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ppc4xx: Add 440EPx SPI driver

PATCH Superseded Steven A. Falco 4 participants 6 messages Dec 8, 2008 – Dec 9, 2008 SPI

v2 of 3 Superseded Latest is v3 →

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Steven A. Falco

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#0 lore raw

PATCH v2 1/2 ppc4xx: Add 440EPx SPI driver

This patch adds an SPI driver for the 440EPx processor.

Tested on Sequoia.

Signed-off-by Steven A. Falco <[email protected]>

---

Regarding Ben's comments:

First, thanks for reviewing. You gave me two different approaches to consider,
1) using in/out functions, and 2) using a structure. So, for this version, I've followed the style of the example you gave, using the structure approach.

This driver may be applicable to other 4xx chips, but after looking at the 405gp and 440gp, neither have a SPI hw device. So, I'm making this one exclusive to the 440epx until someone else wants it on another processor. At that point, it can be adapted as needed.

Regarding Stefan's comments:

I've renamed the file, and cleaned up the nits. Given that I've used the structure approach, I believe the in/out calls are not applicable.

Regarding Wolfgang's comments:

It is not for the fun of it. We are planning a custom board which will use the SPI port. We are entering layout now, and the hardware won't appear for at least a few months. However, the Sequoia board does have a connector for the SPI port, and I have connected a device to that connector for prototyping purposes. Other purchasers of the Sequoia may well have a similar need.

You are certainly welcome to reject this driver if you feel that is insufficient grounds for "usage". Please let me know, so I don't bother the list with it.

 drivers/spi/Makefile      |    1 +
 drivers/spi/ppc4xx_spi.c  |  119 +++++++++++++++++++++++++++++++++++++++++++++
 lude/asm-ppc/ppc4xx_spi.h |   62 +++++++++++++++++++++++
 3 files changed, 182 insertions(+), 0 deletions(-)
 create mode 100644 drivers/spi/ppc4xx_spi.c
 create mode 100644 include/asm-ppc/ppc4xx_spi.h
drivers/spi/Makefile +1 -0
index 15e0f7a..7dbba5d 100644
@@ -28,6 +28,7 @@ LIB	:= $(obj)libspi.a
 COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
+COBJS-$(CONFIG_PPC440EPX_SPI) += ppc4xx_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
 
 COBJS	:= $(COBJS-y)
drivers/spi/ppc4xx_spi.c new file +119 -0

119 lines not on this page · raw message

include/asm-ppc/ppc4xx_spi.h new file +62 -0

62 lines not on this page · raw message

Signature · 1 line
1.6.0.2
#1 lore raw

PATCH v2 1/2 ppc4xx: Add 440EPx SPI driver

Quoted 5 lines · Steven A. Falco

This patch adds an SPI driver for the 440EPx processor.

Tested on Sequoia.

Signed-off-by Steven A. Falco <[email protected]>
Quoted 8 lines

---

Regarding Ben's comments:

First, thanks for reviewing. You gave me two different approaches to consider, 1) using in/out functions, and 2) using a structure. So, for this version, I've followed the style of the example you gave, using the structure approach.

No, you _need_ to use the in_/out_() accessor functions. This is unrelated to using plain addresses and offsets vs. a structure. I really welcome the change to the structure in this version, so please just add the in_()/out_() functions upon accessing the SoC registers.

Quoted 4 lines

This driver may be applicable to other 4xx chips, but after looking at the 405gp and 440gp, neither have a SPI hw device. So, I'm making this one exclusive to the 440epx until someone else wants it on another processor. At that point, it can be adapted as needed.

Many other 4xx PPC's have the same SPI controller as 440EPx. Unfortunately you looked at the wrong examples. Here a (incomplete) list of some other PPC's with the same controller:

405EX, 440EP, 440GR, 440GRx, 460EX, 460GT

But, yes. Your driver seems generic enough to be adapted to other controllers when needed.

Quoted 4 lines

Regarding Stefan's comments:

I've renamed the file, and cleaned up the nits. Given that I've used the structure approach, I believe the in/out calls are not applicable.

No, as mentioned above you need to add the in_()/out_() calls as well.

Please find some more comments below.

Quoted 121 lines

Regarding Wolfgang's comments:

It is not for the fun of it. We are planning a custom board which will use the SPI port. We are entering layout now, and the hardware won't appear for at least a few months. However, the Sequoia board does have a connector for the SPI port, and I have connected a device to that connector for prototyping purposes. Other purchasers of the Sequoia may well have a similar need.

You are certainly welcome to reject this driver if you feel that is insufficient grounds for "usage". Please let me know, so I don't bother the list with it.

 drivers/spi/Makefile      |    1 +
 drivers/spi/ppc4xx_spi.c  |  119
+++++++++++++++++++++++++++++++++++++++++++++ lude/asm-ppc/ppc4xx_spi.h |  
62 +++++++++++++++++++++++
 3 files changed, 182 insertions(+), 0 deletions(-)
 create mode 100644 drivers/spi/ppc4xx_spi.c
 create mode 100644 include/asm-ppc/ppc4xx_spi.h
drivers/spi/Makefile +1 -0
index 15e0f7a..7dbba5d 100644
@@ -28,6 +28,7 @@ LIB	:= $(obj)libspi.a
 COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
+COBJS-$(CONFIG_PPC440EPX_SPI) += ppc4xx_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
 
 COBJS	:= $(COBJS-y)
drivers/spi/ppc4xx_spi.c new file +82 -0
new file mode 100644
index 0000000..156b056
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2008 Harris Corporation
+ * Author: Steven A. Falco <[email protected]>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <malloc.h>
+
+#include <asm/io.h>
+#include <asm/ppc4xx_spi.h>
+
+void spi_init (void)
+{
+	volatile spi4xx_t *spi = (volatile spi4xx_t *) SPI_BASE_ADDR;
+
+	spi->cdm = 0;			/* Default to "go fast" */
+	spi->mode = SPI_MODE_SPE;	/* Enable port */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+			unsigned int max_hz, unsigned int mode)
+{
+	volatile spi4xx_t *spi = (volatile spi4xx_t *) SPI_BASE_ADDR;
+
+	ulong opb = get_OPB_freq();
+	ulong divisor;
+	struct spi_slave *s;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	divisor = ((opb + (max_hz * 4) - 1) / (max_hz * 4)) - 1;
+	if (divisor > 255)
+		return NULL;
+
+	spi->cdm = divisor;
+
+	if (!(s = malloc(sizeof(struct spi_slave))))
+		return NULL;
+
+	if (mode & SPI_CPHA)
+		spi->mode &= ~SPI_MODE_SCP;
+	else
+		spi->mode |= SPI_MODE_SCP;
+
+	if (mode & SPI_CPOL)
+		spi->mode |= SPI_MODE_CI;
+	else
+		spi->mode &= ~SPI_MODE_CI;
+
+	s->bus = bus;
+	s->cs = cs;
+
+	return s;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	free(slave);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{

drivers/spi/ppc4xx_spi.c line 92

Quoted 10 lines
drivers/spi/ppc4xx_spi.c new file +10 -0
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+}
+
+#define GO	spi->cr = SPI_CR_STR
+#define TXWAIT	while(spi->sr & SPI_SR_BSY)
+#define RXWAIT	while(!(spi->sr & SPI_SR_RBR))

I would prefer static inlined functions here.

Quoted 51 lines
drivers/spi/ppc4xx_spi.c new file +26 -0
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+		const void *dout, void *din, unsigned long flags)
+{
+	volatile spi4xx_t *spi = (volatile spi4xx_t *) SPI_BASE_ADDR;
+
+	const u8 *txd = dout;
+	u8 *rxd = din;
+	int ii;
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	/* Do a byte at a time */
+	for (ii = 0; ii < ((bitlen + 7) / 8); ii++) {
+		TXWAIT;
+		spi->txd = *txd++;
+		GO;
+		RXWAIT;
+		*rxd++ = spi->rxd;
+	}
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return 0;
+}
include/asm-ppc/ppc4xx_spi.h new file +19 -0
new file mode 100644
index 0000000..135c9e6
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2008 Harris Corporation
+ * Author: Steven A. Falco <[email protected]>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software

include/asm-ppc/ppc4xx_spi.h line 29

Quoted 10 lines
include/asm-ppc/ppc4xx_spi.h new file +10 -0
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef _4xx_spi_h_
+#define _4xx_spi_h_
+
+#include <asm/types.h>
+
+#if defined(CONFIG_440EPX)

And 440GRx please.

Quoted 9 lines
include/asm-ppc/ppc4xx_spi.h new file +9 -0
+#define SPI_BASE_ADDR	(CONFIG_SYS_PERIPHERAL_BASE + 0x00000900)
+#endif
+
+/* Bits in the command register */
+#define SPI_CR_STR	0x01
+
+/* Bits in the status register */
+#define SPI_SR_RBR	0x01
+#define SPI_SR_BSY	0x02

include/asm-ppc/ppc4xx_spi.h line 48

Quoted 10 lines
include/asm-ppc/ppc4xx_spi.h new file +10 -0
+
+/* Bits in the mode register */
+#define SPI_MODE_IL	0x01
+#define SPI_MODE_CI	0x02
+#define SPI_MODE_RD	0x04
+#define SPI_MODE_SPE	0x08
+#define SPI_MODE_SCP	0x10
+
+#if defined(CONFIG_440EPX) || \
+	defined(CONFIG_440GRX)

Please remove this "#if". All other 4xx PPC's with an SPI controller have the same register layout. So the only thing that is 440EPx/440GRx specific is the base address.

include/asm-ppc/ppc4xx_spi.h line 62

Quoted 13 lines
include/asm-ppc/ppc4xx_spi.h new file +13 -0
+typedef struct spi4xx {
+	u8 mode;	/* mode register */
+	u8 rxd;		/* receive register */
+	u8 txd;		/* transmit register */
+	u8 cr;		/* command register */
+	u8 sr;		/* status register */
+	u8 res0;	/* reserved */
+	u8 cdm;		/* clock divisor */
+} spi4xx_t;
+
+#endif
+
+#endif /* _4xx_spi_h_ */

Thanks.

Best regards,
Stefan

=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================

#2 lore raw

PATCH v2 1/2 ppc4xx: Add 440EPx SPI driver

Dear Stefan Roese,

Quoted 8 lines · In message <[email protected]> you wrote:
Quoted 7 lines

Regarding Ben's comments:

First, thanks for reviewing. You gave me two different approaches to consider, 1) using in/out functions, and 2) using a structure. So, for this version, I've followed the style of the example you gave, using the structure approach.

Quoted 4 lines

No, you _need_ to use the in_/out_() accessor functions. This is unrelated to using plain addresses and offsets vs. a structure. I really welcome the change to the structure in this version, so please just add the in_()/out_() functions upon accessing the SoC registers.

Hm... Seems this is a reply to an off-list message?

Steven, please make sure to keep the ML on Cc: !

Best regards,

Wolfgang Denk

Signature · 4 lines
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"I haven't lost my mind - it's backed up on tape somewhere."
#3 lore raw

PATCH v2 1/2 ppc4xx: Add 440EPx SPI driver

Quoted 17 lines · Wolfgang Denk

Dear Stefan Roese,

Quoted 7 lines · In message <[email protected]> you wrote:
Quoted 7 lines

Regarding Ben's comments:

First, thanks for reviewing. You gave me two different approaches to consider, 1) using in/out functions, and 2) using a structure. So, for this version, I've followed the style of the example you gave, using the structure approach.

Quoted 5 lines

No, you _need_ to use the in_/out_() accessor functions. This is unrelated to using plain addresses and offsets vs. a structure. I really welcome the change to the structure in this version, so please just add the in_()/out_() functions upon accessing the SoC registers.

Quoted 9 lines

Hm... Seems this is a reply to an off-list message?

Steven, please make sure to keep the ML on Cc: !

Best regards,

Wolfgang Denk

Looks on-list to me:

http://article.gmane.org/gmane.comp.boot-loaders.u-boot/51194

regards,
Ben

#4 lore raw

PATCH v2 1/2 ppc4xx: Add 440EPx SPI driver

In reply to Wolfgang Denk
Quoted 11 lines · Wolfgang Denk
Quoted 9 lines
Quoted 4 lines

First, thanks for reviewing. You gave me two different approaches to consider, 1) using in/out functions, and 2) using a structure. So, for this version, I've followed the style of the example you gave, using the structure approach.

No, you _need_ to use the in_/out_() accessor functions. This is unrelated to using plain addresses and offsets vs. a structure. I really welcome the change to the structure in this version, so please just add the in_()/out_() functions upon accessing the SoC registers.

Hm... Seems this is a reply to an off-list message?

No, it's not.

Best regards,
Stefan

=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================

#5 lore raw

PATCH v2 1/2 ppc4xx: Add 440EPx SPI driver

In reply to Steven A. Falco
Quoted 1 line · Steven A. Falco

This patch adds an SPI driver for the 440EPx processor.

I just missed something in my last review comment. So here another comment:

<snip>

Quoted 13 lines
 drivers/spi/Makefile      |    1 +
 drivers/spi/ppc4xx_spi.c  |  119
+++++++++++++++++++++++++++++++++++++++++++++ lude/asm-ppc/ppc4xx_spi.h |  
62 +++++++++++++++++++++++
 3 files changed, 182 insertions(+), 0 deletions(-)
 create mode 100644 drivers/spi/ppc4xx_spi.c
 create mode 100644 include/asm-ppc/ppc4xx_spi.h
drivers/spi/Makefile +0 -0
index 15e0f7a..7dbba5d 100644

drivers/spi/Makefile LIB := $(obj)libspi.a · line 31

Quoted 4 lines
drivers/spi/Makefile +1 -0
@@ -28,6 +28,7 @@ LIB	:= $(obj)libspi.a
 COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
+COBJS-$(CONFIG_PPC440EPX_SPI) += ppc4xx_spi.o

Please use CONFIG_PPC4xx_SPI instead.

Best regards,
Stefan

=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================