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

Zhang Rui
2015-01-05T06:51:56Z

On Mon, 2015-01-05 at 15:20 +0900, Jingoo Han wrote:
> On Monday, January 05, 2015 3:01 PM, Zhang Rui wrote:
> > 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?
>
> Hi Zhang Rui,
>
> I would like you to take the whole patch set.
> This is because 3rd patch makes the build error
> without 1st & 2nd patches. Thank you.
>
okay, thanks!

-rui

> Best regards,
> Jingoo Han
>
> >
> > 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
> > > >
> > >
>
>