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1LEDs connected to GPIO lines
2
3Required properties:
4- compatible : should be "gpio-leds".
5
6Each LED is represented as a sub-node of the gpio-leds device. Each
7node's name represents the name of the corresponding LED.
8
9LED sub-node properties:
10- gpios : Should specify the LED's GPIO, see "Specifying GPIO information
11 for devices" in Documentation/powerpc/booting-without-of.txt. Active
12 low LEDs should be indicated using flags in the GPIO specifier.
13- label : (optional) The label for this LED. If omitted, the label is
14 taken from the node name (excluding the unit address).
15- linux,default-trigger : (optional) This parameter, if present, is a
16 string defining the trigger assigned to the LED. Current triggers are:
17 "backlight" - LED will act as a back-light, controlled by the framebuffer
18 system
19 "default-on" - LED will turn on, but see "default-state" below
20 "heartbeat" - LED "double" flashes at a load average based rate
21 "ide-disk" - LED indicates disk activity
22 "timer" - LED flashes at a fixed, configurable rate
23- default-state: (optional) The initial state of the LED. Valid
24 values are "on", "off", and "keep". If the LED is already on or off
25 and the default-state property is set the to same value, then no
26 glitch should be produced where the LED momentarily turns off (or
27 on). The "keep" setting will keep the LED at whatever its current
28 state is, without producing a glitch. The default is off if this
29 property is not present.
30
31Examples:
32
33leds {
34 compatible = "gpio-leds";
35 hdd {
36 label = "IDE Activity";
37 gpios = <&mcu_pio 0 1>; /* Active low */
38 linux,default-trigger = "ide-disk";
39 };
40
41 fault {
42 gpios = <&mcu_pio 1 0>;
43 /* Keep LED on if BIOS detected hardware fault */
44 default-state = "keep";
45 };
46};
47
48run-control {
49 compatible = "gpio-leds";
50 red {
51 gpios = <&mpc8572 6 0>;
52 default-state = "off";
53 };
54 green {
55 gpios = <&mpc8572 7 0>;
56 default-state = "on";
57 };
58}