tree adac878234cbe372624c5d33e7d70322972392d7
parent b1230ee50a9903a987feaad767fb71e2fd173894
author David Brownell <dbrownell@users.sourceforge.net> 1202290766 -0800
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1202323276 -0800

atmel_lcdfb: backlight control

On the sam9 EK boards, the LCD backlight is hooked up to a PWM output from
the LCD controller.  It's controlled by "contrast" registers though.

This patch lets boards declare that they have that kind of backlight
control.  The driver can then export this control, letting screenblank and
other operations actually take effect ...  reducing the typically
substantial power drain from the backlight.

Note that it's not fully cooked
  - doesn't force backlight off during system suspend
  - the "power" and "blank" events may not be done right
This should be easily added in the future.

[nicolas.ferre@atmel.com: remove unneeded inline and rename functions]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>