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Diffstat (limited to 'Documentation/devicetree/bindings/gpio/led.txt')
-rw-r--r-- | Documentation/devicetree/bindings/gpio/led.txt | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/led.txt b/Documentation/devicetree/bindings/gpio/led.txt new file mode 100644 index 00000000000..064db928c3c --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/led.txt @@ -0,0 +1,58 @@ +LEDs connected to GPIO lines + +Required properties: +- compatible : should be "gpio-leds". + +Each LED is represented as a sub-node of the gpio-leds device. Each +node's name represents the name of the corresponding LED. + +LED sub-node properties: +- gpios : Should specify the LED's GPIO, see "Specifying GPIO information + for devices" in Documentation/powerpc/booting-without-of.txt. Active + low LEDs should be indicated using flags in the GPIO specifier. +- label : (optional) The label for this LED. If omitted, the label is + taken from the node name (excluding the unit address). +- linux,default-trigger : (optional) This parameter, if present, is a + string defining the trigger assigned to the LED. Current triggers are: + "backlight" - LED will act as a back-light, controlled by the framebuffer + system + "default-on" - LED will turn on, but see "default-state" below + "heartbeat" - LED "double" flashes at a load average based rate + "ide-disk" - LED indicates disk activity + "timer" - LED flashes at a fixed, configurable rate +- default-state: (optional) The initial state of the LED. Valid + values are "on", "off", and "keep". If the LED is already on or off + and the default-state property is set the to same value, then no + glitch should be produced where the LED momentarily turns off (or + on). The "keep" setting will keep the LED at whatever its current + state is, without producing a glitch. The default is off if this + property is not present. + +Examples: + +leds { + compatible = "gpio-leds"; + hdd { + label = "IDE Activity"; + gpios = <&mcu_pio 0 1>; /* Active low */ + linux,default-trigger = "ide-disk"; + }; + + fault { + gpios = <&mcu_pio 1 0>; + /* Keep LED on if BIOS detected hardware fault */ + default-state = "keep"; + }; +}; + +run-control { + compatible = "gpio-leds"; + red { + gpios = <&mpc8572 6 0>; + default-state = "off"; + }; + green { + gpios = <&mpc8572 7 0>; + default-state = "on"; + }; +} |