linux/Documentation/devicetree/bindings/leds/leds-pwm.txt
Peter Ujfalusi 08541cbcc7 leds: leds-pwm: Add device tree bindings
The DT binding for the pwm-leds devices are similar to the gpio-leds type.
LEDs are represented as sub-nodes of the pwm-leds device.
The code for handling the DT boot is based on the code found in the
leds-gpio driver and adapted to use PWMs instead of GPIOs.
To avoid having custom cleanup code in case of DT boot the newly created
devm_of_pwm_get() API is used to get the correct PWM instance.

For usage see:
Documentation/devicetree/bindings/leds/leds-pwm.txt

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-02-01 17:47:05 -08:00

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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
- 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>;
};
};