Message ID | 643f71d13d2466b14d7218282b8319f69680bd3d.1516098341.git.meghana.madhyastha@gmail.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Den 16.01.2018 11.33, skrev Meghana Madhyastha: > 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. > > Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com> > --- > Changes in v16: > -Add comment about brightness in of_find_backlight > > drivers/video/backlight/backlight.c | 40 +++++++++++++++++++++++++++++++++++++ > include/linux/backlight.h | 19 ++++++++++++++++++ > 2 files changed, 59 insertions(+) > > diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c > index 8049e7656..7e4a5d77d 100644 > --- a/drivers/video/backlight/backlight.c > +++ b/drivers/video/backlight/backlight.c > @@ -580,6 +580,46 @@ 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. > + * gpio_backlight uses brightness as power state during probe. I was thinking the gpio_backlight issue to be a comment with the code, not the docs. Isn't this sentence a bit confusing as part of the docs? checkpatch complains: -:21: WARNING: Block comments should align the * on each line -:72: WARNING: Block comments should align the * on each line Noralf. > + * > + * 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); > + 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); > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 7b6a9a2a3..32ea510da 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -160,6 +160,16 @@ static inline int backlight_disable(struct backlight_device *bd) > return backlight_update_status(bd); > } > > +/** > + * backlight_put - Drop backlight reference > + * @bd: the backlight device to put > + */ > +static inline void backlight_put(struct backlight_device *bd) > +{ > + if (bd) > + put_device(&bd->dev); > +} > + > 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); > @@ -203,4 +213,13 @@ of_find_backlight_by_node(struct device_node *node) > } > #endif > > +#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) > +struct backlight_device *of_find_backlight(struct device *dev); > +#else > +static inline struct backlight_device *of_find_backlight(struct device *dev) > +{ > + return NULL; > +} > +#endif > + > #endif
On 16/01/18 10:33, Meghana Madhyastha wrote: > 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. > > Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> > --- > Changes in v16: > -Add comment about brightness in of_find_backlight > > drivers/video/backlight/backlight.c | 40 +++++++++++++++++++++++++++++++++++++ > include/linux/backlight.h | 19 ++++++++++++++++++ > 2 files changed, 59 insertions(+) > > diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c > index 8049e7656..7e4a5d77d 100644 > --- a/drivers/video/backlight/backlight.c > +++ b/drivers/video/backlight/backlight.c > @@ -580,6 +580,46 @@ 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. > + * gpio_backlight uses brightness as power state during probe. > + * > + * 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); > + 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); > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 7b6a9a2a3..32ea510da 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -160,6 +160,16 @@ static inline int backlight_disable(struct backlight_device *bd) > return backlight_update_status(bd); > } > > +/** > + * backlight_put - Drop backlight reference > + * @bd: the backlight device to put > + */ > +static inline void backlight_put(struct backlight_device *bd) > +{ > + if (bd) > + put_device(&bd->dev); > +} > + > 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); > @@ -203,4 +213,13 @@ of_find_backlight_by_node(struct device_node *node) > } > #endif > > +#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) > +struct backlight_device *of_find_backlight(struct device *dev); > +#else > +static inline struct backlight_device *of_find_backlight(struct device *dev) > +{ > + return NULL; > +} > +#endif > + > #endif >
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 8049e7656..7e4a5d77d 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -580,6 +580,46 @@ 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. + * gpio_backlight uses brightness as power state during probe. + * + * 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); + 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); diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 7b6a9a2a3..32ea510da 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -160,6 +160,16 @@ static inline int backlight_disable(struct backlight_device *bd) return backlight_update_status(bd); } +/** + * backlight_put - Drop backlight reference + * @bd: the backlight device to put + */ +static inline void backlight_put(struct backlight_device *bd) +{ + if (bd) + put_device(&bd->dev); +} + 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); @@ -203,4 +213,13 @@ of_find_backlight_by_node(struct device_node *node) } #endif +#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) +struct backlight_device *of_find_backlight(struct device *dev); +#else +static inline struct backlight_device *of_find_backlight(struct device *dev) +{ + return NULL; +} +#endif + #endif
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. Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com> --- Changes in v16: -Add comment about brightness in of_find_backlight drivers/video/backlight/backlight.c | 40 +++++++++++++++++++++++++++++++++++++ include/linux/backlight.h | 19 ++++++++++++++++++ 2 files changed, 59 insertions(+)