| pwm-backlight bindings |
| |
| Required properties: |
| - compatible: "pwm-backlight" |
| - pwms: OF device-tree PWM specification (see PWM binding[0]) |
| - brightness-levels: Array of distinct brightness levels. Typically these |
| are in the range from 0 to 255, but any range starting at 0 will do. |
| The actual brightness level (PWM duty cycle) will be interpolated |
| from these values. 0 means a 0% duty cycle (darkest/off), while the |
| 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 |
| "pwms" property (see PWM binding[0]) |
| - enable-gpios: contains a single GPIO specifier for the GPIO which enables |
| and disables the backlight (see GPIO binding[1]) |
| - post-pwm-on-delay-ms: Delay in ms between setting an initial (non-zero) PWM |
| and enabling the backlight using GPIO. |
| - pwm-off-delay-ms: Delay in ms between disabling the backlight using GPIO |
| and setting PWM value to 0. |
| |
| [0]: Documentation/devicetree/bindings/pwm/pwm.txt |
| [1]: Documentation/devicetree/bindings/gpio/gpio.txt |
| |
| Example: |
| |
| backlight { |
| compatible = "pwm-backlight"; |
| pwms = <&pwm 0 5000000>; |
| |
| brightness-levels = <0 4 8 16 32 64 128 255>; |
| default-brightness-level = <6>; |
| |
| power-supply = <&vdd_bl_reg>; |
| enable-gpios = <&gpio 58 0>; |
| post-pwm-on-delay-ms = <10>; |
| pwm-off-delay-ms = <10>; |
| }; |
