[PATCH 2/4] arm64: dts: qcom: msm8996: Pass VDDMX to gpu in power-domains

[Konrad Dybcio <konrad.dybcio@linaro.org>]

Since power-domains is used for perf_level pm_genpd scaling, it's only
fitting that we pass a power domain that's actually supposed to be
scaled (and not only turned on/off) to the GPU. While we don't quite
support CPR3 yet, the next best thing we can do is pass VDDMX, so that
we're at least guaranteed a reasonable vote on the memory side of
things. Do so and leave a note mentioning CPR3 PD should be used here
instead when support is added.

Fixes: 69cc3114ab0f ("arm64: dts: Add Adreno GPU definitions")
Fixes: 3f65d51e9e22 ("arm64: dts: qcom: msm8996: Make GPU node control GPU_GX GDSC")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 arch/arm64/boot/dts/qcom/msm8996.dtsi | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
index 4661a556772e..4dd37f72e018 100644
--- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
@@ -1228,7 +1228,8 @@ gpu: gpu@b00000 {
 			interconnects = <&bimc MASTER_GRAPHICS_3D &bimc SLAVE_EBI_CH0>;
 			interconnect-names = "gfx-mem";
 
-			power-domains = <&mmcc GPU_GX_GDSC>;
+			/* TODO: also scale VDDGFX with CPR3 */
+			power-domains = <&rpmpd MSM8996_VDDMX>;
 			iommus = <&adreno_smmu 0>;
 
 			nvmem-cells = <&speedbin_efuse>;
@@ -2254,7 +2255,13 @@ adreno_smmu: iommu@b40000 {
 				 <&mmcc GPU_AHB_CLK>;
 			clock-names = "bus", "iface";
 
-			power-domains = <&mmcc GPU_GDSC>;
+			/*
+			 * We need both GPU_GDSC and GPU_GX_GDSC to be on, but the
+			 * power-domains entry under gpu is occupied by the scaled
+			 * voltage domain. Since GPU_GDSC is a parent of GX_GDSC,
+			 * we can simply pass GX here to turn them both on!
+			 */
+			power-domains = <&mmcc GPU_GX_GDSC>;
 		};
 
 		venus: video-codec@c00000 {

-- 
2.40.0