backlight: backlight: Introduce backlight_get_brightness()

Based on an idea from Emil Velikov, add a helper that checks
backlight_is_blank() and return 0 as brightness if display is blank or
the property value if not.

This allows us to simplify the update_status() implementation
in most of the backlight drivers.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Sam Ravnborg 2020-07-19 10:07:36 +02:00 committed by Lee Jones
parent 5ab4246cfc
commit 2144d00ed0

View file

@ -417,6 +417,25 @@ static inline bool backlight_is_blank(const struct backlight_device *bd)
bd->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK);
}
/**
* backlight_get_brightness - Returns the current brightness value
* @bd: the backlight device
*
* Returns the current brightness value, taking in consideration the current
* state. If backlight_is_blank() returns true then return 0 as brightness
* otherwise return the current brightness property value.
*
* Backlight drivers are expected to use this function in their update_status()
* operation to get the brightness value.
*/
static inline int backlight_get_brightness(const struct backlight_device *bd)
{
if (backlight_is_blank(bd))
return 0;
else
return bd->props.brightness;
}
struct backlight_device *
backlight_device_register(const char *name, struct device *dev, void *devdata,
const struct backlight_ops *ops,