From 8318fde4ac78f6793b1cbaf57659902253a61617 Mon Sep 17 00:00:00 2001 From: Jingoo Han Date: Wed, 3 Jul 2013 15:05:13 -0700 Subject: [PATCH] backlight: add devm_backlight_device_{register,unregister}() These functions allow the driver core to automatically clean up any allocation made by backlight 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/backlight.c | 75 +++++++++++++++++++++++++++++++++++++ include/linux/backlight.h | 6 +++ 2 files changed, 81 insertions(+) diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index e3c2790..53c52fb 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -370,6 +370,81 @@ void backlight_device_unregister(struct backlight_device *bd) } EXPORT_SYMBOL(backlight_device_unregister); +static void devm_backlight_device_release(struct device *dev, void *res) +{ + struct backlight_device *backlight = *(struct backlight_device **)res; + + backlight_device_unregister(backlight); +} + +static int devm_backlight_device_match(struct device *dev, void *res, + void *data) +{ + struct backlight_device **r = res; + + return *r == data; +} + +/** + * devm_backlight_device_register - resource managed backlight_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 backlight operations structure + * @props: the backlight properties + * + * @return a struct backlight on success, or an ERR_PTR on error + * + * Managed backlight_device_register(). The backlight_device returned + * from this function are automatically freed on driver detach. + * See backlight_device_register() for more information. + */ +struct backlight_device *devm_backlight_device_register(struct device *dev, + const char *name, struct device *parent, void *devdata, + const struct backlight_ops *ops, + const struct backlight_properties *props) +{ + struct backlight_device **ptr, *backlight; + + ptr = devres_alloc(devm_backlight_device_release, sizeof(*ptr), + GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + backlight = backlight_device_register(name, parent, devdata, ops, + props); + if (!IS_ERR(backlight)) { + *ptr = backlight; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return backlight; +} +EXPORT_SYMBOL(devm_backlight_device_register); + +/** + * devm_backlight_device_unregister - resource managed backlight_device_unregister() + * @dev: the device to unregister + * @bd: the backlight device to unregister + * + * Deallocated a backlight allocated with devm_backlight_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_backlight_device_unregister(struct device *dev, + struct backlight_device *bd) +{ + int rc; + + rc = devres_release(dev, devm_backlight_device_release, + devm_backlight_device_match, bd); + WARN_ON(rc); +} +EXPORT_SYMBOL(devm_backlight_device_unregister); + #ifdef CONFIG_OF static int of_parent_match(struct device *dev, const void *data) { diff --git a/include/linux/backlight.h b/include/linux/backlight.h index da9a082..53b7794 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -114,7 +114,13 @@ static inline void backlight_update_status(struct backlight_device *bd) extern struct backlight_device *backlight_device_register(const char *name, struct device *dev, void *devdata, const struct backlight_ops *ops, const struct backlight_properties *props); +extern struct backlight_device *devm_backlight_device_register( + struct device *dev, const char *name, struct device *parent, + void *devdata, const struct backlight_ops *ops, + const struct backlight_properties *props); extern void backlight_device_unregister(struct backlight_device *bd); +extern void devm_backlight_device_unregister(struct device *dev, + struct backlight_device *bd); extern void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason); -- 2.7.4