backlight: Add suspend/resume support to the backlight core

Add suspend/resume support to the backlight core and enable use of it
by appropriate drivers.

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 1ee9488..79ca2da 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -31,6 +31,10 @@
 struct fb_info;
 
 struct backlight_ops {
+	unsigned int options;
+
+#define BL_CORE_SUSPENDRESUME	(1 << 0)
+
 	/* Notify the backlight driver some property has changed */
 	int (*update_status)(struct backlight_device *);
 	/* Return the current backlight brightness (accounting for power,
@@ -51,7 +55,19 @@
 	   modes; 4: full off), see FB_BLANK_XXX */
 	int power;
 	/* FB Blanking active? (values as for power) */
+	/* Due to be removed, please use (state & BL_CORE_FBBLANK) */
 	int fb_blank;
+	/* Flags used to signal drivers of state changes */
+	/* Upper 4 bits are reserved for driver internal use */
+	unsigned int state;
+
+#define BL_CORE_SUSPENDED	(1 << 0)	/* backlight is suspended */
+#define BL_CORE_FBBLANK		(1 << 1)	/* backlight is under an fb blank event */
+#define BL_CORE_DRIVER4		(1 << 28)	/* reserved for driver specific use */
+#define BL_CORE_DRIVER3		(1 << 29)	/* reserved for driver specific use */
+#define BL_CORE_DRIVER2		(1 << 30)	/* reserved for driver specific use */
+#define BL_CORE_DRIVER1		(1 << 31)	/* reserved for driver specific use */
+
 };
 
 struct backlight_device {