backlight: Convert semaphore -> mutex

Convert internal semaphore to a mutex

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

drivers/video/backlight/backlight.c

@@ -32,14 +32,14 @@ static int fb_notifier_callback(struct notifier_block *self,
 		return 0;
 
 	bd = container_of(self, struct backlight_device, fb_notif);
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props)
 		if (!bd->props->check_fb ||
 		    bd->props->check_fb(evdata->info)) {
 			bd->props->fb_blank = *(int *)evdata->data;
 			backlight_update_status(bd);
 		}
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 	return 0;
 }
 
@@ -71,10 +71,10 @@ static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
 	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props)
 		rc = sprintf(buf, "%d\n", bd->props->power);
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	return rc;
 }
@@ -92,14 +92,14 @@ static ssize_t backlight_store_power(struct class_device *cdev, const char *buf,
 	if (size != count)
 		return -EINVAL;
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props) {
 		pr_debug("backlight: set power to %d\n", power);
 		bd->props->power = power;
 		backlight_update_status(bd);
 		rc = count;
 	}
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	return rc;
 }
@@ -109,10 +109,10 @@ static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
 	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props)
 		rc = sprintf(buf, "%d\n", bd->props->brightness);
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	return rc;
 }
@@ -130,7 +130,7 @@ static ssize_t backlight_store_brightness(struct class_device *cdev, const char
 	if (size != count)
 		return -EINVAL;
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props) {
 		if (brightness > bd->props->max_brightness)
 			rc = -EINVAL;
@@ -142,7 +142,7 @@ static ssize_t backlight_store_brightness(struct class_device *cdev, const char
 			rc = count;
 		}
 	}
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	return rc;
 }
@@ -152,10 +152,10 @@ static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *bu
 	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props)
 		rc = sprintf(buf, "%d\n", bd->props->max_brightness);
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	return rc;
 }
@@ -166,10 +166,10 @@ static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
 	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	if (bd->props && bd->props->get_brightness)
 		rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	return rc;
 }
@@ -228,7 +228,7 @@ struct backlight_device *backlight_device_register(const char *name,
 		return ERR_PTR(-ENOMEM);
 
 	mutex_init(&new_bd->update_lock);
-	init_MUTEX(&new_bd->sem);
+	mutex_init(&new_bd->props_lock);
 	new_bd->props = bp;
 	memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
 	new_bd->class_dev.class = &backlight_class;
@@ -285,9 +285,9 @@ void backlight_device_unregister(struct backlight_device *bd)
 		class_device_remove_file(&bd->class_dev,
 					 &bl_class_device_attributes[i]);
 
-	down(&bd->sem);
+	mutex_lock(&bd->props_lock);
 	bd->props = NULL;
-	up(&bd->sem);
+	mutex_unlock(&bd->props_lock);
 
 	backlight_unregister_fb(bd);
 

drivers/video/backlight/lcd.c

@@ -31,11 +31,11 @@ static int fb_notifier_callback(struct notifier_block *self,
 		return 0;
 
 	ld = container_of(self, struct lcd_device, fb_notif);
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	if (ld->props)
 		if (!ld->props->check_fb || ld->props->check_fb(evdata->info))
 			ld->props->set_power(ld, *(int *)evdata->data);
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 	return 0;
 }
 
@@ -66,12 +66,12 @@ static ssize_t lcd_show_power(struct class_device *cdev, char *buf)
 	int rc;
 	struct lcd_device *ld = to_lcd_device(cdev);
 
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	if (ld->props && ld->props->get_power)
 		rc = sprintf(buf, "%d\n", ld->props->get_power(ld));
 	else
 		rc = -ENXIO;
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 
 	return rc;
 }
@@ -89,13 +89,13 @@ static ssize_t lcd_store_power(struct class_device *cdev, const char *buf, size_
 	if (size != count)
 		return -EINVAL;
 
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	if (ld->props && ld->props->set_power) {
 		pr_debug("lcd: set power to %d\n", power);
 		ld->props->set_power(ld, power);
 		rc = count;
 	}
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 
 	return rc;
 }
@@ -105,10 +105,10 @@ static ssize_t lcd_show_contrast(struct class_device *cdev, char *buf)
 	int rc = -ENXIO;
 	struct lcd_device *ld = to_lcd_device(cdev);
 
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	if (ld->props && ld->props->get_contrast)
 		rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 
 	return rc;
 }
@@ -126,13 +126,13 @@ static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, si
 	if (size != count)
 		return -EINVAL;
 
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	if (ld->props && ld->props->set_contrast) {
 		pr_debug("lcd: set contrast to %d\n", contrast);
 		ld->props->set_contrast(ld, contrast);
 		rc = count;
 	}
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 
 	return rc;
 }
@@ -142,10 +142,10 @@ static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf)
 	int rc = -ENXIO;
 	struct lcd_device *ld = to_lcd_device(cdev);
 
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	if (ld->props)
 		rc = sprintf(buf, "%d\n", ld->props->max_contrast);
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 
 	return rc;
 }
@@ -197,7 +197,7 @@ struct lcd_device *lcd_device_register(const char *name, void *devdata,
 	if (!new_ld)
 		return ERR_PTR(-ENOMEM);
 
-	init_MUTEX(&new_ld->sem);
+	mutex_init(&new_ld->props_lock);
 	mutex_init(&new_ld->update_lock);
 	new_ld->props = lp;
 	memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
@@ -253,9 +253,9 @@ void lcd_device_unregister(struct lcd_device *ld)
 		class_device_remove_file(&ld->class_dev,
 					 &lcd_class_device_attributes[i]);
 
-	down(&ld->sem);
+	mutex_lock(&ld->props_lock);
 	ld->props = NULL;
-	up(&ld->sem);
+	mutex_unlock(&ld->props_lock);
 	lcd_unregister_fb(ld);
 	class_device_unregister(&ld->class_dev);
 }

include/linux/backlight.h

@@ -14,8 +14,8 @@
 
 /* Notes on locking:
  *
- * backlight_device->sem is an internal backlight lock protecting the props
- * field and no code outside the core should need to touch it.
+ * backlight_device->props_lock is an internal backlight lock protecting the
+ * props field and no code outside the core should need to touch it.
  *
  * Access to update_status() is serialised by the update_lock mutex since
  * most drivers seem to need this and historically get it wrong.
@@ -57,7 +57,7 @@ struct backlight_device {
 	/* This protects the 'props' field. If 'props' is NULL, the driver that
 	   registered this device has been unloaded, and if class_get_devdata()
 	   points to something in the body of that driver, it is also invalid. */
-	struct semaphore sem;
+	struct mutex props_lock;
 	/* If this is NULL, the backing module is unloaded */
 	struct backlight_properties *props;
 	/* Serialise access to update_status method */

include/linux/lcd.h

@@ -14,7 +14,7 @@
 
 /* Notes on locking:
  *
- * lcd_device->sem is an internal backlight lock protecting the props
+ * lcd_device->props_lock is an internal backlight lock protecting the props
  * field and no code outside the core should need to touch it.
  *
  * Access to set_power() is serialised by the update_lock mutex since
@@ -52,7 +52,7 @@ struct lcd_device {
 	/* This protects the 'props' field. If 'props' is NULL, the driver that
 	   registered this device has been unloaded, and if class_get_devdata()
 	   points to something in the body of that driver, it is also invalid. */
-	struct semaphore sem;
+	struct mutex props_lock;
 	/* If this is NULL, the backing module is unloaded */
 	struct lcd_properties *props;
 	/* Serialise access to set_power method */