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I2C: driver updates

PATCH New Shubhrajyoti D 2 participants 13 messages Jul 21, 2011 – Jul 29, 2011

Subsystems (6)
Arm (32-bit) Arm sub-architectures I2C subsystem host drivers OMAP2+ support +2 more subsystems
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Shubhrajyoti D

author
#0 lore raw

v2 cover I2C: driver updates

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(-)
author
#1 lore raw

PATCH v2 1/5 OMAP: I2C: Add a device reset field to platform data

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 <[email protected]>
---
 include/linux/i2c-omap.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
include/linux/i2c-omap.h +1 -0
index 98ae49b..8aa91b6 100644
@@ -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
Signature · 1 line
1.7.1
#2 lore raw

PATCH v2 1/5 OMAP: I2C: Add a device reset field to platform data

Shubro,

Quoted 14 lines · 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<[email protected]>
---
  include/linux/i2c-omap.h |    1 +
  1 files changed, 1 insertions(+), 0 deletions(-)
include/linux/i2c-omap.h +0 -0
index 98ae49b..8aa91b6 100644

include/linux/i2c-omap.h struct omap_i2c_bus_platform_data { · line 41

Quoted 4 lines
include/linux/i2c-omap.h +1 -0
@@ -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

author
#3 lore raw

PATCH v2 2/5 OMAP: I2C: Reset support

In reply to Shubhrajyoti D

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

Signed-off-by Shubhrajyoti D <[email protected]>
---
 arch/arm/plat-omap/i2c.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)
arch/arm/plat-omap/i2c.c +17 -0
index 2388b8e..98a97b0 100644
@@ -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);
Signature · 1 line
1.7.1
#4 lore raw

PATCH v2 2/5 OMAP: I2C: Reset support

Quoted 5 lines · Shubhrajyoti D

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

Signed-off-by Shubhrajyoti D<[email protected]>

---

As commented on 1/5, this one should be folded with 1/5 unless and until you have some valid reason.

Regards
Santosh

author
#5 lore raw

PATCH v2 2/5 OMAP: I2C: Reset support

Quoted 8 lines · Santosh Shilimkar
Quoted 5 lines · Shubhrajyoti D

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

Signed-off-by Shubhrajyoti D<[email protected]>

---

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.

Quoted 3 lines

Regards
Santosh

author
#6 lore raw

PATCH v2 3/5 OMAP: I2C: Remove the reset in the init path

In reply to 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 <[email protected]>
---
 drivers/i2c/busses/i2c-omap.c |   73 ++++++++++++----------------------------
 1 files changed, 22 insertions(+), 51 deletions(-)
drivers/i2c/busses/i2c-omap.c +22 -51
index 8f87a37..8dc54d5 100644
@@ -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;
Signature · 1 line
1.7.1
#7 lore raw

PATCH v2 3/5 OMAP: I2C: Remove the reset in the init path

Quoted 8 lines · 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<[email protected]>
---
  drivers/i2c/busses/i2c-omap.c |   73 ++++++++++++----------------------------
  1 files changed, 22 insertions(+), 51 deletions(-)

Excellent cleanup. Some minor coments

Quoted 73 lines
drivers/i2c/busses/i2c-omap.c +1 -42
index 8f87a37..8dc54d5 100644
@@ -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);
-			/*

drivers/i2c/busses/i2c-omap.c static int omap_i2c_init(struct omap_i2c_dev *dev) · line 341

Quoted 10 lines
drivers/i2c/busses/i2c-omap.c +1 -9
-			 * 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) {

drivers/i2c/busses/i2c-omap.c static int omap_i2c_init(struct omap_i2c_dev *dev) · line 346

Quoted 5 lines
drivers/i2c/busses/i2c-omap.c +5 -0
+		/*
+		 * 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.

drivers/i2c/busses/i2c-omap.c static int omap_i2c_init(struct omap_i2c_dev *dev) · line 348

Quoted 2 lines
drivers/i2c/busses/i2c-omap.c +2 -0
+		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)

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter *adap, · line 577

Quoted 12 lines
drivers/i2c/busses/i2c-omap.c +5 -0
+			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

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter *adap, · line 588

Quoted 8 lines
drivers/i2c/busses/i2c-omap.c +2 -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 |

You can fix this one as well.

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter *adap,

Quoted 4 lines
drivers/i2c/busses/i2c-omap.c +3 -0
  			    OMAP_I2C_STAT_XUDF)) {
+		if (dev->device_reset != NULL) {
+			r = dev->device_reset(dev->dev);
+			if (r<  0)

here too.

drivers/i2c/busses/i2c-omap.c omap_i2c_probe(struct platform_device *pdev) · line 1000

Quoted 13 lines
drivers/i2c/busses/i2c-omap.c +3 -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;

Regards
Santosh

author
#8 lore raw

PATCH v2 3/5 OMAP: I2C: Remove the reset in the init path

On Thursday 21 July 2011 04:57 PM, Santosh Shilimkar wrote:
Thanks for your review.

Quoted 2 lines · Shubhrajyoti D

<snip>

Quoted 7 lines

drivers/i2c/busses/i2c-omap.c static int omap_i2c_init(struct omap_i2c_dev *dev) · line 346

Quoted 5 lines
drivers/i2c/busses/i2c-omap.c +5 -0
+        /*
+         * 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.

Quoted 49 lines

Review

Quoted 3 lines
(quoted diff) +2 -0
+        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)

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter · line 578

Quoted 13 lines
drivers/i2c/busses/i2c-omap.c +5 -0
+            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

Review static int omap_i2c_xfer_msg(struct i2c_adapter · line 589

Quoted 9 lines
drivers/i2c/busses/i2c-omap.c +2 -0
+                dev_err(dev->dev, "reset failed\n");
+        }
          omap_i2c_init(dev);
          return -ETIMEDOUT;

      }
(quoted diff) +0 -0
@@ -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.

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter *adap,

Quoted 4 lines
drivers/i2c/busses/i2c-omap.c +3 -0
                  OMAP_I2C_STAT_XUDF)) {
+        if (dev->device_reset != NULL) {
+            r = dev->device_reset(dev->dev);
+            if (r<  0)

here too.

drivers/i2c/busses/i2c-omap.c omap_i2c_probe(struct platform_device *pdev) · line 1000

Quoted 13 lines
drivers/i2c/busses/i2c-omap.c +2 -0
+                dev_err(dev->dev, "reset failed\n");
+        }
          omap_i2c_init(dev);
          return -EIO;

      }
drivers/i2c/busses/i2c-omap.c +1 -0
@@ -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

author
#9 lore raw

PATCH v2 4/5 OMAP: I2C: Remove the SYSC register definition

In reply to Shubhrajyoti D

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

Signed-off-by Shubhrajyoti D <[email protected]>
---
 drivers/i2c/busses/i2c-omap.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)
drivers/i2c/busses/i2c-omap.c +0 -4
index 8dc54d5..75bb62d 100644
@@ -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);
 	}
Signature · 1 line
1.7.1
author
#11 lore raw

PATCH v2 5/5 OMAP: I2C: Restore only if context is lost

In reply to 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 <[email protected]>
---
 drivers/i2c/busses/i2c-omap.c |   24 +++++++++++++++++-------
 1 files changed, 17 insertions(+), 7 deletions(-)
drivers/i2c/busses/i2c-omap.c +17 -7
index 75bb62d..dffdbfd 100644
@@ -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);
 }
Signature · 1 line
1.7.1