59 lines
1.9 KiB
Plaintext
59 lines
1.9 KiB
Plaintext
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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 "Specifying GPIO information
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for devices" in Documentation/powerpc/booting-without-of.txt. Active
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low LEDs should be indicated using flags in the GPIO specifier.
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- label : (optional) The label for this LED. If omitted, the label is
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taken from the node name (excluding the unit address).
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- linux,default-trigger : (optional) This parameter, if present, is a
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string defining the trigger assigned to the LED. Current triggers are:
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"backlight" - LED will act as a back-light, controlled by the framebuffer
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system
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"default-on" - LED will turn on, but see "default-state" below
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"heartbeat" - LED "double" flashes at a load average based rate
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"ide-disk" - LED indicates disk activity
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"timer" - LED flashes at a fixed, configurable rate
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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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