linux-kernel - Re: [PATCH v2 3/3] leds: gpio: Support the "panic-indicator" firmware property

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Message-id: <570F5B6B.3000702@samsung.com>
Date:	Thu, 14 Apr 2016 10:57:15 +0200
From:	Jacek Anaszewski <j.anaszewski@...sung.com>
To:	Ezequiel Garcia <ezequiel@...guardiasur.com.ar>
Cc:	linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
	Richard Purdie <rpurdie@...ys.net>,
	Kumar Gala <galak@...eaurora.org>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Mark Rutland <mark.rutland@....com>,
	Pawel Moll <pawel.moll@....com>,
	Rob Herring <robh+dt@...nel.org>
Subject: Re: [PATCH v2 3/3] leds: gpio: Support the "panic-indicator" firmware
 property

Hi Ezequiel,

It would be good to update also leds-gpio bindings,
of course in a separate patch:

Documentation/devicetree/bindings/leds/leds-gpio.txt

Thanks,
Jacek Anaszewski

On 04/13/2016 08:08 PM, Ezequiel Garcia wrote:
> 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@...guardiasur.com.ar>
> ---
>   drivers/leds/leds-gpio.c | 4 ++++
>   include/linux/leds.h     | 1 +
>   2 files changed, 5 insertions(+)
>
> 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 49adf9c6e326..1067fb5f9296 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -359,6 +359,7 @@ 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;
>