From bd36a313dee74aea1681cd1c9265e3279deca03b Mon Sep 17 00:00:00 2001
From: Matt DeVillier <matt.devillier@gmail.com>
Date: Tue, 15 Feb 2022 11:48:30 -0600
Subject: [PATCH] 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 <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77143
Reviewed-by: Tim Wawrzynczak <inforichland@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
---
 src/mainboard/google/volteer/dsdt.asl                         | 1 +
 src/mainboard/google/volteer/variants/baseboard/devicetree.cb | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/mainboard/google/volteer/dsdt.asl b/src/mainboard/google/volteer/dsdt.asl
index 4193d3d1e7..eeaf61379f 100644
--- a/src/mainboard/google/volteer/dsdt.asl
+++ b/src/mainboard/google/volteer/dsdt.asl
@@ -28,6 +28,7 @@ DefinitionBlock(
 			#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 4af59e6ff1..078deb29f2 100644
--- a/src/mainboard/google/volteer/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/volteer/variants/baseboard/devicetree.cb
@@ -357,7 +357,9 @@ chip soc/intel/tigerlake
 	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