BACKLIGHT_ON     1232 drivers/gpu/drm/gma500/psb_intel_reg.h #define BACKLIGHT_ON		(1 << 2)
BACKLIGHT_ON     10727 drivers/gpu/drm/i915/i915_reg.h #define  BACKLIGHT_ON					(1 << 4)
BACKLIGHT_ON       98 drivers/platform/x86/fujitsu-laptop.c #define BACKLIGHT_ON			0