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Correct Tegra20 FUSE driver DMA usage

PATCH Superseded Dmitry Osipenko 2 participants 8 messages Oct 3, 2017 – Oct 5, 2017 6 messages not in the archive Tegra architecture support

v2 of 3 Superseded Latest is v3 →

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Dmitry Osipenko

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#0 lore raw

v2 cover Correct Tegra20 FUSE driver DMA usage

Change log:

v2:
- Dropped DT patch as turned out it was incorrect and made things work by luck.

- Now FUSE driver requests DMA channel from the APB DMA driver utilizing DMA channel filter.

- This patchset now depends on the APB DMA driver patch that allows DMA client to issue a non-flow controlled transfers. I haven't included that patch to this patchset since DMA usage is broken anyway right now. It will work once this patchset and APBDMA patch get applied.

Dmitry Osipenko (2):
soc/tegra: fuse: Fix reading registers using DMA on Tegra20 soc/tegra: fuse: Explicitly request DMA channel from APB DMA driver

 drivers/soc/tegra/fuse/fuse-tegra.c   |  1 +
 drivers/soc/tegra/fuse/fuse-tegra20.c | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)
Signature · 1 line
2.14.1
author
#2 lore raw

PATCH v2 1/2 soc/tegra: fuse: Fix reading registers using DMA on Tegra20

In reply to a message not in the archive

DMA config is incorrect, because of it DMA transfer is never issued and tegra20_fuse_read() always returns 0x0.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra.c   | 1 +
 drivers/soc/tegra/fuse/fuse-tegra20.c | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra.c +1 -0
index b7c552e3133c..73a3a2c74021 100644
@@ -132,6 +132,7 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 
 	/* take over the memory region from the early initialization */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	fuse->phys = res->start;
 	fuse->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(fuse->base))
 		return PTR_ERR(fuse->base);
drivers/soc/tegra/fuse/fuse-tegra20.c +2 -1
index 294413a969a0..a33f48c06771 100644
@@ -59,7 +59,7 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 
 	mutex_lock(&fuse->apbdma.lock);
 
-	fuse->apbdma.config.src_addr = fuse->apbdma.phys + FUSE_BEGIN + offset;
+	fuse->apbdma.config.src_addr = fuse->phys + FUSE_BEGIN + offset;
 
 	err = dmaengine_slave_config(fuse->apbdma.chan, &fuse->apbdma.config);
 	if (err)

@@ -119,6 +119,7 @@ static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 	fuse->apbdma.config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	fuse->apbdma.config.src_maxburst = 1;
 	fuse->apbdma.config.dst_maxburst = 1;
+	fuse->apbdma.config.direction = DMA_DEV_TO_MEM;
 
 	init_completion(&fuse->apbdma.wait);
 	mutex_init(&fuse->apbdma.lock);
Signature · 1 line
2.14.1
author
#9 lore raw

PATCH v2 2/2 soc/tegra: fuse: Explicitly request DMA channel from APB DMA driver

In reply to a message not in the archive

Currently fuse driver requests DMA channel from an arbitrary DMA device, it is not a problem since there is only one DMA provider for Tegra20 yet, but it will become troublesome once another provider will be added.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra20.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra20.c +11 -1
index a33f48c06771..e9e127a24c70 100644
@@ -37,6 +37,11 @@
 #define FUSE_UID_LOW	0x08
 #define FUSE_UID_HIGH	0x0c
 
+static const struct of_device_id apbdma_of_match[] = {
+	{ .compatible = "nvidia,tegra20-apbdma" },
+	{ },
+};
+
 static u32 tegra20_fuse_read_early(struct tegra_fuse *fuse, unsigned int offset)
 {
 	return readl_relaxed(fuse->base + FUSE_BEGIN + offset);

@@ -96,6 +101,11 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 	return value;
 }
 
+static bool dma_filter(struct dma_chan *chan, void *filter_param)
+{
+	return of_match_device(apbdma_of_match, chan->device->dev) != NULL;
+}
+
 static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 {
 	dma_cap_mask_t mask;

@@ -103,7 +113,7 @@ static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	fuse->apbdma.chan = dma_request_channel(mask, NULL, NULL);
+	fuse->apbdma.chan = __dma_request_channel(&mask, dma_filter, NULL);
 	if (!fuse->apbdma.chan)
 		return -EPROBE_DEFER;
Signature · 1 line
2.14.1
Acked-by
#4 lore raw

Re: [PATCH v2 1/2] soc/tegra: fuse: Fix reading registers using DMA on Tegra20

In reply to a message not in the archive
Quoted 35 lines · Dmitry Osipenko

DMA config is incorrect, because of it DMA transfer is never issued and tegra20_fuse_read() always returns 0x0.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra.c   | 1 +
 drivers/soc/tegra/fuse/fuse-tegra20.c | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra.c +1 -0
index b7c552e3133c..73a3a2c74021 100644
@@ -132,6 +132,7 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 
 	/* take over the memory region from the early initialization */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	fuse->phys = res->start;
 	fuse->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(fuse->base))
 		return PTR_ERR(fuse->base);
drivers/soc/tegra/fuse/fuse-tegra20.c +1 -1
index 294413a969a0..a33f48c06771 100644
@@ -59,7 +59,7 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 
 	mutex_lock(&fuse->apbdma.lock);
 
-	fuse->apbdma.config.src_addr = fuse->apbdma.phys + FUSE_BEGIN + offset;
+	fuse->apbdma.config.src_addr = fuse->phys + FUSE_BEGIN + offset;
 
 	err = dmaengine_slave_config(fuse->apbdma.chan, &fuse->apbdma.config);
 	if (err)

drivers/soc/tegra/fuse/fuse-tegra20.c static int tegra20_fuse_probe(struct tegra_fuse *fuse) · line 125

Quoted 7 lines
drivers/soc/tegra/fuse/fuse-tegra20.c +1 -0
@@ -119,6 +119,7 @@ static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 	fuse->apbdma.config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	fuse->apbdma.config.src_maxburst = 1;
 	fuse->apbdma.config.dst_maxburst = 1;
+	fuse->apbdma.config.direction = DMA_DEV_TO_MEM;
 
 	init_completion(&fuse->apbdma.wait);
 	mutex_init(&fuse->apbdma.lock);
Acked-by Jon Hunter <[email protected]>

Cheers
Jon

Signature · 1 line
nvpublic
#11 lore raw

Re: [PATCH v2 2/2] soc/tegra: fuse: Explicitly request DMA channel from APB DMA driver

In reply to a message not in the archive
Quoted 26 lines · Dmitry Osipenko

Currently fuse driver requests DMA channel from an arbitrary DMA device, it is not a problem since there is only one DMA provider for Tegra20 yet, but it will become troublesome once another provider will be added.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra20.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra20.c +5 -0
index a33f48c06771..e9e127a24c70 100644
@@ -37,6 +37,11 @@
 #define FUSE_UID_LOW	0x08
 #define FUSE_UID_HIGH	0x0c
 
+static const struct of_device_id apbdma_of_match[] = {
+	{ .compatible = "nvidia,tegra20-apbdma" },
+	{ },
+};
+
 static u32 tegra20_fuse_read_early(struct tegra_fuse *fuse, unsigned int offset)
 {
 	return readl_relaxed(fuse->base + FUSE_BEGIN + offset);

drivers/soc/tegra/fuse/fuse-tegra20.c static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset) · line 106

Quoted 6 lines
drivers/soc/tegra/fuse/fuse-tegra20.c +3 -0
@@ -96,6 +101,11 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 	return value;
 }
 
+static bool dma_filter(struct dma_chan *chan, void *filter_param)
+{
+	return of_match_device(apbdma_of_match, chan->device->dev) != NULL;

Is it simpler just to use of_device_is_compatible() here?

Cheers
Jon

Signature · 1 line
nvpublic
author
#13 lore raw

Re: [PATCH v2 2/2] soc/tegra: fuse: Explicitly request DMA channel from APB DMA driver

In reply to a message not in the archive
Quoted 32 lines · Jon Hunter
Quoted 29 lines · Dmitry Osipenko

Currently fuse driver requests DMA channel from an arbitrary DMA device, it is not a problem since there is only one DMA provider for Tegra20 yet, but it will become troublesome once another provider will be added.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra20.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra20.c +5 -0
index a33f48c06771..e9e127a24c70 100644
@@ -37,6 +37,11 @@
 #define FUSE_UID_LOW	0x08
 #define FUSE_UID_HIGH	0x0c
 
+static const struct of_device_id apbdma_of_match[] = {
+	{ .compatible = "nvidia,tegra20-apbdma" },
+	{ },
+};
+
 static u32 tegra20_fuse_read_early(struct tegra_fuse *fuse, unsigned int offset)
 {
 	return readl_relaxed(fuse->base + FUSE_BEGIN + offset);

@@ -96,6 +101,11 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 	return value;
 }
Quoted 6 lines

drivers/soc/tegra/fuse/fuse-tegra20.c static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset) · line 106

Quoted 3 lines
drivers/soc/tegra/fuse/fuse-tegra20.c +3 -0
+static bool dma_filter(struct dma_chan *chan, void *filter_param)
+{
+	return of_match_device(apbdma_of_match, chan->device->dev) != NULL;

Is it simpler just to use of_device_is_compatible() here?

Good point! I haven't noticed that function in the OF API.

#6 lore raw

Re: [PATCH v2 1/2] soc/tegra: fuse: Fix reading registers using DMA on Tegra20

In reply to a message not in the archive
Quoted 42 lines · Jon Hunter
Quoted 40 lines · Dmitry Osipenko

DMA config is incorrect, because of it DMA transfer is never issued and tegra20_fuse_read() always returns 0x0.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra.c   | 1 +
 drivers/soc/tegra/fuse/fuse-tegra20.c | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra.c +1 -0
index b7c552e3133c..73a3a2c74021 100644
@@ -132,6 +132,7 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 
 	/* take over the memory region from the early initialization */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	fuse->phys = res->start;
 	fuse->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(fuse->base))
 		return PTR_ERR(fuse->base);
drivers/soc/tegra/fuse/fuse-tegra20.c +2 -1
index 294413a969a0..a33f48c06771 100644
@@ -59,7 +59,7 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 
 	mutex_lock(&fuse->apbdma.lock);
 
-	fuse->apbdma.config.src_addr = fuse->apbdma.phys + FUSE_BEGIN + offset;
+	fuse->apbdma.config.src_addr = fuse->phys + FUSE_BEGIN + offset;
 
 	err = dmaengine_slave_config(fuse->apbdma.chan, &fuse->apbdma.config);
 	if (err)

@@ -119,6 +119,7 @@ static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 	fuse->apbdma.config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	fuse->apbdma.config.src_maxburst = 1;
 	fuse->apbdma.config.dst_maxburst = 1;
+	fuse->apbdma.config.direction = DMA_DEV_TO_MEM;
Quoted 4 lines

drivers/soc/tegra/fuse/fuse-tegra20.c static int tegra20_fuse_probe(struct tegra_fuse *fuse) · line 125

Quoted 2 lines
drivers/soc/tegra/fuse/fuse-tegra20.c +0 -0
 	init_completion(&fuse->apbdma.wait);
 	mutex_init(&fuse->apbdma.lock);
Acked-by Jon Hunter <[email protected]>

BTW, if you do rev this series, then maybe it is worth explicitly setting 'fuse->apbdma.config.device_fc = false'.

Cheers
Jon

Signature · 1 line
nvpublic
author
#8 lore raw

Re: [PATCH v2 1/2] soc/tegra: fuse: Fix reading registers using DMA on Tegra20

In reply to a message not in the archive
Quoted 44 lines · Jon Hunter
Quoted 42 lines · Jon Hunter
Quoted 40 lines · Dmitry Osipenko

DMA config is incorrect, because of it DMA transfer is never issued and tegra20_fuse_read() always returns 0x0.

Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/soc/tegra/fuse/fuse-tegra.c   | 1 +
 drivers/soc/tegra/fuse/fuse-tegra20.c | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
drivers/soc/tegra/fuse/fuse-tegra.c +1 -0
index b7c552e3133c..73a3a2c74021 100644
@@ -132,6 +132,7 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 
 	/* take over the memory region from the early initialization */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	fuse->phys = res->start;
 	fuse->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(fuse->base))
 		return PTR_ERR(fuse->base);
drivers/soc/tegra/fuse/fuse-tegra20.c +2 -1
index 294413a969a0..a33f48c06771 100644
@@ -59,7 +59,7 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 
 	mutex_lock(&fuse->apbdma.lock);
 
-	fuse->apbdma.config.src_addr = fuse->apbdma.phys + FUSE_BEGIN + offset;
+	fuse->apbdma.config.src_addr = fuse->phys + FUSE_BEGIN + offset;
 
 	err = dmaengine_slave_config(fuse->apbdma.chan, &fuse->apbdma.config);
 	if (err)

@@ -119,6 +119,7 @@ static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 	fuse->apbdma.config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	fuse->apbdma.config.src_maxburst = 1;
 	fuse->apbdma.config.dst_maxburst = 1;
+	fuse->apbdma.config.direction = DMA_DEV_TO_MEM;
Quoted 8 lines
Quoted 4 lines

drivers/soc/tegra/fuse/fuse-tegra20.c static int tegra20_fuse_probe(struct tegra_fuse *fuse) · line 125

Quoted 2 lines
drivers/soc/tegra/fuse/fuse-tegra20.c +0 -0
 	init_completion(&fuse->apbdma.wait);
 	mutex_init(&fuse->apbdma.lock);
Acked-by Jon Hunter <[email protected]>

BTW, if you do rev this series, then maybe it is worth explicitly setting 'fuse->apbdma.config.device_fc = false'.

I'll make v3 for sure. Setting device_fc isn't strictly needed, but it is good to have for expressiveness. I'll add it to v3, thanks.