projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| a7d878af | 1 | LEDs connected to GPIO lines |
| 89ae5b2b AV |
2 | |
| 3 | Required properties: | |
| a7d878af TP |
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 | |
| 89ae5b2b | 14 | taken from the node name (excluding the unit address). |
| a7d878af TP |
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 | |
| ed88bae6 | 19 | "default-on" - LED will turn on, but see "default-state" below |
| a7d878af TP |
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 | |
| ed88bae6 TP |
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. | |
| 89ae5b2b | 30 | |
| a7d878af | 31 | Examples: |
| 89ae5b2b | 32 | |
| a7d878af TP |
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 | }; | |
| ed88bae6 TP |
40 | |
| 41 | fault { | |
| 42 | gpios = <&mcu_pio 1 0>; | |
| 43 | /* Keep LED on if BIOS detected hardware fault */ | |
| 44 | default-state = "keep"; | |
| 45 | }; | |
| 89ae5b2b | 46 | }; |
| a7d878af TP |
47 | |
| 48 | run-control { | |
| 49 | compatible = "gpio-leds"; | |
| 50 | red { | |
| 51 | gpios = <&mpc8572 6 0>; | |
| ed88bae6 | 52 | default-state = "off"; |
| a7d878af TP |
53 | }; |
| 54 | green { | |
| 55 | gpios = <&mpc8572 7 0>; | |
| ed88bae6 | 56 | default-state = "on"; |
| a7d878af TP |
57 | }; |
| 58 | } |