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I2C driver updates

PATCH Superseded Shubhrajyoti D 3 participants 9 messages Dec 2, 2011 – Dec 9, 2011

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

v7 of 9 Superseded Latest is v9 →

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Shubhrajyoti D

author
#0 lore raw

v7 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.

Incorporated review comments:

- Fix the indentation.
- Restore in the error path is not needed as we are doing a init.
- Combine the patch 1 and 2 as i2c-omap.h isn't a generic header
- Making the changelogs more descriptive.

This is rebased on Kevin's tree for_3.2/fixes/i2c branch.

Acknowledge Balaji ,Santosh and Kevin for the review comments.

Shubhrajyoti D (3):
OMAP: I2C: Reset support
OMAP: I2C: Remove the reset in the init path
OMAP: I2C: Remove the SYSC register definition

 arch/arm/plat-omap/i2c.c      |   18 ++++++++
 drivers/i2c/busses/i2c-omap.c |   87 ++++++++++------------------------------
 include/linux/i2c-omap.h      |    1 +
 3 files changed, 41 insertions(+), 65 deletions(-)
author
#1 lore raw

PATCH v7 1/3 OMAP: I2C: Reset support

Under some error conditions the i2c driver may do a reset. Adding a reset field and support in the device-specific code.

Signed-off-by Shubhrajyoti D <[email protected]>
---
 arch/arm/plat-omap/i2c.c |   18 ++++++++++++++++++
 include/linux/i2c-omap.h |    1 +
 2 files changed, 19 insertions(+), 0 deletions(-)
arch/arm/plat-omap/i2c.c +18 -0
index db071bc..883229c 100644
@@ -74,6 +74,22 @@ static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
 static struct platform_device omap_i2c_devices[] = {
 	I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
 };
+/**
+ * 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;
+}
 
 #define OMAP_I2C_CMDLINE_SETUP	(BIT(31))
 

@@ -179,6 +195,8 @@ 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;
 	pdev = omap_device_build(name, bus_id, oh, pdata,
 			sizeof(struct omap_i2c_bus_platform_data),
 			NULL, 0, 0);
include/linux/i2c-omap.h +1 -0
index 92a0dc7..fd38249 100644
@@ -35,6 +35,7 @@ struct omap_i2c_bus_platform_data {
 	u32		rev;
 	u32		flags;
 	void		(*set_mpu_wkup_lat)(struct device *dev, long set);
+	int		(*device_reset) (struct device *dev);
 };
 
 #endif
Signature · 1 line
1.7.1
#2 lore raw

PATCH v7 1/3 OMAP: I2C: Reset support

Hi

some comments

Quoted 23 lines · Shubhrajyoti D

Under some error conditions the i2c driver may do a reset. Adding a reset field and support in the device-specific code.

Signed-off-by Shubhrajyoti D <[email protected]>
---
 arch/arm/plat-omap/i2c.c |   18 ++++++++++++++++++
 include/linux/i2c-omap.h |    1 +
 2 files changed, 19 insertions(+), 0 deletions(-)
arch/arm/plat-omap/i2c.c +6 -0
index db071bc..883229c 100644
@@ -74,6 +74,22 @@ static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
 static struct platform_device omap_i2c_devices[] = {
 	I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
 };
+/**
+ * omap2_i2c_reset - reset the omap i2c module.
+ * @dev: struct device*
+ */
+
+static int omap2_i2c_reset(struct device *dev)

arch/arm/plat-omap/i2c.c static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS]; · line 92

Quoted 10 lines
arch/arm/plat-omap/i2c.c +10 -0
+{
+	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;
+}

This function should go into arch/arm/plat-omap/omap_device.c, and it should be renamed to omap_device_reset(), since it's not I2C specific. Also it shouldn't assume that there's only one hwmod - it should iterate over all of the hwmods in the omap_device and call omap_hwmod_reset() on each.

arch/arm/plat-omap/i2c.c static inline int omap2_i2c_add_bus(int bus_id) · line 199

Quoted 9 lines
arch/arm/plat-omap/i2c.c +2 -0
 #define OMAP_I2C_CMDLINE_SETUP	(BIT(31))
 

@@ -179,6 +195,8 @@ 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;

omap_device_reset

Quoted 23 lines
arch/arm/plat-omap/i2c.c +0 -0
 	pdev = omap_device_build(name, bus_id, oh, pdata,
 			sizeof(struct omap_i2c_bus_platform_data),
 			NULL, 0, 0);
include/linux/i2c-omap.h +1 -0
index 92a0dc7..fd38249 100644
@@ -35,6 +35,7 @@ struct omap_i2c_bus_platform_data {
 	u32		rev;
 	u32		flags;
 	void		(*set_mpu_wkup_lat)(struct device *dev, long set);
+	int		(*device_reset) (struct device *dev);
 };
 
 #endif
Signature · 6 lines
1.7.1

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- Paul

author
#3 lore raw

PATCH v7 1/3 OMAP: I2C: Reset support

Quoted 32 lines · Paul Walmsley

Hi

some comments

Quoted 26 lines · Shubhrajyoti D

Under some error conditions the i2c driver may do a reset. Adding a reset field and support in the device-specific code.

Signed-off-by Shubhrajyoti D <[email protected]>
---
 arch/arm/plat-omap/i2c.c |   18 ++++++++++++++++++
 include/linux/i2c-omap.h |    1 +
 2 files changed, 19 insertions(+), 0 deletions(-)
arch/arm/plat-omap/i2c.c +9 -0
index db071bc..883229c 100644
@@ -74,6 +74,22 @@ static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
 static struct platform_device omap_i2c_devices[] = {
 	I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
 };
+/**
+ * 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);
Quoted 8 lines

arch/arm/plat-omap/i2c.c static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS]; · line 92

Quoted 7 lines
arch/arm/plat-omap/i2c.c +7 -0
+	struct omap_device *odev = to_omap_device(pdev);
+	struct omap_hwmod *oh;
+
+	oh = odev->hwmods[0];
+	r = omap_hwmod_reset(oh);
+	return r;
+}

This function should go into arch/arm/plat-omap/omap_device.c, and it

agree

Quoted 4 lines

should be renamed to omap_device_reset(), since it's not I2C specific. Also it shouldn't assume that there's only one hwmod - it should iterate over all of the hwmods in the omap_device and call omap_hwmod_reset() on each.

Yes agree will fix in the next version.

Quoted 36 lines

arch/arm/plat-omap/i2c.c static inline int omap2_i2c_add_bus(int bus_id) · line 199

Quoted 9 lines
arch/arm/plat-omap/i2c.c +2 -0
 #define OMAP_I2C_CMDLINE_SETUP	(BIT(31))
 

@@ -179,6 +195,8 @@ 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;

omap_device_reset

Quoted 23 lines
arch/arm/plat-omap/i2c.c +0 -0
 	pdev = omap_device_build(name, bus_id, oh, pdata,
 			sizeof(struct omap_i2c_bus_platform_data),
 			NULL, 0, 0);
include/linux/i2c-omap.h +1 -0
index 92a0dc7..fd38249 100644
@@ -35,6 +35,7 @@ struct omap_i2c_bus_platform_data {
 	u32		rev;
 	u32		flags;
 	void		(*set_mpu_wkup_lat)(struct device *dev, long set);
+	int		(*device_reset) (struct device *dev);
 };
 
 #endif
Signature · 6 lines
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- Paul

author
#4 lore raw

PATCH v7 2/3 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.
- Reset is removed from omap_i2c_init, which was called not only during probe, but also after time out and error handling. device_reset were added in those places to effect the reset.
- Earlier the hwmod SYSC settings were over-written in the driver. Removing the same and letting the hwmod take care of the settings.

-  Clean up the SYSS_RESETDONE_MASK macro as it is no longer needed.
-  Clean up the SYSCONFIG SYSC bit defination macros.
-  Fix the typos in wakeup.
Signed-off-by Shubhrajyoti D <[email protected]>
---
 drivers/i2c/busses/i2c-omap.c |   82 +++++++++++------------------------------
 1 files changed, 22 insertions(+), 60 deletions(-)
drivers/i2c/busses/i2c-omap.c +22 -60
index fa23faa..beff9f3 100644
@@ -155,19 +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)
-#define SYSC_ENAWAKEUP_MASK		(1 << 2)
-#define SYSC_SOFTRESET_MASK		(1 << 1)
-#define SYSC_AUTOIDLE_MASK		(1 << 0)
-
-#define SYSC_IDLEMODE_SMART		0x2
-#define SYSC_CLOCKACTIVITY_FCLK		0x2
-
 /* Errata definitions */
 #define I2C_OMAP_ERRATA_I207		(1 << 0)
 #define I2C_OMAP3_1P153			(1 << 1)

@@ -182,6 +169,7 @@ 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;

@@ -317,60 +305,23 @@ 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 omap_i2c_bus_platform_data *pdata;
 
 	pdata = dev->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;
-			omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
-							dev->westate);
-		}
+	if (dev->rev >= OMAP_I2C_REV_ON_3430) {
+		/*
+		 * Enabling all wakeup sources to stop I2C freezing on
+		 * WFI instruction.
+		 * REVISIT: Some wakeup sources might not be needed.
+		 */
+		dev->westate = OMAP_I2C_WE_ALL;
+		omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
+						dev->westate);
 	}
+
 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 
 	if (pdata->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {

@@ -594,6 +545,11 @@ 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) {
+			r = dev->device_reset(dev->dev);
+			if (r < 0)
+				dev_err(dev->dev, "reset failed\n");
+		}
 		omap_i2c_init(dev);
 		return -ETIMEDOUT;
 	}

@@ -604,6 +560,11 @@ 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) {
+			r = dev->device_reset(dev->dev);
+			if (r < 0)
+				dev_err(dev->dev, "reset failed\n");
+		}
 		omap_i2c_init(dev);
 		return -EIO;
 	}

@@ -1004,6 +965,7 @@ 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
#5 lore raw

PATCH v7 2/3 OMAP: I2C: Remove the reset in the init path

Hi Shubhrajyoti,

Quoted 83 lines · Shubhrajyoti D
(quoted diff) +0 -6
-  The reset in the driver at init is not needed anymore as the
    hwmod framework takes care of reseting it.
-  Reset is removed from omap_i2c_init, which was called
    not only during probe, but also after time out and error handling.
    device_reset were added in those places to effect the reset.
-  Earlier the hwmod SYSC settings were over-written in the driver.
    Removing the same and letting the hwmod take care of the settings.
-  Clean up the SYSS_RESETDONE_MASK macro as it is no longer needed.
-  Clean up the SYSCONFIG SYSC bit defination macros.
-  Fix the typos in wakeup.
Signed-off-by Shubhrajyoti D<[email protected]>
---
  drivers/i2c/busses/i2c-omap.c |   82 +++++++++++------------------------------
  1 files changed, 22 insertions(+), 60 deletions(-)
drivers/i2c/busses/i2c-omap.c +1 -38
index fa23faa..beff9f3 100644
@@ -155,19 +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)
-#define SYSC_ENAWAKEUP_MASK		(1<<  2)
-#define SYSC_SOFTRESET_MASK		(1<<  1)
-#define SYSC_AUTOIDLE_MASK		(1<<  0)
-
-#define SYSC_IDLEMODE_SMART		0x2
-#define SYSC_CLOCKACTIVITY_FCLK		0x2
-
  /* Errata definitions */
  #define I2C_OMAP_ERRATA_I207		(1<<  0)
  #define I2C_OMAP3_1P153			(1<<  1)

@@ -182,6 +169,7 @@ 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;

@@ -317,60 +305,23 @@ 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 omap_i2c_bus_platform_data *pdata;
 
  	pdata = dev->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) {
-

drivers/i2c/busses/i2c-omap.c static int omap_i2c_init(struct omap_i2c_dev *dev) · line 360

Quoted 10 lines
drivers/i2c/busses/i2c-omap.c +0 -10
-			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));

The issue I see with this change is that you are removing the above code to set the CLKACTIVITY field. Today, AFAIK, hwmod does not set this. Ideally it should. However, from discussing this with Richard W, this can cause timeouts to occur for i2c transactions. So before removing this we need to make sure that this is handled by hwmod or else where.

Quoted 26 lines
drivers/i2c/busses/i2c-omap.c +10 -11
-			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;
-			omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
-							dev->westate);
-		}
+	if (dev->rev>= OMAP_I2C_REV_ON_3430) {
+		/*
+		 * Enabling all wakeup sources to stop I2C freezing on
+		 * WFI instruction.
+		 * REVISIT: Some wakeup sources might not be needed.
+		 */
+		dev->westate = OMAP_I2C_WE_ALL;
+		omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
+						dev->westate);
  	}
+
  	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 
  	if (pdata->flags&  OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter *adap, · line 553

Quoted 9 lines
drivers/i2c/busses/i2c-omap.c +5 -0
@@ -594,6 +545,11 @@ 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) {
+			r = dev->device_reset(dev->dev);
+			if (r<  0)
+				dev_err(dev->dev, "reset failed\n");
+		}
  		omap_i2c_init(dev);

Why put the reset here? The function omap_i2c_init is going to perform a soft reset. So why not replace the reset in that function?

Furthermore does this work for omap1 devices? I think that you would need to remove the existing soft-reset from omap_i2c_init() into an omap1.

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter *adap, · line 568

Quoted 12 lines
drivers/i2c/busses/i2c-omap.c +5 -0
  		return -ETIMEDOUT;
  	}

@@ -604,6 +560,11 @@ 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) {
+			r = dev->device_reset(dev->dev);
+			if (r<  0)
+				dev_err(dev->dev, "reset failed\n");
+		}
  		omap_i2c_init(dev);

Same as above.

drivers/i2c/busses/i2c-omap.c omap_i2c_probe(struct platform_device *pdev) · line 971

Quoted 10 lines
drivers/i2c/busses/i2c-omap.c +1 -0
  		return -EIO;
  	}

@@ -1004,6 +965,7 @@ 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;

Cheers
Jon

#6 lore raw

PATCH v7 2/3 OMAP: I2C: Remove the reset in the init path

Hi Shubhrajyoti,

On 12/2/2011 15:37, Jon Hunter wrote:

[snip]

Quoted 15 lines

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter · line 554

Quoted 11 lines
drivers/i2c/busses/i2c-omap.c +5 -0
@@ -594,6 +545,11 @@ 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) {
+ r = dev->device_reset(dev->dev);
+ if (r< 0)
+ dev_err(dev->dev, "reset failed\n");
+ }
 omap_i2c_init(dev);

Why put the reset here? The function omap_i2c_init is going to perform a soft reset. So why not replace the reset in that function?

Quoted 2 lines

Furthermore does this work for omap1 devices? I think that you would need to remove the existing soft-reset from omap_i2c_init() into an omap1.

Sorry, I see you did remove the soft-reset in the omap_i2c_init(). However, why not just replace the reset in the omap_i2c_init() instead of moving it?

As for omap1, I see we don't perform a soft-reset so that is a don't care.

Cheers
Jon

author
#7 lore raw

PATCH v7 2/3 OMAP: I2C: Remove the reset in the init path

In reply to Jon Hunter
Quoted 99 lines · Jon Hunter

Hi Shubhrajyoti,

Quoted 96 lines · Shubhrajyoti D
(quoted diff) +0 -6
-  The reset in the driver at init is not needed anymore as the
    hwmod framework takes care of reseting it.
-  Reset is removed from omap_i2c_init, which was called
    not only during probe, but also after time out and error handling.
    device_reset were added in those places to effect the reset.
-  Earlier the hwmod SYSC settings were over-written in the driver.
    Removing the same and letting the hwmod take care of the settings.
-  Clean up the SYSS_RESETDONE_MASK macro as it is no longer needed.
-  Clean up the SYSCONFIG SYSC bit defination macros.
-  Fix the typos in wakeup.
Signed-off-by Shubhrajyoti D<[email protected]>
---
  drivers/i2c/busses/i2c-omap.c |   82
+++++++++++------------------------------
  1 files changed, 22 insertions(+), 60 deletions(-)
drivers/i2c/busses/i2c-omap.c +0 -0
index fa23faa..beff9f3 100644
@@ -155,19 +155,6 @@ enum {
  #define OMAP_I2C_SYSTEST_SDA_O        (1<<  0)    /* SDA line drive

out */
#endif

drivers/i2c/busses/i2c-omap.c +1 -47
-/* 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)
-#define SYSC_ENAWAKEUP_MASK        (1<<  2)
-#define SYSC_SOFTRESET_MASK        (1<<  1)
-#define SYSC_AUTOIDLE_MASK        (1<<  0)
-
-#define SYSC_IDLEMODE_SMART        0x2
-#define SYSC_CLOCKACTIVITY_FCLK        0x2
-
  /* Errata definitions */
  #define I2C_OMAP_ERRATA_I207        (1<<  0)
  #define I2C_OMAP3_1P153            (1<<  1)

@@ -182,6 +169,7 @@ 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;

@@ -317,60 +305,23 @@ 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 omap_i2c_bus_platform_data *pdata;
 
      pdata = dev->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<<
Quoted 8 lines

drivers/i2c/busses/i2c-omap.c static int omap_i2c_init(struct omap_i2c_dev *dev) · line 360

Quoted 1 line
drivers/i2c/busses/i2c-omap.c +0 -1
-                  __ffs(SYSC_CLOCKACTIVITY_MASK));

The issue I see with this change is that you are removing the above code to set the CLKACTIVITY field. Today, AFAIK, hwmod does not set this. Ideally it should. However, from discussing this with Richard W, this can cause timeouts to occur for i2c transactions. So before removing this we need to make sure that this is handled by hwmod or else where.

Agree.
Thanks will try to fix in the next version.

Quoted 74 lines
Quoted 27 lines
drivers/i2c/busses/i2c-omap.c +10 -11
-            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;
-            omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
-                            dev->westate);
-        }
+    if (dev->rev>= OMAP_I2C_REV_ON_3430) {
+        /*
+         * Enabling all wakeup sources to stop I2C freezing on
+         * WFI instruction.
+         * REVISIT: Some wakeup sources might not be needed.
+         */
+        dev->westate = OMAP_I2C_WE_ALL;
+        omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
+                        dev->westate);
      }
+
      omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 
      if (pdata->flags&  OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter · line 554

Quoted 10 lines
drivers/i2c/busses/i2c-omap.c +5 -0
@@ -594,6 +545,11 @@ 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) {
+            r = dev->device_reset(dev->dev);
+            if (r<  0)
+                dev_err(dev->dev, "reset failed\n");
+        }
          omap_i2c_init(dev);

Why put the reset here? The function omap_i2c_init is going to perform a soft reset. So why not replace the reset in that function?

Furthermore does this work for omap1 devices? I think that you would need to remove the existing soft-reset from omap_i2c_init() into an omap1.

drivers/i2c/busses/i2c-omap.c static int omap_i2c_xfer_msg(struct i2c_adapter · line 569

Quoted 13 lines
drivers/i2c/busses/i2c-omap.c +0 -0
          return -ETIMEDOUT;

      }
drivers/i2c/busses/i2c-omap.c +5 -0
@@ -604,6 +560,11 @@ 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) {
+            r = dev->device_reset(dev->dev);
+            if (r<  0)
+                dev_err(dev->dev, "reset failed\n");
+        }
          omap_i2c_init(dev);

Same as above.

drivers/i2c/busses/i2c-omap.c omap_i2c_probe(struct platform_device *pdev) · line 971

Quoted 10 lines
drivers/i2c/busses/i2c-omap.c +0 -0
          return -EIO;

      }
drivers/i2c/busses/i2c-omap.c +1 -0
@@ -1004,6 +965,7 @@ 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;

Cheers
Jon

author
#8 lore raw

PATCH v7 3/3 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.
Also clean up the syscstate from the omap_i2c_dev struct.

Acked-by Santosh Shilimkar <[email protected]>
Signed-off-by Shubhrajyoti D <[email protected]>
---
 drivers/i2c/busses/i2c-omap.c |    5 -----
 1 files changed, 0 insertions(+), 5 deletions(-)
drivers/i2c/busses/i2c-omap.c +0 -5
index beff9f3..8a60b95 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,

@@ -187,7 +186,6 @@ struct omap_i2c_dev {
 	u16			scllstate;
 	u16			sclhstate;
 	u16			bufstate;
-	u16			syscstate;
 	u16			westate;
 	u16			errata;
 };

@@ -202,7 +200,6 @@ static const 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,

@@ -223,7 +220,6 @@ static const 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,

@@ -264,7 +260,6 @@ 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