]> git.baikalelectronics.ru Git - kernel.git/commit
lcd: add callbacks for early fb event blank support
authorInki Dae <inki.dae@samsung.com>
Tue, 29 May 2012 22:07:13 +0000 (15:07 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 May 2012 23:22:29 +0000 (16:22 -0700)
commit50fa76071fdb83b8211fe9a93f794b6cd194698b
treebf4a27b9df5b86e03938a6c11d1e993e010e431e
parent50c9af4ad4f981a42cf5b87c17d9cdcdc9a432ae
lcd: add callbacks for early fb event blank support

This patchset adds early fb blank feature that a callback of lcd panel
driver is called prior to specific fb driver's one.  In the case of
MIPI-DSI based video mode LCD Panel, for lcd power off, the power off
commands should be transferred to lcd panel with display and mipi-dsi
controller enabled because the commands is set to lcd panel at vsync porch
period.  and in opposite case, the callback of fb driver should be called
prior to lcd panel driver's one because of same issue.  Also if fb_blank
mode is changed to FB_BLANK_POWERDOWN then display controller would be
off(clock disable) but lcd panel would be still on.  at this time, you
could see some issue like sparkling on lcd panel because video clock to be
delivered to ldi module of lcd panel was disabled.  this issue could
occurs for all lcd panels.

The callback order is as the following:

at fb_blank function of fbmem.c
-> fb_notifier_call_chain(FB_EARLY_EVENT_BLANK)
       -> lcd panel driver's early_set_power()
-> info->fbops->fb_blank()
       -> spcefic fb driver's fb_blank()
-> fb_notifier_call_chain(FB_EVENT_BLANK)
       -> lcd panel driver's set_power()
   -> fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK) if
info->fops->fb_blank() was failed.

fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK) would be called to revert
the effects of previous FB_EARLY_EVENT_BLANK call.  and note that if
early_set_power() of lcd_ops is NULL then early fb blank callback would be
ignored.

This patch:

Add early_set_power and r_early_set_power callbacks.  early_set_power
callback is called prior to fb_blank() of fbmem.c and r_early_set_power
callback is called if fb_blank() was failed to revert the effects of the
early_set_power call of lcd panel driver.

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>
Cc: 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>
drivers/video/backlight/lcd.c
include/linux/lcd.h