Merge tag 'topic/drm-fixes-2015-11-11' of git://anongit.freedesktop.org/drm-intel...

[firefly-linux-kernel-4.4.55.git] / drivers / i2c / busses / i2c-designware-baytrail.c

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 5f1ff4cc5c34036ea6284adf9d00fce0ef1fabae..7d7ae97476e2c4cec01765e700e0748bece538bc 100644 (file)
--- 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");