Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight

* 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight:
  backlight: Remove bogus SYSFS dependency
  backlight: simplify corgi_bl locking
  backlight: Separate backlight properties from backlight ops pointers
  backlight: Clean up pmac_backlight handling
  backlight: Improve backlight selection for fbdev drivers
  backlight: Rework backlight/fb interaction simplifying, lots
  backlight: Remove unneeded backlight update_status calls
  backlight: Remove uneeded update_status call from chipsfb.c
  backlight/fbcon: Add FB_EVENT_CONBLANK
  backlight: Fix Kconfig entries
  backlight: Remove uneeded nvidia set_power calls
  backlight: Convert semaphore -> mutex
  backlight: Fix external uses of backlight internal semaphore
  backlight: Minor code cleanups for hp680_bl.c
  backlight: Minor code cleanups for corgi_bl.c
  backlight: Remove excessive (un)likelys
  backlight: Remove unneeded owner field
  backlight: Fix error handling
  backlight: Add Frontpath ProGear HX1050+ driver
  backlight: Add maintainer entry

3 files changed, 81 insertions, 27 deletions

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index a5cf1beacb44..1023ba0d6e55 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) */
@@ -41,20 +55,34 @@ 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;
 };
 
+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,
-        struct device *dev,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)
diff --git a/include/linux/fb.h b/include/linux/fb.h
index a78e25683f82..be913ec87169 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -516,13 +516,15 @@ struct fb_cursor_user {
 #define FB_EVENT_GET_CONSOLE_MAP        0x07
 /*      CONSOLE-SPECIFIC: set console to framebuffer mapping */
 #define FB_EVENT_SET_CONSOLE_MAP        0x08
-/*      A display blank is requested       */
+/*      A hardware display blank change occured */
 #define FB_EVENT_BLANK                  0x09
 /*      Private modelist is to be replaced */
 #define FB_EVENT_NEW_MODELIST           0x0A
 /*      The resolution of the passed in fb_info about to change and
         all vc's should be changed         */
 #define FB_EVENT_MODE_CHANGE_ALL        0x0B
+/*      A software display blank change occured */
+#define FB_EVENT_CONBLANK               0x0C
 
 struct fb_event {
         struct fb_info *info;
@@ -767,16 +769,13 @@ struct fb_info {
         struct fb_videomode *mode;      /* current mode */
 
 #ifdef CONFIG_FB_BACKLIGHT
-        /* Lock ordering:
-         * bl_mutex (protects bl_dev and bl_curve)
-         *   bl_dev->sem (backlight class)
-         */
-        struct mutex bl_mutex;
-
         /* assigned backlight device */
+        /* set before framebuffer registration, 
+           remove after unregister */
         struct backlight_device *bl_dev;
 
         /* Backlight level curve */
+        struct mutex bl_curve_mutex;    
         u8 bl_curve[FB_BACKLIGHT_LEVELS];
 #endif
 
diff --git a/include/linux/lcd.h b/include/linux/lcd.h
index d739b2e7eac2..598793c0745b 100644
--- a/include/linux/lcd.h
+++ b/include/linux/lcd.h
@@ -9,22 +9,38 @@
 #define _LINUX_LCD_H
 
 #include <linux/device.h>
+#include <linux/mutex.h>
 #include <linux/notifier.h>
 
+/* Notes on locking:
+ *
+ * lcd_device->ops_lock is an internal backlight lock protecting the ops
+ * field and no code outside the core should need to touch it.
+ *
+ * Access to set_power() 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_power() 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 lcd_device;
 struct fb_info;
 
-/* This structure defines all the properties of a LCD flat panel. */
 struct lcd_properties {
-        /* Owner module */
-        struct module *owner;
+        /* The maximum value for contrast (read-only) */
+        int max_contrast;
+};
+
+struct lcd_ops {
         /* Get the LCD panel power status (0: full on, 1..3: controller
            power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
         int (*get_power)(struct lcd_device *);
         /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
         int (*set_power)(struct lcd_device *, int power);
-        /* The maximum value for contrast (read-only) */
-        int max_contrast;
         /* Get the current contrast setting (0-max_contrast) */
         int (*get_contrast)(struct lcd_device *);
         /* Set LCD panel contrast */
@@ -35,20 +51,31 @@ struct lcd_properties {
 };
 
 struct lcd_device {
-        /* This protects the 'props' field. If 'props' is NULL, the driver that
+        struct lcd_properties props;
+        /* 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;
+        struct mutex ops_lock;
         /* If this is NULL, the backing module is unloaded */
-        struct lcd_properties *props;
+        struct lcd_ops *ops;
+        /* Serialise access to set_power method */
+        struct mutex update_lock;
         /* The framebuffer notifier block */
         struct notifier_block fb_notif;
         /* The class device structure */
         struct class_device class_dev;
 };
 
+static inline void lcd_set_power(struct lcd_device *ld, int power)
+{
+        mutex_lock(&ld->update_lock);
+        if (ld->ops && ld->ops->set_power)
+                ld->ops->set_power(ld, power);
+        mutex_unlock(&ld->update_lock);
+}
+
 extern struct lcd_device *lcd_device_register(const char *name,
-        void *devdata, struct lcd_properties *lp);
+        void *devdata, struct lcd_ops *ops);
 extern void lcd_device_unregister(struct lcd_device *ld);
 
 #define to_lcd_device(obj) container_of(obj, struct lcd_device, class_dev)