X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=include%2Flinux%2Fbacklight.h;h=1ee9488ca2e40589adf8634c5131c00424a7696f;hb=feeedc6c820e1026453ad865076cee435f24d30a;hp=75e91f5b6a04ce7dc0626599d9d21ac08f8b3059;hpb=f1f76afd71e0f17af9a35fcb649f4bab53304a4d;p=linux-2.6-omap-h63xx.git

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 75e91f5b6a0..1ee9488ca2e 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -9,17 +9,28 @@
 #define _LINUX_BACKLIGHT_H
 
 #include <linux/device.h>
+#include <linux/mutex.h>
 #include <linux/notifier.h>
 
+/* Notes on locking:
+ *
+ * backlight_device->ops_lock is an internal backlight lock protecting the
+ * ops pointer 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.
+ *
+ * Most drivers don't need locking on their get_brightness() method.
+ * If yours does, you need to implement it in the driver. You can use the
+ * update_lock mutex if appropriate.
+ *
+ * Any other use of the locks below is probably wrong.
+ */
+
 struct backlight_device;
 struct fb_info;
 
-/* This structure defines all the properties of a backlight
-   (usually attached to a LCD). */
-struct backlight_properties {
-	/* Owner module */
-	struct module *owner;
-
+struct backlight_ops {
 	/* Notify the backlight driver some property has changed */
 	int (*update_status)(struct backlight_device *);
 	/* Return the current backlight brightness (accounting for power,
@@ -28,7 +39,10 @@ struct backlight_properties {
 	/* Check if given framebuffer device is the one bound to this backlight;
 	   return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
 	int (*check_fb)(struct fb_info *);
+};
 
+/* This structure defines all the properties of a backlight */
+struct backlight_properties {
 	/* Current User requested brightness (0 - max_brightness) */
 	int brightness;
 	/* Maximal value for brightness (read-only) */
@@ -41,22 +55,50 @@ struct backlight_properties {
 };
 
 struct backlight_device {
-	/* This protects the 'props' field. If 'props' is NULL, the driver that
+	/* Backlight properties */
+	struct backlight_properties props;
+
+	/* Serialise access to update_status method */
+	struct mutex update_lock;
+
+	/* This protects the 'ops' field. If 'ops' 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;
-	/* If this is NULL, the backing module is unloaded */
-	struct backlight_properties *props;
+	struct mutex ops_lock;
+	struct backlight_ops *ops;
+
 	/* The framebuffer notifier block */
 	struct notifier_block fb_notif;
-	/* The class device structure */
-	struct class_device class_dev;
+
+	struct device dev;
 };
 
+static inline void backlight_update_status(struct backlight_device *bd)
+{
+	mutex_lock(&bd->update_lock);
+	if (bd->ops && bd->ops->update_status)
+		bd->ops->update_status(bd);
+	mutex_unlock(&bd->update_lock);
+}
+
 extern struct backlight_device *backlight_device_register(const char *name,
-	void *devdata, struct backlight_properties *bp);
+	struct device *dev, void *devdata, struct backlight_ops *ops);
 extern void backlight_device_unregister(struct backlight_device *bd);
 
-#define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev)
+#define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
+
+static inline void * bl_get_data(struct backlight_device *bl_dev)
+{
+	return dev_get_drvdata(&bl_dev->dev);
+}
+
+struct generic_bl_info {
+	const char *name;
+	int max_intensity;
+	int default_intensity;
+	int limit_mask;
+	void (*set_bl_intensity)(int intensity);
+	void (*kick_battery)(void);
+};
 
 #endif