[XS] Change in coreboot[master]: mb/google/volteer: Add ACPI display brightness support

[Matt DeVillier (Code Review)]

Matt DeVillier has submitted this change. ( https://review.coreboot.org/c/coreboot/+/77143?usp=email )

Change subject: mb/google/volteer: Add ACPI display brightness support
......................................................................

mb/google/volteer: Add ACPI display brightness support

Add support for ACPI display brightness controls, so that panel
adjustment is available under Windows.

TEST=build/boot Win11 on google/drobit, verify panel brightness
controls available and functional.

Change-Id: Ic0c026ae09b3fde648db4bdeb4971423953c96a1
Signed-off-by: Matt DeVillier 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77143
Reviewed-by: Tim Wawrzynczak 
Tested-by: build bot (Jenkins) 
---
M src/mainboard/google/volteer/dsdt.asl
M src/mainboard/google/volteer/variants/baseboard/devicetree.cb
2 files changed, 4 insertions(+), 1 deletion(-)

Approvals:
  build bot (Jenkins): Verified
  Tim Wawrzynczak: Looks good to me, approved

diff --git a/src/mainboard/google/volteer/dsdt.asl b/src/mainboard/google/volteer/dsdt.asl
index 4193d3d..eeaf613 100644
--- a/src/mainboard/google/volteer/dsdt.asl
+++ b/src/mainboard/google/volteer/dsdt.asl
@@ -28,6 +28,7 @@
    		#include <soc/intel/common/block/acpi/acpi/northbridge.asl>
    		#include <soc/intel/tigerlake/acpi/southbridge.asl>
    		#include <soc/intel/tigerlake/acpi/tcss.asl>
+			#include <drivers/intel/gma/acpi/default_brightness_levels.asl>
 #if CONFIG(VARIANT_HAS_MIPI_CAMERA)
    		#include <soc/intel/common/block/acpi/acpi/ipu.asl>
 #endif
diff --git a/src/mainboard/google/volteer/variants/baseboard/devicetree.cb b/src/mainboard/google/volteer/variants/baseboard/devicetree.cb
index 4af59e6..078deb2 100644
--- a/src/mainboard/google/volteer/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/volteer/variants/baseboard/devicetree.cb
@@ -357,7 +357,9 @@
    register "FastPkgCRampDisable" = "1"

device domain 0 on
-		device ref igpu on end
+		device ref igpu on
+			register "gfx" = "GMA_DEFAULT_PANEL(0)"
+		end
    	device ref dptf on
    		# Default DPTF Policy for all Volteer boards if not overridden
    		chip drivers/intel/dptf