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 <[email protected]> --- Documentation/devicetree/bindings/leds/leds-gpio.txt | 2 ++ drivers/leds/leds-gpio.c | 4 ++++ include/linux/leds.h | 1 + 3 files changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/leds/leds-gpio.txt b/Documentation/devicetree/bindings/leds/leds-gpio.txt index fea1ebfe24a9..cbbeb1850910 100644 --- a/Documentation/devicetree/bindings/leds/leds-gpio.txt +++ b/Documentation/devicetree/bindings/leds/leds-gpio.txt @@ -23,6 +23,8 @@ LED sub-node properties: 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: diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c index 61143f55597e..8229f063b483 100644 --- a/drivers/leds/leds-gpio.c +++ b/drivers/leds/leds-gpio.c @@ -127,6 +127,8 @@ static int create_gpio_led(const struct gpio_led *template, led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; if (!template->retain_state_suspended) led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; + if (template->panic_indicator) + led_dat->cdev.flags |= LED_PANIC_INDICATOR; ret = gpiod_direction_output(led_dat->gpiod, state); if (ret < 0) @@ -200,6 +202,8 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) if (fwnode_property_present(child, "retain-state-suspended")) led.retain_state_suspended = 1; + if (fwnode_property_present(child, "panic-indicator")) + led.panic_indicator = 1; ret = create_gpio_led(&led, &priv->leds[priv->num_leds], dev, NULL); diff --git a/include/linux/leds.h b/include/linux/leds.h index 7e9fb00e15e8..d2b13066e781 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -365,6 +365,7 @@ struct gpio_led { unsigned gpio; unsigned active_low : 1; unsigned retain_state_suspended : 1; + unsigned panic_indicator : 1; unsigned default_state : 2; /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */ struct gpio_desc *gpiod; -- 2.7.0
