[PATCH 0/2] ARM: shmobile: r8a7740: move I2C errata handling into the driver

[PATCH 0/2] ARM: shmobile: r8a7740: move I2C errata handling into the driver

[Wolfram Sang]

This series moves the errata handling from the setup function into the driver.
It has been tested that this changeset does not cause a regression on the
armadillo board we had access to. Unfortunately, this board did not need the
workaround at all, only some revisions of the r8a7740 are affected.

After a short discussion with Simon, we agreed this should go via I2C.

Wolfram Sang (2):
  i2c: sh_mobile: add errata workaround
  ARM: shmobile: r8a7740: remove I2C errata handling

 arch/arm/mach-shmobile/setup-r8a7740.c | 55 ----------------------------------
 drivers/i2c/busses/i2c-sh_mobile.c     | 40 +++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 55 deletions(-)

-- 
2.1.4

[PATCH 2/2] ARM: shmobile: r8a7740: remove I2C errata handling

[Wolfram Sang]

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

This is now done in the I2C driver.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 arch/arm/mach-shmobile/setup-r8a7740.c | 55 ----------------------------------
 1 file changed, 55 deletions(-)

diff --git a/arch/arm/mach-shmobile/setup-r8a7740.c b/arch/arm/mach-shmobile/setup-r8a7740.c
index 9832e48396a40a..00291cc1772df9 100644
--- a/arch/arm/mach-shmobile/setup-r8a7740.c
+++ b/arch/arm/mach-shmobile/setup-r8a7740.c
@@ -13,7 +13,6 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */
-#include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -690,56 +689,6 @@ void __init r8a7740_meram_workaround(void)
 	}
 }
 
-#define ICCR	0x0004
-#define ICSTART	0x0070
-
-#define i2c_read(reg, offset)		ioread8(reg + offset)
-#define i2c_write(reg, offset, data)	iowrite8(data, reg + offset)
-
-/*
- * r8a7740 chip has lasting errata on I2C I/O pad reset.
- * this is work-around for it.
- */
-static void r8a7740_i2c_workaround(struct platform_device *pdev)
-{
-	struct resource *res;
-	void __iomem *reg;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (unlikely(!res)) {
-		pr_err("r8a7740 i2c workaround fail (cannot find resource)\n");
-		return;
-	}
-
-	reg = ioremap(res->start, resource_size(res));
-	if (unlikely(!reg)) {
-		pr_err("r8a7740 i2c workaround fail (cannot map IO)\n");
-		return;
-	}
-
-	i2c_write(reg, ICCR, i2c_read(reg, ICCR) | 0x80);
-	i2c_read(reg, ICCR); /* dummy read */
-
-	i2c_write(reg, ICSTART, i2c_read(reg, ICSTART) | 0x10);
-	i2c_read(reg, ICSTART); /* dummy read */
-
-	udelay(10);
-
-	i2c_write(reg, ICCR, 0x01);
-	i2c_write(reg, ICSTART, 0x00);
-
-	udelay(10);
-
-	i2c_write(reg, ICCR, 0x10);
-	udelay(10);
-	i2c_write(reg, ICCR, 0x00);
-	udelay(10);
-	i2c_write(reg, ICCR, 0x10);
-	udelay(10);
-
-	iounmap(reg);
-}
-
 void __init r8a7740_add_standard_devices(void)
 {
 	static struct pm_domain_device domain_devices[] __initdata = {
@@ -766,10 +715,6 @@ void __init r8a7740_add_standard_devices(void)
 		{ "A3SP", &usb_dma_device },
 	};
 
-	/* I2C work-around */
-	r8a7740_i2c_workaround(&i2c0_device);
-	r8a7740_i2c_workaround(&i2c1_device);
-
 	r8a7740_init_pm_domains();
 
 	/* add devices */
-- 
2.1.4

Re: [PATCH 0/2] ARM: shmobile: r8a7740: move I2C errata handling into the driver

[Laurent Pinchart]

Hi Wolfram,

Thank you for the patches.

On Tuesday 09 June 2015 16:14:38 Wolfram Sang wrote:
> This series moves the errata handling from the setup function into the
> driver. It has been tested that this changeset does not cause a regression
> on the armadillo board we had access to. Unfortunately, this board did not
> need the workaround at all, only some revisions of the r8a7740 are
> affected.
> 
> After a short discussion with Simon, we agreed this should go via I2C.

Looks good to me.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> Wolfram Sang (2):
>   i2c: sh_mobile: add errata workaround
>   ARM: shmobile: r8a7740: remove I2C errata handling
> 
>  arch/arm/mach-shmobile/setup-r8a7740.c | 55 -------------------------------
>  drivers/i2c/busses/i2c-sh_mobile.c     | 40 +++++++++++++++++++++++++
>  2 files changed, 40 insertions(+), 55 deletions(-)

-- 
Regards,

Laurent Pinchart

Re: [PATCH 0/2] ARM: shmobile: r8a7740: move I2C errata handling into the driver

[Simon Horman]

On Tue, Jun 09, 2015 at 04:14:38PM +0900, Wolfram Sang wrote:
> This series moves the errata handling from the setup function into the driver.
> It has been tested that this changeset does not cause a regression on the
> armadillo board we had access to. Unfortunately, this board did not need the
> workaround at all, only some revisions of the r8a7740 are affected.
> 
> After a short discussion with Simon, we agreed this should go via I2C.

Acked-by: Simon Horman <horms+renesas@verge.net.au>

> 
> Wolfram Sang (2):
>   i2c: sh_mobile: add errata workaround
>   ARM: shmobile: r8a7740: remove I2C errata handling
> 
>  arch/arm/mach-shmobile/setup-r8a7740.c | 55 ----------------------------------
>  drivers/i2c/busses/i2c-sh_mobile.c     | 40 +++++++++++++++++++++++++
>  2 files changed, 40 insertions(+), 55 deletions(-)
> 
> -- 
> 2.1.4
> 
> --
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> 

[PATCH 1/2] i2c: sh_mobile: add errata workaround

[Wolfram Sang]

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

This used to be in platform init code. We want it to do in the driver
now. This is basically a code move and a new compatible added.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/busses/i2c-sh_mobile.c | 40 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 007818b3e1745b..7193bcfdd94013 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -150,6 +150,7 @@ struct sh_mobile_i2c_data {
 
 struct sh_mobile_dt_config {
 	int clks_per_count;
+	void (*setup)(struct sh_mobile_i2c_data *pd);
 };
 
 #define IIC_FLAG_HAS_ICIC67	(1 << 0)
@@ -164,6 +165,7 @@ struct sh_mobile_dt_config {
 #define ICIC			0x0c
 #define ICCL			0x10
 #define ICCH			0x14
+#define ICSTART			0x70
 
 /* Register bits */
 #define ICCR_ICE		0x80
@@ -190,6 +192,8 @@ struct sh_mobile_dt_config {
 #define ICIC_WAITE		0x02
 #define ICIC_DTEE		0x01
 
+#define ICSTART_ICSTART		0x10
+
 static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
 {
 	if (offs = ICIC)
@@ -782,6 +786,33 @@ static struct i2c_algorithm sh_mobile_i2c_algorithm = {
 	.master_xfer	= sh_mobile_i2c_xfer,
 };
 
+/*
+ * r8a7740 chip has lasting errata on I2C I/O pad reset.
+ * this is work-around for it.
+ */
+static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
+{
+	iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+	iic_rd(pd, ICCR); /* dummy read */
+
+	iic_set_clr(pd, ICSTART, ICSTART_ICSTART, 0);
+	iic_rd(pd, ICSTART); /* dummy read */
+
+	udelay(10);
+
+	iic_wr(pd, ICCR, ICCR_SCP);
+	iic_wr(pd, ICSTART, 0);
+
+	udelay(10);
+
+	iic_wr(pd, ICCR, ICCR_TRS);
+	udelay(10);
+	iic_wr(pd, ICCR, 0);
+	udelay(10);
+	iic_wr(pd, ICCR, ICCR_TRS);
+	udelay(10);
+}
+
 static const struct sh_mobile_dt_config default_dt_config = {
 	.clks_per_count = 1,
 };
@@ -790,9 +821,15 @@ static const struct sh_mobile_dt_config fast_clock_dt_config = {
 	.clks_per_count = 2,
 };
 
+static const struct sh_mobile_dt_config r8a7740_dt_config = {
+	.clks_per_count = 1,
+	.setup = sh_mobile_i2c_r8a7740_workaround,
+};
+
 static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
 	{ .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
 	{ .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config },
+	{ .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config },
 	{ .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config },
 	{ .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config },
 	{ .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
@@ -885,6 +922,9 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 
 			config = match->data;
 			pd->clks_per_count = config->clks_per_count;
+
+			if (config->setup)
+				config->setup(pd);
 		}
 	} else {
 		if (pdata && pdata->bus_speed)
-- 
2.1.4

Re: [PATCH 0/2] ARM: shmobile: r8a7740: move I2C errata handling into the driver

[Kuninori Morimoto]

Hi Wolfram

> This series moves the errata handling from the setup function into the driver.
> It has been tested that this changeset does not cause a regression on the
> armadillo board we had access to. Unfortunately, this board did not need the
> workaround at all, only some revisions of the r8a7740 are affected.
> 
> After a short discussion with Simon, we agreed this should go via I2C.
> 
> Wolfram Sang (2):
>   i2c: sh_mobile: add errata workaround
>   ARM: shmobile: r8a7740: remove I2C errata handling
> 
>  arch/arm/mach-shmobile/setup-r8a7740.c | 55 ----------------------------------
>  drivers/i2c/busses/i2c-sh_mobile.c     | 40 +++++++++++++++++++++++++
>  2 files changed, 40 insertions(+), 55 deletions(-)

Thank you for your patches

For all patches

Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>


Best regards
---
Kuninori Morimoto

Re: [PATCH 0/2] ARM: shmobile: r8a7740: move I2C errata handling into the driver

[Wolfram Sang]

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On Tue, Jun 09, 2015 at 04:14:38PM +0900, Wolfram Sang wrote:
> This series moves the errata handling from the setup function into the driver.
> It has been tested that this changeset does not cause a regression on the
> armadillo board we had access to. Unfortunately, this board did not need the
> workaround at all, only some revisions of the r8a7740 are affected.
> 
> After a short discussion with Simon, we agreed this should go via I2C.
> 
> Wolfram Sang (2):
>   i2c: sh_mobile: add errata workaround
>   ARM: shmobile: r8a7740: remove I2C errata handling
> 

Applied to for-next, thanks!


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