backlight: Nuke unused backlight.props.state states

The backlight power state handling is supremely confusing. We have:
- props.power, using FB_BLANK_* defines
- props.fb_blank, using the same, but deprecated int favour of
  props.state
- props.state, using the BL_CORE_* defines
- and finally a bunch of backlight drivers treat brightness == 0 as
  off. But of course not all of them.

This is way too much confusion to fix in a simple patch, but at least
prevent more hilarity from spreading by removing the unused BL_CORE_*
defines. I have no idea why exactly anyone would need that.

Wrt the ideal state, we really just want a boolean state. The 4 power
saving states that the fbdev subsystem uses are overkill in todays hw
(this was only relevant for VGA and similar analog circuits like
TV-out), the new drm atomic modeset api simplified even the uapi to a
simple bool. And there was never a valid technical reason to have the
intermediate fbdev power states for backlights (those really only can
be either off or on).

Cleanup motivated by Meghana's questions about all this.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 2baab6f3861d20ec998266dd0d36e30b3f446262..1db67662bfcb0514bf8cef090f58ed1ecddf9978 100644 (file)
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -84,9 +84,6 @@ struct backlight_properties {
 
 #define BL_CORE_SUSPENDED      (1 << 0)        /* backlight is suspended */
 #define BL_CORE_FBBLANK                (1 << 1)        /* backlight is under an fb blank event */
-#define BL_CORE_DRIVER4                (1 << 28)       /* reserved for driver specific use */
-#define BL_CORE_DRIVER3                (1 << 29)       /* reserved for driver specific use */
-#define BL_CORE_DRIVER2                (1 << 30)       /* reserved for driver specific use */
 #define BL_CORE_DRIVER1                (1 << 31)       /* reserved for driver specific use */
 
 };