Messages in this thread | | | Subject | Re: [PATCH v16 01/10] video: backlight: Add helpers to enable and disable backlight | From | Daniel Thompson <> | Date | Wed, 17 Jan 2018 17:00:27 +0000 |
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On 16/01/18 10:31, Meghana Madhyastha wrote: > Add helper functions backlight_enable and backlight_disable to > enable/disable a backlight device. These helper functions can > then be used by different drm and tinydrm drivers to avoid > repetition of code and also to enforce a uniform and consistent > way to enable/disable a backlight device. > > Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com>
To be clear I don't disagree with anthing Daniel V. said about the horribly confused (and confusing) power states for backlight.
Nevertheless I don't recall seeing any response (positive or negative) to this post from v13: https://www.spinics.net/lists/dri-devel/msg154459.html
Daniel.
> --- > include/linux/backlight.h | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index af7003548..7b6a9a2a3 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -130,6 +130,36 @@ static inline int backlight_update_status(struct backlight_device *bd) > return ret; > } > > +/** > + * backlight_enable - Enable backlight > + * @bd: the backlight device to enable > + */ > +static inline int backlight_enable(struct backlight_device *bd) > +{ > + if (!bd) > + return 0; > + > + bd->props.power = FB_BLANK_UNBLANK; > + bd->props.state &= ~BL_CORE_FBBLANK; > + > + return backlight_update_status(bd); > +} > + > +/** > + * backlight_disable - Disable backlight > + * @bd: the backlight device to disable > + */ > +static inline int backlight_disable(struct backlight_device *bd) > +{ > + if (!bd) > + return 0; > + > + bd->props.power = FB_BLANK_POWERDOWN; > + bd->props.state |= BL_CORE_FBBLANK; > + > + return backlight_update_status(bd); > +} > + > extern struct backlight_device *backlight_device_register(const char *name, > struct device *dev, void *devdata, const struct backlight_ops *ops, > const struct backlight_properties *props); >
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