Kernel-4.18.0-80.el8_pwm-backlight

pwm-backlight bindings

Required properties:

• compatible: “pwm-backlight”
• pwms: OF device-tree PWM specification (see PWM binding0)
• 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.
  

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>;
};