leds: leds-pwm: implement PWM inversion
authorRussell King <rmk+kernel@arm.linux.org.uk>
Sun, 6 Apr 2014 22:20:18 +0000 (15:20 -0700)
committerBryan Wu <cooloney@gmail.com>
Thu, 8 May 2014 06:28:07 +0000 (14:28 +0800)
commitd19a8a7078a9a8e254c030bcdb6732d26cbd6c16
tree3951de02ae3cbb710876d0436f0b24f6e26d3ed8
parentb795e6d94f2193d5e9087f05c445b069a7aa0dcd
leds: leds-pwm: implement PWM inversion

Some PWM outputs are wired such that the LED they're controlling is
connected to supply rather than ground.  These PWMs may not support
output inversion, or when they do, disabling the PWM may set the
PWM output low, causing a "brightness" value of zero to turn the LED
fully on.

The platform data for this driver already indicates that this was
thought about, and we have the "active_low" property there already.
However, the implementation for this is missing.

Add the trivial implementation for this feature.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
drivers/leds/leds-pwm.c