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>
Setting a display timing parameter too high or too low may cause it to
wrap around and thus become completely wrong. Validate the timings in
atmel_lcdfb_check_var() and saturate to the highest or lowest possible
value if necessary.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
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>
Adds a framebuffer driver to ATMEL AT91SAM9x and AT32 aka AVR32 platforms.
Those chips share quite the same IP and this code is suitable for both
architectures.
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Brownell
Haavard Skinnemoen
Nicolas Ferre