Add Intel ACPI IGD OpRegion support
This adds the support necessary for allowing ACPI backlight control to
work on some newer Intel-based graphics systems. Tested on Thinkpad T61
and HP 2510p hardware.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 477c64e..43ad2cb 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -740,6 +740,7 @@
#define BLC_PWM_CTL 0x61254
#define BACKLIGHT_MODULATION_FREQ_SHIFT (17)
#define BLC_PWM_CTL2 0x61250 /* 965+ only */
+#define BLM_COMBINATION_MODE (1 << 30)
/*
* This is the most significant 15 bits of the number of backlight cycles in a
* complete cycle of the modulated backlight control.