59 lines
1.9 KiB
Plaintext
59 lines
1.9 KiB
Plaintext
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";
|
|
};
|
|
}
|