From f5808ac158f2b16b686a3d3c0879c5d6048aba14 Mon Sep 17 00:00:00 2001 From: Andrew Jeffery Date: Mon, 28 Aug 2017 09:47:11 +0930 Subject: [PATCH] leds: gpio: Allow LED to retain state at shutdown In some systems, such as Baseboard Management Controllers (BMCs), we want to retain the state of LEDs across a reboot of the BMC (whilst the host remains up). Implement support for the retain-state-shutdown devicetree property in leds-gpio. Signed-off-by: Andrew Jeffery Acked-by: Pavel Machek Tested-by: Brandon Wyman Signed-off-by: Jacek Anaszewski --- drivers/leds/leds-gpio.c | 7 ++++++- include/linux/leds.h | 2 ++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c index e753ba93ba1e..764c31301f90 100644 --- a/drivers/leds/leds-gpio.c +++ b/drivers/leds/leds-gpio.c @@ -134,6 +134,8 @@ static int create_gpio_led(const struct gpio_led *template, led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; if (template->panic_indicator) led_dat->cdev.flags |= LED_PANIC_INDICATOR; + if (template->retain_state_shutdown) + led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; ret = gpiod_direction_output(led_dat->gpiod, state); if (ret < 0) @@ -205,6 +207,8 @@ 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, "retain-state-shutdown")) + led.retain_state_shutdown = 1; if (fwnode_property_present(child, "panic-indicator")) led.panic_indicator = 1; @@ -267,7 +271,8 @@ static void gpio_led_shutdown(struct platform_device *pdev) for (i = 0; i < priv->num_leds; i++) { struct gpio_led_data *led = &priv->leds[i]; - gpio_led_set(&led->cdev, LED_OFF); + if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) + gpio_led_set(&led->cdev, LED_OFF); } } diff --git a/include/linux/leds.h b/include/linux/leds.h index 64c56d454f7d..bf6db4fe895b 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -49,6 +49,7 @@ struct led_classdev { #define LED_HW_PLUGGABLE (1 << 19) #define LED_PANIC_INDICATOR (1 << 20) #define LED_BRIGHT_HW_CHANGED (1 << 21) +#define LED_RETAIN_AT_SHUTDOWN (1 << 22) /* set_brightness_work / blink_timer flags, atomic, private. */ unsigned long work_flags; @@ -392,6 +393,7 @@ struct gpio_led { unsigned retain_state_suspended : 1; unsigned panic_indicator : 1; unsigned default_state : 2; + unsigned retain_state_shutdown : 1; /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */ struct gpio_desc *gpiod; };