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![Simon Glass](/assets/img/avatar_default.png)
Add a simple driver which allows use of LEDs attached to GPIOs. The linux device tree binding is used. Signed-off-by: Simon Glass <sjg@chromium.org>
53 lines
1.5 KiB
Plaintext
53 lines
1.5 KiB
Plaintext
LEDs connected to GPIO lines
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Required properties:
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- compatible : should be "gpio-leds".
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Each LED is represented as a sub-node of the gpio-leds device. Each
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node's name represents the name of the corresponding LED.
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LED sub-node properties:
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- gpios : Should specify the LED's GPIO, see "gpios property" in
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Documentation/devicetree/bindings/gpio/gpio.txt. Active low LEDs should be
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indicated using flags in the GPIO specifier.
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- label : (optional)
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see Documentation/devicetree/bindings/leds/common.txt
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- linux,default-trigger : (optional)
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see Documentation/devicetree/bindings/leds/common.txt
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- default-state: (optional) The initial state of the LED. Valid
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values are "on", "off", and "keep". If the LED is already on or off
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and the default-state property is set the to same value, then no
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glitch should be produced where the LED momentarily turns off (or
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on). The "keep" setting will keep the LED at whatever its current
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state is, without producing a glitch. The default is off if this
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property is not present.
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Examples:
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leds {
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compatible = "gpio-leds";
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hdd {
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label = "IDE Activity";
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gpios = <&mcu_pio 0 1>; /* Active low */
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linux,default-trigger = "ide-disk";
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};
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fault {
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gpios = <&mcu_pio 1 0>;
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/* Keep LED on if BIOS detected hardware fault */
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default-state = "keep";
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};
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};
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run-control {
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compatible = "gpio-leds";
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red {
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gpios = <&mpc8572 6 0>;
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default-state = "off";
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};
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green {
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gpios = <&mpc8572 7 0>;
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default-state = "on";
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};
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};
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