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authorPeter Ujfalusi <peter.ujfalusi@ti.com>2012-12-21 01:44:01 -0800
committerBryan Wu <cooloney@gmail.com>2013-02-01 17:47:05 -0800
commit08541cbcc7386fa78efb454a92ddbfb1a2859cf9 (patch)
tree288c9a3b4fcd689cb4551999afa39dbfa2fd0ee2 /Documentation/devicetree/bindings/leds
parent8a66a579083a20172a46e74d175a57621dccae0a (diff)
downloadvexpress-lsk-08541cbcc7386fa78efb454a92ddbfb1a2859cf9.tar.gz
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>
Diffstat (limited to 'Documentation/devicetree/bindings/leds')
-rw-r--r--Documentation/devicetree/bindings/leds/leds-pwm.txt48
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diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.txt b/Documentation/devicetree/bindings/leds/leds-pwm.txt
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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>;
+ };
+};