Re: [PATCH 1/3] video / backlight: add two APIs for drivers to use

Aaron Lu
2015-01-05T05:46:39Z

On 01/03/2015 09:04 AM, Jingoo Han wrote:
> 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@intel.com>
>
> Acked-by: Jingoo Han <jg1.han@samsung.com>

Thanks for the review!

Regards,
Aaron

>
> 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
>