pwm-backlight: Add power supply support

Backlights require a power supply to work properly. This commit adds a
regulator to power up and power down the backlight.

Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
index 72810cc2dbc1..764db86d441a 100644
--- a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
+++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
@@ -10,6 +10,7 @@ Required properties:
       last value in the array represents a 100% duty cycle (brightest).
   - default-brightness-level: the default brightness level (index into the
       array defined by the "brightness-levels" property)
+  - power-supply: regulator for supply voltage
 
 Optional properties:
   - pwm-names: a list of names for the PWM devices specified in the
@@ -29,5 +30,6 @@ Example:
                 brightness-levels = <0 4 8 16 32 64 128 255>;
                 default-brightness-level = <6>;
 
+                power-supply = <&vdd_bl_reg>;
                 enable-gpios = <&gpio 58 0>;
         };