From 1d0c48e66b3f1cf40660f69a87f55af3df0b2ae3 Mon Sep 17 00:00:00 2001 From: Jingoo Han Date: Wed, 3 Jul 2013 15:05:14 -0700 Subject: [PATCH] lcd: add devm_lcd_device_{register,unregister}() These functions allow the driver core to automatically clean up any allocation made by lcd drivers. Thus it simplifies the error paths. Signed-off-by: Jingoo Han Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/backlight/lcd.c | 70 +++++++++++++++++++++++++++++++++++++++++++ include/linux/lcd.h | 5 ++++ 2 files changed, 75 insertions(+) diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c index 3649fd9..41964a7 100644 --- a/drivers/video/backlight/lcd.c +++ b/drivers/video/backlight/lcd.c @@ -260,6 +260,76 @@ void lcd_device_unregister(struct lcd_device *ld) } EXPORT_SYMBOL(lcd_device_unregister); +static void devm_lcd_device_release(struct device *dev, void *res) +{ + struct lcd_device *lcd = *(struct lcd_device **)res; + + lcd_device_unregister(lcd); +} + +static int devm_lcd_device_match(struct device *dev, void *res, void *data) +{ + struct lcd_device **r = res; + + return *r == data; +} + +/** + * devm_lcd_device_register - resource managed lcd_device_register() + * @dev: the device to register + * @name: the name of the device + * @parent: a pointer to the parent device + * @devdata: an optional pointer to be stored for private driver use + * @ops: the lcd operations structure + * + * @return a struct lcd on success, or an ERR_PTR on error + * + * Managed lcd_device_register(). The lcd_device returned from this function + * are automatically freed on driver detach. See lcd_device_register() + * for more information. + */ +struct lcd_device *devm_lcd_device_register(struct device *dev, + const char *name, struct device *parent, + void *devdata, struct lcd_ops *ops) +{ + struct lcd_device **ptr, *lcd; + + ptr = devres_alloc(devm_lcd_device_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + lcd = lcd_device_register(name, parent, devdata, ops); + if (!IS_ERR(lcd)) { + *ptr = lcd; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return lcd; +} +EXPORT_SYMBOL(devm_lcd_device_register); + +/** + * devm_lcd_device_unregister - resource managed lcd_device_unregister() + * @dev: the device to unregister + * @ld: the lcd device to unregister + * + * Deallocated a lcd allocated with devm_lcd_device_register(). Normally + * this function will not need to be called and the resource management + * code will ensure that the resource is freed. + */ +void devm_lcd_device_unregister(struct device *dev, struct lcd_device *ld) +{ + int rc; + + rc = devres_release(dev, devm_lcd_device_release, + devm_lcd_device_match, ld); + WARN_ON(rc); +} +EXPORT_SYMBOL(devm_lcd_device_unregister); + + static void __exit lcd_class_exit(void) { class_destroy(lcd_class); diff --git a/include/linux/lcd.h b/include/linux/lcd.h index e00c3b0..504f624 100644 --- a/include/linux/lcd.h +++ b/include/linux/lcd.h @@ -112,7 +112,12 @@ static inline void lcd_set_power(struct lcd_device *ld, int power) extern struct lcd_device *lcd_device_register(const char *name, struct device *parent, void *devdata, struct lcd_ops *ops); +extern struct lcd_device *devm_lcd_device_register(struct device *dev, + const char *name, struct device *parent, + void *devdata, struct lcd_ops *ops); extern void lcd_device_unregister(struct lcd_device *ld); +extern void devm_lcd_device_unregister(struct device *dev, + struct lcd_device *ld); #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev) -- 2.7.4