrs->ap_2_ap_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_DSP:
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->bp_2_ap_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->ap_2_bp_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_FIRI:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->firi_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->firi_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_firi_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_firi_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_UART:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->uart_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->uart_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_app_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_app_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_UART_SP:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->uartsh_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->uartsh_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_shp_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_shp_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_ATA:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->ata_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_ata_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_CSPI:
+ ? ? ? case IMX_DMATYPE_EXT:
+ ? ? ? case IMX_DMATYPE_SSI:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->app_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->app_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_app_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_app_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_SSI_SP:
+ ? ? ? case IMX_DMATYPE_MMC:
+ ? ? ? case IMX_DMATYPE_SDHC:
+ ? ? ? case IMX_DMATYPE_CSPI_SP:
+ ? ? ? case IMX_DMATYPE_ESAI:
+ ? ? ? case IMX_DMATYPE_MSHC_SP:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->shp_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->shp_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_shp_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_shp_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_ASRC:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->asrc_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->asrc_2_mcu_addr;
+ ? ? ? ? ? ? ? per_2_per = sdma_script_addrs->per_2_per_addr;

drivers/dma/imx-sdma.c line 633

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_MSHC:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->mshc_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_mshc_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_CCM:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->dptc_dvfs_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_FIFO_MEMORY:
+ ? ? ? ? ? ? ? res = sdma_script_addrs->ap_2_ap_fixed_addr;

res? This thing is never used.

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_SPDIF:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->spdif_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_spdif_addr;

drivers/dma/imx-sdma.c line 647

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_IPU_MEMORY:
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->ext_mem_2_ipu_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? default:
+ ? ? ? ? ? ? ? break;
+ ? ? ? }
+
+ ? ? ? sdma->pc_from_device = per_2_emi;
+ ? ? ? sdma->pc_to_device = emi_2_per;

Return res? You're assigning it a value in some cases.

Quoted 14 lines
drivers/dma/imx-sdma.c new file +14 -0
+}
+
+static int sdma_load_context(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int load_address;
+ ? ? ? struct sdma_buffer_descriptor *bd0 = sdma_data[0].bd;
+ ? ? ? int ret;
+
+ ? ? ? if (sdma->direction == DMA_FROM_DEVICE) {
+ ? ? ? ? ? ? ? load_address = sdma->pc_from_device;
+ ? ? ? } else {
+ ? ? ? ? ? ? ? load_address = sdma->pc_to_device;
+ ? ? ? }

drivers/dma/imx-sdma.c line 671

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+
+ ? ? ? if (load_address < 0)
+ ? ? ? ? ? ? ? return load_address;
+
+ ? ? ? pr_debug("%s: load_address = %d\n", __func__, load_address);
+ ? ? ? pr_debug("%s: wml = 0x%08x\n", __func__, sdma->watermark_level);
+ ? ? ? pr_debug("%s: shp_addr = 0x%08x\n", __func__, sdma->shp_addr);
+ ? ? ? pr_debug("%s: per_addr = 0x%08x\n", __func__, sdma->per_addr);
+ ? ? ? pr_debug("%s: event_mask1 = 0x%08x\n", __func__, sdma->event_mask1);
+ ? ? ? pr_debug("%s: event_mask2 = 0x%08x\n", __func__, sdma->event_mask2);

Surely it must be possible to get the struct device * pointer for the channels host and use dev_dbg() instead?

Quoted 40 lines
drivers/dma/imx-sdma.c new file +40 -0
+
+ ? ? ? memset(sdma_context, 0, sizeof(*sdma_context));
+ ? ? ? sdma_context->channel_state.pc = load_address;
+
+ ? ? ? /* Send by context the event mask,base address for peripheral
+ ? ? ? ?* and watermark level
+ ? ? ? ?*/
+ ? ? ? sdma_context->gReg[0] = sdma->event_mask2;
+ ? ? ? sdma_context->gReg[1] = sdma->event_mask1;
+ ? ? ? sdma_context->gReg[2] = sdma->per_addr;
+ ? ? ? sdma_context->gReg[6] = sdma->shp_addr;
+ ? ? ? sdma_context->gReg[7] = sdma->watermark_level;
+
+ ? ? ? bd0->mode.command = C0_SETDM;
+ ? ? ? bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
+ ? ? ? bd0->mode.count = sizeof(*sdma_context) / 4;
+ ? ? ? bd0->buffer_addr = sdma_context_phys;
+ ? ? ? bd0->ext_buffer_addr = 2048 + (sizeof(*sdma_context) / 4) * channel;
+
+ ? ? ? ret = sdma_run_channel(0);
+
+ ? ? ? return ret;
+}
+
+static void sdma_disable_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+
+ ? ? ? writel(1 << channel, SDMA_H_STATSTOP);
+ ? ? ? sdma->busy = 0;
+}
+
+static int sdma_config_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int ret;
+
+ ? ? ? sdma_disable_channel(channel);
+
+ ? ? ? sdma->event_mask1 = 0;

drivers/dma/imx-sdma.c line 721

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? sdma->event_mask2 = 0;
+ ? ? ? sdma->shp_addr = 0;
+ ? ? ? sdma->per_addr = 0;
+
+ ? ? ? if (sdma->event_id)
+ ? ? ? ? ? ? ? sdma_event_enable(channel, sdma->event_id);
+
+ ? ? ? switch (sdma->peripheral_type) {
+ ? ? ? case IMX_DMATYPE_DSP:
+ ? ? ? ? ? ? ? sdma_config_ownership(channel, 0, 1, 1);

The parameters here makes yoy believe that the types should be bool rather than int...

Quoted 57 lines
drivers/dma/imx-sdma.c new file +57 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_MEMORY:
+ ? ? ? ? ? ? ? sdma_config_ownership(channel, 0, 1, 0);
+ ? ? ? ? ? ? ? break;
+ ? ? ? default:
+ ? ? ? ? ? ? ? sdma_config_ownership(channel, 1, 1, 0);
+ ? ? ? ? ? ? ? break;
+ ? ? ? }
+
+ ? ? ? sdma_get_pc(sdma, sdma->peripheral_type);
+
+ ? ? ? if ((sdma->peripheral_type != IMX_DMATYPE_MEMORY) &&
+ ? ? ? ? ? ? ? ? ? ? ? (sdma->peripheral_type != IMX_DMATYPE_DSP)) {
+ ? ? ? ? ? ? ? /* Handle multiple event channels differently */
+ ? ? ? ? ? ? ? if (sdma->event_id2) {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask2 = 1 << (sdma->event_id2 % 32);
+ ? ? ? ? ? ? ? ? ? ? ? if (sdma->event_id2 > 31)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level |= 1 << 31;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask1 = 1 << (sdma->event_id % 32);
+ ? ? ? ? ? ? ? ? ? ? ? if (sdma->event_id > 31)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level |= 1 << 30;
+ ? ? ? ? ? ? ? } else {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask1 = 1 << sdma->event_id;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask2 = 1 << (sdma->event_id - 32);
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? /* Watermark Level */
+ ? ? ? ? ? ? ? sdma->watermark_level |= sdma->watermark_level;
+ ? ? ? ? ? ? ? /* Address */
+ ? ? ? ? ? ? ? sdma->shp_addr = sdma->per_address;
+ ? ? ? } else {
+ ? ? ? ? ? ? ? sdma->watermark_level = 0; /* FIXME: M3_BASE_ADDRESS */
+ ? ? ? }
+
+ ? ? ? ret = sdma_load_context(channel);
+
+ ? ? ? return ret;
+}
+
+static int sdma_set_channel_priority(unsigned int channel, unsigned int priority)
+{
+ ? ? ? if (priority < MXC_SDMA_MIN_PRIORITY
+ ? ? ? ? ? || priority > MXC_SDMA_MAX_PRIORITY) {
+ ? ? ? ? ? ? ? return -EINVAL;
+ ? ? ? }
+
+ ? ? ? writel(priority, SDMA_CHNPRI_0 + 4 * channel);
+
+ ? ? ? return 0;
+}
+
+static int sdma_request_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int ret = -EBUSY;
+
+ ? ? ? sdma->bd = dma_alloc_coherent(NULL, PAGE_SIZE, &sdma->bd_phys, GFP_KERNEL);
+ ? ? ? if (!sdma->bd) {

drivers/dma/imx-sdma.c line 788

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto out;
+ ? ? ? }
+
+ ? ? ? memset(sdma->bd, 0, PAGE_SIZE);
+
+ ? ? ? channel_control[channel].base_bd_ptr = sdma->bd_phys;
+ ? ? ? channel_control[channel].current_bd_ptr = sdma->bd_phys;
+
+ ? ? ? clk_enable(sdma_clk);

Aha you're enabling it once for every channel and rely on clk reference counting that's clever!

Quoted 32 lines
drivers/dma/imx-sdma.c new file +32 -0
+
+ ? ? ? sdma_set_channel_priority(channel, MXC_SDMA_DEFAULT_PRIORITY);
+
+ ? ? ? init_waitqueue_head(&sdma->waitq);
+
+ ? ? ? sdma->buf_tail = 0;
+
+ ? ? ? return 0;
+out:
+
+ ? ? ? return ret;
+}
+
+static void sdma_enable_channel(int channel)
+{
+ ? ? ? writel(1 << channel, SDMA_H_START);
+}
+
+static int __init sdma_init(unsigned long phys_base, int irq, int version,
+ ? ? ? ? ? ? ? void *ram_code,
+ ? ? ? ? ? ? ? int ram_code_size)
+{
+ ? ? ? int i, ret;
+ ? ? ? int channel;
+ ? ? ? dma_addr_t ccb_phys;
+
+ ? ? ? sdma_version = version;
+ ? ? ? switch (sdma_version) {
+ ? ? ? case 1:
+ ? ? ? ? ? ? ? sdma_num_events = 32;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case 2:

drivers/dma/imx-sdma.c line 830

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? sdma_num_events = 48;
+ ? ? ? ? ? ? ? break;
+ ? ? ? default:
+ ? ? ? ? ? ? ? pr_err("SDMA: Unknown version %d. aborting\n", sdma_version);
+ ? ? ? ? ? ? ? return -ENODEV;
+ ? ? ? }
+
+ ? ? ? clk_enable(sdma_clk);
+
+ ? ? ? sdma_base = ioremap(phys_base, 4096);

Use SZ_4K instead of 4096.

Quoted 125 lines
drivers/dma/imx-sdma.c new file +125 -0
+ ? ? ? if (!sdma_base) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_ioremap;
+ ? ? ? }
+
+ ? ? ? /* Initialize SDMA private data */
+ ? ? ? memset(sdma_data, 0, sizeof(struct sdma_channel) * MAX_DMA_CHANNELS);
+
+ ? ? ? for (channel = 0; channel < MAX_DMA_CHANNELS; channel++)
+ ? ? ? ? ? ? ? sdma_data[channel].channel = channel;
+
+ ? ? ? ret = request_irq(irq, sdma_int_handler, 0, "sdma", NULL);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_request_irq;
+
+ ? ? ? /* Be sure SDMA has not started yet */
+ ? ? ? writel(0, SDMA_H_C0PTR);
+
+ ? ? ? channel_control = dma_alloc_coherent(NULL,
+ ? ? ? ? ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control) +
+ ? ? ? ? ? ? ? ? ? ? ? sizeof(struct sdma_context_data),
+ ? ? ? ? ? ? ? ? ? ? ? &ccb_phys, GFP_KERNEL);
+
+ ? ? ? if (!channel_control) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_dma_alloc;
+ ? ? ? }
+
+ ? ? ? sdma_context = (void *)channel_control +
+ ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control);
+ ? ? ? sdma_context_phys = ccb_phys +
+ ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control);
+
+ ? ? ? /* Zero-out the CCB structures array just allocated */
+ ? ? ? memset(channel_control, 0,
+ ? ? ? ? ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control));
+
+ ? ? ? /* disable all channels */
+ ? ? ? for (i = 0; i < sdma_num_events; i++)
+ ? ? ? ? ? ? ? writel(0, SDMA_CHNENBL_0 + i * 4);
+
+ ? ? ? /* All channels have priority 0 */
+ ? ? ? for (i = 0; i < MAX_DMA_CHANNELS; i++)
+ ? ? ? ? ? ? ? writel(0, SDMA_CHNPRI_0 + i * 4);
+
+ ? ? ? ret = sdma_request_channel(0);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_dma_alloc;
+
+ ? ? ? sdma_config_ownership(0, 0, 1, 0);
+
+ ? ? ? /* Set Command Channel (Channel Zero) */
+ ? ? ? writel(0x4050, SDMA_CHN0ADDR);
+
+ ? ? ? /* Set bits of CONFIG register but with static context switching */
+ ? ? ? /* FIXME: Check whether to set ACR bit depending on clock ratios */
+ ? ? ? writel(0, SDMA_H_CONFIG);
+
+ ? ? ? writel(ccb_phys, SDMA_H_C0PTR);
+
+ ? ? ? /* download the RAM image for SDMA */
+ ? ? ? sdma_load_script(ram_code,
+ ? ? ? ? ? ? ? ? ? ? ? ram_code_size,
+ ? ? ? ? ? ? ? ? ? ? ? sdma_script_addrs->ram_code_start_addr);
+
+ ? ? ? /* Set bits of CONFIG register with given context switching mode */
+ ? ? ? writel(SDMA_H_CONFIG_CSM, SDMA_H_CONFIG);
+
+ ? ? ? /* Initializes channel's priorities */
+ ? ? ? sdma_set_channel_priority(0, 7);
+
+ ? ? ? clk_disable(sdma_clk);
+
+ ? ? ? return 0;
+
+err_dma_alloc:
+ ? ? ? free_irq(irq, NULL);
+err_request_irq:
+ ? ? ? iounmap(sdma_base);
+err_ioremap:
+ ? ? ? clk_disable(sdma_clk);
+ ? ? ? pr_err("%s failed with %d\n", __func__, ret);
+ ? ? ? return ret;
+}
+
+static dma_cookie_t sdma_assign_cookie(struct sdma_channel *sdma)
+{
+ ? ? ? dma_cookie_t cookie = sdma->chan.cookie;
+
+ ? ? ? if (++cookie < 0)
+ ? ? ? ? ? ? ? cookie = 1;
+
+ ? ? ? sdma->chan.cookie = cookie;
+ ? ? ? sdma->desc.cookie = cookie;
+
+ ? ? ? return cookie;
+}
+
+static struct sdma_channel *to_sdma_chan(struct dma_chan *chan)
+{
+ ? ? ? return container_of(chan, struct sdma_channel, chan);
+}
+
+static dma_cookie_t sdma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(tx->chan);
+ ? ? ? dma_cookie_t cookie;
+
+ ? ? ? spin_lock_irq(&sdma->lock);
+
+ ? ? ? cookie = sdma_assign_cookie(sdma);
+
+ ? ? ? sdma_enable_channel(tx->chan->chan_id);
+
+ ? ? ? spin_unlock_irq(&sdma->lock);
+
+ ? ? ? return cookie;
+}
+
+static int sdma_alloc_chan_resources(struct dma_chan *chan)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? struct imx_dma_data *data = chan->private;
+ ? ? ? int prio, ret;
+

drivers/dma/imx-sdma.c line 965

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? /* No need to execute this for internal channel 0 */
+ ? ? ? if (!chan->chan_id)
+ ? ? ? ? ? ? ? return 0;
+
+ ? ? ? if (!data)
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? switch (data->priority) {
+ ? ? ? case DMA_PRIO_HIGH:
+ ? ? ? ? ? ? ? prio = 3;

Wait, aren't these enumerated?
Add some enum sdma_channel_prio {}..

Quoted 59 lines
drivers/dma/imx-sdma.c new file +59 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case DMA_PRIO_MEDIUM:
+ ? ? ? ? ? ? ? prio = 2;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case DMA_PRIO_LOW:
+ ? ? ? default:
+ ? ? ? ? ? ? ? prio = 1;
+ ? ? ? ? ? ? ? break;
+ ? ? ? }
+
+ ? ? ? sdma->peripheral_type = data->peripheral_type;
+ ? ? ? sdma->event_id = data->dma_request;
+ ? ? ? ret = sdma_set_channel_priority(chan->chan_id, prio);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? return ret;
+
+ ? ? ? if (chan->chan_id) {
+ ? ? ? ? ? ? ? ret = sdma_request_channel(chan->chan_id);
+ ? ? ? ? ? ? ? if (ret)
+ ? ? ? ? ? ? ? ? ? ? ? return ret;
+ ? ? ? }
+
+ ? ? ? dma_async_tx_descriptor_init(&sdma->desc, chan);
+ ? ? ? sdma->desc.tx_submit = sdma_tx_submit;
+ ? ? ? /* txd.flags will be overwritten in prep funcs */
+ ? ? ? sdma->desc.flags = DMA_CTRL_ACK;
+
+ ? ? ? return 0;
+}
+
+static void sdma_free_chan_resources(struct dma_chan *chan)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? int channel = chan->chan_id;
+
+ ? ? ? sdma_disable_channel(channel);
+
+ ? ? ? if (sdma->event_id)
+ ? ? ? ? ? ? ? sdma_event_disable(channel, sdma->event_id);
+ ? ? ? if (sdma->event_id2)
+ ? ? ? ? ? ? ? sdma_event_disable(channel, sdma->event_id2);
+
+ ? ? ? sdma->event_id = 0;
+ ? ? ? sdma->event_id2 = 0;
+
+ ? ? ? sdma_set_channel_priority(channel, 0);
+
+ ? ? ? dma_free_coherent(NULL, PAGE_SIZE, sdma->bd, sdma->bd_phys);
+
+ ? ? ? clk_disable(sdma_clk);
+}
+
+#define NUM_BD (int)(PAGE_SIZE / sizeof(struct sdma_buffer_descriptor))
+
+static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
+ ? ? ? ? ? ? ? struct dma_chan *chan, struct scatterlist *sgl,
+ ? ? ? ? ? ? ? unsigned int sg_len, enum dma_data_direction direction,
+ ? ? ? ? ? ? ? unsigned long flags)
+{

drivers/dma/imx-sdma.c line 1034

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? int ret, i, count;
+ ? ? ? int channel = chan->chan_id;
+ ? ? ? struct scatterlist *sg;
+
+ ? ? ? if (sdma->busy)
+ ? ? ? ? ? ? ? return NULL;
+ ? ? ? sdma->busy = 1;
+
+ ? ? ? sdma->flags = 0;

What are those flags anyway? I think you will need some #define:s for them.

Quoted 69 lines
drivers/dma/imx-sdma.c new file +69 -0
+
+ ? ? ? pr_debug("SDMA: setting up %d entries for channel %d.\n",
+ ? ? ? ? ? ? ? ? ? ? ? sg_len, channel);
+
+ ? ? ? sdma->direction = direction;
+ ? ? ? ret = sdma_load_context(channel);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_out;
+
+ ? ? ? if (sg_len > NUM_BD) {
+ ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, sg_len, NUM_BD);
+ ? ? ? ? ? ? ? ret = -EINVAL;
+ ? ? ? ? ? ? ? goto err_out;
+ ? ? ? }
+
+ ? ? ? for_each_sg(sgl, sg, sg_len, i) {
+ ? ? ? ? ? ? ? struct sdma_buffer_descriptor *bd = &sdma->bd[i];
+ ? ? ? ? ? ? ? int param;
+
+ ? ? ? ? ? ? ? bd->buffer_addr = sgl->dma_address;
+
+ ? ? ? ? ? ? ? count = sg->length;
+
+ ? ? ? ? ? ? ? if (count > 0xffff) {
+ ? ? ? ? ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, count, 0xffff);
+ ? ? ? ? ? ? ? ? ? ? ? ret = -EINVAL;
+ ? ? ? ? ? ? ? ? ? ? ? goto err_out;
+ ? ? ? ? ? ? ? }
+
+ ? ? ? ? ? ? ? bd->mode.count = count;
+
+ ? ? ? ? ? ? ? if (sdma->word_size > 4) {
+ ? ? ? ? ? ? ? ? ? ? ? ret = ?-EINVAL;
+ ? ? ? ? ? ? ? ? ? ? ? goto err_out;
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? if (sdma->word_size == 4)
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = 0;
+ ? ? ? ? ? ? ? else
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = sdma->word_size;
+
+ ? ? ? ? ? ? ? param = BD_DONE | BD_EXTD | BD_CONT;
+
+ ? ? ? ? ? ? ? if (sdma->flags & IMX_DMA_SG_LOOP) {
+ ? ? ? ? ? ? ? ? ? ? ? param |= BD_INTR;
+ ? ? ? ? ? ? ? ? ? ? ? if (i + 1 == sg_len)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param |= BD_WRAP;
+ ? ? ? ? ? ? ? }
+
+ ? ? ? ? ? ? ? if (i + 1 == sg_len)
+ ? ? ? ? ? ? ? ? ? ? ? param |= BD_INTR;
+
+ ? ? ? ? ? ? ? pr_debug("entry %d: count: %d dma: 0x%08x %s%s\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? i, count, sg->dma_address,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_WRAP ? "wrap" : "",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_INTR ? " intr" : "");
+
+ ? ? ? ? ? ? ? bd->mode.status = param;
+ ? ? ? }
+
+ ? ? ? sdma->num_bd = sg_len;
+ ? ? ? channel_control[channel].current_bd_ptr = sdma->bd_phys;
+
+ ? ? ? return &sdma->desc;
+err_out:
+ ? ? ? return NULL;
+}
+

drivers/dma/imx-sdma.c line 1113

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
+ ? ? ? ? ? ? ? struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
+ ? ? ? ? ? ? ? size_t period_len, enum dma_data_direction direction)
+{
+ ? ? ? int num_periods = buf_len / period_len;
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? int channel = chan->chan_id;
+ ? ? ? int ret, i = 0, buf = 0;
+
+ ? ? ? pr_debug("%s channel: %d\n", __func__, channel);

Must be possible to find struct device * and use dev_dbg()

Quoted 212 lines
drivers/dma/imx-sdma.c new file +212 -0
+
+ ? ? ? if (sdma->busy)
+ ? ? ? ? ? ? ? return NULL;
+
+ ? ? ? sdma->busy = 1;
+
+ ? ? ? sdma->flags |= IMX_DMA_SG_LOOP;
+ ? ? ? sdma->direction = direction;
+ ? ? ? ret = sdma_load_context(channel);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_out;
+
+ ? ? ? if (num_periods > NUM_BD) {
+ ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, num_periods, NUM_BD);
+ ? ? ? ? ? ? ? goto err_out;
+ ? ? ? }
+
+ ? ? ? if (period_len > 0xffff) {
+ ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum period size exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, period_len, 0xffff);
+ ? ? ? ? ? ? ? goto err_out;
+ ? ? ? }
+
+ ? ? ? while (buf < buf_len) {
+ ? ? ? ? ? ? ? struct sdma_buffer_descriptor *bd = &sdma->bd[i];
+ ? ? ? ? ? ? ? int param;
+
+ ? ? ? ? ? ? ? bd->buffer_addr = dma_addr;
+
+ ? ? ? ? ? ? ? bd->mode.count = period_len;
+
+ ? ? ? ? ? ? ? if (sdma->word_size > 4)
+ ? ? ? ? ? ? ? ? ? ? ? goto err_out;
+ ? ? ? ? ? ? ? if (sdma->word_size == 4)
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = 0;
+ ? ? ? ? ? ? ? else
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = sdma->word_size;
+
+ ? ? ? ? ? ? ? param = BD_DONE | BD_EXTD | BD_CONT | BD_INTR;
+ ? ? ? ? ? ? ? if (i + 1 == num_periods)
+ ? ? ? ? ? ? ? ? ? ? ? param |= BD_WRAP;
+
+ ? ? ? ? ? ? ? pr_debug("entry %d: count: %d dma: 0x%08x %s%s\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? i, period_len, dma_addr,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_WRAP ? "wrap" : "",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_INTR ? " intr" : "");
+
+ ? ? ? ? ? ? ? bd->mode.status = param;
+
+ ? ? ? ? ? ? ? dma_addr += period_len;
+ ? ? ? ? ? ? ? buf += period_len;
+
+ ? ? ? ? ? ? ? i++;
+ ? ? ? }
+
+ ? ? ? sdma->num_bd = num_periods;
+ ? ? ? channel_control[channel].current_bd_ptr = sdma->bd_phys;
+
+ ? ? ? return &sdma->desc;
+err_out:
+ ? ? ? sdma->busy = 0;
+ ? ? ? return NULL;
+}
+
+static int sdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ ? ? ? ? ? ? ? unsigned long arg)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? struct dma_slave_config *dmaengine_cfg = (void *)arg;
+
+ ? ? ? switch (cmd) {
+ ? ? ? case DMA_TERMINATE_ALL:
+ ? ? ? ? ? ? ? sdma_disable_channel(chan->chan_id);
+ ? ? ? ? ? ? ? return 0;
+ ? ? ? case DMA_SLAVE_CONFIG:
+ ? ? ? ? ? ? ? if (dmaengine_cfg->direction == DMA_FROM_DEVICE) {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->per_address = dmaengine_cfg->src_addr;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level = dmaengine_cfg->src_maxburst;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->word_size = dmaengine_cfg->src_addr_width;
+ ? ? ? ? ? ? ? } else {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->per_address = dmaengine_cfg->dst_addr;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level = dmaengine_cfg->dst_maxburst;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->word_size = dmaengine_cfg->dst_addr_width;
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? return sdma_config_channel(chan->chan_id);
+ ? ? ? default:
+ ? ? ? ? ? ? ? return -ENOSYS;
+ ? ? ? }
+
+ ? ? ? return -EINVAL;
+}
+
+static enum dma_status sdma_tx_status(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? dma_cookie_t cookie,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct dma_tx_state *txstate)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? dma_cookie_t last_used;
+ ? ? ? enum dma_status ret;
+
+ ? ? ? last_used = chan->cookie;
+
+ ? ? ? ret = dma_async_is_complete(cookie, sdma->last_completed, last_used);
+ ? ? ? dma_set_tx_state(txstate, sdma->last_completed, last_used, 0);
+
+ ? ? ? return ret;
+}
+
+static void sdma_issue_pending(struct dma_chan *chan)
+{
+ ? ? ? /*
+ ? ? ? ?* Nothing to do. We only have a single descriptor
+ ? ? ? ?*/
+}
+
+static int __devinit sdma_probe(struct platform_device *pdev)
+{
+ ? ? ? int ret;
+ ? ? ? const struct firmware *fw;
+ ? ? ? const struct sdma_firmware_header *header;
+ ? ? ? const struct sdma_script_start_addrs *addr;
+ ? ? ? int irq;
+ ? ? ? unsigned short *ram_code;
+ ? ? ? struct resource *iores;
+ ? ? ? struct sdma_platform_data *pdata = pdev->dev.platform_data;
+ ? ? ? int version;
+ ? ? ? char *cpustr, *fwname;
+ ? ? ? int i;
+ ? ? ? dma_cap_mask_t mask;
+
+ ? ? ? /* there can be only one */
+ ? ? ? BUG_ON(sdma_base);
+
+ ? ? ? iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ? ? ? irq = platform_get_irq(pdev, 0);
+ ? ? ? if (!iores || irq < 0 || !pdata)
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? sdma_clk = clk_get(&pdev->dev, NULL);
+ ? ? ? if (IS_ERR(sdma_clk)) {
+ ? ? ? ? ? ? ? ret = PTR_ERR(sdma_clk);
+ ? ? ? ? ? ? ? goto err_clk;
+ ? ? ? }
+
+ ? ? ? if (cpu_is_mx31()) {
+ ? ? ? ? ? ? ? cpustr = "imx31";
+ ? ? ? ? ? ? ? version = mx31_revision() >> 4;
+ ? ? ? } else if (cpu_is_mx35()) {
+ ? ? ? ? ? ? ? cpustr = "imx35";
+/* FIXME: ? ? ?version = mx35_revision(); */
+ ? ? ? ? ? ? ? version = 2;
+ ? ? ? } else {
+ ? ? ? ? ? ? ? ret = -EINVAL;
+ ? ? ? ? ? ? ? goto err_cputype;
+ ? ? ? }
+
+ ? ? ? fwname = kasprintf(GFP_KERNEL, "sdma-%s-to%d.bin", cpustr, version);
+ ? ? ? if (!fwname) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_cputype;
+ ? ? ? }
+
+ ? ? ? ret = request_firmware(&fw, fwname, &pdev->dev);
+ ? ? ? if (ret) {
+ ? ? ? ? ? ? ? dev_err(&pdev->dev, "request firmware \"%s\" failed with %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fwname, ret);
+ ? ? ? ? ? ? ? kfree(fwname);
+ ? ? ? ? ? ? ? goto err_cputype;
+ ? ? ? }
+ ? ? ? kfree(fwname);
+
+ ? ? ? if (fw->size < sizeof(*header))
+ ? ? ? ? ? ? ? goto err_firmware;
+
+ ? ? ? header = (struct sdma_firmware_header *)fw->data;
+
+ ? ? ? if (header->magic != SDMA_FIRMWARE_MAGIC)
+ ? ? ? ? ? ? ? goto err_firmware;
+ ? ? ? if (header->ram_code_start + header->ram_code_size > fw->size)
+ ? ? ? ? ? ? ? goto err_firmware;
+
+ ? ? ? addr = (void *)header + header->script_addrs_start;
+ ? ? ? ram_code = (void *)header + header->ram_code_start;
+ ? ? ? memcpy(&__sdma_script_addrs, addr, sizeof(*addr));
+
+ ? ? ? ret = sdma_init(iores->start, irq, pdata->sdma_version,
+ ? ? ? ? ? ? ? ? ? ? ? ram_code, header->ram_code_size);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_firmware;
+
+ ? ? ? INIT_LIST_HEAD(&sdma_dma_device->channels);
+
+ ? ? ? /* Initialize channel parameters */
+ ? ? ? for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+ ? ? ? ? ? ? ? struct sdma_channel *sdma = &sdma_data[i];
+
+ ? ? ? ? ? ? ? spin_lock_init(&sdma->lock);
+
+ ? ? ? ? ? ? ? dma_cap_set(DMA_SLAVE, sdma_dma_device->cap_mask);
+ ? ? ? ? ? ? ? dma_cap_set(DMA_CYCLIC, sdma_dma_device->cap_mask);
+
+ ? ? ? ? ? ? ? sdma->chan.device = sdma_dma_device;
+ ? ? ? ? ? ? ? sdma->chan.chan_id = i;
+
+ ? ? ? ? ? ? ? /* Add the channel to the DMAC list */
+ ? ? ? ? ? ? ? list_add_tail(&sdma->chan.device_node, &sdma_dma_device->channels);
+ ? ? ? }
+
+ ? ? ? sdma_dma_device->dev = &pdev->dev;
+
+ ? ? ? sdma_dma_device->device_alloc_chan_resources = sdma_alloc_chan_resources;

drivers/dma/imx-sdma.c line 1335

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? sdma_dma_device->device_free_chan_resources = sdma_free_chan_resources;
+ ? ? ? sdma_dma_device->device_tx_status = sdma_tx_status;
+ ? ? ? sdma_dma_device->device_prep_slave_sg = sdma_prep_slave_sg;
+ ? ? ? sdma_dma_device->device_prep_dma_cyclic = sdma_prep_dma_cyclic;
+ ? ? ? sdma_dma_device->device_control = sdma_control;
+ ? ? ? sdma_dma_device->device_issue_pending = sdma_issue_pending;
+
+ ? ? ? ret = dma_async_device_register(sdma_dma_device);
+ ? ? ? if (ret) {
+ ? ? ? ? ? ? ? dev_err(&pdev->dev, "unable to register DMAC\n");

SDMAC even?

Quoted 49 lines
drivers/dma/imx-sdma.c new file +48 -1
+ ? ? ? ? ? ? ? goto err_firmware;
+ ? ? ? }
+
+ ? ? ? dev_info(&pdev->dev, "initialized (firmware %d.%d)\n",
+ ? ? ? ? ? ? ? ? ? ? ? header->version_major,
+ ? ? ? ? ? ? ? ? ? ? ? header->version_minor);
+
+ ? ? ? /* request channel 0. This is an internal control channel
+ ? ? ? ?* to the SDMA engine and not available to clients.
+ ? ? ? ?*/
+ ? ? ? dma_cap_zero(mask);
+ ? ? ? dma_cap_set(DMA_SLAVE, mask);
+ ? ? ? dma_request_channel(mask, NULL, NULL);
+
+ ? ? ? release_firmware(fw);
+
+ ? ? ? return 0;
+
+err_firmware:
+ ? ? ? release_firmware(fw);
+err_cputype:
+ ? ? ? clk_put(sdma_clk);
+err_clk:
+ ? ? ? return 0;
+}
+
+static int __devexit sdma_remove(struct platform_device *pdev)
+{
+ ? ? ? return -EBUSY;
+}
+
+static struct platform_driver sdma_driver = {
+ ? ? ? .driver ? ? ? ? = {
+ ? ? ? ? ? ? ? .name ? = "imx-sdma",
+ ? ? ? },
+ ? ? ? .probe ? ? ? ? ?= sdma_probe,
+ ? ? ? .remove ? ? ? ? = __devexit_p(sdma_remove),
+};
+
+static int __init sdma_module_init(void)
+{
+ ? ? ? return platform_driver_register(&sdma_driver);
+}
+subsys_initcall(sdma_module_init);
+
+MODULE_AUTHOR("Sascha Hauer, Pengutronix <[email protected]>");
+MODULE_DESCRIPTION("i.MX SDMA driver");
+MODULE_LICENSE("GPL");
--
Quoted 1 line

1.7.1

Thanks for using this API
Sascha!

Yours,
Linus Walleij

author maintainer
#17 lore raw

Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support

Hi Linus,

Thank you for the review. Sorry for so many trival mistakes in the code, but I'm staring at this code in many different variants for some time now and I'm getting blind on it.

Quoted 14 lines · Linus Walleij

2010/8/16 Sascha Hauer <[email protected]>:

Quoted 1 line

This patch adds support for the Freescale i.MX SDMA engine.

I like it!

Quoted 7 lines

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.

Quoted 3 lines

Quite fun, if the spec for the microcode is open this opens up for dynamic firmware generation for specific DMA jobs does it not?

Unfortunately the specs are not open, so we are sticked to the binary microcode from Freescale. I'm pretty sure though that the SDMA engine could do at least a device_prep_dma_xor operation.

Quoted 9 lines
Quoted 6 lines

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

If you want to add memcpy() capability later you're gonna need this I think, but you can take that when that need arise.

Yes, I left this as an exercise for those who want to have this feature ;)

I think it's better to have tested code in the Kernel than having a complicated list handling which is completely untested for anything other than a single entry in the list.

Quoted 85 lines
Quoted 11 lines

(...)
+++ b/arch/arm/plat-mxc/include/mach/dma.h

arch/arm/plat-mxc/include/mach/dma.h new file +7 -0
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */

arch/arm/plat-mxc/include/mach/dma.h line 17

Quoted 10 lines
arch/arm/plat-mxc/include/mach/dma.h new file +10 -0
+
+#ifndef __ASM_ARCH_MXC_DMA_H__
+#define __ASM_ARCH_MXC_DMA_H__
+
+#include <linux/scatterlist.h>
+
+/*
+ * This enumerates peripheral types. Used for SDMA.
+ */
+typedef enum {

The kernel is not really happy about typedefs, can't this be a regular enum?

Quoted 22 lines
(quoted diff) +22 -0
+ ? ? ? IMX_DMATYPE_SSI, ? ? ? ?/* MCU domain SSI */
+ ? ? ? IMX_DMATYPE_SSI_SP, ? ? /* Shared SSI */
+ ? ? ? IMX_DMATYPE_MMC, ? ? ? ?/* MMC */
+ ? ? ? IMX_DMATYPE_SDHC, ? ? ? /* SDHC */
+ ? ? ? IMX_DMATYPE_UART, ? ? ? /* MCU domain UART */
+ ? ? ? IMX_DMATYPE_UART_SP, ? ?/* Shared UART */
+ ? ? ? IMX_DMATYPE_FIRI, ? ? ? /* FIRI */
+ ? ? ? IMX_DMATYPE_CSPI, ? ? ? /* MCU domain CSPI */
+ ? ? ? IMX_DMATYPE_CSPI_SP, ? ?/* Shared CSPI */
+ ? ? ? IMX_DMATYPE_SIM, ? ? ? ?/* SIM */
+ ? ? ? IMX_DMATYPE_ATA, ? ? ? ?/* ATA */
+ ? ? ? IMX_DMATYPE_CCM, ? ? ? ?/* CCM */
+ ? ? ? IMX_DMATYPE_EXT, ? ? ? ?/* External peripheral */
+ ? ? ? IMX_DMATYPE_MSHC, ? ? ? /* Memory Stick Host Controller */
+ ? ? ? IMX_DMATYPE_MSHC_SP, ? ?/* Shared Memory Stick Host Controller */
+ ? ? ? IMX_DMATYPE_DSP, ? ? ? ?/* DSP */
+ ? ? ? IMX_DMATYPE_MEMORY, ? ? /* Memory */
+ ? ? ? IMX_DMATYPE_FIFO_MEMORY,/* FIFO type Memory */
+ ? ? ? IMX_DMATYPE_SPDIF, ? ? ?/* SPDIF */
+ ? ? ? IMX_DMATYPE_IPU_MEMORY, /* IPU Memory */
+ ? ? ? IMX_DMATYPE_ASRC, ? ? ? /* ASRC */
+ ? ? ? IMX_DMATYPE_ESAI, ? ? ? /* ESAI */

Review line 49

Quoted 10 lines
(quoted diff) +10 -0
+} sdma_peripheral_type;
+
+enum imx_dma_prio {
+ ? ? ? DMA_PRIO_HIGH = 0,
+ ? ? ? DMA_PRIO_MEDIUM = 1,
+ ? ? ? DMA_PRIO_LOW = 2
+};
+
+struct imx_dma_data {
+ ? ? ? int dma_request; /* DMA request line */

Can this be negative and what is the range? I would suspect something like u8 or u16 would surely be more apropriate...

Review line 51

Quoted 2 lines
(quoted diff) +2 -0
+ ? ? ? sdma_peripheral_type peripheral_type;
+ ? ? ? int priority;

Isn't this an enum imx_dma_prio?

Quoted 18 lines
arch/arm/plat-mxc/include/mach/dma.h new file +13 -0
+};
+
+static inline int imx_dma_is_ipu(struct dma_chan *chan)
+{
+ ? ? ? return !strcmp(dev_name(chan->device->dev), "ipu-core");
+}
+
+static inline int imx_dma_is_general_purpose(struct dma_chan *chan)
+{
+ ? ? ? return !strcmp(dev_name(chan->device->dev), "imx-sdma");
+}
+
+#endif
arch/arm/plat-mxc/include/mach/sdma.h new file +0 -0
new file mode 100644
index 0000000..5d542b8
Quoted 8 lines

arch/arm/plat-mxc/include/mach/sdma.h line 5

Quoted 6 lines
arch/arm/plat-mxc/include/mach/sdma.h new file +5 -0
@@ -0,0 +1,8 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__
+
+struct sdma_platform_data {
+ ? ? ? int sdma_version;

Do you have negative versions or can it be unsigned?

nope, will change this to an unsigned type.

Quoted 109 lines
Quoted 94 lines
arch/arm/plat-mxc/include/mach/sdma.h new file +3 -0
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +0 -0
index 9520cf0..f76bda9 100644
@@ -195,6 +195,14 @@ config PCH_DMA

? ? ? ?help
? ? ? ? ?Enable support for the Topcliff PCH DMA engine.

drivers/dma/Kconfig +8 -0
+config IMX_SDMA
+ ? ? ? tristate "Atmel AHB DMA support"
+ ? ? ? depends on ARCH_MXC
+ ? ? ? select DMA_ENGINE
+ ? ? ? help
+ ? ? ? ? Support the i.MX SDMA engine. This engine is integrated into
+ ? ? ? ? Freescale i.MX25/31/35/51 chips.
+

?config DMA_ENGINE
? ? ? ?bool

drivers/dma/Makefile +0 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o

?obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o ?obj-$(CONFIG_PL330_DMA) += pl330.o ?obj-$(CONFIG_PCH_DMA) += pch_dma.o

drivers/dma/Makefile +1 -0
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +56 -0
new file mode 100644
index 0000000..3ba7905
@@ -0,0 +1,1383 @@
+/*
+ * drivers/dma/imx-sdma.c
+ *
+ * This file contains a driver for the Freescale Smart DMA engine
+ *
+ * Copyright 2010 Sascha Hauer, Pengutronix <[email protected]>
+ *
+ * Based on code from Freescale:
+ *
+ * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/firmware.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+
+#include <asm/irq.h>
+#include <mach/sdma.h>
+#include <mach/dma.h>
+#include <mach/hardware.h>
+
+/* SDMA registers */
+#define SDMA_H_C0PTR ? ? ? ? ? (sdma_base + 0x000)
+#define SDMA_H_INTR ? ? ? ? ? ?(sdma_base + 0x004)
+#define SDMA_H_STATSTOP ? ? ? ? ? ? ? ?(sdma_base + 0x008)
+#define SDMA_H_START ? ? ? ? ? (sdma_base + 0x00c)
+#define SDMA_H_EVTOVR ? ? ? ? ?(sdma_base + 0x010)
+#define SDMA_H_DSPOVR ? ? ? ? ?(sdma_base + 0x014)
+#define SDMA_H_HOSTOVR ? ? ? ? (sdma_base + 0x018)
+#define SDMA_H_EVTPEND ? ? ? ? (sdma_base + 0x01c)
+#define SDMA_H_DSPENBL ? ? ? ? (sdma_base + 0x020)
+#define SDMA_H_RESET ? ? ? ? ? (sdma_base + 0x024)
+#define SDMA_H_EVTERR ? ? ? ? ?(sdma_base + 0x028)
+#define SDMA_H_INTRMSK ? ? ? ? (sdma_base + 0x02c)
+#define SDMA_H_PSW ? ? ? ? ? ? (sdma_base + 0x030)
+#define SDMA_H_EVTERRDBG ? ? ? (sdma_base + 0x034)
+#define SDMA_H_CONFIG ? ? ? ? ?(sdma_base + 0x038)
+#define SDMA_ONCE_ENB ? ? ? ? ?(sdma_base + 0x040)
+#define SDMA_ONCE_DATA ? ? ? ? (sdma_base + 0x044)
+#define SDMA_ONCE_INSTR ? ? ? ? ? ? ? ?(sdma_base + 0x048)

drivers/dma/imx-sdma.c line 66

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+#define SDMA_ONCE_STAT ? ? ? ? (sdma_base + 0x04c)
+#define SDMA_ONCE_CMD ? ? ? ? ?(sdma_base + 0x050)
+#define SDMA_EVT_MIRROR ? ? ? ? ? ? ? ?(sdma_base + 0x054)
+#define SDMA_ILLINSTADDR ? ? ? (sdma_base + 0x058)
+#define SDMA_CHN0ADDR ? ? ? ? ?(sdma_base + 0x05c)
+#define SDMA_ONCE_RTB ? ? ? ? ?(sdma_base + 0x060)
+#define SDMA_XTRIG_CONF1 ? ? ? (sdma_base + 0x070)
+#define SDMA_XTRIG_CONF2 ? ? ? (sdma_base + 0x074)
+#define SDMA_CHNENBL_0 ? ? ? ? (sdma_base + (sdma_version == 2 ? 0x200 : 0x80))
+#define SDMA_CHNPRI_0 ? ? ? ? ?(sdma_base + 0x100)

All these rely on a fixed sdma_base which makes the driver a singleton. This is not so good if you imagine the situation with a platform with two SDMA engines on different addresses.

Quoted 2 lines

Can't you create a runtime allocated stateholder to hold the base and access relative to the offset?

This could be done since a dma channel is a pointer now. Originally a channel was referenced by its number only. Doing this would only be for the beauty of the code though since I don't think there will be ever more than one SDMA engine in one SoC. Famous last words...

Quoted 52 lines
Quoted 52 lines
drivers/dma/imx-sdma.c new file +51 -0
+
+/*
+ * Buffer descriptor status values.
+ */
+#define BD_DONE ?0x01
+#define BD_WRAP ?0x02
+#define BD_CONT ?0x04
+#define BD_INTR ?0x08
+#define BD_RROR ?0x10
+#define BD_LAST ?0x20
+#define BD_EXTD ?0x80
+
+/*
+ * Data Node descriptor status values.
+ */
+#define DND_END_OF_FRAME ?0x80
+#define DND_END_OF_XFER ? 0x40
+#define DND_DONE ? ? ? ? ?0x20
+#define DND_UNUSED ? ? ? ?0x01
+
+/*
+ * IPCV2 descriptor status values.
+ */
+#define BD_IPCV2_END_OF_FRAME ?0x40
+
+#define IPCV2_MAX_NODES ? ? ? ?50
+/*
+ * Error bit set in the CCB status field by the SDMA,
+ * in setbd routine, in case of a transfer error
+ */
+#define DATA_ERROR ?0x10000000
+
+/*
+ * Buffer descriptor commands.
+ */
+#define C0_ADDR ? ? ? ? ? ? 0x01
+#define C0_LOAD ? ? ? ? ? ? 0x02
+#define C0_DUMP ? ? ? ? ? ? 0x03
+#define C0_SETCTX ? ? ? ? ? 0x07
+#define C0_GETCTX ? ? ? ? ? 0x03
+#define C0_SETDM ? ? ? ? ? ?0x01
+#define C0_SETPM ? ? ? ? ? ?0x04
+#define C0_GETDM ? ? ? ? ? ?0x02
+#define C0_GETPM ? ? ? ? ? ?0x08
+/*
+ * Change endianness indicator in the BD command field
+ */
+#define CHANGE_ENDIANNESS ? 0x80
+
+/*
+ * Mode/Count of data node descriptors - IPCv2
Quoted 8 lines

drivers/dma/imx-sdma.c

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+ */
+#ifdef __BIG_ENDIAN
+struct sdma_mode_count {
+ ? ? ? u32 command : ?8; /* command mostlky used for channel 0 */

There are a lot of inline commented struct members, please use kerneldoc, that's simple. (Applies all over the patch...) Documentation/kernel-doc-nano-HOWTO

Ok.

Quoted 17 lines

drivers/dma/imx-sdma.c line 131

Quoted 11 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? u32 status ?: ?8; /* E,R,I,C,W,D status bits stored here */
+ ? ? ? u32 count ? : 16; /* size of the buffer pointed by this BD */
+};
+#else
+struct sdma_mode_count {
+ ? ? ? u32 count ? : 16; /* size of the buffer pointed by this BD */
+ ? ? ? u32 status ?: ?8; /* E,R,I,C,W,D status bits stored here */
+ ? ? ? u32 command : ?8; /* command mostlky used for channel 0 */
+};
+#endif

This use of #ifdef is odd to me but others are probably more experienced. Anyway, the way it is used with different :n suffixes makes me believe that you need a packed compiler directive for this layout to be explicitly coherent.

Quoted 2 lines

Atleast add some comment on what this #ifdef construction does so guys like me can understand what's going on.

This is a direct copy from the Freescale code. Since Linux does not support i.MX SoCs in big endian modes I think we can remove the ifdef completely. Adding this again will be the smallest problem when we want to add big endian mode in the future.

Quoted 13 lines

drivers/dma/imx-sdma.c

Quoted 9 lines
drivers/dma/imx-sdma.c new file +8 -0
+
+/*
+ * Buffer descriptor
+ */
+struct sdma_buffer_descriptor {
+ ? ? ? struct sdma_mode_count ?mode;
+ ? ? ? u32 buffer_addr; ? ?/* address of the buffer described */
+ ? ? ? u32 ext_buffer_addr; /* extended buffer address */

Shouldn't these be dma_addr_t? OK that's probably u32 anyway but just to make a marker...

Quoted 12 lines

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+};
+
+/*
+ * Channel control Block
+ */
+struct sdma_channel_control {
+ ? ? ? u32 current_bd_ptr; /* current buffer descriptor processed */
+ ? ? ? u32 base_bd_ptr; ? ?/* first element of buffer descriptor array */
+ ? ? ? void *unused;
+ ? ? ? void *unused1;

Hm, can you comment on what these unused things are for...?

The SDMA engine expects an array of these structures (one for each channel). The unused fields are just to make the structure the correct size. They should be of type u32 though.

Quoted 79 lines
Quoted 25 lines
drivers/dma/imx-sdma.c new file +24 -0
+};
+
+/**
+ * Context structure.
+ */
+#ifdef __BIG_ENDIAN
+struct sdma_state_registers {
+ ? ? ? u32 sf ? ? : 1; /* source fault while loading data */
+ ? ? ? u32 unused0: 1;
+ ? ? ? u32 rpc ? ?:14; /* return program counter */
+ ? ? ? u32 t ? ? ?: 1; /* test bit:status of arithmetic & test instruction*/
+ ? ? ? u32 unused1: 1;
+ ? ? ? u32 pc ? ? :14; /* program counter */
+ ? ? ? u32 lm ? ? : 2; /* loop mode */
+ ? ? ? u32 epc ? ?:14; /* loop end program counter */
+ ? ? ? u32 df ? ? : 1; /* destination fault while storing data */
+ ? ? ? u32 unused2: 1;
+ ? ? ? u32 spc ? ?:14; /* loop start program counter */
+};
+#else
+struct sdma_state_registers {
+ ? ? ? u32 pc ? ? :14; /* program counter */
+ ? ? ? u32 unused1: 1;
+ ? ? ? u32 t ? ? ?: 1; /* test bit: status of arithmetic & test instruction*/

drivers/dma/imx-sdma.c line 183

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? u32 rpc ? ?:14; /* return program counter */
+ ? ? ? u32 unused0: 1;
+ ? ? ? u32 sf ? ? : 1; /* source fault while loading data */
+ ? ? ? u32 spc ? ?:14; /* loop start program counter */
+ ? ? ? u32 unused2: 1;
+ ? ? ? u32 df ? ? : 1; /* destination fault while storing data */
+ ? ? ? u32 epc ? ?:14; /* loop end program counter */
+ ? ? ? u32 lm ? ? : 2; /* loop mode */
+};
+#endif

Again this is odd to me...

Quoted 21 lines
drivers/dma/imx-sdma.c new file +21 -0
+
+struct sdma_context_data {
+ ? ? ? struct sdma_state_registers ?channel_state; /* channel state bits */
+ ? ? ? u32 ?gReg[8]; /* general registers */
+ ? ? ? u32 ?mda; /* burst dma destination address register */
+ ? ? ? u32 ?msa; /* burst dma source address register */
+ ? ? ? u32 ?ms; ?/* burst dma status ?register */
+ ? ? ? u32 ?md; ?/* burst dma data ? ?register */
+ ? ? ? u32 ?pda; /* peripheral dma destination address register */
+ ? ? ? u32 ?psa; /* peripheral dma source address register */
+ ? ? ? u32 ?ps; ?/* peripheral dma ?status ?register */
+ ? ? ? u32 ?pd; ?/* peripheral dma ?data ? ?register */
+ ? ? ? u32 ?ca; ?/* CRC polynomial ?register */
+ ? ? ? u32 ?cs; ?/* CRC accumulator register */
+ ? ? ? u32 ?dda; /* dedicated core destination address register */
+ ? ? ? u32 ?dsa; /* dedicated core source address register */
+ ? ? ? u32 ?ds; ?/* dedicated core status ?register */
+ ? ? ? u32 ?dd; ?/* dedicated core data ? ?register */
+ ? ? ? u32 ?scratch0;
+ ? ? ? u32 ?scratch1;
+ ? ? ? u32 ?scratch2;

drivers/dma/imx-sdma.c line 214

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? u32 ?scratch3;
+ ? ? ? u32 ?scratch4;
+ ? ? ? u32 ?scratch5;
+ ? ? ? u32 ?scratch6;
+ ? ? ? u32 ?scratch7;
+};
+
+struct sdma_channel {
+ ? ? ? /* Channel number */
+ ? ? ? int channel;

Unsigned?

drivers/dma/imx-sdma.c line 220

Quoted 6 lines
drivers/dma/imx-sdma.c new file +6 -0
+ ? ? ? /* Transfer type. Needed for setting SDMA script */
+ ? ? ? enum dma_data_direction direction;
+ ? ? ? /* Peripheral type. Needed for setting SDMA script */
+ ? ? ? sdma_peripheral_type peripheral_type;
+ ? ? ? /* Peripheral event id */
+ ? ? ? int event_id;
Quoted 6 lines

Unsigned?

drivers/dma/imx-sdma.c line 222

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+ ? ? ? /* Peripheral event id2 (for channels that use 2 events) */
+ ? ? ? int event_id2;

Unsigned?

Ok for all the 'unsigned'. Will change.

Quoted 7 lines

drivers/dma/imx-sdma.c line 224

Quoted 3 lines
drivers/dma/imx-sdma.c new file +2 -0
+ ? ? ? /* SDMA data access word size */
+ ? ? ? unsigned long word_size;

Is this in bits, bytes etc? Isn't e.g. an u8 enough to hold this, and further, isn't it possible to recycle enum dma_slave_buswidth from dmaengine.h instead?

Yes, will change.

Quoted 19 lines

drivers/dma/imx-sdma.c line 231

Quoted 8 lines
drivers/dma/imx-sdma.c new file +7 -0
+
+ ? ? ? /* ID of the buffer that was processed */
+ ? ? ? unsigned int buf_tail;
+
+ ? ? ? wait_queue_head_t waitq; ? ? ? ?/* channel completion waitqeue */
+
+ ? ? ? int num_bd;

Unsigned? Range?

drivers/dma/imx-sdma.c line 236

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+
+ ? ? ? struct sdma_buffer_descriptor *bd;
+ ? ? ? dma_addr_t ? ? ?bd_phys;
+
+ ? ? ? int pc_from_device, pc_to_device;

Unsigned?

Quoted 4 lines

drivers/dma/imx-sdma.c line 238

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+
+ ? ? ? unsigned long flags;

Is this an u32?

There is no need to tie this to a particular size.

Quoted 16 lines
Quoted 4 lines
drivers/dma/imx-sdma.c new file +3 -0
+ ? ? ? dma_addr_t per_address;
+
+ ? ? ? uint32_t event_mask1, event_mask2;

drivers/dma/imx-sdma.c line 251

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? uint32_t watermark_level;
+ ? ? ? uint32_t shp_addr, per_addr;
+
+ ? ? ? /* DMA-Engine Channel */
+ ? ? ? struct dma_chan chan;
+
+ ? ? ? spinlock_t ? ? ? ? ? ? ?lock;
+ ? ? ? struct dma_async_tx_descriptor desc;
+ ? ? ? dma_cookie_t ? ? ? ? ? ?last_completed;
+ ? ? ? int busy;

Shouldn't this be a bool?

ok

Quoted 87 lines
Quoted 4 lines
drivers/dma/imx-sdma.c new file +3 -0
+};
+
+#define IMX_DMA_SG_LOOP ? ? ? ? ? ? ? ?(1 << 0)

drivers/dma/imx-sdma.c line 264

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+
+#define MAX_DMA_CHANNELS 32
+#define MXC_SDMA_DEFAULT_PRIORITY 1
+#define MXC_SDMA_MIN_PRIORITY 1
+#define MXC_SDMA_MAX_PRIORITY 7
+
+/*
+ * This enumerates transfer types
+ */
+typedef enum {

Again a typedef, please plain enum is fine.

Quoted 70 lines
drivers/dma/imx-sdma.c new file +70 -0
+ ? ? ? emi_2_per = 0, ? ? ? ? ?/* EMI memory to peripheral */
+ ? ? ? emi_2_int, ? ? ? ? ? ? ?/* EMI memory to internal RAM */
+ ? ? ? emi_2_emi, ? ? ? ? ? ? ?/* EMI memory to EMI memory */
+ ? ? ? emi_2_dsp, ? ? ? ? ? ? ?/* EMI memory to DSP memory */
+ ? ? ? per_2_int, ? ? ? ? ? ? ?/* Peripheral to internal RAM */
+ ? ? ? per_2_emi, ? ? ? ? ? ? ?/* Peripheral to internal EMI memory */
+ ? ? ? per_2_dsp, ? ? ? ? ? ? ?/* Peripheral to DSP memory */
+ ? ? ? per_2_per, ? ? ? ? ? ? ?/* Peripheral to Peripheral */
+ ? ? ? int_2_per, ? ? ? ? ? ? ?/* Internal RAM to peripheral */
+ ? ? ? int_2_int, ? ? ? ? ? ? ?/* Internal RAM to Internal RAM */
+ ? ? ? int_2_emi, ? ? ? ? ? ? ?/* Internal RAM to EMI memory */
+ ? ? ? int_2_dsp, ? ? ? ? ? ? ?/* Internal RAM to DSP memory */
+ ? ? ? dsp_2_per, ? ? ? ? ? ? ?/* DSP memory to peripheral */
+ ? ? ? dsp_2_int, ? ? ? ? ? ? ?/* DSP memory to internal RAM */
+ ? ? ? dsp_2_emi, ? ? ? ? ? ? ?/* DSP memory to EMI memory */
+ ? ? ? dsp_2_dsp, ? ? ? ? ? ? ?/* DSP memory to DSP memory */
+ ? ? ? emi_2_dsp_loop, ? ? ? ? /* EMI memory to DSP memory loopback */
+ ? ? ? dsp_2_emi_loop, ? ? ? ? /* DSP memory to EMI memory loopback */
+ ? ? ? dvfs_pll, ? ? ? ? ? ? ? /* DVFS script with PLL change ? ? ? */
+ ? ? ? dvfs_pdr ? ? ? ? ? ? ? ?/* DVFS script without PLL change ? ?*/
+} sdma_transfer_type;
+
+/*
+ * Structure containing sdma request ?parameters.
+ */
+struct sdma_script_start_addrs {
+ ? ? ? int ap_2_ap_addr;
+ ? ? ? int ap_2_bp_addr;
+ ? ? ? int ap_2_ap_fixed_addr;
+ ? ? ? int bp_2_ap_addr;
+ ? ? ? int loopback_on_dsp_side_addr;
+ ? ? ? int mcu_interrupt_only_addr;
+
+ ? ? ? int firi_2_per_addr;
+ ? ? ? int firi_2_mcu_addr;
+ ? ? ? int per_2_firi_addr;
+ ? ? ? int mcu_2_firi_addr;
+
+ ? ? ? int uart_2_per_addr;
+ ? ? ? int uart_2_mcu_addr;
+ ? ? ? int per_2_app_addr;
+ ? ? ? int mcu_2_app_addr;
+ ? ? ? int per_2_per_addr;
+
+ ? ? ? int uartsh_2_per_addr;
+ ? ? ? int uartsh_2_mcu_addr;
+ ? ? ? int per_2_shp_addr;
+ ? ? ? int mcu_2_shp_addr;
+
+ ? ? ? int ata_2_mcu_addr;
+ ? ? ? int mcu_2_ata_addr;
+
+ ? ? ? int app_2_per_addr;
+ ? ? ? int app_2_mcu_addr;
+ ? ? ? int shp_2_per_addr;
+ ? ? ? int shp_2_mcu_addr;
+
+ ? ? ? int mshc_2_mcu_addr;
+ ? ? ? int mcu_2_mshc_addr;
+
+ ? ? ? int spdif_2_mcu_addr;
+ ? ? ? int mcu_2_spdif_addr;
+
+ ? ? ? int asrc_2_mcu_addr;
+
+ ? ? ? int ext_mem_2_ipu_addr;
+
+ ? ? ? int descrambler_addr;
+
+ ? ? ? int dptc_dvfs_addr;
Quoted 8 lines

drivers/dma/imx-sdma.c line 338

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+
+ ? ? ? int utra_addr;
+
+ ? ? ? int ram_code_start_addr;

All these addresses, are they really integers with valid negative values... Aren't they dma_addr_t or atleast u32?

Since this struct must match the layout of the firmware, they should be u32, yes. They are no dma_addr_t since it's the sdma controller address space described here.

Quoted 17 lines

drivers/dma/imx-sdma.c line 350

Quoted 13 lines
drivers/dma/imx-sdma.c new file +12 -0
+};
+
+#define SDMA_FIRMWARE_MAGIC 0x414d4453
+
+struct sdma_firmware_header {
+ ? ? ? uint32_t ? ? ? ?magic; /* "SDMA" */
+ ? ? ? uint32_t ? ? ? ?version_major; ?/* increased whenever layout of struct sdma_script_start_addrs changes */
+ ? ? ? uint32_t ? ? ? ?version_minor; ?/* firmware version */
+ ? ? ? uint32_t ? ? ? ?script_addrs_start; /* offset of struct sdma_script_start_addrs in this image */
+ ? ? ? uint32_t ? ? ? ?num_script_addrs; /* Number of script addresses in this image */
+ ? ? ? uint32_t ? ? ? ?ram_code_start; /* offset of SDMA ram image in this firmware image */
+ ? ? ? uint32_t ? ? ? ?ram_code_size; /* size of SDMA ram image */

Please use u32. uint32_t is not the preferred kernel type. (Still I've seen people use it in some cases so I might be wrong, feel welcome to bit back on this.)

At least one type should be consequently used in a driver. Changed them all to u32.

Quoted 26 lines

drivers/dma/imx-sdma.c line 356

Quoted 7 lines
drivers/dma/imx-sdma.c new file +6 -0
+};
+
+static struct sdma_channel sdma_data[MAX_DMA_CHANNELS];
+static struct sdma_channel_control *channel_control;
+static void __iomem *sdma_base;
+static int sdma_version;

Unsigned?

drivers/dma/imx-sdma.c line 357

Quoted 1 line
drivers/dma/imx-sdma.c new file +1 -0
+static int sdma_num_events;

Unsigned?

drivers/dma/imx-sdma.c line 361

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+static struct sdma_context_data *sdma_context;
+dma_addr_t sdma_context_phys;
+static struct dma_device __sdma_dma_device;
+static struct dma_device *sdma_dma_device = &__sdma_dma_device;

This is what I suspected: local variables making the entire driver a singleton, which means you can never have more than one SDMA. Atleast collect all of these in a struct, call it "struct sdma" simply (if you ask me) and use as a stateholder. This makes it easier to kzalloc() that struct later if you want to support non-singletons.

Quoted 3 lines

I know this require some work but I've done it to several drivers (always asked on mailinglists to do this) and I don't regret a single rewrite. Last time was for the PL18x DMAengine driver actually.

I've done it myself often enough. Ok, will change.

Quoted 49 lines
Quoted 49 lines
drivers/dma/imx-sdma.c new file +48 -0
+
+#define SDMA_H_CONFIG_DSPDMA ? (1 << 12) /* indicates if the DSPDMA is used */
+#define SDMA_H_CONFIG_RTD_PINS (1 << 11) /* indicates if Real-Time Debug pins are enabled */
+#define SDMA_H_CONFIG_ACR ? ? ?(1 << 4) ?/* indicates if AHB freq /core freq = 2 or 1 */
+#define SDMA_H_CONFIG_CSM ? ? ?(3) ? ? ? /* indicates which context switch mode is selected*/
+
+static int sdma_config_ownership(int channel, int event_override,
+ ? ? ? ? ? ? ? ? ?int mcu_verride, int dsp_override)
+{
+ ? ? ? u32 evt, mcu, dsp;
+
+ ? ? ? if (event_override && mcu_verride && dsp_override)
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? evt = readl(SDMA_H_EVTOVR);
+ ? ? ? mcu = readl(SDMA_H_HOSTOVR);
+ ? ? ? dsp = readl(SDMA_H_DSPOVR);
+
+ ? ? ? if (dsp_override)
+ ? ? ? ? ? ? ? dsp &= ~(1 << channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? dsp |= (1 << channel);
+
+ ? ? ? if (event_override)
+ ? ? ? ? ? ? ? evt &= ~(1 << channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? evt |= (1 << channel);
+
+ ? ? ? if (mcu_verride)
+ ? ? ? ? ? ? ? mcu &= ~(1 << channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? mcu |= (1 << channel);
+
+ ? ? ? writel(evt, SDMA_H_EVTOVR);
+ ? ? ? writel(mcu, SDMA_H_HOSTOVR);
+ ? ? ? writel(dsp, SDMA_H_DSPOVR);
+
+ ? ? ? return 0;
+}
+
+/*
+ * sdma_run_channel - run a channel and wait till it's done
+ */
+static int sdma_run_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int ret;
+
Quoted 8 lines

drivers/dma/imx-sdma.c line 413

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+ ? ? ? writel(1 << channel, SDMA_H_START);
+
+ ? ? ? ret = wait_event_interruptible(sdma->waitq,
+ ? ? ? ? ? ? ? ? ? ? ? !(readl(SDMA_H_STATSTOP) & (1 << channel)));

OK not the biggest thing in the world, but can't you use a completion for this? (I'm not so clever with waitqueues so forgive me if this is malinformed.)

Ok.

Quoted 42 lines
Quoted 27 lines
drivers/dma/imx-sdma.c new file +26 -0
+ ? ? ? return ret;
+}
+
+static int sdma_load_script(void *buf, int size, u32 address)
+{
+ ? ? ? struct sdma_buffer_descriptor *bd0 = sdma_data[0].bd;
+ ? ? ? void *buf_virt;
+ ? ? ? dma_addr_t buf_phys;
+ ? ? ? int ret;
+
+ ? ? ? buf_virt = dma_alloc_coherent(NULL,
+ ? ? ? ? ? ? ? ? ? ? ? size,
+ ? ? ? ? ? ? ? ? ? ? ? &buf_phys, GFP_KERNEL);
+ ? ? ? if (!buf_virt)
+ ? ? ? ? ? ? ? return -ENOMEM;
+
+ ? ? ? bd0->mode.command = C0_SETPM;
+ ? ? ? bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
+ ? ? ? bd0->mode.count = size / 2;
+ ? ? ? bd0->buffer_addr = buf_phys;
+ ? ? ? bd0->ext_buffer_addr = address;
+
+ ? ? ? memcpy(buf_virt, buf, size);
+
+ ? ? ? ret = sdma_run_channel(0);
+

drivers/dma/imx-sdma.c line 449

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? dma_free_coherent(NULL, size, buf_virt, buf_phys);
+
+ ? ? ? return ret;
+}
+
+static void sdma_event_enable(int channel, int event)
+{
+ ? ? ? u32 val;
+
+ ? ? ? val = readl(SDMA_CHNENBL_0 + event * 4);

This use indicates that event should probably be unsigned, and probably not greater than u16 atleast. I suspect it is never more than an u8 really.

Quoted 13 lines

drivers/dma/imx-sdma.c line 460

Quoted 11 lines
drivers/dma/imx-sdma.c new file +11 -0
+ ? ? ? val |= (1 << channel);
+ ? ? ? writel(val, SDMA_CHNENBL_0 + event * 4);
+}
+
+static void sdma_event_disable(int channel, int event)
+{
+ ? ? ? u32 val;
+
+ ? ? ? val = readl(SDMA_CHNENBL_0 + event * 4);
+ ? ? ? val &= ~(1 << channel);
+ ? ? ? writel(val, SDMA_CHNENBL_0 + event * 4);

Same comment here.

Ok, changed to unsigned and added a check for valid values in sdma_config_channel.

Quoted 9 lines

drivers/dma/imx-sdma.c

Quoted 6 lines
drivers/dma/imx-sdma.c new file +5 -0
+}
+
+static void mxc_sdma_handle_channel_loop(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];

This indicates that channel should be unsigned.

Quoted 4 lines

drivers/dma/imx-sdma.c line 467

Quoted 2 lines
drivers/dma/imx-sdma.c new file +2 -0
+ ? ? ? struct sdma_buffer_descriptor *bd;
+ ? ? ? int error = 0;

Unused variable?

Originally the callback function had a status parameter where errors were signalled. I assume device_tx_status is the function to which this error should be passed, right?

Quoted 102 lines
Quoted 36 lines
drivers/dma/imx-sdma.c new file +35 -0
+
+ ? ? ? /*
+ ? ? ? ?* loop mode. Iterate over descriptors, re-setup them and
+ ? ? ? ?* call callback function.
+ ? ? ? ?*/
+ ? ? ? while (1) {
+ ? ? ? ? ? ? ? bd = &sdma->bd[sdma->buf_tail];
+
+ ? ? ? ? ? ? ? if (bd->mode.status & BD_DONE)
+ ? ? ? ? ? ? ? ? ? ? ? break;
+
+ ? ? ? ? ? ? ? if (bd->mode.status & BD_RROR)
+ ? ? ? ? ? ? ? ? ? ? ? error = -EIO;
+
+ ? ? ? ? ? ? ? bd->mode.status |= BD_DONE;
+ ? ? ? ? ? ? ? sdma->buf_tail++;
+ ? ? ? ? ? ? ? sdma->buf_tail %= sdma->num_bd;
+
+ ? ? ? ? ? ? ? if (sdma->desc.callback)
+ ? ? ? ? ? ? ? ? ? ? ? sdma->desc.callback(sdma->desc.callback_param);
+ ? ? ? }
+}
+
+static void mxc_sdma_handle_channel_normal(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? struct sdma_buffer_descriptor *bd;
+ ? ? ? int i, error = 0;
+
+ ? ? ? /*
+ ? ? ? ?* non loop mode. Iterate over all descriptors, collect
+ ? ? ? ?* errors and call callback function
+ ? ? ? ?*/
+ ? ? ? for (i = 0; i < sdma->num_bd; i++) {
+ ? ? ? ? ? ? ? bd = &sdma->bd[i];

drivers/dma/imx-sdma.c line 512

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+
+ ? ? ? ? ? ? ? ?if (bd->mode.status & (BD_DONE | BD_RROR))
+ ? ? ? ? ? ? ? ? ? ? ? error = -EIO;
+ ? ? ? }
+
+ ? ? ? if (sdma->desc.callback)
+ ? ? ? ? ? ? ? sdma->desc.callback(sdma->desc.callback_param);
+ ? ? ? sdma->last_completed = sdma->desc.cookie;
+
+ ? ? ? sdma->busy = 0;

= true if you switch this to bool..

Quoted 53 lines
drivers/dma/imx-sdma.c new file +53 -0
+}
+
+static void mxc_sdma_handle_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+
+ ? ? ? wake_up_interruptible(&sdma->waitq);
+
+ ? ? ? /* not interested in channel 0 interrupts */
+ ? ? ? if (!channel)
+ ? ? ? ? ? ? ? return;
+
+ ? ? ? if (sdma->flags & IMX_DMA_SG_LOOP)
+ ? ? ? ? ? ? ? mxc_sdma_handle_channel_loop(channel);
+ ? ? ? else
+ ? ? ? ? ? ? ? mxc_sdma_handle_channel_normal(channel);
+}
+
+static irqreturn_t sdma_int_handler(int irq, void *dev_id)
+{
+ ? ? ? u32 stat;
+
+ ? ? ? stat = readl(SDMA_H_INTR);
+ ? ? ? writel(stat, SDMA_H_INTR);
+
+ ? ? ? while (stat) {
+ ? ? ? ? ? ? ? int channel = fls(stat) - 1;
+
+ ? ? ? ? ? ? ? mxc_sdma_handle_channel(channel);
+
+ ? ? ? ? ? ? ? stat &= ~(1 << channel);
+ ? ? ? }
+
+ ? ? ? return IRQ_HANDLED;
+}
+
+static struct clk *sdma_clk;
+
+/*
+ * Stores the start address of the SDMA scripts
+ */
+static struct sdma_script_start_addrs __sdma_script_addrs;
+static struct sdma_script_start_addrs *sdma_script_addrs = &__sdma_script_addrs;
+
+/*
+ * sets the pc of SDMA script according to the peripheral type
+ */
+static void sdma_get_pc(struct sdma_channel *sdma,
+ ? ? ? ? ? ? ? sdma_peripheral_type peripheral_type)
+{
+ ? ? ? int res = 0;
+ ? ? ? int per_2_emi = 0, emi_2_per = 0;
+ ? ? ? int per_2_int = 0, int_2_per = 0;
Quoted 8 lines

drivers/dma/imx-sdma.c line 569

Quoted 4 lines
drivers/dma/imx-sdma.c new file +4 -0
+ ? ? ? int per_2_per = 0, emi_2_emi = 0;
+
+ ? ? ? sdma->pc_from_device = 0;
+ ? ? ? sdma->pc_to_device = 0;

There are a *lot* of local variables here, and only two of them are used eventually, at the end of the function. I cannot quite follow this, what is going on?

'per' is for peripheral (like sdhc, ssi unit or similar) 'int' is for internal SRAM
'emi' is for SDRAM

currently we only support transfers from per to emi and emi to per and so the other variables are unused. We could make this function simpler by removing the unused variables, but I suggest to keep them for making it easier to support other transfer types later. I can add a comment what these variables are for and why they are unused.

Quoted 72 lines

Some like emi_2_emi seem to be totally unused.

The types here look like some kind of enum or other similar construction is really what's being asked for here.

Quoted 54 lines
drivers/dma/imx-sdma.c new file +54 -0
+
+ ? ? ? switch (peripheral_type) {
+ ? ? ? case IMX_DMATYPE_MEMORY:
+ ? ? ? ? ? ? ? emi_2_emi = sdma_script_addrs->ap_2_ap_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_DSP:
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->bp_2_ap_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->ap_2_bp_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_FIRI:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->firi_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->firi_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_firi_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_firi_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_UART:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->uart_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->uart_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_app_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_app_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_UART_SP:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->uartsh_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->uartsh_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_shp_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_shp_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_ATA:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->ata_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_ata_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_CSPI:
+ ? ? ? case IMX_DMATYPE_EXT:
+ ? ? ? case IMX_DMATYPE_SSI:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->app_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->app_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_app_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_app_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_SSI_SP:
+ ? ? ? case IMX_DMATYPE_MMC:
+ ? ? ? case IMX_DMATYPE_SDHC:
+ ? ? ? case IMX_DMATYPE_CSPI_SP:
+ ? ? ? case IMX_DMATYPE_ESAI:
+ ? ? ? case IMX_DMATYPE_MSHC_SP:
+ ? ? ? ? ? ? ? per_2_int = sdma_script_addrs->shp_2_per_addr;
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->shp_2_mcu_addr;
+ ? ? ? ? ? ? ? int_2_per = sdma_script_addrs->per_2_shp_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_shp_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_ASRC:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->asrc_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->asrc_2_mcu_addr;
+ ? ? ? ? ? ? ? per_2_per = sdma_script_addrs->per_2_per_addr;

drivers/dma/imx-sdma.c line 633

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_MSHC:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->mshc_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_mshc_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_CCM:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->dptc_dvfs_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_FIFO_MEMORY:
+ ? ? ? ? ? ? ? res = sdma_script_addrs->ap_2_ap_fixed_addr;
Quoted 1 line

res? This thing is never used.

I have no idea what DMATYPE_FIFO_MEMORY is. Will remove this.

Quoted 37 lines
Quoted 5 lines
drivers/dma/imx-sdma.c new file +4 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_SPDIF:
+ ? ? ? ? ? ? ? per_2_emi = sdma_script_addrs->spdif_2_mcu_addr;
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->mcu_2_spdif_addr;

drivers/dma/imx-sdma.c line 647

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_IPU_MEMORY:
+ ? ? ? ? ? ? ? emi_2_per = sdma_script_addrs->ext_mem_2_ipu_addr;
+ ? ? ? ? ? ? ? break;
+ ? ? ? default:
+ ? ? ? ? ? ? ? break;
+ ? ? ? }
+
+ ? ? ? sdma->pc_from_device = per_2_emi;
+ ? ? ? sdma->pc_to_device = emi_2_per;

Return res? You're assigning it a value in some cases.

Quoted 19 lines
drivers/dma/imx-sdma.c new file +19 -0
+}
+
+static int sdma_load_context(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int load_address;
+ ? ? ? struct sdma_buffer_descriptor *bd0 = sdma_data[0].bd;
+ ? ? ? int ret;
+
+ ? ? ? if (sdma->direction == DMA_FROM_DEVICE) {
+ ? ? ? ? ? ? ? load_address = sdma->pc_from_device;
+ ? ? ? } else {
+ ? ? ? ? ? ? ? load_address = sdma->pc_to_device;
+ ? ? ? }
+
+ ? ? ? if (load_address < 0)
+ ? ? ? ? ? ? ? return load_address;
+
+ ? ? ? pr_debug("%s: load_address = %d\n", __func__, load_address);
Quoted 8 lines

drivers/dma/imx-sdma.c line 671

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+ ? ? ? pr_debug("%s: wml = 0x%08x\n", __func__, sdma->watermark_level);
+ ? ? ? pr_debug("%s: shp_addr = 0x%08x\n", __func__, sdma->shp_addr);
+ ? ? ? pr_debug("%s: per_addr = 0x%08x\n", __func__, sdma->per_addr);
+ ? ? ? pr_debug("%s: event_mask1 = 0x%08x\n", __func__, sdma->event_mask1);
+ ? ? ? pr_debug("%s: event_mask2 = 0x%08x\n", __func__, sdma->event_mask2);

Surely it must be possible to get the struct device * pointer for the channels host and use dev_dbg() instead?

Ok, will do

Quoted 46 lines
Quoted 46 lines
drivers/dma/imx-sdma.c new file +45 -0
+
+ ? ? ? memset(sdma_context, 0, sizeof(*sdma_context));
+ ? ? ? sdma_context->channel_state.pc = load_address;
+
+ ? ? ? /* Send by context the event mask,base address for peripheral
+ ? ? ? ?* and watermark level
+ ? ? ? ?*/
+ ? ? ? sdma_context->gReg[0] = sdma->event_mask2;
+ ? ? ? sdma_context->gReg[1] = sdma->event_mask1;
+ ? ? ? sdma_context->gReg[2] = sdma->per_addr;
+ ? ? ? sdma_context->gReg[6] = sdma->shp_addr;
+ ? ? ? sdma_context->gReg[7] = sdma->watermark_level;
+
+ ? ? ? bd0->mode.command = C0_SETDM;
+ ? ? ? bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
+ ? ? ? bd0->mode.count = sizeof(*sdma_context) / 4;
+ ? ? ? bd0->buffer_addr = sdma_context_phys;
+ ? ? ? bd0->ext_buffer_addr = 2048 + (sizeof(*sdma_context) / 4) * channel;
+
+ ? ? ? ret = sdma_run_channel(0);
+
+ ? ? ? return ret;
+}
+
+static void sdma_disable_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+
+ ? ? ? writel(1 << channel, SDMA_H_STATSTOP);
+ ? ? ? sdma->busy = 0;
+}
+
+static int sdma_config_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int ret;
+
+ ? ? ? sdma_disable_channel(channel);
+
+ ? ? ? sdma->event_mask1 = 0;
+ ? ? ? sdma->event_mask2 = 0;
+ ? ? ? sdma->shp_addr = 0;
+ ? ? ? sdma->per_addr = 0;
+
+ ? ? ? if (sdma->event_id)
Quoted 8 lines

drivers/dma/imx-sdma.c line 721

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+ ? ? ? ? ? ? ? sdma_event_enable(channel, sdma->event_id);
+
+ ? ? ? switch (sdma->peripheral_type) {
+ ? ? ? case IMX_DMATYPE_DSP:
+ ? ? ? ? ? ? ? sdma_config_ownership(channel, 0, 1, 1);

The parameters here makes yoy believe that the types should be bool rather than int...

ok.

Quoted 108 lines
Quoted 58 lines
drivers/dma/imx-sdma.c new file +57 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case IMX_DMATYPE_MEMORY:
+ ? ? ? ? ? ? ? sdma_config_ownership(channel, 0, 1, 0);
+ ? ? ? ? ? ? ? break;
+ ? ? ? default:
+ ? ? ? ? ? ? ? sdma_config_ownership(channel, 1, 1, 0);
+ ? ? ? ? ? ? ? break;
+ ? ? ? }
+
+ ? ? ? sdma_get_pc(sdma, sdma->peripheral_type);
+
+ ? ? ? if ((sdma->peripheral_type != IMX_DMATYPE_MEMORY) &&
+ ? ? ? ? ? ? ? ? ? ? ? (sdma->peripheral_type != IMX_DMATYPE_DSP)) {
+ ? ? ? ? ? ? ? /* Handle multiple event channels differently */
+ ? ? ? ? ? ? ? if (sdma->event_id2) {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask2 = 1 << (sdma->event_id2 % 32);
+ ? ? ? ? ? ? ? ? ? ? ? if (sdma->event_id2 > 31)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level |= 1 << 31;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask1 = 1 << (sdma->event_id % 32);
+ ? ? ? ? ? ? ? ? ? ? ? if (sdma->event_id > 31)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level |= 1 << 30;
+ ? ? ? ? ? ? ? } else {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask1 = 1 << sdma->event_id;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->event_mask2 = 1 << (sdma->event_id - 32);
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? /* Watermark Level */
+ ? ? ? ? ? ? ? sdma->watermark_level |= sdma->watermark_level;
+ ? ? ? ? ? ? ? /* Address */
+ ? ? ? ? ? ? ? sdma->shp_addr = sdma->per_address;
+ ? ? ? } else {
+ ? ? ? ? ? ? ? sdma->watermark_level = 0; /* FIXME: M3_BASE_ADDRESS */
+ ? ? ? }
+
+ ? ? ? ret = sdma_load_context(channel);
+
+ ? ? ? return ret;
+}
+
+static int sdma_set_channel_priority(unsigned int channel, unsigned int priority)
+{
+ ? ? ? if (priority < MXC_SDMA_MIN_PRIORITY
+ ? ? ? ? ? || priority > MXC_SDMA_MAX_PRIORITY) {
+ ? ? ? ? ? ? ? return -EINVAL;
+ ? ? ? }
+
+ ? ? ? writel(priority, SDMA_CHNPRI_0 + 4 * channel);
+
+ ? ? ? return 0;
+}
+
+static int sdma_request_channel(int channel)
+{
+ ? ? ? struct sdma_channel *sdma = &sdma_data[channel];
+ ? ? ? int ret = -EBUSY;
+
+ ? ? ? sdma->bd = dma_alloc_coherent(NULL, PAGE_SIZE, &sdma->bd_phys, GFP_KERNEL);
+ ? ? ? if (!sdma->bd) {

drivers/dma/imx-sdma.c line 788

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto out;
+ ? ? ? }
+
+ ? ? ? memset(sdma->bd, 0, PAGE_SIZE);
+
+ ? ? ? channel_control[channel].base_bd_ptr = sdma->bd_phys;
+ ? ? ? channel_control[channel].current_bd_ptr = sdma->bd_phys;
+
+ ? ? ? clk_enable(sdma_clk);

Aha you're enabling it once for every channel and rely on clk reference counting that's clever!

Quoted 36 lines
drivers/dma/imx-sdma.c new file +36 -0
+
+ ? ? ? sdma_set_channel_priority(channel, MXC_SDMA_DEFAULT_PRIORITY);
+
+ ? ? ? init_waitqueue_head(&sdma->waitq);
+
+ ? ? ? sdma->buf_tail = 0;
+
+ ? ? ? return 0;
+out:
+
+ ? ? ? return ret;
+}
+
+static void sdma_enable_channel(int channel)
+{
+ ? ? ? writel(1 << channel, SDMA_H_START);
+}
+
+static int __init sdma_init(unsigned long phys_base, int irq, int version,
+ ? ? ? ? ? ? ? void *ram_code,
+ ? ? ? ? ? ? ? int ram_code_size)
+{
+ ? ? ? int i, ret;
+ ? ? ? int channel;
+ ? ? ? dma_addr_t ccb_phys;
+
+ ? ? ? sdma_version = version;
+ ? ? ? switch (sdma_version) {
+ ? ? ? case 1:
+ ? ? ? ? ? ? ? sdma_num_events = 32;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case 2:
+ ? ? ? ? ? ? ? sdma_num_events = 48;
+ ? ? ? ? ? ? ? break;
+ ? ? ? default:
+ ? ? ? ? ? ? ? pr_err("SDMA: Unknown version %d. aborting\n", sdma_version);
Quoted 8 lines

drivers/dma/imx-sdma.c line 830

Quoted 6 lines
drivers/dma/imx-sdma.c new file +6 -0
+ ? ? ? ? ? ? ? return -ENODEV;
+ ? ? ? }
+
+ ? ? ? clk_enable(sdma_clk);
+
+ ? ? ? sdma_base = ioremap(phys_base, 4096);

Use SZ_4K instead of 4096.

Or even better resouce_size(iores)

Quoted 131 lines
Quoted 131 lines
drivers/dma/imx-sdma.c new file +130 -0
+ ? ? ? if (!sdma_base) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_ioremap;
+ ? ? ? }
+
+ ? ? ? /* Initialize SDMA private data */
+ ? ? ? memset(sdma_data, 0, sizeof(struct sdma_channel) * MAX_DMA_CHANNELS);
+
+ ? ? ? for (channel = 0; channel < MAX_DMA_CHANNELS; channel++)
+ ? ? ? ? ? ? ? sdma_data[channel].channel = channel;
+
+ ? ? ? ret = request_irq(irq, sdma_int_handler, 0, "sdma", NULL);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_request_irq;
+
+ ? ? ? /* Be sure SDMA has not started yet */
+ ? ? ? writel(0, SDMA_H_C0PTR);
+
+ ? ? ? channel_control = dma_alloc_coherent(NULL,
+ ? ? ? ? ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control) +
+ ? ? ? ? ? ? ? ? ? ? ? sizeof(struct sdma_context_data),
+ ? ? ? ? ? ? ? ? ? ? ? &ccb_phys, GFP_KERNEL);
+
+ ? ? ? if (!channel_control) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_dma_alloc;
+ ? ? ? }
+
+ ? ? ? sdma_context = (void *)channel_control +
+ ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control);
+ ? ? ? sdma_context_phys = ccb_phys +
+ ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control);
+
+ ? ? ? /* Zero-out the CCB structures array just allocated */
+ ? ? ? memset(channel_control, 0,
+ ? ? ? ? ? ? ? ? ? ? ? MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control));
+
+ ? ? ? /* disable all channels */
+ ? ? ? for (i = 0; i < sdma_num_events; i++)
+ ? ? ? ? ? ? ? writel(0, SDMA_CHNENBL_0 + i * 4);
+
+ ? ? ? /* All channels have priority 0 */
+ ? ? ? for (i = 0; i < MAX_DMA_CHANNELS; i++)
+ ? ? ? ? ? ? ? writel(0, SDMA_CHNPRI_0 + i * 4);
+
+ ? ? ? ret = sdma_request_channel(0);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_dma_alloc;
+
+ ? ? ? sdma_config_ownership(0, 0, 1, 0);
+
+ ? ? ? /* Set Command Channel (Channel Zero) */
+ ? ? ? writel(0x4050, SDMA_CHN0ADDR);
+
+ ? ? ? /* Set bits of CONFIG register but with static context switching */
+ ? ? ? /* FIXME: Check whether to set ACR bit depending on clock ratios */
+ ? ? ? writel(0, SDMA_H_CONFIG);
+
+ ? ? ? writel(ccb_phys, SDMA_H_C0PTR);
+
+ ? ? ? /* download the RAM image for SDMA */
+ ? ? ? sdma_load_script(ram_code,
+ ? ? ? ? ? ? ? ? ? ? ? ram_code_size,
+ ? ? ? ? ? ? ? ? ? ? ? sdma_script_addrs->ram_code_start_addr);
+
+ ? ? ? /* Set bits of CONFIG register with given context switching mode */
+ ? ? ? writel(SDMA_H_CONFIG_CSM, SDMA_H_CONFIG);
+
+ ? ? ? /* Initializes channel's priorities */
+ ? ? ? sdma_set_channel_priority(0, 7);
+
+ ? ? ? clk_disable(sdma_clk);
+
+ ? ? ? return 0;
+
+err_dma_alloc:
+ ? ? ? free_irq(irq, NULL);
+err_request_irq:
+ ? ? ? iounmap(sdma_base);
+err_ioremap:
+ ? ? ? clk_disable(sdma_clk);
+ ? ? ? pr_err("%s failed with %d\n", __func__, ret);
+ ? ? ? return ret;
+}
+
+static dma_cookie_t sdma_assign_cookie(struct sdma_channel *sdma)
+{
+ ? ? ? dma_cookie_t cookie = sdma->chan.cookie;
+
+ ? ? ? if (++cookie < 0)
+ ? ? ? ? ? ? ? cookie = 1;
+
+ ? ? ? sdma->chan.cookie = cookie;
+ ? ? ? sdma->desc.cookie = cookie;
+
+ ? ? ? return cookie;
+}
+
+static struct sdma_channel *to_sdma_chan(struct dma_chan *chan)
+{
+ ? ? ? return container_of(chan, struct sdma_channel, chan);
+}
+
+static dma_cookie_t sdma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(tx->chan);
+ ? ? ? dma_cookie_t cookie;
+
+ ? ? ? spin_lock_irq(&sdma->lock);
+
+ ? ? ? cookie = sdma_assign_cookie(sdma);
+
+ ? ? ? sdma_enable_channel(tx->chan->chan_id);
+
+ ? ? ? spin_unlock_irq(&sdma->lock);
+
+ ? ? ? return cookie;
+}
+
+static int sdma_alloc_chan_resources(struct dma_chan *chan)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? struct imx_dma_data *data = chan->private;
+ ? ? ? int prio, ret;
+
+ ? ? ? /* No need to execute this for internal channel 0 */
+ ? ? ? if (!chan->chan_id)
+ ? ? ? ? ? ? ? return 0;
+
+ ? ? ? if (!data)
Quoted 8 lines

drivers/dma/imx-sdma.c line 965

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? switch (data->priority) {
+ ? ? ? case DMA_PRIO_HIGH:
+ ? ? ? ? ? ? ? prio = 3;

Wait, aren't these enumerated?
Add some enum sdma_channel_prio {}..

Hm, The SDMA engine has priorities from 1 to 7 from which we happen to use the lowest priorities only. I think this should not be an enum. (The DMA_PRIO_* are only used in an attempt to provide the same API for the i.MX2 SoCs which have a different DMA engine which is not so flexible)

Quoted 66 lines
Quoted 66 lines
drivers/dma/imx-sdma.c new file +64 -0
+ ? ? ? ? ? ? ? break;
+ ? ? ? case DMA_PRIO_MEDIUM:
+ ? ? ? ? ? ? ? prio = 2;
+ ? ? ? ? ? ? ? break;
+ ? ? ? case DMA_PRIO_LOW:
+ ? ? ? default:
+ ? ? ? ? ? ? ? prio = 1;
+ ? ? ? ? ? ? ? break;
+ ? ? ? }
+
+ ? ? ? sdma->peripheral_type = data->peripheral_type;
+ ? ? ? sdma->event_id = data->dma_request;
+ ? ? ? ret = sdma_set_channel_priority(chan->chan_id, prio);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? return ret;
+
+ ? ? ? if (chan->chan_id) {
+ ? ? ? ? ? ? ? ret = sdma_request_channel(chan->chan_id);
+ ? ? ? ? ? ? ? if (ret)
+ ? ? ? ? ? ? ? ? ? ? ? return ret;
+ ? ? ? }
+
+ ? ? ? dma_async_tx_descriptor_init(&sdma->desc, chan);
+ ? ? ? sdma->desc.tx_submit = sdma_tx_submit;
+ ? ? ? /* txd.flags will be overwritten in prep funcs */
+ ? ? ? sdma->desc.flags = DMA_CTRL_ACK;
+
+ ? ? ? return 0;
+}
+
+static void sdma_free_chan_resources(struct dma_chan *chan)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? int channel = chan->chan_id;
+
+ ? ? ? sdma_disable_channel(channel);
+
+ ? ? ? if (sdma->event_id)
+ ? ? ? ? ? ? ? sdma_event_disable(channel, sdma->event_id);
+ ? ? ? if (sdma->event_id2)
+ ? ? ? ? ? ? ? sdma_event_disable(channel, sdma->event_id2);
+
+ ? ? ? sdma->event_id = 0;
+ ? ? ? sdma->event_id2 = 0;
+
+ ? ? ? sdma_set_channel_priority(channel, 0);
+
+ ? ? ? dma_free_coherent(NULL, PAGE_SIZE, sdma->bd, sdma->bd_phys);
+
+ ? ? ? clk_disable(sdma_clk);
+}
+
+#define NUM_BD (int)(PAGE_SIZE / sizeof(struct sdma_buffer_descriptor))
+
+static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
+ ? ? ? ? ? ? ? struct dma_chan *chan, struct scatterlist *sgl,
+ ? ? ? ? ? ? ? unsigned int sg_len, enum dma_data_direction direction,
+ ? ? ? ? ? ? ? unsigned long flags)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? int ret, i, count;
+ ? ? ? int channel = chan->chan_id;
+ ? ? ? struct scatterlist *sg;
+
Quoted 8 lines

drivers/dma/imx-sdma.c line 1034

Quoted 5 lines
drivers/dma/imx-sdma.c new file +5 -0
+ ? ? ? if (sdma->busy)
+ ? ? ? ? ? ? ? return NULL;
+ ? ? ? sdma->busy = 1;
+
+ ? ? ? sdma->flags = 0;

What are those flags anyway? I think you will need some #define:s for them.

There's only one currently: IMX_DMA_SG_LOOP indicating that we are doing cyclic transfers.

Quoted 299 lines
Quoted 70 lines
drivers/dma/imx-sdma.c new file +69 -0
+
+ ? ? ? pr_debug("SDMA: setting up %d entries for channel %d.\n",
+ ? ? ? ? ? ? ? ? ? ? ? sg_len, channel);
+
+ ? ? ? sdma->direction = direction;
+ ? ? ? ret = sdma_load_context(channel);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_out;
+
+ ? ? ? if (sg_len > NUM_BD) {
+ ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, sg_len, NUM_BD);
+ ? ? ? ? ? ? ? ret = -EINVAL;
+ ? ? ? ? ? ? ? goto err_out;
+ ? ? ? }
+
+ ? ? ? for_each_sg(sgl, sg, sg_len, i) {
+ ? ? ? ? ? ? ? struct sdma_buffer_descriptor *bd = &sdma->bd[i];
+ ? ? ? ? ? ? ? int param;
+
+ ? ? ? ? ? ? ? bd->buffer_addr = sgl->dma_address;
+
+ ? ? ? ? ? ? ? count = sg->length;
+
+ ? ? ? ? ? ? ? if (count > 0xffff) {
+ ? ? ? ? ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, count, 0xffff);
+ ? ? ? ? ? ? ? ? ? ? ? ret = -EINVAL;
+ ? ? ? ? ? ? ? ? ? ? ? goto err_out;
+ ? ? ? ? ? ? ? }
+
+ ? ? ? ? ? ? ? bd->mode.count = count;
+
+ ? ? ? ? ? ? ? if (sdma->word_size > 4) {
+ ? ? ? ? ? ? ? ? ? ? ? ret = ?-EINVAL;
+ ? ? ? ? ? ? ? ? ? ? ? goto err_out;
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? if (sdma->word_size == 4)
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = 0;
+ ? ? ? ? ? ? ? else
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = sdma->word_size;
+
+ ? ? ? ? ? ? ? param = BD_DONE | BD_EXTD | BD_CONT;
+
+ ? ? ? ? ? ? ? if (sdma->flags & IMX_DMA_SG_LOOP) {
+ ? ? ? ? ? ? ? ? ? ? ? param |= BD_INTR;
+ ? ? ? ? ? ? ? ? ? ? ? if (i + 1 == sg_len)
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param |= BD_WRAP;
+ ? ? ? ? ? ? ? }
+
+ ? ? ? ? ? ? ? if (i + 1 == sg_len)
+ ? ? ? ? ? ? ? ? ? ? ? param |= BD_INTR;
+
+ ? ? ? ? ? ? ? pr_debug("entry %d: count: %d dma: 0x%08x %s%s\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? i, count, sg->dma_address,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_WRAP ? "wrap" : "",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_INTR ? " intr" : "");
+
+ ? ? ? ? ? ? ? bd->mode.status = param;
+ ? ? ? }
+
+ ? ? ? sdma->num_bd = sg_len;
+ ? ? ? channel_control[channel].current_bd_ptr = sdma->bd_phys;
+
+ ? ? ? return &sdma->desc;
+err_out:
+ ? ? ? return NULL;
+}
+

drivers/dma/imx-sdma.c line 1113

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
+ ? ? ? ? ? ? ? struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
+ ? ? ? ? ? ? ? size_t period_len, enum dma_data_direction direction)
+{
+ ? ? ? int num_periods = buf_len / period_len;
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? int channel = chan->chan_id;
+ ? ? ? int ret, i = 0, buf = 0;
+
+ ? ? ? pr_debug("%s channel: %d\n", __func__, channel);

Must be possible to find struct device * and use dev_dbg()

Quoted 216 lines
drivers/dma/imx-sdma.c new file +216 -0
+
+ ? ? ? if (sdma->busy)
+ ? ? ? ? ? ? ? return NULL;
+
+ ? ? ? sdma->busy = 1;
+
+ ? ? ? sdma->flags |= IMX_DMA_SG_LOOP;
+ ? ? ? sdma->direction = direction;
+ ? ? ? ret = sdma_load_context(channel);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_out;
+
+ ? ? ? if (num_periods > NUM_BD) {
+ ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, num_periods, NUM_BD);
+ ? ? ? ? ? ? ? goto err_out;
+ ? ? ? }
+
+ ? ? ? if (period_len > 0xffff) {
+ ? ? ? ? ? ? ? pr_err("SDMA channel %d: maximum period size exceeded: %d > %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? channel, period_len, 0xffff);
+ ? ? ? ? ? ? ? goto err_out;
+ ? ? ? }
+
+ ? ? ? while (buf < buf_len) {
+ ? ? ? ? ? ? ? struct sdma_buffer_descriptor *bd = &sdma->bd[i];
+ ? ? ? ? ? ? ? int param;
+
+ ? ? ? ? ? ? ? bd->buffer_addr = dma_addr;
+
+ ? ? ? ? ? ? ? bd->mode.count = period_len;
+
+ ? ? ? ? ? ? ? if (sdma->word_size > 4)
+ ? ? ? ? ? ? ? ? ? ? ? goto err_out;
+ ? ? ? ? ? ? ? if (sdma->word_size == 4)
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = 0;
+ ? ? ? ? ? ? ? else
+ ? ? ? ? ? ? ? ? ? ? ? bd->mode.command = sdma->word_size;
+
+ ? ? ? ? ? ? ? param = BD_DONE | BD_EXTD | BD_CONT | BD_INTR;
+ ? ? ? ? ? ? ? if (i + 1 == num_periods)
+ ? ? ? ? ? ? ? ? ? ? ? param |= BD_WRAP;
+
+ ? ? ? ? ? ? ? pr_debug("entry %d: count: %d dma: 0x%08x %s%s\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? i, period_len, dma_addr,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_WRAP ? "wrap" : "",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? param & BD_INTR ? " intr" : "");
+
+ ? ? ? ? ? ? ? bd->mode.status = param;
+
+ ? ? ? ? ? ? ? dma_addr += period_len;
+ ? ? ? ? ? ? ? buf += period_len;
+
+ ? ? ? ? ? ? ? i++;
+ ? ? ? }
+
+ ? ? ? sdma->num_bd = num_periods;
+ ? ? ? channel_control[channel].current_bd_ptr = sdma->bd_phys;
+
+ ? ? ? return &sdma->desc;
+err_out:
+ ? ? ? sdma->busy = 0;
+ ? ? ? return NULL;
+}
+
+static int sdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ ? ? ? ? ? ? ? unsigned long arg)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? struct dma_slave_config *dmaengine_cfg = (void *)arg;
+
+ ? ? ? switch (cmd) {
+ ? ? ? case DMA_TERMINATE_ALL:
+ ? ? ? ? ? ? ? sdma_disable_channel(chan->chan_id);
+ ? ? ? ? ? ? ? return 0;
+ ? ? ? case DMA_SLAVE_CONFIG:
+ ? ? ? ? ? ? ? if (dmaengine_cfg->direction == DMA_FROM_DEVICE) {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->per_address = dmaengine_cfg->src_addr;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level = dmaengine_cfg->src_maxburst;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->word_size = dmaengine_cfg->src_addr_width;
+ ? ? ? ? ? ? ? } else {
+ ? ? ? ? ? ? ? ? ? ? ? sdma->per_address = dmaengine_cfg->dst_addr;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->watermark_level = dmaengine_cfg->dst_maxburst;
+ ? ? ? ? ? ? ? ? ? ? ? sdma->word_size = dmaengine_cfg->dst_addr_width;
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? return sdma_config_channel(chan->chan_id);
+ ? ? ? default:
+ ? ? ? ? ? ? ? return -ENOSYS;
+ ? ? ? }
+
+ ? ? ? return -EINVAL;
+}
+
+static enum dma_status sdma_tx_status(struct dma_chan *chan,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? dma_cookie_t cookie,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct dma_tx_state *txstate)
+{
+ ? ? ? struct sdma_channel *sdma = to_sdma_chan(chan);
+ ? ? ? dma_cookie_t last_used;
+ ? ? ? enum dma_status ret;
+
+ ? ? ? last_used = chan->cookie;
+
+ ? ? ? ret = dma_async_is_complete(cookie, sdma->last_completed, last_used);
+ ? ? ? dma_set_tx_state(txstate, sdma->last_completed, last_used, 0);
+
+ ? ? ? return ret;
+}
+
+static void sdma_issue_pending(struct dma_chan *chan)
+{
+ ? ? ? /*
+ ? ? ? ?* Nothing to do. We only have a single descriptor
+ ? ? ? ?*/
+}
+
+static int __devinit sdma_probe(struct platform_device *pdev)
+{
+ ? ? ? int ret;
+ ? ? ? const struct firmware *fw;
+ ? ? ? const struct sdma_firmware_header *header;
+ ? ? ? const struct sdma_script_start_addrs *addr;
+ ? ? ? int irq;
+ ? ? ? unsigned short *ram_code;
+ ? ? ? struct resource *iores;
+ ? ? ? struct sdma_platform_data *pdata = pdev->dev.platform_data;
+ ? ? ? int version;
+ ? ? ? char *cpustr, *fwname;
+ ? ? ? int i;
+ ? ? ? dma_cap_mask_t mask;
+
+ ? ? ? /* there can be only one */
+ ? ? ? BUG_ON(sdma_base);
+
+ ? ? ? iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ? ? ? irq = platform_get_irq(pdev, 0);
+ ? ? ? if (!iores || irq < 0 || !pdata)
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? sdma_clk = clk_get(&pdev->dev, NULL);
+ ? ? ? if (IS_ERR(sdma_clk)) {
+ ? ? ? ? ? ? ? ret = PTR_ERR(sdma_clk);
+ ? ? ? ? ? ? ? goto err_clk;
+ ? ? ? }
+
+ ? ? ? if (cpu_is_mx31()) {
+ ? ? ? ? ? ? ? cpustr = "imx31";
+ ? ? ? ? ? ? ? version = mx31_revision() >> 4;
+ ? ? ? } else if (cpu_is_mx35()) {
+ ? ? ? ? ? ? ? cpustr = "imx35";
+/* FIXME: ? ? ?version = mx35_revision(); */
+ ? ? ? ? ? ? ? version = 2;
+ ? ? ? } else {
+ ? ? ? ? ? ? ? ret = -EINVAL;
+ ? ? ? ? ? ? ? goto err_cputype;
+ ? ? ? }
+
+ ? ? ? fwname = kasprintf(GFP_KERNEL, "sdma-%s-to%d.bin", cpustr, version);
+ ? ? ? if (!fwname) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_cputype;
+ ? ? ? }
+
+ ? ? ? ret = request_firmware(&fw, fwname, &pdev->dev);
+ ? ? ? if (ret) {
+ ? ? ? ? ? ? ? dev_err(&pdev->dev, "request firmware \"%s\" failed with %d\n",
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fwname, ret);
+ ? ? ? ? ? ? ? kfree(fwname);
+ ? ? ? ? ? ? ? goto err_cputype;
+ ? ? ? }
+ ? ? ? kfree(fwname);
+
+ ? ? ? if (fw->size < sizeof(*header))
+ ? ? ? ? ? ? ? goto err_firmware;
+
+ ? ? ? header = (struct sdma_firmware_header *)fw->data;
+
+ ? ? ? if (header->magic != SDMA_FIRMWARE_MAGIC)
+ ? ? ? ? ? ? ? goto err_firmware;
+ ? ? ? if (header->ram_code_start + header->ram_code_size > fw->size)
+ ? ? ? ? ? ? ? goto err_firmware;
+
+ ? ? ? addr = (void *)header + header->script_addrs_start;
+ ? ? ? ram_code = (void *)header + header->ram_code_start;
+ ? ? ? memcpy(&__sdma_script_addrs, addr, sizeof(*addr));
+
+ ? ? ? ret = sdma_init(iores->start, irq, pdata->sdma_version,
+ ? ? ? ? ? ? ? ? ? ? ? ram_code, header->ram_code_size);
+ ? ? ? if (ret)
+ ? ? ? ? ? ? ? goto err_firmware;
+
+ ? ? ? INIT_LIST_HEAD(&sdma_dma_device->channels);
+
+ ? ? ? /* Initialize channel parameters */
+ ? ? ? for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+ ? ? ? ? ? ? ? struct sdma_channel *sdma = &sdma_data[i];
+
+ ? ? ? ? ? ? ? spin_lock_init(&sdma->lock);
+
+ ? ? ? ? ? ? ? dma_cap_set(DMA_SLAVE, sdma_dma_device->cap_mask);
+ ? ? ? ? ? ? ? dma_cap_set(DMA_CYCLIC, sdma_dma_device->cap_mask);
+
+ ? ? ? ? ? ? ? sdma->chan.device = sdma_dma_device;
+ ? ? ? ? ? ? ? sdma->chan.chan_id = i;
+
+ ? ? ? ? ? ? ? /* Add the channel to the DMAC list */
+ ? ? ? ? ? ? ? list_add_tail(&sdma->chan.device_node, &sdma_dma_device->channels);
+ ? ? ? }
+
+ ? ? ? sdma_dma_device->dev = &pdev->dev;
+
+ ? ? ? sdma_dma_device->device_alloc_chan_resources = sdma_alloc_chan_resources;
+ ? ? ? sdma_dma_device->device_free_chan_resources = sdma_free_chan_resources;
+ ? ? ? sdma_dma_device->device_tx_status = sdma_tx_status;
+ ? ? ? sdma_dma_device->device_prep_slave_sg = sdma_prep_slave_sg;
+ ? ? ? sdma_dma_device->device_prep_dma_cyclic = sdma_prep_dma_cyclic;
Quoted 8 lines

drivers/dma/imx-sdma.c line 1335

Quoted 6 lines
drivers/dma/imx-sdma.c new file +6 -0
+ ? ? ? sdma_dma_device->device_control = sdma_control;
+ ? ? ? sdma_dma_device->device_issue_pending = sdma_issue_pending;
+
+ ? ? ? ret = dma_async_device_register(sdma_dma_device);
+ ? ? ? if (ret) {
+ ? ? ? ? ? ? ? dev_err(&pdev->dev, "unable to register DMAC\n");

SDMAC even?

Better just "unable to register". The name of the device will give enough information.

Quoted 58 lines
Quoted 50 lines
drivers/dma/imx-sdma.c new file +48 -1
+ ? ? ? ? ? ? ? goto err_firmware;
+ ? ? ? }
+
+ ? ? ? dev_info(&pdev->dev, "initialized (firmware %d.%d)\n",
+ ? ? ? ? ? ? ? ? ? ? ? header->version_major,
+ ? ? ? ? ? ? ? ? ? ? ? header->version_minor);
+
+ ? ? ? /* request channel 0. This is an internal control channel
+ ? ? ? ?* to the SDMA engine and not available to clients.
+ ? ? ? ?*/
+ ? ? ? dma_cap_zero(mask);
+ ? ? ? dma_cap_set(DMA_SLAVE, mask);
+ ? ? ? dma_request_channel(mask, NULL, NULL);
+
+ ? ? ? release_firmware(fw);
+
+ ? ? ? return 0;
+
+err_firmware:
+ ? ? ? release_firmware(fw);
+err_cputype:
+ ? ? ? clk_put(sdma_clk);
+err_clk:
+ ? ? ? return 0;
+}
+
+static int __devexit sdma_remove(struct platform_device *pdev)
+{
+ ? ? ? return -EBUSY;
+}
+
+static struct platform_driver sdma_driver = {
+ ? ? ? .driver ? ? ? ? = {
+ ? ? ? ? ? ? ? .name ? = "imx-sdma",
+ ? ? ? },
+ ? ? ? .probe ? ? ? ? ?= sdma_probe,
+ ? ? ? .remove ? ? ? ? = __devexit_p(sdma_remove),
+};
+
+static int __init sdma_module_init(void)
+{
+ ? ? ? return platform_driver_register(&sdma_driver);
+}
+subsys_initcall(sdma_module_init);
+
+MODULE_AUTHOR("Sascha Hauer, Pengutronix <[email protected]>");
+MODULE_DESCRIPTION("i.MX SDMA driver");
+MODULE_LICENSE("GPL");
--
Quoted 1 line

1.7.1

Thanks for using this API
Sascha!

Yours,
Linus Walleij

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#18 lore raw

Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support

Hi Sascha,

Quoted 10 lines · Sascha Hauer
Quoted 9 lines · Linus Walleij

2010/8/16 Sascha Hauer <[email protected]>:

Quoted 7 lines

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.

Quoted 7 lines
Quoted 3 lines

Quite fun, if the spec for the microcode is open this opens up for dynamic firmware generation for specific DMA jobs does it not?

Unfortunately the specs are not open, so we are sticked to the binary microcode from Freescale. I'm pretty sure though that the SDMA engine could do at least a device_prep_dma_xor operation.

Chapter 38 in the i.MX25 Reference Manual seems to include almost everything there is to know about the SDMA. Isn't this enough for writing custom SDMA microcodes?

baruch

Signature · 3 lines
                                                     ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
author maintainer
#19 lore raw

Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support

Quoted 17 lines · Baruch Siach

Hi Sascha,

Quoted 14 lines · Sascha Hauer
Quoted 12 lines · Linus Walleij

2010/8/16 Sascha Hauer <[email protected]>:

Quoted 7 lines

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.

Quite fun, if the spec for the microcode is open this opens up for dynamic firmware generation for specific DMA jobs does it not?

Quoted 7 lines
Quoted 3 lines

Unfortunately the specs are not open, so we are sticked to the binary microcode from Freescale. I'm pretty sure though that the SDMA engine could do at least a device_prep_dma_xor operation.

Chapter 38 in the i.MX25 Reference Manual seems to include almost everything there is to know about the SDMA. Isn't this enough for writing custom SDMA microcodes?

Unfortunately not, the assembler is missing.

Sascha

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#20 lore raw

PATCH 3/3 dmaengine: Add Freescale i.MX SDMA support

Quoted 1 line

Unfortunately not, the assembler is missing.

The instruction set, if I'm not mistaken, is similar to the M-core

Signature · 4 lines
Regards,
Alexei Babich, circuit design engineer, Rezonans plc., Chelyabinsk, Russia
http://www.rez.ru
Jabber ID: impatt at jabber.ru
#21 lore raw

PATCH 3/3 dmaengine: Add Freescale i.MX SDMA support

Hi Alexei,

Quoted 2 lines · Alexei Babich
Quoted 1 line

Unfortunately not, the assembler is missing.

The instruction set, if I'm not mistaken, is similar to the M-core

Thanks for the tip.

The document with the necessary M-core assembly instructions details, the MCORERC/AD, is not publicly available, as far as I can see.

baruch

Signature · 3 lines
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=}------------------------------------------------ooO--U--Ooo------------{=
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#22 lore raw

Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

Le mardi, 17 ao?t 2010 08.47:34, Sascha Hauer a ?crit :

Quoted 22 lines · Baruch Siach
Quoted 21 lines

Hi Sascha,

Quoted 17 lines · Sascha Hauer
Quoted 9 lines · Linus Walleij

2010/8/16 Sascha Hauer <[email protected]>:

Quoted 7 lines

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.

Quoted 3 lines

Quite fun, if the spec for the microcode is open this opens up for dynamic firmware generation for specific DMA jobs does it not?

Unfortunately the specs are not open, so we are sticked to the binary microcode from Freescale. I'm pretty sure though that the SDMA engine could do at least a device_prep_dma_xor operation.

Quoted 6 lines
Quoted 3 lines

Chapter 38 in the i.MX25 Reference Manual seems to include almost everything there is to know about the SDMA. Isn't this enough for writing custom SDMA microcodes?

Unfortunately not, the assembler is missing.

I think the instruction list and encoding is available in the imx31 reference manual at section 40.19.

BTW, I tested the non-dmaengine version of your patch on imx31, works great !

Regards,

Philippe

author maintainer Reviewed-by Linus Walleij
#23 lore raw

Re: [PATCH 3/3 v3] dmaengine: Add Freescale i.MX SDMA support

In reply to Linus Walleij

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.
The original Freescale code also supports support for transfering data to the internal SRAM which needs different entry points to the firmware. Support for this is currently not implemented. Also, support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

---
 arch/arm/mach-imx/include/mach/dma-v1.h |    8 +-
 arch/arm/mach-mx3/Kconfig               |    2 +
 arch/arm/plat-mxc/Kconfig               |   10 +
 arch/arm/plat-mxc/include/mach/dma.h    |   64 ++
 arch/arm/plat-mxc/include/mach/sdma.h   |   17 +
 drivers/dma/Kconfig                     |    8 +
 drivers/dma/Makefile                    |    1 +
 drivers/dma/imx-sdma.c                  | 1386 +++++++++++++++++++++++++++++++
 8 files changed, 1490 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/plat-mxc/include/mach/dma.h
 create mode 100644 arch/arm/plat-mxc/include/mach/sdma.h
 create mode 100644 drivers/dma/imx-sdma.c
arch/arm/mach-imx/include/mach/dma-v1.h +2 -6
index 287431c..ac6fd71 100644
@@ -27,6 +27,8 @@
 
 #define imx_has_dma_v1()	(cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
 
+#include <mach/dma.h>
+
 #define IMX_DMA_CHANNELS  16
 
 #define DMA_MODE_READ		0
@@ -96,12 +98,6 @@ int imx_dma_request(int channel, const char *name);
 
 void imx_dma_free(int channel);
 
-enum imx_dma_prio {
-	DMA_PRIO_HIGH = 0,
-	DMA_PRIO_MEDIUM = 1,
-	DMA_PRIO_LOW = 2
-};
-
 int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio);
 
 #endif	/* __MACH_DMA_V1_H__ */
arch/arm/mach-mx3/Kconfig +2 -0
index 85beece..301375c 100644
@@ -3,12 +3,14 @@ if ARCH_MX3
 config ARCH_MX31
 	select ARCH_HAS_RNGA
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 	bool
 
 config ARCH_MX35
 	bool
 	select ARCH_MXC_IOMUX_V3
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 
 comment "MX3 platforms:"
 
arch/arm/plat-mxc/Kconfig +10 -0
index 0527e65..6741625 100644
@@ -109,4 +109,14 @@ config ARCH_MXC_AUDMUX_V1
 config ARCH_MXC_AUDMUX_V2
 	bool
 
+config IMX_HAVE_SDMA
+	bool
+
+config IMX_SDMA
+	depends on IMX_HAVE_SDMA
+	tristate "Enable SDMA support"
+	help
+	  Include support for the SDMA engine. The SDMA engine needs additional
+	  firmware support. SDMA can be compiled as a module to support loading
+	  the firmware when a rootfs is present.
 endif
arch/arm/plat-mxc/include/mach/dma.h new file +64 -0

64 lines not on this page · raw message

arch/arm/plat-mxc/include/mach/sdma.h new file +17 -0
new file mode 100644
index 0000000..9be1122
@@ -0,0 +1,17 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__
+
+/**
+ * struct sdma_platform_data - platform specific data for SDMA engine
+ *
+ * @sdma_version	The version of this SDMA engine
+ * @cpu_name		used to generate the firmware name
+ * @to_version		CPU Tape out version
+ */
+struct sdma_platform_data {
+	int sdma_version;
+	char *cpu_name;
+	int to_version;
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +8 -0
index 9520cf0..ff68307 100644
@@ -195,6 +195,14 @@ config PCH_DMA
 	help
 	  Enable support for the Topcliff PCH DMA engine.
 
+config IMX_SDMA
+	tristate "i.MX SDMA support"
+	depends on ARCH_MXC
+	select DMA_ENGINE
+	help
+	  Support the i.MX SDMA engine. This engine is integrated into
+	  Freescale i.MX25/31/35/51 chips.
+
 config DMA_ENGINE
 	bool
 
drivers/dma/Makefile +1 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +1386 -0

1,386 lines not on this page · raw message

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1.7.1

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#24 lore raw

Re: [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support

In reply to Linus Walleij
Quoted 10 lines · Linus Walleij

drivers/dma/imx-sdma.c

Quoted 7 lines
drivers/dma/imx-sdma.c new file +7 -0
+/*
+ * Buffer descriptor
+ */
+struct sdma_buffer_descriptor {
+ ? ? ? struct sdma_mode_count ?mode;
+ ? ? ? u32 buffer_addr; ? ?/* address of the buffer described */
+ ? ? ? u32 ext_buffer_addr; /* extended buffer address */

Shouldn't these be dma_addr_t? OK that's probably u32 anyway but just to make a marker...

If this is describing hardware, then it makes sense to use uNN rather than dma_addr_t. dma_addr_t may be subject to change in the future.

author maintainer
#25 lore raw

PATCH v2 3/3 dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.
The original Freescale code also supports support for transfering data to the internal SRAM which needs different entry points to the firmware. Support for this is currently not implemented. Also, support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

Changes since v1:

- included comments from Linus Walleij

---
 arch/arm/mach-imx/include/mach/dma-v1.h |    8 +-
 arch/arm/mach-mx3/Kconfig               |    2 +
 arch/arm/plat-mxc/Kconfig               |   10 +
 arch/arm/plat-mxc/include/mach/dma.h    |   64 ++
 arch/arm/plat-mxc/include/mach/sdma.h   |   17 +
 drivers/dma/Kconfig                     |    8 +
 drivers/dma/Makefile                    |    1 +
 drivers/dma/imx-sdma.c                  | 1395 +++++++++++++++++++++++++++++++
 8 files changed, 1499 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/plat-mxc/include/mach/dma.h
 create mode 100644 arch/arm/plat-mxc/include/mach/sdma.h
 create mode 100644 drivers/dma/imx-sdma.c
arch/arm/mach-imx/include/mach/dma-v1.h +2 -6
index 287431c..ac6fd71 100644
@@ -27,6 +27,8 @@
 
 #define imx_has_dma_v1()	(cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
 
+#include <mach/dma.h>
+
 #define IMX_DMA_CHANNELS  16
 
 #define DMA_MODE_READ		0
@@ -96,12 +98,6 @@ int imx_dma_request(int channel, const char *name);
 
 void imx_dma_free(int channel);
 
-enum imx_dma_prio {
-	DMA_PRIO_HIGH = 0,
-	DMA_PRIO_MEDIUM = 1,
-	DMA_PRIO_LOW = 2
-};
-
 int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio);
 
 #endif	/* __MACH_DMA_V1_H__ */
arch/arm/mach-mx3/Kconfig +2 -0
index 85beece..301375c 100644
@@ -3,12 +3,14 @@ if ARCH_MX3
 config ARCH_MX31
 	select ARCH_HAS_RNGA
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 	bool
 
 config ARCH_MX35
 	bool
 	select ARCH_MXC_IOMUX_V3
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 
 comment "MX3 platforms:"
 
arch/arm/plat-mxc/Kconfig +10 -0
index 0527e65..6741625 100644
@@ -109,4 +109,14 @@ config ARCH_MXC_AUDMUX_V1
 config ARCH_MXC_AUDMUX_V2
 	bool
 
+config IMX_HAVE_SDMA
+	bool
+
+config IMX_SDMA
+	depends on IMX_HAVE_SDMA
+	tristate "Enable SDMA support"
+	help
+	  Include support for the SDMA engine. The SDMA engine needs additional
+	  firmware support. SDMA can be compiled as a module to support loading
+	  the firmware when a rootfs is present.
 endif
arch/arm/plat-mxc/include/mach/dma.h new file +64 -0

64 lines not on this page · raw message

arch/arm/plat-mxc/include/mach/sdma.h new file +17 -0
new file mode 100644
index 0000000..9be1122
@@ -0,0 +1,17 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__
+
+/**
+ * struct sdma_platform_data - platform specific data for SDMA engine
+ *
+ * @sdma_version	The version of this SDMA engine
+ * @cpu_name		used to generate the firmware name
+ * @to_version		CPU Tape out version
+ */
+struct sdma_platform_data {
+	int sdma_version;
+	char *cpu_name;
+	int to_version;
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +8 -0
index 9520cf0..ff68307 100644
@@ -195,6 +195,14 @@ config PCH_DMA
 	help
 	  Enable support for the Topcliff PCH DMA engine.
 
+config IMX_SDMA
+	tristate "i.MX SDMA support"
+	depends on ARCH_MXC
+	select DMA_ENGINE
+	help
+	  Support the i.MX SDMA engine. This engine is integrated into
+	  Freescale i.MX25/31/35/51 chips.
+
 config DMA_ENGINE
 	bool
 
drivers/dma/Makefile +1 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +1395 -0

1,395 lines not on this page · raw message

Signature · 7 lines
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-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
Reviewed-by on v2 3/3
#26 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

2010/8/23 Sascha Hauer <[email protected]>:

Quoted 1 line

This patch adds support for the Freescale i.MX SDMA engine.

Great progress!

Quoted 22 lines

(...)

drivers/dma/imx-sdma.c +19 -0
(...)
+/* SDMA registers */
+#define SDMA_H_C0PTR ? ? ? ? ? (sdma->regs + 0x000)
+#define SDMA_H_INTR ? ? ? ? ? ?(sdma->regs + 0x004)
+#define SDMA_H_STATSTOP ? ? ? ? ? ? ? ?(sdma->regs + 0x008)
+#define SDMA_H_START ? ? ? ? ? (sdma->regs + 0x00c)
+#define SDMA_H_EVTOVR ? ? ? ? ?(sdma->regs + 0x010)
+#define SDMA_H_DSPOVR ? ? ? ? ?(sdma->regs + 0x014)
+#define SDMA_H_HOSTOVR ? ? ? ? (sdma->regs + 0x018)
+#define SDMA_H_EVTPEND ? ? ? ? (sdma->regs + 0x01c)
+#define SDMA_H_DSPENBL ? ? ? ? (sdma->regs + 0x020)
+#define SDMA_H_RESET ? ? ? ? ? (sdma->regs + 0x024)
+#define SDMA_H_EVTERR ? ? ? ? ?(sdma->regs + 0x028)
+#define SDMA_H_INTRMSK ? ? ? ? (sdma->regs + 0x02c)
+#define SDMA_H_PSW ? ? ? ? ? ? (sdma->regs + 0x030)
+#define SDMA_H_EVTERRDBG ? ? ? (sdma->regs + 0x034)
+#define SDMA_H_CONFIG ? ? ? ? ?(sdma->regs + 0x038)
+#define SDMA_ONCE_ENB ? ? ? ? ?(sdma->regs + 0x040)
+#define SDMA_ONCE_DATA ? ? ? ? (sdma->regs + 0x044)
+#define SDMA_ONCE_INSTR ? ? ? ? ? ? ? ?(sdma->regs + 0x048)

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c +10 -0
+#define SDMA_ONCE_STAT ? ? ? ? (sdma->regs + 0x04c)
+#define SDMA_ONCE_CMD ? ? ? ? ?(sdma->regs + 0x050)
+#define SDMA_EVT_MIRROR ? ? ? ? ? ? ? ?(sdma->regs + 0x054)
+#define SDMA_ILLINSTADDR ? ? ? (sdma->regs + 0x058)
+#define SDMA_CHN0ADDR ? ? ? ? ?(sdma->regs + 0x05c)
+#define SDMA_ONCE_RTB ? ? ? ? ?(sdma->regs + 0x060)
+#define SDMA_XTRIG_CONF1 ? ? ? (sdma->regs + 0x070)
+#define SDMA_XTRIG_CONF2 ? ? ? (sdma->regs + 0x074)
+#define SDMA_CHNENBL_0 ? ? ? ? (sdma->regs + (sdma->version == 2 ? 0x200 : 0x80))
+#define SDMA_CHNPRI_0 ? ? ? ? ?(sdma->regs + 0x100)

These macros expand to the local variable "sdma" which must be present in all functions using them. I don't know what is considered moste readable, but I would certainly just

#define SDMA_FOO (0x0123)
(...)
u32 foo = readl(sdma->regs + SDMA_FOO);

That is more common I think.

Quoted 3 lines

(...)
+/*
+ * Channel control Block

Some kerneldoc here describing especially
@unused: padding for register cast
@usused1: padding for register cast

Hm "unused" and "unused1" wrinkles my binary brain, can you call the first one "unused0" for my perceptions sake?

Quoted 20 lines

+ */

drivers/dma/imx-sdma.c +17 -0
+struct sdma_channel_control {
+ ? ? ? dma_addr_t current_bd_ptr; /* current buffer descriptor processed */
+ ? ? ? dma_addr_t base_bd_ptr; ? ?/* first element of buffer descriptor array */
+ ? ? ? u32 unused;
+ ? ? ? u32 unused1;
+} __attribute__ ((packed));
 
(...)
+/**
+ * struct sdma_channel - housekeeping for a SDMA channel
+ *
+ * @sdma ? ? ? ? ? ? ? pointer to the SDMA engine for this channel
+ * @channel ? ? ? ? ? ?the channel number, matches dmaengine chan_id
+ * @direction ? ? ? ? ?transfer type. Needed for setting SDMA script
+ * @peripheral_type ? ?Peripheral type. Needed for setting SDMA script
+ * @event_id ? ? ? ? ? aka dma request line
+ * @event_id2 ? ? ? ? ?for channels that use 2 events
+ * @word_size ? ? ? ? ?peripheral access size
+ * @buf_tail ? ? ? ? ? ID of the buffer that was processed

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c +10 -0
+ * @done ? ? ? ? ? ? ? channel completion
+ * @num_bd ? ? ? ? ? ? max NUM_BD. number of descriptors currently handling
+ */
+struct sdma_channel {
+ ? ? ? struct sdma_engine ? ? ? ? ? ? ?*sdma;
+ ? ? ? unsigned int ? ? ? ? ? ? ? ? ? ?channel;
+ ? ? ? enum dma_data_direction ? ? ? ? direction;
+ ? ? ? enum sdma_peripheral_type ? ? ? peripheral_type;
+ ? ? ? unsigned int ? ? ? ? ? ? ? ? ? ?event_id;
+ ? ? ? unsigned int ? ? ? ? ? ? ? ? ? ?event_id2;

id1 und id2 oder
id0 und id1 fierleicht?

Quoted 10 lines

+ ? ? ? enum dma_slave_buswidth ? ? ? ? word_size;
+ ? ? ? unsigned int ? ? ? ? ? ? ? ? ? ?buf_tail;
+ ? ? ? struct completion ? ? ? ? ? ? ? done;
+ ? ? ? unsigned int ? ? ? ? ? ? ? ? ? ?num_bd;
+ ? ? ? struct sdma_buffer_descriptor ? *bd;
+ ? ? ? dma_addr_t ? ? ? ? ? ? ? ? ? ? ?bd_phys;
+ ? ? ? unsigned int ? ? ? ? ? ? ? ? ? ?pc_from_device, pc_to_device;
+ ? ? ? unsigned long ? ? ? ? ? ? ? ? ? flags;
+ ? ? ? dma_addr_t ? ? ? ? ? ? ? ? ? ? ?per_address;
+ ? ? ? u32 ? ? ? ? ? ? ? ? ? ? ? ? ? ? event_mask1, event_mask2;

1 and 2, else unnumbered and 1, else unnumbered and 2 X-)

Quoted 31 lines

+ ? ? ? u32 ? ? ? ? ? ? ? ? ? ? ? ? ? ? watermark_level;
+ ? ? ? u32 ? ? ? ? ? ? ? ? ? ? ? ? ? ? shp_addr, per_addr;
+ ? ? ? struct dma_chan ? ? ? ? ? ? ? ? chan;
+ ? ? ? spinlock_t ? ? ? ? ? ? ? ? ? ? ?lock;
+ ? ? ? struct dma_async_tx_descriptor ?desc;
+ ? ? ? dma_cookie_t ? ? ? ? ? ? ? ? ? ?last_completed;
+ ? ? ? enum dma_status ? ? ? ? ? ? ? ? status;

drivers/dma/imx-sdma.c +24 -0
+};
+
+#define IMX_DMA_SG_LOOP ? ? ? ? ? ? ? ?(1 << 0)
+
+#define MAX_DMA_CHANNELS 32
+#define MXC_SDMA_DEFAULT_PRIORITY 1
+#define MXC_SDMA_MIN_PRIORITY 1
+#define MXC_SDMA_MAX_PRIORITY 7
+
+/*
+ * This enumerates transfer types
+ */
+enum {
+ ? ? ? emi_2_per = 0, ? ? ? ? ?/* EMI memory to peripheral */
+ ? ? ? emi_2_int, ? ? ? ? ? ? ?/* EMI memory to internal RAM */
+ ? ? ? emi_2_emi, ? ? ? ? ? ? ?/* EMI memory to EMI memory */
+ ? ? ? emi_2_dsp, ? ? ? ? ? ? ?/* EMI memory to DSP memory */
+ ? ? ? per_2_int, ? ? ? ? ? ? ?/* Peripheral to internal RAM */
+ ? ? ? per_2_emi, ? ? ? ? ? ? ?/* Peripheral to internal EMI memory */
+ ? ? ? per_2_dsp, ? ? ? ? ? ? ?/* Peripheral to DSP memory */
+ ? ? ? per_2_per, ? ? ? ? ? ? ?/* Peripheral to Peripheral */
+ ? ? ? int_2_per, ? ? ? ? ? ? ?/* Internal RAM to peripheral */
+ ? ? ? int_2_int, ? ? ? ? ? ? ?/* Internal RAM to Internal RAM */
+ ? ? ? int_2_emi, ? ? ? ? ? ? ?/* Internal RAM to EMI memory */

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c +10 -0
+ ? ? ? int_2_dsp, ? ? ? ? ? ? ?/* Internal RAM to DSP memory */
+ ? ? ? dsp_2_per, ? ? ? ? ? ? ?/* DSP memory to peripheral */
+ ? ? ? dsp_2_int, ? ? ? ? ? ? ?/* DSP memory to internal RAM */
+ ? ? ? dsp_2_emi, ? ? ? ? ? ? ?/* DSP memory to EMI memory */
+ ? ? ? dsp_2_dsp, ? ? ? ? ? ? ?/* DSP memory to DSP memory */
+ ? ? ? emi_2_dsp_loop, ? ? ? ? /* EMI memory to DSP memory loopback */
+ ? ? ? dsp_2_emi_loop, ? ? ? ? /* DSP memory to EMI memory loopback */
+ ? ? ? dvfs_pll, ? ? ? ? ? ? ? /* DVFS script with PLL change ? ? ? */
+ ? ? ? dvfs_pdr ? ? ? ? ? ? ? ?/* DVFS script without PLL change ? ?*/
+} sdma_transfer_type;

Picky me, but it's no type, its an enum. I understand that it is a technical term...

What about just calling is sdma_transfer? Short and nice. Or sdma_transfer_line?

drivers/dma/imx-sdma.c line 580

Quoted 6 lines

(...)

drivers/dma/imx-sdma.c +5 -0
+/*
+ * Stores the start address of the SDMA scripts
+ */
+static struct sdma_script_start_addrs __sdma_script_addrs;
+static struct sdma_script_start_addrs *sdma_script_addrs = &__sdma_script_addrs;

What's the rationale behind prefixing that variable with __?

The same name for struct and variable is perfectly viable.

Apart from these smallies (and it's all minor stuff) it's nice and clean so:

Yours,
Linus Walleij

author maintainer
#27 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

Quoted 78 lines · Linus Walleij

2010/8/23 Sascha Hauer <[email protected]>:

Quoted 1 line

This patch adds support for the Freescale i.MX SDMA engine.

Great progress!

Quoted 22 lines

(...)

drivers/dma/imx-sdma.c +19 -0
(...)
+/* SDMA registers */
+#define SDMA_H_C0PTR ? ? ? ? ? (sdma->regs + 0x000)
+#define SDMA_H_INTR ? ? ? ? ? ?(sdma->regs + 0x004)
+#define SDMA_H_STATSTOP ? ? ? ? ? ? ? ?(sdma->regs + 0x008)
+#define SDMA_H_START ? ? ? ? ? (sdma->regs + 0x00c)
+#define SDMA_H_EVTOVR ? ? ? ? ?(sdma->regs + 0x010)
+#define SDMA_H_DSPOVR ? ? ? ? ?(sdma->regs + 0x014)
+#define SDMA_H_HOSTOVR ? ? ? ? (sdma->regs + 0x018)
+#define SDMA_H_EVTPEND ? ? ? ? (sdma->regs + 0x01c)
+#define SDMA_H_DSPENBL ? ? ? ? (sdma->regs + 0x020)
+#define SDMA_H_RESET ? ? ? ? ? (sdma->regs + 0x024)
+#define SDMA_H_EVTERR ? ? ? ? ?(sdma->regs + 0x028)
+#define SDMA_H_INTRMSK ? ? ? ? (sdma->regs + 0x02c)
+#define SDMA_H_PSW ? ? ? ? ? ? (sdma->regs + 0x030)
+#define SDMA_H_EVTERRDBG ? ? ? (sdma->regs + 0x034)
+#define SDMA_H_CONFIG ? ? ? ? ?(sdma->regs + 0x038)
+#define SDMA_ONCE_ENB ? ? ? ? ?(sdma->regs + 0x040)
+#define SDMA_ONCE_DATA ? ? ? ? (sdma->regs + 0x044)
+#define SDMA_ONCE_INSTR ? ? ? ? ? ? ? ?(sdma->regs + 0x048)

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c +10 -0
+#define SDMA_ONCE_STAT ? ? ? ? (sdma->regs + 0x04c)
+#define SDMA_ONCE_CMD ? ? ? ? ?(sdma->regs + 0x050)
+#define SDMA_EVT_MIRROR ? ? ? ? ? ? ? ?(sdma->regs + 0x054)
+#define SDMA_ILLINSTADDR ? ? ? (sdma->regs + 0x058)
+#define SDMA_CHN0ADDR ? ? ? ? ?(sdma->regs + 0x05c)
+#define SDMA_ONCE_RTB ? ? ? ? ?(sdma->regs + 0x060)
+#define SDMA_XTRIG_CONF1 ? ? ? (sdma->regs + 0x070)
+#define SDMA_XTRIG_CONF2 ? ? ? (sdma->regs + 0x074)
+#define SDMA_CHNENBL_0 ? ? ? ? (sdma->regs + (sdma->version == 2 ? 0x200 : 0x80))
+#define SDMA_CHNPRI_0 ? ? ? ? ?(sdma->regs + 0x100)

These macros expand to the local variable "sdma" which must be present in all functions using them. I don't know what is considered moste readable, but I would certainly just

#define SDMA_FOO (0x0123)
(...)
u32 foo = readl(sdma->regs + SDMA_FOO);

That is more common I think.

Quoted 16 lines
drivers/dma/imx-sdma.c +16 -0
+
+/*
+ * This enumerates transfer types
+ */
+enum {
+ ? ? ? emi_2_per = 0, ? ? ? ? ?/* EMI memory to peripheral */
+ ? ? ? emi_2_int, ? ? ? ? ? ? ?/* EMI memory to internal RAM */
+ ? ? ? emi_2_emi, ? ? ? ? ? ? ?/* EMI memory to EMI memory */
+ ? ? ? emi_2_dsp, ? ? ? ? ? ? ?/* EMI memory to DSP memory */
+ ? ? ? per_2_int, ? ? ? ? ? ? ?/* Peripheral to internal RAM */
+ ? ? ? per_2_emi, ? ? ? ? ? ? ?/* Peripheral to internal EMI memory */
+ ? ? ? per_2_dsp, ? ? ? ? ? ? ?/* Peripheral to DSP memory */
+ ? ? ? per_2_per, ? ? ? ? ? ? ?/* Peripheral to Peripheral */
+ ? ? ? int_2_per, ? ? ? ? ? ? ?/* Internal RAM to peripheral */
+ ? ? ? int_2_int, ? ? ? ? ? ? ?/* Internal RAM to Internal RAM */
+ ? ? ? int_2_emi, ? ? ? ? ? ? ?/* Internal RAM to EMI memory */

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c +10 -0
+ ? ? ? int_2_dsp, ? ? ? ? ? ? ?/* Internal RAM to DSP memory */
+ ? ? ? dsp_2_per, ? ? ? ? ? ? ?/* DSP memory to peripheral */
+ ? ? ? dsp_2_int, ? ? ? ? ? ? ?/* DSP memory to internal RAM */
+ ? ? ? dsp_2_emi, ? ? ? ? ? ? ?/* DSP memory to EMI memory */
+ ? ? ? dsp_2_dsp, ? ? ? ? ? ? ?/* DSP memory to DSP memory */
+ ? ? ? emi_2_dsp_loop, ? ? ? ? /* EMI memory to DSP memory loopback */
+ ? ? ? dsp_2_emi_loop, ? ? ? ? /* DSP memory to EMI memory loopback */
+ ? ? ? dvfs_pll, ? ? ? ? ? ? ? /* DVFS script with PLL change ? ? ? */
+ ? ? ? dvfs_pdr ? ? ? ? ? ? ? ?/* DVFS script without PLL change ? ?*/
+} sdma_transfer_type;

Picky me, but it's no type, its an enum. I understand that it is a technical term...

Quoted 2 lines

What about just calling is sdma_transfer? Short and nice. Or sdma_transfer_line?

This turned out to be unused anyway, so the simple fix was to remove it.

Quoted 11 lines

drivers/dma/imx-sdma.c line 580

Quoted 7 lines

(...)

drivers/dma/imx-sdma.c +5 -0
+/*
+ * Stores the start address of the SDMA scripts
+ */
+static struct sdma_script_start_addrs __sdma_script_addrs;
+static struct sdma_script_start_addrs *sdma_script_addrs = &__sdma_script_addrs;

What's the rationale behind prefixing that variable with __?

The same name for struct and variable is perfectly viable.

The rationale was to statically allocate a struct sdma_script_start_addrs and create a pointer to it so that I don't have to use &__sdma_script_addrs in the code.

I forgot this one while converting the driver to multi instance, so this is now part of struct sdma_engine.

Fixed the other stuff aswell, I will send an update shortly.

Regards,
Sascha

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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#28 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

Hallo Sascha,

Quoted 110 lines · Sascha Hauer

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.
The original Freescale code also supports support for transfering data to the internal SRAM which needs different entry points to the firmware. Support for this is currently not implemented. Also, support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

Changes since v1:

- included comments from Linus Walleij

---
 arch/arm/mach-imx/include/mach/dma-v1.h |    8 +-
 arch/arm/mach-mx3/Kconfig               |    2 +
 arch/arm/plat-mxc/Kconfig               |   10 +
 arch/arm/plat-mxc/include/mach/dma.h    |   64 ++
 arch/arm/plat-mxc/include/mach/sdma.h   |   17 +
 drivers/dma/Kconfig                     |    8 +
 drivers/dma/Makefile                    |    1 +
 drivers/dma/imx-sdma.c                  | 1395 +++++++++++++++++++++++++++++++
 8 files changed, 1499 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/plat-mxc/include/mach/dma.h
 create mode 100644 arch/arm/plat-mxc/include/mach/sdma.h
 create mode 100644 drivers/dma/imx-sdma.c
arch/arm/mach-imx/include/mach/dma-v1.h +2 -6
index 287431c..ac6fd71 100644
@@ -27,6 +27,8 @@
 
 #define imx_has_dma_v1()	(cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
 
+#include <mach/dma.h>
+
 #define IMX_DMA_CHANNELS  16
 
 #define DMA_MODE_READ		0
@@ -96,12 +98,6 @@ int imx_dma_request(int channel, const char *name);
 
 void imx_dma_free(int channel);
 
-enum imx_dma_prio {
-	DMA_PRIO_HIGH = 0,
-	DMA_PRIO_MEDIUM = 1,
-	DMA_PRIO_LOW = 2
-};
-
 int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio);
 
 #endif	/* __MACH_DMA_V1_H__ */
arch/arm/mach-mx3/Kconfig +2 -0
index 85beece..301375c 100644
@@ -3,12 +3,14 @@ if ARCH_MX3
 config ARCH_MX31
 	select ARCH_HAS_RNGA
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 	bool
 
 config ARCH_MX35
 	bool
 	select ARCH_MXC_IOMUX_V3
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 
 comment "MX3 platforms:"
 
arch/arm/plat-mxc/Kconfig +10 -0
index 0527e65..6741625 100644
@@ -109,4 +109,14 @@ config ARCH_MXC_AUDMUX_V1
 config ARCH_MXC_AUDMUX_V2
 	bool
 
+config IMX_HAVE_SDMA
+	bool
+
+config IMX_SDMA
+	depends on IMX_HAVE_SDMA
+	tristate "Enable SDMA support"
+	help
+	  Include support for the SDMA engine. The SDMA engine needs additional
+	  firmware support. SDMA can be compiled as a module to support loading
+	  the firmware when a rootfs is present.
 endif
arch/arm/plat-mxc/include/mach/dma.h new file +0 -0
new file mode 100644
index 0000000..69d181f

arch/arm/plat-mxc/include/mach/dma.h line 10

Quoted 10 lines
arch/arm/plat-mxc/include/mach/dma.h new file +10 -0
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_ARCH_MXC_DMA_H__
+#define __ASM_ARCH_MXC_DMA_H__

__MACH_DMA_H__ please

Quoted 60 lines
arch/arm/plat-mxc/include/mach/dma.h new file +54 -0
+
+#include <linux/scatterlist.h>
+
+/*
+ * This enumerates peripheral types. Used for SDMA.
+ */
+enum sdma_peripheral_type {
+	IMX_DMATYPE_SSI,	/* MCU domain SSI */
+	IMX_DMATYPE_SSI_SP,	/* Shared SSI */
+	IMX_DMATYPE_MMC,	/* MMC */
+	IMX_DMATYPE_SDHC,	/* SDHC */
+	IMX_DMATYPE_UART,	/* MCU domain UART */
+	IMX_DMATYPE_UART_SP,	/* Shared UART */
+	IMX_DMATYPE_FIRI,	/* FIRI */
+	IMX_DMATYPE_CSPI,	/* MCU domain CSPI */
+	IMX_DMATYPE_CSPI_SP,	/* Shared CSPI */
+	IMX_DMATYPE_SIM,	/* SIM */
+	IMX_DMATYPE_ATA,	/* ATA */
+	IMX_DMATYPE_CCM,	/* CCM */
+	IMX_DMATYPE_EXT,	/* External peripheral */
+	IMX_DMATYPE_MSHC,	/* Memory Stick Host Controller */
+	IMX_DMATYPE_MSHC_SP,	/* Shared Memory Stick Host Controller */
+	IMX_DMATYPE_DSP,	/* DSP */
+	IMX_DMATYPE_MEMORY,	/* Memory */
+	IMX_DMATYPE_FIFO_MEMORY,/* FIFO type Memory */
+	IMX_DMATYPE_SPDIF,	/* SPDIF */
+	IMX_DMATYPE_IPU_MEMORY,	/* IPU Memory */
+	IMX_DMATYPE_ASRC,	/* ASRC */
+	IMX_DMATYPE_ESAI,	/* ESAI */
+};
+
+enum imx_dma_prio {
+	DMA_PRIO_HIGH = 0,
+	DMA_PRIO_MEDIUM = 1,
+	DMA_PRIO_LOW = 2
+};
+
+struct imx_dma_data {
+	int dma_request; /* DMA request line */
+	enum sdma_peripheral_type peripheral_type;
+	int priority;
+};
+
+static inline int imx_dma_is_ipu(struct dma_chan *chan)
+{
+	return !strcmp(dev_name(chan->device->dev), "ipu-core");
+}
+
+static inline int imx_dma_is_general_purpose(struct dma_chan *chan)
+{
+	return !strcmp(dev_name(chan->device->dev), "imx-sdma");
+}
+
+#endif
arch/arm/plat-mxc/include/mach/sdma.h new file +0 -0
new file mode 100644
index 0000000..9be1122

arch/arm/plat-mxc/include/mach/sdma.h line 2

Quoted 2 lines
arch/arm/plat-mxc/include/mach/sdma.h new file +2 -0
@@ -0,0 +1,17 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__

__MACH_SDMA_H__

Quoted 108 lines
arch/arm/plat-mxc/include/mach/sdma.h new file +15 -0
+
+/**
+ * struct sdma_platform_data - platform specific data for SDMA engine
+ *
+ * @sdma_version	The version of this SDMA engine
+ * @cpu_name		used to generate the firmware name
+ * @to_version		CPU Tape out version
+ */
+struct sdma_platform_data {
+	int sdma_version;
+	char *cpu_name;
+	int to_version;
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +8 -0
index 9520cf0..ff68307 100644
@@ -195,6 +195,14 @@ config PCH_DMA
 	help
 	  Enable support for the Topcliff PCH DMA engine.
 
+config IMX_SDMA
+	tristate "i.MX SDMA support"
+	depends on ARCH_MXC
+	select DMA_ENGINE
+	help
+	  Support the i.MX SDMA engine. This engine is integrated into
+	  Freescale i.MX25/31/35/51 chips.
+
 config DMA_ENGINE
 	bool
 
drivers/dma/Makefile +1 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +59 -0
new file mode 100644
index 0000000..c447fc0
@@ -0,0 +1,1395 @@
+/*
+ * drivers/dma/imx-sdma.c
+ *
+ * This file contains a driver for the Freescale Smart DMA engine
+ *
+ * Copyright 2010 Sascha Hauer, Pengutronix <[email protected]>
+ *
+ * Based on code from Freescale:
+ *
+ * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/firmware.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+
+#include <asm/irq.h>
+#include <mach/sdma.h>
+#include <mach/dma.h>
+#include <mach/hardware.h>
+
+/* SDMA registers */
+#define SDMA_H_C0PTR		(sdma->regs + 0x000)
+#define SDMA_H_INTR		(sdma->regs + 0x004)
+#define SDMA_H_STATSTOP		(sdma->regs + 0x008)
+#define SDMA_H_START		(sdma->regs + 0x00c)
+#define SDMA_H_EVTOVR		(sdma->regs + 0x010)
+#define SDMA_H_DSPOVR		(sdma->regs + 0x014)
+#define SDMA_H_HOSTOVR		(sdma->regs + 0x018)
+#define SDMA_H_EVTPEND		(sdma->regs + 0x01c)
+#define SDMA_H_DSPENBL		(sdma->regs + 0x020)
+#define SDMA_H_RESET		(sdma->regs + 0x024)
+#define SDMA_H_EVTERR		(sdma->regs + 0x028)
+#define SDMA_H_INTRMSK		(sdma->regs + 0x02c)
+#define SDMA_H_PSW		(sdma->regs + 0x030)
+#define SDMA_H_EVTERRDBG	(sdma->regs + 0x034)
+#define SDMA_H_CONFIG		(sdma->regs + 0x038)
+#define SDMA_ONCE_ENB		(sdma->regs + 0x040)
+#define SDMA_ONCE_DATA		(sdma->regs + 0x044)
+#define SDMA_ONCE_INSTR		(sdma->regs + 0x048)

drivers/dma/imx-sdma.c line 69

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+#define SDMA_ONCE_STAT		(sdma->regs + 0x04c)
+#define SDMA_ONCE_CMD		(sdma->regs + 0x050)
+#define SDMA_EVT_MIRROR		(sdma->regs + 0x054)
+#define SDMA_ILLINSTADDR	(sdma->regs + 0x058)
+#define SDMA_CHN0ADDR		(sdma->regs + 0x05c)
+#define SDMA_ONCE_RTB		(sdma->regs + 0x060)
+#define SDMA_XTRIG_CONF1	(sdma->regs + 0x070)
+#define SDMA_XTRIG_CONF2	(sdma->regs + 0x074)
+#define SDMA_CHNENBL_0		(sdma->regs + (sdma->version == 2 ? 0x200 : 0x80))
+#define SDMA_CHNPRI_0		(sdma->regs + 0x100)

I'd prefer having an accessor function like

	u32 sdma_read(struct whatever *sdma, unsigned offset)
	{
		return __raw_readl(sdma->regs + offset);
	}
	...
Quoted 46 lines
drivers/dma/imx-sdma.c new file +46 -0
+
+/*
+ * Buffer descriptor status values.
+ */
+#define BD_DONE  0x01
+#define BD_WRAP  0x02
+#define BD_CONT  0x04
+#define BD_INTR  0x08
+#define BD_RROR  0x10
+#define BD_LAST  0x20
+#define BD_EXTD  0x80
+
+/*
+ * Data Node descriptor status values.
+ */
+#define DND_END_OF_FRAME  0x80
+#define DND_END_OF_XFER   0x40
+#define DND_DONE          0x20
+#define DND_UNUSED        0x01
+
+/*
+ * IPCV2 descriptor status values.
+ */
+#define BD_IPCV2_END_OF_FRAME  0x40
+
+#define IPCV2_MAX_NODES        50
+/*
+ * Error bit set in the CCB status field by the SDMA,
+ * in setbd routine, in case of a transfer error
+ */
+#define DATA_ERROR  0x10000000
+
+/*
+ * Buffer descriptor commands.
+ */
+#define C0_ADDR             0x01
+#define C0_LOAD             0x02
+#define C0_DUMP             0x03
+#define C0_SETCTX           0x07
+#define C0_GETCTX           0x03
+#define C0_SETDM            0x01
+#define C0_SETPM            0x04
+#define C0_GETDM            0x02
+#define C0_GETPM            0x08
+/*
+ * Change endianness indicator in the BD command field

drivers/dma/imx-sdma.c line 125

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+ */
+#define CHANGE_ENDIANNESS   0x80
+
+/*
+ * Mode/Count of data node descriptors - IPCv2
+ */
+struct sdma_mode_count {
+	u32 count   : 16; /* size of the buffer pointed by this BD */
+	u32 status  :  8; /* E,R,I,C,W,D status bits stored here */
+	u32 command :  8; /* command mostlky used for channel 0 */

s/mostlky/mostly/

Quoted 36 lines
drivers/dma/imx-sdma.c new file +36 -0
+};
+
+/*
+ * Buffer descriptor
+ */
+struct sdma_buffer_descriptor {
+	struct sdma_mode_count  mode;
+	dma_addr_t buffer_addr;    /* address of the buffer described */
+	dma_addr_t ext_buffer_addr; /* extended buffer address */
+} __attribute__ ((packed));
+
+/*
+ * Channel control Block
+ */
+struct sdma_channel_control {
+	dma_addr_t current_bd_ptr; /* current buffer descriptor processed */
+	dma_addr_t base_bd_ptr;    /* first element of buffer descriptor array */
+	u32 unused;
+	u32 unused1;
+} __attribute__ ((packed));
+
+/**
+ * struct sdma_state_registers - SDMA context for a channel
+ *
+ * @pc:		program counter
+ * @t:		test bit: status of arithmetic & test instruction
+ * @rpc:	return program counter
+ * @sf:		source fault while loading data
+ * @spc:	loop start program counter
+ * @df:		destination fault while storing data
+ * @epc:	loop end program counter
+ * @lm:		loop mode
+ */
+struct sdma_state_registers {
+	u32 pc     :14;
+	u32 unused1: 1;

drivers/dma/imx-sdma.c line 171

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+	u32 t      : 1;
+	u32 rpc    :14;
+	u32 unused0: 1;
+	u32 sf     : 1;
+	u32 spc    :14;
+	u32 unused2: 1;
+	u32 df     : 1;
+	u32 epc    :14;
+	u32 lm     : 2;
+} __attribute__ ((packed));

I'm not sure what CodingStyle recommends, but I'd not add a space between __attribute__ and (.

Quoted 37 lines
drivers/dma/imx-sdma.c new file +37 -0
+
+/**
+ * struct sdma_context_data - sdma context specific to a channel
+ *
+ * @channel_state:	channel state bits
+ * @gReg:		general registers
+ * @mda:		burst dma destination address register
+ * @msa:		burst dma source address register
+ * @ms:			burst dma status register
+ * @md:			burst dma data register
+ * @pda:		peripheral dma destination address register
+ * @psa:		peripheral dma source address register
+ * @ps:			peripheral dma status register
+ * @pd:			peripheral dma data register
+ * @ca:			CRC polynomial register
+ * @cs:			CRC accumulator register
+ * @dda:		dedicated core destination address register
+ * @dsa:		dedicated core source address register
+ * @ds:			dedicated core status register
+ * @dd:			dedicated core data register
+ */
+struct sdma_context_data {
+	struct sdma_state_registers  channel_state;
+	u32  gReg[8];
+	u32  mda;
+	u32  msa;
+	u32  ms;
+	u32  md;
+	u32  pda;
+	u32  psa;
+	u32  ps;
+	u32  pd;
+	u32  ca;
+	u32  cs;
+	u32  dda;
+	u32  dsa;
+	u32  ds;

drivers/dma/imx-sdma.c line 218

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+	u32  dd;
+	u32  scratch0;
+	u32  scratch1;
+	u32  scratch2;
+	u32  scratch3;
+	u32  scratch4;
+	u32  scratch5;
+	u32  scratch6;
+	u32  scratch7;
+} __attribute__ ((packed));

s/ / /?

Quoted 51 lines
drivers/dma/imx-sdma.c new file +51 -0
+
+#define NUM_BD (int)(PAGE_SIZE / sizeof(struct sdma_buffer_descriptor))
+
+struct sdma_engine;
+
+/**
+ * struct sdma_channel - housekeeping for a SDMA channel
+ *
+ * @sdma		pointer to the SDMA engine for this channel
+ * @channel		the channel number, matches dmaengine chan_id
+ * @direction		transfer type. Needed for setting SDMA script
+ * @peripheral_type	Peripheral type. Needed for setting SDMA script
+ * @event_id		aka dma request line
+ * @event_id2		for channels that use 2 events
+ * @word_size		peripheral access size
+ * @buf_tail		ID of the buffer that was processed
+ * @done		channel completion
+ * @num_bd		max NUM_BD. number of descriptors currently handling
+ */
+struct sdma_channel {
+	struct sdma_engine		*sdma;
+	unsigned int			channel;
+	enum dma_data_direction		direction;
+	enum sdma_peripheral_type	peripheral_type;
+	unsigned int			event_id;
+	unsigned int			event_id2;
+	enum dma_slave_buswidth		word_size;
+	unsigned int			buf_tail;
+	struct completion		done;
+	unsigned int			num_bd;
+	struct sdma_buffer_descriptor	*bd;
+	dma_addr_t			bd_phys;
+	unsigned int			pc_from_device, pc_to_device;
+	unsigned long			flags;
+	dma_addr_t			per_address;
+	u32				event_mask1, event_mask2;
+	u32				watermark_level;
+	u32				shp_addr, per_addr;
+	struct dma_chan			chan;
+	spinlock_t			lock;
+	struct dma_async_tx_descriptor	desc;
+	dma_cookie_t			last_completed;
+	enum dma_status			status;
+};
+
+#define IMX_DMA_SG_LOOP		(1 << 0)
+
+#define MAX_DMA_CHANNELS 32
+#define MXC_SDMA_DEFAULT_PRIORITY 1
+#define MXC_SDMA_MIN_PRIORITY 1
+#define MXC_SDMA_MAX_PRIORITY 7

drivers/dma/imx-sdma.c line 279

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+
+/*
+ * This enumerates transfer types
+ */
+enum {
+	emi_2_per = 0,		/* EMI memory to peripheral */
+	emi_2_int,		/* EMI memory to internal RAM */
+	emi_2_emi,		/* EMI memory to EMI memory */
+	emi_2_dsp,		/* EMI memory to DSP memory */
+	per_2_int,		/* Peripheral to internal RAM */

s/int/iram/ maybe?

Quoted 50 lines
drivers/dma/imx-sdma.c new file +50 -0
+	per_2_emi,		/* Peripheral to internal EMI memory */
+	per_2_dsp,		/* Peripheral to DSP memory */
+	per_2_per,		/* Peripheral to Peripheral */
+	int_2_per,		/* Internal RAM to peripheral */
+	int_2_int,		/* Internal RAM to Internal RAM */
+	int_2_emi,		/* Internal RAM to EMI memory */
+	int_2_dsp,		/* Internal RAM to DSP memory */
+	dsp_2_per,		/* DSP memory to peripheral */
+	dsp_2_int,		/* DSP memory to internal RAM */
+	dsp_2_emi,		/* DSP memory to EMI memory */
+	dsp_2_dsp,		/* DSP memory to DSP memory */
+	emi_2_dsp_loop,		/* EMI memory to DSP memory loopback */
+	dsp_2_emi_loop,		/* DSP memory to EMI memory loopback */
+	dvfs_pll,		/* DVFS script with PLL change       */
+	dvfs_pdr		/* DVFS script without PLL change    */
+} sdma_transfer_type;
+
+/**
+ * struct sdma_script_start_addrs - SDMA script start pointers
+ *
+ * start addresses of the different functions in the physical
+ * address space of the SDMA engine.
+ */
+struct sdma_script_start_addrs {
+	u32 ap_2_ap_addr;
+	u32 ap_2_bp_addr;
+	u32 ap_2_ap_fixed_addr;
+	u32 bp_2_ap_addr;
+	u32 loopback_on_dsp_side_addr;
+	u32 mcu_interrupt_only_addr;
+	u32 firi_2_per_addr;
+	u32 firi_2_mcu_addr;
+	u32 per_2_firi_addr;
+	u32 mcu_2_firi_addr;
+	u32 uart_2_per_addr;
+	u32 uart_2_mcu_addr;
+	u32 per_2_app_addr;
+	u32 mcu_2_app_addr;
+	u32 per_2_per_addr;
+	u32 uartsh_2_per_addr;
+	u32 uartsh_2_mcu_addr;
+	u32 per_2_shp_addr;
+	u32 mcu_2_shp_addr;
+	u32 ata_2_mcu_addr;
+	u32 mcu_2_ata_addr;
+	u32 app_2_per_addr;
+	u32 app_2_mcu_addr;
+	u32 shp_2_per_addr;
+	u32 shp_2_mcu_addr;
+	u32 mshc_2_mcu_addr;

drivers/dma/imx-sdma.c line 339

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+	u32 mcu_2_mshc_addr;
+	u32 spdif_2_mcu_addr;
+	u32 mcu_2_spdif_addr;
+	u32 asrc_2_mcu_addr;
+	u32 ext_mem_2_ipu_addr;
+	u32 descrambler_addr;
+	u32 dptc_dvfs_addr;
+	u32 utra_addr;
+	u32 ram_code_start_addr;
+};

You didn't comment my suggestion to use an array here. Something like

	struct {
		const char *name;
		u32 addr;
	} start_addr[];
Quoted 46 lines
drivers/dma/imx-sdma.c new file +46 -0
+
+#define SDMA_FIRMWARE_MAGIC 0x414d4453
+
+/**
+ * struct sdma_firmware_header - Layout of the firmware image
+ *
+ * @magic		"SDMA"
+ * @version_major	increased whenever layout of struct sdma_script_start_addrs
+ *			changes.
+ * @version_minor	firmware minor version (for binary compatible changes)
+ * @script_addrs_start	offset of struct sdma_script_start_addrs in this image
+ * @num_script_addrs	Number of script addresses in this image
+ * @ram_code_start	offset of SDMA ram image in this firmware image
+ * @ram_code_size	size of SDMA ram image
+ */
+struct sdma_firmware_header {
+	u32	magic;
+	u32	version_major;
+	u32	version_minor;
+	u32	script_addrs_start;
+	u32	num_script_addrs;
+	u32	ram_code_start;
+	u32	ram_code_size;
+};
+
+struct sdma_engine {
+	struct device			*dev;
+	struct sdma_channel		channel[MAX_DMA_CHANNELS];
+	struct sdma_channel_control	*channel_control;
+	void __iomem			*regs;
+	unsigned int			version;
+	unsigned int			num_events;
+	struct sdma_context_data	*context;
+	dma_addr_t			context_phys;
+	struct dma_device		dma_device;
+	struct clk			*clk;
+};
+
+#define SDMA_H_CONFIG_DSPDMA	(1 << 12) /* indicates if the DSPDMA is used */
+#define SDMA_H_CONFIG_RTD_PINS	(1 << 11) /* indicates if Real-Time Debug pins are enabled */
+#define SDMA_H_CONFIG_ACR	(1 << 4)  /* indicates if AHB freq /core freq = 2 or 1 */
+#define SDMA_H_CONFIG_CSM	(3)       /* indicates which context switch mode is selected*/
+
+static int sdma_config_ownership(struct sdma_channel *sdmac,
+		bool event_override, bool mcu_verride, bool dsp_override)
+{

drivers/dma/imx-sdma.c line 395

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+	struct sdma_engine *sdma = sdmac->sdma;
+	int channel = sdmac->channel;
+	u32 evt, mcu, dsp;
+
+	if (event_override && mcu_verride && dsp_override)
+		return -EINVAL;
+
+	evt = readl(SDMA_H_EVTOVR);
+	mcu = readl(SDMA_H_HOSTOVR);
+	dsp = readl(SDMA_H_DSPOVR);

__raw_readl?

Best regards
Uwe

Signature · 2 lines
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
#29 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

2010/8/23 Uwe Kleine-K?nig <[email protected]>:

Quoted 4 lines
Quoted 3 lines

+ ? ? evt = readl(SDMA_H_EVTOVR);
+ ? ? mcu = readl(SDMA_H_HOSTOVR);
+ ? ? dsp = readl(SDMA_H_DSPOVR);

__raw_readl?

Sorry I never understood this __raw_[read|write][b|w|l] vs. plain read[b|w|l] proliferation in some drivers and code.

What's the reason for?

Yours,
Linus Walleij

#30 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

Dne So 28. srpna 2010 17:18:17 Linus Walleij napsal(a):

Quoted 11 lines

2010/8/23 Uwe Kleine-K?nig <[email protected]>:

Quoted 5 lines

drivers/dma/imx-sdma.c line 395

Quoted 3 lines
drivers/dma/imx-sdma.c new file +3 -0
+     evt = readl(SDMA_H_EVTOVR);
+     mcu = readl(SDMA_H_HOSTOVR);
+     dsp = readl(SDMA_H_DSPOVR);

__raw_readl?

Sorry I never understood this __raw_[read|write][b|w|l] vs. plain read[b|w|l] proliferation in some drivers and code.

What's the reason for?

Hey,

this trick is, if you create the VA<->PA mapping at the kernel start (eg. see how pxa_map_io() is replacedon some devices for instance), you then use the VA address you specified and use __raw_{read,write}[b,w,l](). So use __raw_{read,write}[b,w,l]() on drivers specific for certain device and use {read,write}[b,w,l]() on ioremap()ed memory areas, aka. in common drivers.

Cheers

Quoted 8 lines

Yours,
Linus Walleij

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

author maintainer
#31 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

Quoted 13 lines · Marek Vasut

Dne So 28. srpna 2010 17:18:17 Linus Walleij napsal(a):

Quoted 11 lines

2010/8/23 Uwe Kleine-K?nig <[email protected]>:

Quoted 5 lines

drivers/dma/imx-sdma.c line 395

Quoted 3 lines
drivers/dma/imx-sdma.c new file +3 -0
+     evt = readl(SDMA_H_EVTOVR);
+     mcu = readl(SDMA_H_HOSTOVR);
+     dsp = readl(SDMA_H_DSPOVR);

__raw_readl?

Sorry I never understood this __raw_[read|write][b|w|l] vs. plain read[b|w|l] proliferation in some drivers and code.

What's the reason for?

Quoted 7 lines

Hey,

this trick is, if you create the VA<->PA mapping at the kernel start (eg. see how pxa_map_io() is replacedon some devices for instance), you then use the VA address you specified and use __raw_{read,write}[b,w,l](). So use __raw_{read,write}[b,w,l]() on drivers specific for certain device and use {read,write}[b,w,l]() on ioremap()ed memory areas, aka. in common drivers.

Nope, this has nothing to do with static mappings vs. ioremap. The difference is that read[b,w,l] do little endian accesses suitable for PCI whereas the __raw_* functions do accesses in CPU endianess. Peripherals integrated into a SoC like the SDMA engine here are normally accessible in native endianess and thus need the __raw_* functions. An external network controller (for example a LAN9117) will probably need the non raw functions. Note that 99% of the arm users use little endian only and thus cpu_to_le* is a noop, so both types will work for most people.

Sascha

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#32 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

Dne So 28. srpna 2010 18:18:58 Sascha Hauer napsal(a):

Quoted 23 lines · Marek Vasut
Quoted 13 lines

Dne So 28. srpna 2010 17:18:17 Linus Walleij napsal(a):

Quoted 11 lines

2010/8/23 Uwe Kleine-K?nig <[email protected]>:

Quoted 5 lines

drivers/dma/imx-sdma.c line 395

Quoted 3 lines
drivers/dma/imx-sdma.c new file +3 -0
+     evt = readl(SDMA_H_EVTOVR);
+     mcu = readl(SDMA_H_HOSTOVR);
+     dsp = readl(SDMA_H_DSPOVR);

__raw_readl?

Sorry I never understood this __raw_[read|write][b|w|l] vs. plain read[b|w|l] proliferation in some drivers and code.

What's the reason for?

Quoted 8 lines

Hey,

this trick is, if you create the VA<->PA mapping at the kernel start (eg. see how pxa_map_io() is replacedon some devices for instance), you then use the VA address you specified and use __raw_{read,write}[b,w,l](). So use __raw_{read,write}[b,w,l]() on drivers specific for certain device and use {read,write}[b,w,l]() on ioremap()ed memory areas, aka. in common drivers.

Quoted 9 lines

Nope, this has nothing to do with static mappings vs. ioremap. The difference is that read[b,w,l] do little endian accesses suitable for PCI whereas the __raw_* functions do accesses in CPU endianess. Peripherals integrated into a SoC like the SDMA engine here are normally accessible in native endianess and thus need the __raw_* functions. An external network controller (for example a LAN9117) will probably need the non raw functions. Note that 99% of the arm users use little endian only and thus cpu_to_le* is a noop, so both types will work for most people.

Sorry, you got me here. Why do we have io{read,write} then btw. ? That's for x86's io space, right ?

Thanks, cheers and sorry for the confusion

Quoted 2 lines

Sascha

author maintainer
#33 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

Quoted 34 lines · Marek Vasut

Dne So 28. srpna 2010 18:18:58 Sascha Hauer napsal(a):

Quoted 23 lines · Marek Vasut
Quoted 13 lines

Dne So 28. srpna 2010 17:18:17 Linus Walleij napsal(a):

Quoted 11 lines

2010/8/23 Uwe Kleine-K?nig <[email protected]>:

Quoted 5 lines

drivers/dma/imx-sdma.c line 395

Quoted 3 lines
drivers/dma/imx-sdma.c new file +3 -0
+     evt = readl(SDMA_H_EVTOVR);
+     mcu = readl(SDMA_H_HOSTOVR);
+     dsp = readl(SDMA_H_DSPOVR);

__raw_readl?

Sorry I never understood this __raw_[read|write][b|w|l] vs. plain read[b|w|l] proliferation in some drivers and code.

What's the reason for?

Quoted 8 lines

Hey,

this trick is, if you create the VA<->PA mapping at the kernel start (eg. see how pxa_map_io() is replacedon some devices for instance), you then use the VA address you specified and use __raw_{read,write}[b,w,l](). So use __raw_{read,write}[b,w,l]() on drivers specific for certain device and use {read,write}[b,w,l]() on ioremap()ed memory areas, aka. in common drivers.

Quoted 9 lines

Nope, this has nothing to do with static mappings vs. ioremap. The difference is that read[b,w,l] do little endian accesses suitable for PCI whereas the __raw_* functions do accesses in CPU endianess. Peripherals integrated into a SoC like the SDMA engine here are normally accessible in native endianess and thus need the __raw_* functions. An external network controller (for example a LAN9117) will probably need the non raw functions. Note that 99% of the arm users use little endian only and thus cpu_to_le* is a noop, so both types will work for most people.

Quoted 2 lines

Sorry, you got me here. Why do we have io{read,write} then btw. ? That's for x86's io space, right ?

Looking at the implementation in lib/iomap.c it seems that io{read,write} can do both PIO and MMIO accesses depending on the address given to them.

Sascha

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#34 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

In reply to Marek Vasut
Quoted 11 lines · Marek Vasut

Dne So 28. srpna 2010 18:18:58 Sascha Hauer napsal(a):

Quoted 9 lines

Nope, this has nothing to do with static mappings vs. ioremap. The difference is that read[b,w,l] do little endian accesses suitable for PCI whereas the __raw_* functions do accesses in CPU endianess. Peripherals integrated into a SoC like the SDMA engine here are normally accessible in native endianess and thus need the __raw_* functions. An external network controller (for example a LAN9117) will probably need the non raw functions. Note that 99% of the arm users use little endian only and thus cpu_to_le* is a noop, so both types will work for most people.

Quoted 2 lines

Sorry, you got me here. Why do we have io{read,write} then btw. ? That's for x86's io space, right ?

io{read,write} are for use with ioremap/ioport_map, and allow drivers to be written which can access registers via MMIO or the PC IO space.

If your driver doesn't support the PC IO space (iow, doesn't use ioport_map) there's no point using the io{read,write} APIs.

Also note that there's one very big difference between read[bwl] and __raw_read[bwl]. The former have a barrier to ensure correct ordering for drivers doing DMA, the latter do not. So if you use the latter and you care about data being visible to a DMA agent, you have to ensure you have proper barriers in place.

#35 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

2010/8/28 Sascha Hauer <[email protected]>:

Quoted 3 lines

Peripherals integrated into a SoC like the SDMA engine here are normally accessible in native endianess and thus need the __raw_* functions.

So the SDMA actually switch and twist around the endianness of its registers if it's synthesized into a bigendian version of the system?

Or hardware-dynamically even depending on the setting of the endianness bit in the ARM core?

How can that possibly even work...

But I'm still impressed by the statemachines some silicon engineers come up with so wouldn't surprise me. X-) I understand the code now atleast. Our hardware is always synthesized LE so we so handily use [read|write][b|w|l] everywhere, luckily.

Yours,
Linus Walleij

author maintainer
#36 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

Quoted 11 lines · Linus Walleij

2010/8/28 Sascha Hauer <[email protected]>:

Quoted 3 lines

Peripherals integrated into a SoC like the SDMA engine here are normally accessible in native endianess and thus need the __raw_* functions.

So the SDMA actually switch and twist around the endianness of its registers if it's synthesized into a bigendian version of the system?

Or hardware-dynamically even depending on the setting of the endianness bit in the ARM core?

I think it's the bus between the ARM core and the periherals which changes the endianess. I have never tried running an i.MX in big endian mode, so I can only guess how the system really behaves in BE mode.

Sascha

Signature · 4 lines
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
#37 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

Hi,

Quoted 22 lines

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.
The original Freescale code also supports support for transfering data to the internal SRAM which needs different entry points to the firmware. Support for this is currently not implemented. Also, support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

Changes since v1:

[...]

Quoted 2 lines

+static int __devinit sdma_probe(struct platform_device *pdev)

__devinit/__devexit is for hot-pluggable devices. I don't think the SDMA controller is hot-pluggable, so __init/__exit could be used here.

Quoted 23 lines
drivers/dma/imx-sdma.c new file +23 -0
+{
+	int ret;
+	const struct firmware *fw;
+	const struct sdma_firmware_header *header;
+	const struct sdma_script_start_addrs *addr;
+	int irq;
+	unsigned short *ram_code;
+	struct resource *iores;
+	struct sdma_platform_data *pdata = pdev->dev.platform_data;
+	char *fwname;
+	int i;
+	dma_cap_mask_t mask;
+	struct sdma_engine *sdma;
+
+	sdma = kzalloc(sizeof(*sdma), GFP_KERNEL);
+	if (!sdma)
+		return -ENOMEM;
+
+	sdma->dev = &pdev->dev;
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_get_irq(pdev, 0);
+	if (!iores || irq < 0 || !pdata) {

drivers/dma/imx-sdma.c line 1263

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+		ret = -EINVAL;
+		goto err_irq;
+	}
+
+	sdma->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sdma->clk)) {
+		ret = PTR_ERR(sdma->clk);
+		goto err_clk;
+	}
+

request_mem_region()?

drivers/dma/imx-sdma.c

Quoted 10 lines
drivers/dma/imx-sdma.c new file +8 -0
+	sdma->regs = ioremap(iores->start, resource_size(iores));
+	if (!sdma->regs) {
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+
 
+static int __devexit sdma_remove(struct platform_device *pdev)

see above.

Lothar Wa?mann

Signature · 9 lines
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch?ftsf?hrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info at karo-electronics.de
___________________________________________________________
#38 lore raw

Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support

2010/8/24 Lothar Wa?mann <[email protected]>:

Quoted 6 lines

[Sacha]
[...]

Quoted 2 lines

+static int __devinit sdma_probe(struct platform_device *pdev)

__devinit/__devexit is for hot-pluggable devices. I don't think the SDMA controller is hot-pluggable, so __init/__exit could be used here.

Then the .probe member has to be removed from the struct platform_driver and platform_driver_probe() used instead of platform_driver_register().

But it'd work fine I think.

Yours,
Linus Walleij

author maintainer Reviewed-by Linus Walleij on v1 3/3
#39 lore raw

Re: [PATCH 3/3 v3] dmaengine: Add Freescale i.MX SDMA support

In reply to Sascha Hauer

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented as a seperate coprocessor. SDMA needs its own firmware which is requested using the standard request_firmware mechanism. The firmware has different entry points for each peripheral type, so drivers have to pass the peripheral type to the DMA engine which in turn picks the correct firmware entry point from a table contained in the firmware image itself.
The original Freescale code also supports support for transfering data to the internal SRAM which needs different entry points to the firmware. Support for this is currently not implemented. Also, support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only a single descriptor is statically assigned to a each channel. This means that transfers can't be queued up but only a single transfer is in progress. This simplifies implementation a lot and is sufficient for the usual device/memory transfers.

---

changes since v2:

- use __raw_readl/__raw_writel
- use __init/__exit instead of __devinit/__devexit
- use request_mem_region.

 arch/arm/mach-imx/include/mach/dma-v1.h |    8 +-
 arch/arm/mach-mx3/Kconfig               |    2 +
 arch/arm/plat-mxc/Kconfig               |   10 +
 arch/arm/plat-mxc/include/mach/dma.h    |   64 ++
 arch/arm/plat-mxc/include/mach/sdma.h   |   17 +
 drivers/dma/Kconfig                     |    8 +
 drivers/dma/Makefile                    |    1 +
 drivers/dma/imx-sdma.c                  | 1392 +++++++++++++++++++++++++++++++
 8 files changed, 1496 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/plat-mxc/include/mach/dma.h
 create mode 100644 arch/arm/plat-mxc/include/mach/sdma.h
 create mode 100644 drivers/dma/imx-sdma.c
arch/arm/mach-imx/include/mach/dma-v1.h +2 -6
index 287431c..ac6fd71 100644
@@ -27,6 +27,8 @@
 
 #define imx_has_dma_v1()	(cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
 
+#include <mach/dma.h>
+
 #define IMX_DMA_CHANNELS  16
 
 #define DMA_MODE_READ		0
@@ -96,12 +98,6 @@ int imx_dma_request(int channel, const char *name);
 
 void imx_dma_free(int channel);
 
-enum imx_dma_prio {
-	DMA_PRIO_HIGH = 0,
-	DMA_PRIO_MEDIUM = 1,
-	DMA_PRIO_LOW = 2
-};
-
 int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio);
 
 #endif	/* __MACH_DMA_V1_H__ */
arch/arm/mach-mx3/Kconfig +2 -0
index 85beece..301375c 100644
@@ -3,12 +3,14 @@ if ARCH_MX3
 config ARCH_MX31
 	select ARCH_HAS_RNGA
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 	bool
 
 config ARCH_MX35
 	bool
 	select ARCH_MXC_IOMUX_V3
 	select ARCH_MXC_AUDMUX_V2
+	select IMX_HAVE_SDMA
 
 comment "MX3 platforms:"
 
arch/arm/plat-mxc/Kconfig +10 -0
index 0527e65..6741625 100644
@@ -109,4 +109,14 @@ config ARCH_MXC_AUDMUX_V1
 config ARCH_MXC_AUDMUX_V2
 	bool
 
+config IMX_HAVE_SDMA
+	bool
+
+config IMX_SDMA
+	depends on IMX_HAVE_SDMA
+	tristate "Enable SDMA support"
+	help
+	  Include support for the SDMA engine. The SDMA engine needs additional
+	  firmware support. SDMA can be compiled as a module to support loading
+	  the firmware when a rootfs is present.
 endif
arch/arm/plat-mxc/include/mach/dma.h new file +64 -0

64 lines not on this page · raw message

arch/arm/plat-mxc/include/mach/sdma.h new file +17 -0
new file mode 100644
index 0000000..9be1122
@@ -0,0 +1,17 @@
+#ifndef __MACH_MXC_SDMA_H__
+#define __MACH_MXC_SDMA_H__
+
+/**
+ * struct sdma_platform_data - platform specific data for SDMA engine
+ *
+ * @sdma_version	The version of this SDMA engine
+ * @cpu_name		used to generate the firmware name
+ * @to_version		CPU Tape out version
+ */
+struct sdma_platform_data {
+	int sdma_version;
+	char *cpu_name;
+	int to_version;
+};
+
+#endif /* __MACH_MXC_SDMA_H__ */
drivers/dma/Kconfig +8 -0
index 9520cf0..ff68307 100644
@@ -195,6 +195,14 @@ config PCH_DMA
 	help
 	  Enable support for the Topcliff PCH DMA engine.
 
+config IMX_SDMA
+	tristate "i.MX SDMA support"
+	depends on ARCH_MXC
+	select DMA_ENGINE
+	help
+	  Support the i.MX SDMA engine. This engine is integrated into
+	  Freescale i.MX25/31/35/51 chips.
+
 config DMA_ENGINE
 	bool
 
drivers/dma/Makefile +1 -0
index 72bd703..14d7a1b 100644
@@ -25,3 +25,4 @@ obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
+obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
drivers/dma/imx-sdma.c new file +1392 -0

1,392 lines not on this page · raw message

Signature · 7 lines
1.7.1

-- 
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#40 lore raw

PATCH v3 3/3 dmaengine: Add Freescale i.MX SDMA support

Hi,

Just a typo and a minor niggle..

Quoted 27 lines · Sascha Hauer

This patch adds support for the Freescale i.MX SDMA engine.

drivers/dma/imx-sdma.c new file +25 -0
+static int sdma_config_ownership(struct sdma_channel *sdmac,
+		bool event_override, bool mcu_verride, bool dsp_override)
+{
+	struct sdma_engine *sdma = sdmac->sdma;
+	int channel = sdmac->channel;
+	u32 evt, mcu, dsp;
+
+	if (event_override && mcu_verride && dsp_override)
+		return -EINVAL;
+
+	evt = __raw_readl(sdma->regs + SDMA_H_EVTOVR);
+	mcu = __raw_readl(sdma->regs + SDMA_H_HOSTOVR);
+	dsp = __raw_readl(sdma->regs + SDMA_H_DSPOVR);
+
+	if (dsp_override)
+		dsp &= ~(1 << channel);
+	else
+		dsp |= (1 << channel);
+
+	if (event_override)
+		evt &= ~(1 << channel);
+	else
+		evt |= (1 << channel);
+
+	if (mcu_verride)

drivers/dma/imx-sdma.c line 406

Quoted 10 lines
drivers/dma/imx-sdma.c new file +10 -0
+		mcu &= ~(1 << channel);
+	else
+		mcu |= (1 << channel);
+
+	__raw_writel(evt, sdma->regs + SDMA_H_EVTOVR);
+	__raw_writel(mcu, sdma->regs + SDMA_H_HOSTOVR);
+	__raw_writel(dsp, sdma->regs + SDMA_H_DSPOVR);
+
+	return 0;
+}

s/mcu_verride/mcu_override

drivers/dma/imx-sdma.c line 465

Quoted 11 lines

+static void sdma_event_enable(struct sdma_channel *sdmac, unsigned int event) +{

drivers/dma/imx-sdma.c new file +9 -0
+	struct sdma_engine *sdma = sdmac->sdma;
+	int channel = sdmac->channel;
+	u32 val;
+	u32 chnenbl = chnenbl_ofs(sdma, event);
+
+	val = __raw_readl(sdma->regs + chnenbl);
+	val |= (1 << channel);
+	__raw_writel(val, sdma->regs + chnenbl);
+}

s/chnenbl/chanenbl ?
(or chanenable, etc.)
Everything else was easily readable, but I did a double take when I read through this.

Cheers,
Marc