| Message ID | 20191007124437.20367-4-jjhiblot@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add a generic driver for LED-based backlight | expand |
Hi! > 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 <jjhiblot@ti.com> > Acked-by: Pavel Machek <pavel@ucw.cz> > --- > 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 1d1f1d546dc7..639224392ffa 100644 > --- a/drivers/leds/led-class.c > +++ b/drivers/leds/led-class.c > @@ -264,6 +264,55 @@ 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); > + > + /* Consummer not using device tree? */ Typo "consumer". I may fix it before applying the patch. Best regards, Pavel
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 1d1f1d546dc7..639224392ffa 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -264,6 +264,55 @@ 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); + + /* Consummer not using device tree? */ + if (!dev_of_node(dev)) + return ERR_PTR(-ENOTSUPP); + + led = of_led_get(dev_of_node(dev), 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 6f7371bc7757..9b94cf752012 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -199,6 +199,8 @@ extern 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