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

Zhang Rui
2015-01-05T06:01:23Z

On Mon, 2015-01-05 at 13:46 +0800, Aaron Lu wrote:
> 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>
>
So Jingoo and Lee, will you take the first two patches, or you'd like me
the take the whole patch set?

thanks,
rui
> 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
> >
>