[PATCHV2 0/5] I2C: driver updates

[PATCHV2 0/5] I2C: driver updates

[Shubhrajyoti D]

The series attempts to do the following
- The reset should not be done in the driver 
  have support for the same.
- Remove the sysc register access in the driver.
- Restore the context only if the context is lost.

version 2
 - Fix the indentation.
 - Restore in the error path is not needed as we are
   doing a init.

Tested on sdp4430 and on omap3430

Shubhrajyoti D (5):
  OMAP: I2C: Add a device reset field to platform data
  OMAP: I2C: Reset support
  OMAP: I2C: Remove the reset in the init path
  OMAP: I2C: Remove the SYSC register definition
  OMAP: I2C: Restore only if context is lost

 arch/arm/plat-omap/i2c.c      |   17 +++++++
 drivers/i2c/busses/i2c-omap.c |  101 ++++++++++++++++-------------------------
 include/linux/i2c-omap.h      |    1 +
 3 files changed, 57 insertions(+), 62 deletions(-)

[PATCHV2 1/5] OMAP: I2C: Add a device reset field to platform data

[Shubhrajyoti D]

Under some conditions the driver may want to do a reset
of the device. Adding a reset field  to the platform
data.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 include/linux/i2c-omap.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h
index 98ae49b..8aa91b6 100644
--- a/include/linux/i2c-omap.h
+++ b/include/linux/i2c-omap.h
@@ -38,6 +38,7 @@ struct omap_i2c_bus_platform_data {
 	int		(*device_enable) (struct platform_device *pdev);
 	int		(*device_shutdown) (struct platform_device *pdev);
 	int		(*device_idle) (struct platform_device *pdev);
+	int		(*device_reset) (struct device *dev);
 };
 
 #endif
-- 
1.7.1

Re: [PATCHV2 1/5] OMAP: I2C: Add a device reset field to platform data

[Santosh Shilimkar]

Shubro,

On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
> Under some conditions the driver may want to do a reset
> of the device. Adding a reset field  to the platform
> data.
>
> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com>
> ---
>   include/linux/i2c-omap.h |    1 +
>   1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h
> index 98ae49b..8aa91b6 100644
> --- a/include/linux/i2c-omap.h
> +++ b/include/linux/i2c-omap.h
> @@ -38,6 +38,7 @@ struct omap_i2c_bus_platform_data {
>   	int		(*device_enable) (struct platform_device *pdev);
>   	int		(*device_shutdown) (struct platform_device *pdev);
>   	int		(*device_idle) (struct platform_device *pdev);
> +	int		(*device_reset) (struct device *dev);
Any reason you haven't clubbed this with the omap i2c reset
implementation patch ?
Since i2c-omap.h isn't a generic header file and specific
to omap i2c drive, you could combine 1/5 and 2/5

[PATCHV2 2/5] OMAP: I2C: Reset support

[Shubhrajyoti D]

Under some error conditions the i2c  driver may do a reset
adding support in the platform.

Signed-off-by: Shubhrajyoti D <shubhrajyoti-l0cyMroinI0@public.gmane.org>
---
 arch/arm/plat-omap/i2c.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
index 2388b8e..98a97b0 100644
--- a/arch/arm/plat-omap/i2c.c
+++ b/arch/arm/plat-omap/i2c.c
@@ -146,6 +146,22 @@ static struct omap_device_pm_latency omap_i2c_latency[] = {
 		.flags			= OMAP_DEVICE_LATENCY_AUTO_ADJUST,
 	},
 };
+/**
+ * omap2_i2c_reset - reset the omap i2c module.
+ * @dev: struct device*
+ */
+
+static int omap2_i2c_reset(struct device *dev)
+{
+	int r = 0;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct omap_device *odev = to_omap_device(pdev);
+	struct omap_hwmod *oh;
+
+	oh = odev->hwmods[0];
+	r = omap_hwmod_reset(oh);
+	return r;
+}
 
 static inline int omap2_i2c_add_bus(int bus_id)
 {
@@ -187,6 +203,7 @@ static inline int omap2_i2c_add_bus(int bus_id)
 	 */
 	if (cpu_is_omap34xx())
 		pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;
+	pdata->device_reset = omap2_i2c_reset;
 	od = omap_device_build(name, bus_id, oh, pdata,
 			sizeof(struct omap_i2c_bus_platform_data),
 			omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0);
-- 
1.7.1

Re: [PATCHV2 2/5] OMAP: I2C: Reset support

[Santosh Shilimkar]

On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
> Under some error conditions the i2c  driver may do a reset
> adding support in the platform.
>
> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com>
> ---
As commented on 1/5, this one should be folded
with 1/5 unless and until you have some valid reason.

Regards
Santosh

Re: [PATCHV2 2/5] OMAP: I2C: Reset support

[Shubhrajyoti]

On Thursday 21 July 2011 04:49 PM, Santosh Shilimkar wrote:
> On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
>> Under some error conditions the i2c  driver may do a reset
>> adding support in the platform.
>>
>> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com>
>> ---
> As commented on 1/5, this one should be folded
> with 1/5 unless and until you have some valid reason.
Thanks for your review.
Will combine the patches and send.
>
> Regards
> Santosh

[PATCHV2 3/5] OMAP: I2C: Remove the reset in the init path

[Shubhrajyoti D]

The reset in the driver at init is not needed
anymore as the hwmod framework takes care of
reseting it.

Signed-off-by: Shubhrajyoti D <shubhrajyoti-l0cyMroinI0@public.gmane.org>
---
 drivers/i2c/busses/i2c-omap.c |   73 ++++++++++++----------------------------
 1 files changed, 22 insertions(+), 51 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 8f87a37..8dc54d5 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -155,9 +155,6 @@ enum {
 #define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
 #endif
 
-/* OCP_SYSSTATUS bit definitions */
-#define SYSS_RESETDONE_MASK		(1 << 0)
-
 /* OCP_SYSCONFIG bit definitions */
 #define SYSC_CLOCKACTIVITY_MASK		(0x3 << 8)
 #define SYSC_SIDLEMODE_MASK		(0x3 << 3)
@@ -182,6 +179,7 @@ struct omap_i2c_dev {
 	u32			latency;	/* maximum mpu wkup latency */
 	void			(*set_mpu_wkup_lat)(struct device *dev,
 						    long latency);
+	int			(*device_reset)(struct device *dev);
 	u32			speed;		/* Speed of bus in Khz */
 	u16			cmd_err;
 	u8			*buf;
@@ -332,7 +330,6 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
 	u16 psc = 0, scll = 0, sclh = 0, buf = 0;
 	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
 	unsigned long fclk_rate = 12000000;
-	unsigned long timeout;
 	unsigned long internal_clk = 0;
 	struct clk *fclk;
 	struct platform_device *pdev;
@@ -341,53 +338,16 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
 	pdev = to_platform_device(dev->dev);
 	pdata = pdev->dev.platform_data;
 
-	if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
-		/* Disable I2C controller before soft reset */
-		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
-			omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
-				~(OMAP_I2C_CON_EN));
-
-		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
-		/* For some reason we need to set the EN bit before the
-		 * reset done bit gets set. */
-		timeout = jiffies + OMAP_I2C_TIMEOUT;
-		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
-		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
-			 SYSS_RESETDONE_MASK)) {
-			if (time_after(jiffies, timeout)) {
-				dev_warn(dev->dev, "timeout waiting "
-						"for controller reset\n");
-				return -ETIMEDOUT;
-			}
-			msleep(1);
-		}
-
-		/* SYSC register is cleared by the reset; rewrite it */
-		if (dev->rev == OMAP_I2C_REV_ON_2430) {
-
-			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
-					   SYSC_AUTOIDLE_MASK);
-
-		} else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
-			dev->syscstate = SYSC_AUTOIDLE_MASK;
-			dev->syscstate |= SYSC_ENAWAKEUP_MASK;
-			dev->syscstate |= (SYSC_IDLEMODE_SMART <<
-			      __ffs(SYSC_SIDLEMODE_MASK));
-			dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
-			      __ffs(SYSC_CLOCKACTIVITY_MASK));
-
-			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
-							dev->syscstate);
-			/*
-			 * Enabling all wakup sources to stop I2C freezing on
-			 * WFI instruction.
-			 * REVISIT: Some wkup sources might not be needed.
-			 */
-			dev->westate = OMAP_I2C_WE_ALL;
-			if (dev->rev < OMAP_I2C_REV_ON_3530_4430)
-				omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
-								dev->westate);
-		}
+	if (dev->rev >= OMAP_I2C_REV_ON_3430) {
+		/*
+		 * Enabling all wakup sources to stop I2C freezing on
+		 * WFI instruction.
+		 * REVISIT: Some wkup sources might not be needed.
+		 */
+		dev->westate = OMAP_I2C_WE_ALL;
+		if (dev->rev < OMAP_I2C_REV_ON_3530_4430)
+			omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
+							dev->westate);
 	}
 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 
@@ -612,6 +572,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 		return r;
 	if (r == 0) {
 		dev_err(dev->dev, "controller timed out\n");
+		if (dev->device_reset != NULL) {
+			r = dev->device_reset(dev->dev);
+			if (r < 0)
+				dev_err(dev->dev, "reset failed\n");
+		}
 		omap_i2c_init(dev);
 		return -ETIMEDOUT;
 	}
@@ -622,6 +587,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	/* We have an error */
 	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
 			    OMAP_I2C_STAT_XUDF)) {
+		if (dev->device_reset != NULL) {
+			r = dev->device_reset(dev->dev);
+			if (r < 0)
+				dev_err(dev->dev, "reset failed\n");
+		}
 		omap_i2c_init(dev);
 		return -EIO;
 	}
@@ -1024,6 +994,7 @@ omap_i2c_probe(struct platform_device *pdev)
 	if (pdata != NULL) {
 		speed = pdata->clkrate;
 		dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
+		dev->device_reset = pdata->device_reset;
 	} else {
 		speed = 100;	/* Default speed */
 		dev->set_mpu_wkup_lat = NULL;
-- 
1.7.1

Re: [PATCHV2 3/5] OMAP: I2C: Remove the reset in the init path

[Santosh Shilimkar]

On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
> The reset in the driver at init is not needed
> anymore as the hwmod framework takes care of
> reseting it.
>
> Signed-off-by: Shubhrajyoti D<shubhrajyoti-l0cyMroinI0@public.gmane.org>
> ---
>   drivers/i2c/busses/i2c-omap.c |   73 ++++++++++++----------------------------
>   1 files changed, 22 insertions(+), 51 deletions(-)

Excellent cleanup. Some minor coments

>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 8f87a37..8dc54d5 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -155,9 +155,6 @@ enum {
>   #define OMAP_I2C_SYSTEST_SDA_O		(1<<  0)	/* SDA line drive out */
>   #endif
>
> -/* OCP_SYSSTATUS bit definitions */
> -#define SYSS_RESETDONE_MASK		(1<<  0)
> -
>   /* OCP_SYSCONFIG bit definitions */
>   #define SYSC_CLOCKACTIVITY_MASK		(0x3<<  8)
>   #define SYSC_SIDLEMODE_MASK		(0x3<<  3)
> @@ -182,6 +179,7 @@ struct omap_i2c_dev {
>   	u32			latency;	/* maximum mpu wkup latency */
>   	void			(*set_mpu_wkup_lat)(struct device *dev,
>   						    long latency);
> +	int			(*device_reset)(struct device *dev);
>   	u32			speed;		/* Speed of bus in Khz */
>   	u16			cmd_err;
>   	u8			*buf;
> @@ -332,7 +330,6 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
>   	u16 psc = 0, scll = 0, sclh = 0, buf = 0;
>   	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
>   	unsigned long fclk_rate = 12000000;
> -	unsigned long timeout;
>   	unsigned long internal_clk = 0;
>   	struct clk *fclk;
>   	struct platform_device *pdev;
> @@ -341,53 +338,16 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
>   	pdev = to_platform_device(dev->dev);
>   	pdata = pdev->dev.platform_data;
>
> -	if (dev->rev>= OMAP_I2C_OMAP1_REV_2) {
> -		/* Disable I2C controller before soft reset */
> -		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
> -			omap_i2c_read_reg(dev, OMAP_I2C_CON_REG)&
> -				~(OMAP_I2C_CON_EN));
> -
> -		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
> -		/* For some reason we need to set the EN bit before the
> -		 * reset done bit gets set. */
> -		timeout = jiffies + OMAP_I2C_TIMEOUT;
> -		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
> -		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG)&
> -			 SYSS_RESETDONE_MASK)) {
> -			if (time_after(jiffies, timeout)) {
> -				dev_warn(dev->dev, "timeout waiting "
> -						"for controller reset\n");
> -				return -ETIMEDOUT;
> -			}
> -			msleep(1);
> -		}
> -
> -		/* SYSC register is cleared by the reset; rewrite it */
> -		if (dev->rev == OMAP_I2C_REV_ON_2430) {
> -
> -			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
> -					   SYSC_AUTOIDLE_MASK);
> -
> -		} else if (dev->rev>= OMAP_I2C_REV_ON_3430) {
> -			dev->syscstate = SYSC_AUTOIDLE_MASK;
> -			dev->syscstate |= SYSC_ENAWAKEUP_MASK;
> -			dev->syscstate |= (SYSC_IDLEMODE_SMART<<
> -			      __ffs(SYSC_SIDLEMODE_MASK));
> -			dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK<<
> -			      __ffs(SYSC_CLOCKACTIVITY_MASK));
> -
> -			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
> -							dev->syscstate);
> -			/*
> -			 * Enabling all wakup sources to stop I2C freezing on
> -			 * WFI instruction.
> -			 * REVISIT: Some wkup sources might not be needed.
> -			 */
> -			dev->westate = OMAP_I2C_WE_ALL;
> -			if (dev->rev<  OMAP_I2C_REV_ON_3530_4430)
> -				omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
> -								dev->westate);
> -		}
> +	if (dev->rev>= OMAP_I2C_REV_ON_3430) {
Space please if (dev->rev >= OMAP_I2C_REV_ON_3430) {
> +		/*
> +		 * Enabling all wakup sources to stop I2C freezing on
> +		 * WFI instruction.
> +		 * REVISIT: Some wkup sources might not be needed.
> +		 */
Surely not related to your patch. But the 'REVISIT:' caught
my attention. Is the comment still valid.

> +		dev->westate = OMAP_I2C_WE_ALL;
> +		if (dev->rev<  OMAP_I2C_REV_ON_3530_4430)
Space if (dev->rev <  OMAP_I2C_REV_ON_3530_4430)
> +			omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
> +							dev->westate);
>   	}
>   	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
>
> @@ -612,6 +572,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
>   		return r;
>   	if (r == 0) {
>   		dev_err(dev->dev, "controller timed out\n");
> +		if (dev->device_reset != NULL) {
> +			r = dev->device_reset(dev->dev);
> +			if (r<  0)
ditto
> +				dev_err(dev->dev, "reset failed\n");
> +		}
>   		omap_i2c_init(dev);
>   		return -ETIMEDOUT;
>   	}
> @@ -622,6 +587,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
>   	/* We have an error */
>   	if (dev->cmd_err&  (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
You can fix this one as well.
>   			    OMAP_I2C_STAT_XUDF)) {
> +		if (dev->device_reset != NULL) {
> +			r = dev->device_reset(dev->dev);
> +			if (r<  0)
here too.
> +				dev_err(dev->dev, "reset failed\n");
> +		}
>   		omap_i2c_init(dev);
>   		return -EIO;
>   	}
> @@ -1024,6 +994,7 @@ omap_i2c_probe(struct platform_device *pdev)
>   	if (pdata != NULL) {
>   		speed = pdata->clkrate;
>   		dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
> +		dev->device_reset = pdata->device_reset;
>   	} else {
>   		speed = 100;	/* Default speed */
>   		dev->set_mpu_wkup_lat = NULL;

Regards
Santosh

Re: [PATCHV2 3/5] OMAP: I2C: Remove the reset in the init path

[Shubhrajyoti]

On Thursday 21 July 2011 04:57 PM, Santosh Shilimkar wrote:
Thanks for your review.
> On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
>
<snip>
>> +        /*
>> +         * Enabling all wakup sources to stop I2C freezing on
>> +         * WFI instruction.
>> +         * REVISIT: Some wkup sources might not be needed.
>> +         */
> Surely not related to your patch. But the 'REVISIT:' caught
> my attention. Is the comment still valid.

Yes I will look and optimise the settings. Obviously all of them may not 
be needed.
Will get back on this.

Also I see that we are not writing it for " < OMAP_I2C_REV_ON_3530_4430"
I will send a patch correcting the same.

>
>> +        dev->westate = OMAP_I2C_WE_ALL;
>> +        if (dev->rev<  OMAP_I2C_REV_ON_3530_4430)
> Space if (dev->rev <  OMAP_I2C_REV_ON_3530_4430)
>> +            omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
>> +                            dev->westate);
>>       }
>>       omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
>>
>> @@ -612,6 +572,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter 
>> *adap,
>>           return r;
>>       if (r == 0) {
>>           dev_err(dev->dev, "controller timed out\n");
>> +        if (dev->device_reset != NULL) {
>> +            r = dev->device_reset(dev->dev);
>> +            if (r<  0)
> ditto
>> +                dev_err(dev->dev, "reset failed\n");
>> +        }
>>           omap_i2c_init(dev);
>>           return -ETIMEDOUT;
>>       }
>> @@ -622,6 +587,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter 
>> *adap,
>>       /* We have an error */
>>       if (dev->cmd_err&  (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
> You can fix this one as well.
>>                   OMAP_I2C_STAT_XUDF)) {
>> +        if (dev->device_reset != NULL) {
>> +            r = dev->device_reset(dev->dev);
>> +            if (r<  0)
> here too.
>> +                dev_err(dev->dev, "reset failed\n");
>> +        }
>>           omap_i2c_init(dev);
>>           return -EIO;
>>       }
>> @@ -1024,6 +994,7 @@ omap_i2c_probe(struct platform_device *pdev)
>>       if (pdata != NULL) {
>>           speed = pdata->clkrate;
>>           dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
>> +        dev->device_reset = pdata->device_reset;
>>       } else {
>>           speed = 100;    /* Default speed */
>>           dev->set_mpu_wkup_lat = NULL;
>
> Regards
> Santosh

[PATCHV2 4/5] OMAP: I2C: Remove the SYSC register definition

[Shubhrajyoti D]

The SYSC register should not accessed in the driver removing the
define from the driver.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 8dc54d5..75bb62d 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -63,7 +63,6 @@ enum {
 	OMAP_I2C_BUF_REG,
 	OMAP_I2C_CNT_REG,
 	OMAP_I2C_DATA_REG,
-	OMAP_I2C_SYSC_REG,
 	OMAP_I2C_CON_REG,
 	OMAP_I2C_OA_REG,
 	OMAP_I2C_SA_REG,
@@ -213,7 +212,6 @@ const static u8 reg_map_ip_v1[] = {
 	[OMAP_I2C_BUF_REG] = 0x05,
 	[OMAP_I2C_CNT_REG] = 0x06,
 	[OMAP_I2C_DATA_REG] = 0x07,
-	[OMAP_I2C_SYSC_REG] = 0x08,
 	[OMAP_I2C_CON_REG] = 0x09,
 	[OMAP_I2C_OA_REG] = 0x0a,
 	[OMAP_I2C_SA_REG] = 0x0b,
@@ -234,7 +232,6 @@ const static u8 reg_map_ip_v2[] = {
 	[OMAP_I2C_BUF_REG] = 0x94,
 	[OMAP_I2C_CNT_REG] = 0x98,
 	[OMAP_I2C_DATA_REG] = 0x9c,
-	[OMAP_I2C_SYSC_REG] = 0x20,
 	[OMAP_I2C_CON_REG] = 0xa4,
 	[OMAP_I2C_OA_REG] = 0xa8,
 	[OMAP_I2C_SA_REG] = 0xac,
@@ -281,7 +278,6 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 		omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
 		omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
 		omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
-		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate);
 		omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
 	}
-- 
1.7.1

Re: [PATCHV2 4/5] OMAP: I2C: Remove the SYSC register definition

[Santosh Shilimkar]

On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
> The SYSC register should not accessed in the driver removing the
> define from the driver.
>
> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com>

Looks good.
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>	

[PATCHV2 5/5] OMAP: I2C: Restore only if context is lost

[Shubhrajyoti D]

Currently restore is done always.
Adding conditional restore. The restore is done only if the context is lost.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |   24 +++++++++++++++++-------
 1 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 75bb62d..dffdbfd 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -40,6 +40,7 @@
 #include <linux/slab.h>
 #include <linux/i2c-omap.h>
 #include <linux/pm_runtime.h>
+#include <plat/omap_device.h>
 
 /* I2C controller revisions */
 #define OMAP_I2C_OMAP1_REV_2		0x20
@@ -200,6 +201,7 @@ struct omap_i2c_dev {
 	u16			syscstate;
 	u16			westate;
 	u16			errata;
+	u32			dev_lost_count;
 };
 
 const static u8 reg_map_ip_v1[] = {
@@ -260,6 +262,17 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
 				(i2c_dev->regs[reg] << i2c_dev->reg_shift));
 }
 
+static void omap_i2c_restore(struct omap_i2c_dev *dev)
+{
+	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
+	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
+	omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
+	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+}
+
 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 {
 	struct platform_device *pdev;
@@ -273,13 +286,9 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 	pm_runtime_get_sync(&pdev->dev);
 
 	if (pdata->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
-		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
-		omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
-		omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
-		omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
-		omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
-		omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
-		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+		u32 loss_cnt = omap_device_get_context_loss_count(pdev);
+		if (dev->dev_lost_count != loss_cnt)
+			omap_i2c_restore(dev);
 	}
 	dev->idle = 0;
 
@@ -318,6 +327,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
 	}
 	dev->idle = 1;
 
+	dev->dev_lost_count = omap_device_get_context_loss_count(pdev);
 	pm_runtime_put_sync(&pdev->dev);
 }
 
-- 
1.7.1

Re: [PATCHV2 5/5] OMAP: I2C: Restore only if context is lost

[Santosh Shilimkar]

On 7/21/2011 4:39 PM, Shubhrajyoti D wrote:
> Currently restore is done always.
> Adding conditional restore. The restore is done only if the context is lost.
>
Minor comment. You may want to say 'i2c register restore'
instead of just 'restore'

> Signed-off-by: Shubhrajyoti D<shubhrajyoti@ti.com>
o.w
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>