On Fri, Jan 19, 2018 at 10:44:33AM +0000, Meghana Madhyastha wrote:
> Add devm_of_find_backlight and the corresponding release
> function because some drivers use devres versions of functions
> for acquiring device resources.
>
> Signed-off-by: Meghana Madhyastha <meghana.madhyas...@gmail.com>
Acked-by: Daniel Thompson <daniel.thomp...@linaro.org>
> ---
> changes in v17:
> -fix checkpath errors/warnings
> -rename devm_backlight_put to
> devm_backlight_release
>
> drivers/video/backlight/backlight.c | 30 ++++++++++++++++++++++++++++++
> include/linux/backlight.h | 7 +++++++
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/video/backlight/backlight.c
> b/drivers/video/backlight/backlight.c
> index 553bf5c48..deb824bef 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 ddc9bade4..2baab6f38 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
> --
> 2.11.0
>
