LED connected to PWM
Required properties:
- compatible : should be “pwm-leds”.
Each LED is represented as a sub-node of the pwm-leds device. Each
node’s name represents the name of the corresponding LED.
LED sub-node properties:
- pwms : PWM property to point to the PWM device (phandle)/port (id) and to
specify the period time to be used: <&phandle id period_ns>; - pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device
For the pwms and pwm-names property please refer to:
Documentation/devicetree/bindings/pwm/pwm.txt - max-brightness : Maximum brightness possible for the LED
- active-low : (optional) For PWMs where the LED is wired to supply
rather than ground. - label : (optional)
see Documentation/devicetree/bindings/leds/common.txt - linux,default-trigger : (optional)
see Documentation/devicetree/bindings/leds/common.txt
Example:
twl_pwm: pwm {
/* provides two PWMs (id 0, 1 for PWM1 and PWM2) */
compatible = “ti,twl6030-pwm”;
#pwm-cells = <2>;
};
twl_pwmled: pwmled {
/* provides one PWM (id 0 for Charing indicator LED) */
compatible = “ti,twl6030-pwmled”;
#pwm-cells = <2>;
};
pwmleds {
compatible = “pwm-leds”;
kpad {
label = “omap4::keypad”;
pwms = <&twl_pwm 0 7812500>;
max-brightness = <127>;
};
charging {
label = "omap4:green:chrg";
pwms = <&twl_pwmled 0 7812500>;
max-brightness = <255>;
};
};