fbdev: add events for early fb event support

Add FB_EARLY_EVENT_BLANK and FB_R_EARLY_EVENT_BLANK event mode supports.
first, fb_notifier_call_chain() is called with FB_EARLY_EVENT_BLANK and
fb_blank() of specific fb driver is called and then
fb_notifier_call_chain() is called with FB_EVENT_BLANK again at
fb_blank().  and if fb_blank() was failed then fb_nitifier_call_chain()
would be called with FB_R_EARLY_EVENT_BLANK to revert the previous
effects.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fb.h b/include/linux/fb.h
index d31cb68..a3229d7 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -554,6 +554,10 @@
 #define FB_EVENT_FB_UNBIND              0x0E
 /*      CONSOLE-SPECIFIC: remap all consoles to new fb - for vga switcheroo */
 #define FB_EVENT_REMAP_ALL_CONSOLE      0x0F
+/*      A hardware display blank early change occured */
+#define FB_EARLY_EVENT_BLANK		0x10
+/*      A hardware display blank revert early change occured */
+#define FB_R_EARLY_EVENT_BLANK		0x11
 
 struct fb_event {
 	struct fb_info *info;