[PATCH v4 12/19] arm64: dts: mediatek: mt8192-asurada: Couple VGPU and VSRAM_OTHER regulators

[AngeloGioacchino Del Regno]

Add coupling for these regulators, as VSRAM_OTHER is used to power the
GPU SRAM, and they have a strict voltage output relation to satisfy in
order to ensure GPU stable operation.
While at it, also add voltage constraint overrides for the GPU SRAM
regulator "mt6359_vsram_others" so that we stay in a safe range of
0.75-0.80V.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
 arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
index 8570b78c04a4..f858eca219d7 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
@@ -447,6 +447,13 @@ &mt6359_vrf12_ldo_reg {
 	regulator-always-on;
 };
 
+&mt6359_vsram_others_ldo_reg {
+	regulator-min-microvolt = <750000>;
+	regulator-max-microvolt = <800000>;
+	regulator-coupled-with = <&mt6315_7_vbuck1>;
+	regulator-coupled-max-spread = <10000>;
+};
+
 &mt6359_vufs_ldo_reg {
 	regulator-always-on;
 };
@@ -1411,6 +1418,8 @@ mt6315_7_vbuck1: vbuck1 {
 				regulator-max-microvolt = <800000>;
 				regulator-enable-ramp-delay = <256>;
 				regulator-allowed-modes = <0 1 2>;
+				regulator-coupled-with = <&mt6359_vsram_others_ldo_reg>;
+				regulator-coupled-max-spread = <10000>;
 			};
 		};
 	};
-- 
2.39.2