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linux/Documentation/devicetree/bindings/leds/leds-gpio.txt
Ezequiel Garcia 80d6737b27 leds: gpio: Support the "panic-indicator" firmware property
Calling a GPIO LEDs is quite likely to work even if the kernel
has paniced, so they are ideal to blink in this situation.
This commit adds support for the new "panic-indicator"
firmware property, allowing to mark a given LED to blink on
a kernel panic.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
2016-05-06 10:26:07 +02:00

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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 "gpios property" in
Documentation/devicetree/bindings/gpio/gpio.txt. Active low LEDs should be
indicated using flags in the GPIO specifier.
- label : (optional)
see Documentation/devicetree/bindings/leds/common.txt
- linux,default-trigger : (optional)
see Documentation/devicetree/bindings/leds/common.txt
- 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.
- retain-state-suspended: (optional) The suspend state can be retained.Such
as charge-led gpio.
- panic-indicator : (optional)
see Documentation/devicetree/bindings/leds/common.txt
Examples:
#include <dt-bindings/gpio/gpio.h>
leds {
compatible = "gpio-leds";
hdd {
label = "IDE Activity";
gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW>;
linux,default-trigger = "ide-disk";
};
fault {
gpios = <&mcu_pio 1 GPIO_ACTIVE_HIGH>;
/* Keep LED on if BIOS detected hardware fault */
default-state = "keep";
};
};
run-control {
compatible = "gpio-leds";
red {
gpios = <&mpc8572 6 GPIO_ACTIVE_HIGH>;
default-state = "off";
};
green {
gpios = <&mpc8572 7 GPIO_ACTIVE_HIGH>;
default-state = "on";
};
};
leds {
compatible = "gpio-leds";
charger-led {
gpios = <&gpio1 2 GPIO_ACTIVE_HIGH>;
linux,default-trigger = "max8903-charger-charging";
retain-state-suspended;
};
};