From 9b5c9f043e7a70665b2eb092f316d5d5cd238d49 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 10 Feb 2015 19:06:06 +0200
Subject: [PATCH 1/6] i2c: designware-baytrail: describe magic numbers

The patch converts hardcoded numerical constants to a named ones.

While here, align the variable name in get_sem() and reset_semaphore().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 5f1ff4cc5c34..e9cb3555dc79 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -22,22 +22,24 @@
 
 #define SEMAPHORE_TIMEOUT	100
 #define PUNIT_SEMAPHORE		0x7
+#define PUNIT_SEMAPHORE_BIT	BIT(0)
+#define PUNIT_SEMAPHORE_ACQUIRE	BIT(1)
 
 static unsigned long acquired;
 
 static int get_sem(struct device *dev, u32 *sem)
 {
-	u32 reg_val;
+	u32 data;
 	int ret;
 
 	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ, PUNIT_SEMAPHORE,
-			    &reg_val);
+				&data);
 	if (ret) {
 		dev_err(dev, "iosf failed to read punit semaphore\n");
 		return ret;
 	}
 
-	*sem = reg_val & 0x1;
+	*sem = data & PUNIT_SEMAPHORE_BIT;
 
 	return 0;
 }
@@ -52,9 +54,9 @@ static void reset_semaphore(struct device *dev)
 		return;
 	}
 
-	data = data & 0xfffffffe;
+	data &= ~PUNIT_SEMAPHORE_BIT;
 	if (iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
-				 PUNIT_SEMAPHORE, data))
+				PUNIT_SEMAPHORE, data))
 		dev_err(dev, "iosf failed to reset punit semaphore during write\n");
 }
 
@@ -70,9 +72,9 @@ int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	if (!dev->acquire_lock)
 		return 0;
 
-	/* host driver writes 0x2 to side band semaphore register */
+	/* host driver writes to side band semaphore register */
 	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
-				 PUNIT_SEMAPHORE, 0x2);
+				PUNIT_SEMAPHORE, PUNIT_SEMAPHORE_ACQUIRE);
 	if (ret) {
 		dev_err(dev->dev, "iosf punit semaphore request failed\n");
 		return ret;

From 259aada436e13ec75a8b0f252a78e6577879008e Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 10 Feb 2015 19:06:07 +0200
Subject: [PATCH 2/6] i2c: designware-baytrail: fix typo in error path

It seems we have same message for different return values in get_sem() and
baytrail_i2c_acquire(). I suspect this is just a typo, so this patch fixes it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index e9cb3555dc79..9b6765554c70 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -99,8 +99,8 @@ int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	reset_semaphore(dev->dev);
 
 	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
-		PUNIT_SEMAPHORE, &sem);
-	if (!ret)
+				PUNIT_SEMAPHORE, &sem);
+	if (ret)
 		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
 	else
 		dev_err(dev->dev, "PUNIT SEM: %d\n", sem);

From c8e043e6f717b0256b1cfc55d03c232e8a5c8cbd Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 10 Feb 2015 19:06:08 +0200
Subject: [PATCH 3/6] i2c: designware-baytrail: fix sparse warnings

There is no need to export functions that are used as the callbacks in the
struct dw_i2c_dev. Otherwise we get the following warnings:

drivers/i2c/busses/i2c-designware-baytrail.c:63:5: warning: symbol 'baytrail_i2c_acquire' was not declared. Should it be static?
drivers/i2c/busses/i2c-designware-baytrail.c:114:6: warning: symbol 'baytrail_i2c_release' was not declared. Should it be static?

While here, do few indentation fixes, remove i2c_dw_eval_lock_support() from
functions exported to the modules and redundant assignment of local sem
variable.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 9b6765554c70..d33474422003 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -17,7 +17,9 @@
 #include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+
 #include <asm/iosf_mbi.h>
+
 #include "i2c-designware-core.h"
 
 #define SEMAPHORE_TIMEOUT	100
@@ -60,9 +62,9 @@ static void reset_semaphore(struct device *dev)
 		dev_err(dev, "iosf failed to reset punit semaphore during write\n");
 }
 
-int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
+static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 {
-	u32 sem = 0;
+	u32 sem;
 	int ret;
 	unsigned long start, end;
 
@@ -109,9 +111,8 @@ int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 
 	return -ETIMEDOUT;
 }
-EXPORT_SYMBOL(baytrail_i2c_acquire);
 
-void baytrail_i2c_release(struct dw_i2c_dev *dev)
+static void baytrail_i2c_release(struct dw_i2c_dev *dev)
 {
 	if (!dev || !dev->dev)
 		return;
@@ -123,7 +124,6 @@ void baytrail_i2c_release(struct dw_i2c_dev *dev)
 	dev_dbg(dev->dev, "punit semaphore held for %ums\n",
 		jiffies_to_msecs(jiffies - acquired));
 }
-EXPORT_SYMBOL(baytrail_i2c_release);
 
 int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
 {
@@ -139,7 +139,6 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
 		return 0;
 
 	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
-
 	if (ACPI_FAILURE(status))
 		return 0;
 
@@ -155,7 +154,6 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
 
 	return 0;
 }
-EXPORT_SYMBOL(i2c_dw_eval_lock_support);
 
 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
 MODULE_DESCRIPTION("Baytrail I2C Semaphore driver");

From 30be774b38d845791b1acbd750f19e56c57f0185 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 10 Feb 2015 19:06:09 +0200
Subject: [PATCH 4/6] i2c: designware-baytrail: cross-check lock functions

It seems the idea behind the cross-check is to prevent acquire semaphore when
there is no release callback and vice versa. Thus, patch fixes a typo.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index d33474422003..036d9bdc0aaa 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -71,7 +71,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	if (!dev || !dev->dev)
 		return -ENODEV;
 
-	if (!dev->acquire_lock)
+	if (!dev->release_lock)
 		return 0;
 
 	/* host driver writes to side band semaphore register */

From ebf2ef8f613433aaffac53aef2f6703445821fc6 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 10 Feb 2015 19:06:10 +0200
Subject: [PATCH 5/6] i2c: designware-baytrail: baytrail_i2c_acquire() might
 sleep

This patch marks baytrail_i2c_acquire() that it might sleep. Also it chages
while-loop to do-while and, though it is matter of taste, gives a chance to
check one more time before report a timeout.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 036d9bdc0aaa..7d7ae97476e2 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -68,6 +68,8 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	int ret;
 	unsigned long start, end;
 
+	might_sleep();
+
 	if (!dev || !dev->dev)
 		return -ENODEV;
 
@@ -85,7 +87,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	/* host driver waits for bit 0 to be set in semaphore register */
 	start = jiffies;
 	end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT);
-	while (!time_after(jiffies, end)) {
+	do {
 		ret = get_sem(dev->dev, &sem);
 		if (!ret && sem) {
 			acquired = jiffies;
@@ -95,7 +97,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 		}
 
 		usleep_range(1000, 2000);
-	}
+	} while (time_before(jiffies, end));
 
 	dev_err(dev->dev, "punit semaphore timed out, resetting\n");
 	reset_semaphore(dev->dev);

From 5d232112f94b0f3920dc4fec09688ef6cb5c09df Mon Sep 17 00:00:00 2001
From: Matt Porter <mporter@konsulko.com>
Date: Tue, 3 Mar 2015 11:57:08 -0500
Subject: [PATCH 6/6] i2c: imx: add required clocks property to binding

A clock specifier is required for i.MX I2C and is
provided in all DTS implementations. Add this to the
list of required properties in the binding.

Signed-off-by: Matt Porter <mporter@konsulko.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 Documentation/devicetree/bindings/i2c/i2c-imx.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
index 52d37fd8d3e5..ce4311d726ae 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
@@ -7,6 +7,7 @@ Required properties:
   - "fsl,vf610-i2c" for I2C compatible with the one integrated on Vybrid vf610 SoC
 - reg : Should contain I2C/HS-I2C registers location and length
 - interrupts : Should contain I2C/HS-I2C interrupt
+- clocks : Should contain the I2C/HS-I2C clock specifier
 
 Optional properties:
 - clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.