diff options
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 000000000000..064db928c3c1 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/led.txt | |||
@@ -0,0 +1,58 @@ | |||
1 | LEDs connected to GPIO lines | ||
2 | |||
3 | Required properties: | ||
4 | - compatible : should be "gpio-leds". | ||
5 | |||
6 | Each LED is represented as a sub-node of the gpio-leds device. Each | ||
7 | node's name represents the name of the corresponding LED. | ||
8 | |||
9 | LED 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 | |||
31 | Examples: | ||
32 | |||
33 | leds { | ||
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 | |||
48 | run-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 | } | ||