From c2adda27d202fa8f70a5d6e8b0c12b449c8868b8 Mon Sep 17 00:00:00 2001 From: Meghana Madhyastha Date: Wed, 24 Jan 2018 16:35:30 +0000 Subject: video: backlight: Add of_find_backlight helper in backlight.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add of_find_backlight, a helper function which is a generic version of tinydrm_of_find_backlight that can be used by other drivers to avoid repetition of code and simplify things. Acked-by: Daniel Thompson Reviewed-by: Noralf Trønnes Reviewed-by: Sean Paul Reviewed-by: Thierry Reding Signed-off-by: Meghana Madhyastha Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/116d160ba78be2e6dcbdcb6855622bce67da9472.1516810725.git.meghana.madhyastha@gmail.com --- drivers/video/backlight/backlight.c | 43 +++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'drivers/video') diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 8049e7656daa..553bf5c4807c 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -580,6 +580,49 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node) EXPORT_SYMBOL(of_find_backlight_by_node); #endif +/** + * of_find_backlight - Get backlight device + * @dev: Device + * + * This function looks for a property named 'backlight' on the DT node + * connected to @dev and looks up the backlight device. + * + * Call backlight_put() to drop the reference on the backlight device. + * + * Returns: + * A pointer to the backlight device if found. + * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight + * device is found. + * NULL if there's no backlight property. + */ +struct backlight_device *of_find_backlight(struct device *dev) +{ + struct backlight_device *bd = NULL; + struct device_node *np; + + if (!dev) + return NULL; + + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { + np = of_parse_phandle(dev->of_node, "backlight", 0); + if (np) { + bd = of_find_backlight_by_node(np); + of_node_put(np); + if (!bd) + return ERR_PTR(-EPROBE_DEFER); + /* + * Note: gpio_backlight uses brightness as + * power state during probe + */ + if (!bd->props.brightness) + bd->props.brightness = bd->props.max_brightness; + } + } + + return bd; +} +EXPORT_SYMBOL(of_find_backlight); + static void __exit backlight_class_exit(void) { class_destroy(backlight_class); -- cgit v1.2.3 From 2e4ef3347b4a4eb65c4fd950d94bbd75fed4d798 Mon Sep 17 00:00:00 2001 From: Meghana Madhyastha Date: Wed, 24 Jan 2018 16:37:23 +0000 Subject: video: backlight: Add devres versions of of_find_backlight MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add devm_of_find_backlight and the corresponding release function because some drivers use devres versions of functions for acquiring device resources. Acked-by: Daniel Thompson Reviewed-by: Noralf Trønnes Reviewed-by: Sean Paul Signed-off-by: Meghana Madhyastha Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/021f8fecfa3f374dc5dcb70fb07a6f6b019bea7b.1516810725.git.meghana.madhyastha@gmail.com --- drivers/video/backlight/backlight.c | 30 ++++++++++++++++++++++++++++++ include/linux/backlight.h | 7 +++++++ 2 files changed, 37 insertions(+) (limited to 'drivers/video') diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 553bf5c4807c..deb824bef6e2 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -623,6 +623,36 @@ struct backlight_device *of_find_backlight(struct device *dev) } EXPORT_SYMBOL(of_find_backlight); +static void devm_backlight_release(void *data) +{ + backlight_put(data); +} + +/** + * devm_of_find_backlight - Resource-managed of_find_backlight() + * @dev: Device + * + * Device managed version of of_find_backlight(). + * The reference on the backlight device is automatically + * dropped on driver detach. + */ +struct backlight_device *devm_of_find_backlight(struct device *dev) +{ + struct backlight_device *bd; + int ret; + + bd = of_find_backlight(dev); + if (IS_ERR_OR_NULL(bd)) + return bd; + ret = devm_add_action(dev, devm_backlight_release, bd); + if (ret) { + backlight_put(bd); + return ERR_PTR(ret); + } + return bd; +} +EXPORT_SYMBOL(devm_of_find_backlight); + static void __exit backlight_class_exit(void) { class_destroy(backlight_class); diff --git a/include/linux/backlight.h b/include/linux/backlight.h index ddc9bade4fb2..2baab6f3861d 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -217,11 +217,18 @@ of_find_backlight_by_node(struct device_node *node) #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) struct backlight_device *of_find_backlight(struct device *dev); +struct backlight_device *devm_of_find_backlight(struct device *dev); #else static inline struct backlight_device *of_find_backlight(struct device *dev) { return NULL; } + +static inline struct backlight_device * +devm_of_find_backlight(struct device *dev) +{ + return NULL; +} #endif #endif -- cgit v1.2.3