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authorLinus Torvalds <torvalds@linux-foundation.org>2015-03-07 11:56:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-03-07 11:56:30 -0800
commit2cf3afcd4cbe0e32b8722fc291e9255de1b4d6c6 (patch)
treead3743cf1dee763f52547c37fc622474c0c5b9d7 /drivers
parent374dab2366c64666612b8f6275f8c373a373b8d0 (diff)
parent5d232112f94b0f3920dc4fec09688ef6cb5c09df (diff)
downloadkernel-2cf3afcd4cbe0e32b8722fc291e9255de1b4d6c6.tar.gz
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang: "A set of updates and bugfixes for the new designware-baytrail driver. And a documentation bugfix" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: imx: add required clocks property to binding i2c: designware-baytrail: baytrail_i2c_acquire() might sleep i2c: designware-baytrail: cross-check lock functions i2c: designware-baytrail: fix sparse warnings i2c: designware-baytrail: fix typo in error path i2c: designware-baytrail: describe magic numbers
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/busses/i2c-designware-baytrail.c40
1 files changed, 21 insertions, 19 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 5f1ff4cc5c34..7d7ae97476e2 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -17,27 +17,31 @@
#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
#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;
}
@@ -52,27 +56,29 @@ 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");
}
-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;
+ might_sleep();
+
if (!dev || !dev->dev)
return -ENODEV;
- if (!dev->acquire_lock)
+ if (!dev->release_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;
@@ -81,7 +87,7 @@ 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;
@@ -91,14 +97,14 @@ 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);
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);
@@ -107,9 +113,8 @@ 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;
@@ -121,7 +126,6 @@ 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)
{
@@ -137,7 +141,6 @@ 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;
@@ -153,7 +156,6 @@ 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");