On Wednesday, December 31, 2014 12:50 PM, Aaron Lu wrote:
>
> It is useful to get the backlight device's pointer and use it to set
> backlight in some cases(the following patch will make use of it) so add
> the two APIs and export them.
>
> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
Acked-by: Jingoo Han <jg1.han@xxxxxxxxxxx>
Best regards,
Jingoo Han
> ---
> drivers/video/backlight/backlight.c | 44 ++++++++++++++++++++++++-------------
> include/linux/backlight.h | 2 ++
> 2 files changed, 31 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
> index bddc8b17a4d8..bea749329236 100644
> --- a/drivers/video/backlight/backlight.c
> +++ b/drivers/video/backlight/backlight.c
> @@ -164,28 +164,19 @@ static ssize_t brightness_show(struct device *dev,
> return sprintf(buf, "%d\n", bd->props.brightness);
> }
>
> -static ssize_t brightness_store(struct device *dev,
> - struct device_attribute *attr, const char *buf, size_t count)
> +int backlight_device_set_brightness(struct backlight_device *bd, int brightness)
> {
> - int rc;
> - struct backlight_device *bd = to_backlight_device(dev);
> - unsigned long brightness;
> -
> - rc = kstrtoul(buf, 0, &brightness);
> - if (rc)
> - return rc;
> -
> - rc = -ENXIO;
> + int rc = -ENXIO;
>
> mutex_lock(&bd->ops_lock);
> if (bd->ops) {
> if (brightness > bd->props.max_brightness)
> rc = -EINVAL;
> else {
> - pr_debug("set brightness to %lu\n", brightness);
> + pr_debug("set brightness to %u\n", brightness);
> bd->props.brightness = brightness;
> backlight_update_status(bd);
> - rc = count;
> + rc = 0;
> }
> }
> mutex_unlock(&bd->ops_lock);
> @@ -194,6 +185,23 @@ static ssize_t brightness_store(struct device *dev,
>
> return rc;
> }
> +EXPORT_SYMBOL(backlight_device_set_brightness);
> +
> +static ssize_t brightness_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + int rc;
> + struct backlight_device *bd = to_backlight_device(dev);
> + unsigned long brightness;
> +
> + rc = kstrtoul(buf, 0, &brightness);
> + if (rc)
> + return rc;
> +
> + rc = backlight_device_set_brightness(bd, brightness);
> +
> + return rc ? rc : count;
> +}
> static DEVICE_ATTR_RW(brightness);
>
> static ssize_t type_show(struct device *dev, struct device_attribute *attr,
> @@ -380,7 +388,7 @@ struct backlight_device *backlight_device_register(const char *name,
> }
> EXPORT_SYMBOL(backlight_device_register);
>
> -bool backlight_device_registered(enum backlight_type type)
> +struct backlight_device *backlight_device_get_by_type(enum backlight_type type)
> {
> bool found = false;
> struct backlight_device *bd;
> @@ -394,7 +402,13 @@ bool backlight_device_registered(enum backlight_type type)
> }
> mutex_unlock(&backlight_dev_list_mutex);
>
> - return found;
> + return found ? bd : NULL;
> +}
> +EXPORT_SYMBOL(backlight_device_get_by_type);
> +
> +bool backlight_device_registered(enum backlight_type type)
> +{
> + return backlight_device_get_by_type(type) ? true : false;
> }
> EXPORT_SYMBOL(backlight_device_registered);
>
> diff --git a/include/linux/backlight.h b/include/linux/backlight.h
> index adb14a8616df..c59a020df3f8 100644
> --- a/include/linux/backlight.h
> +++ b/include/linux/backlight.h
> @@ -140,6 +140,8 @@ extern void backlight_force_update(struct backlight_device *bd,
> extern bool backlight_device_registered(enum backlight_type type);
> extern int backlight_register_notifier(struct notifier_block *nb);
> extern int backlight_unregister_notifier(struct notifier_block *nb);
> +extern struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
> +extern int backlight_device_set_brightness(struct backlight_device *bd, int brightness);
>
> #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
>
> --
> 2.1.0
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