From e389240ad99292d52a4f8ff30f16830dc9c63779 Mon Sep 17 00:00:00 2001 From: Jean-Jacques Hiblot Date: Thu, 3 Oct 2019 10:28:10 +0200 Subject: [PATCH] leds: Add managed API to get a LED from a device driver If the LED is acquired by a consumer device with devm_led_get(), it is automatically released when the device is detached. Signed-off-by: Jean-Jacques Hiblot Acked-by: Pavel Machek Signed-off-by: Pavel Machek --- drivers/leds/led-class.c | 49 ++++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 2 ++ 2 files changed, 51 insertions(+) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 03ce74a2e6a9..0868f841d656 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -258,6 +258,55 @@ void led_put(struct led_classdev *led_cdev) } EXPORT_SYMBOL_GPL(led_put); +static void devm_led_release(struct device *dev, void *res) +{ + struct led_classdev **p = res; + + led_put(*p); +} + +/** + * devm_of_led_get - Resource-managed request of a LED device + * @dev: LED consumer + * @index: index of the LED to obtain in the consumer + * + * The device node of the device is parse to find the request LED device. + * The LED device returned from this function is automatically released + * on driver detach. + * + * @return a pointer to a LED device or ERR_PTR(errno) on failure. + */ +struct led_classdev *__must_check devm_of_led_get(struct device *dev, + int index) +{ + struct led_classdev *led; + struct led_classdev **dr; + + if (!dev) + return ERR_PTR(-EINVAL); + + /* Not using device tree? */ + if (!IS_ENABLED(CONFIG_OF) || !dev->of_node) + return ERR_PTR(-ENOTSUPP); + + led = of_led_get(dev->of_node, index); + if (IS_ERR(led)) + return led; + + dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), + GFP_KERNEL); + if (!dr) { + led_put(led); + return ERR_PTR(-ENOMEM); + } + + *dr = led; + devres_add(dev, dr); + + return led; +} +EXPORT_SYMBOL_GPL(devm_of_led_get); + static int led_classdev_next_name(const char *init_name, char *name, size_t len) { diff --git a/include/linux/leds.h b/include/linux/leds.h index dcfb6a325866..75353e5f9d13 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -199,6 +199,8 @@ void led_classdev_resume(struct led_classdev *led_cdev); extern struct led_classdev *of_led_get(struct device_node *np, int index); extern void led_put(struct led_classdev *led_cdev); +struct led_classdev *__must_check devm_of_led_get(struct device *dev, + int index); /** * led_blink_set - set blinking with software fallback -- 2.30.2