[PATCH 1/3] arm64: dts: mediatek: mt8192-asurada: Add ramp-delay for MT6315 regulators

[PATCH 1/3] arm64: dts: mediatek: mt8192-asurada: Add ramp-delay for MT6315 regulators

[Chen-Yu Tsai]

On Asurada, the MT6315 buck regulators (Vbcpu, Vlcpu, and Vgpu) are
missing the regulator-ramp-delay property. Without the slew rate
specified, voltage increases may not have settled before switching CPU
or GPU to higher operating points, risking undervoltage crashes.

Add regulator-ramp-delay properties matching the slew rates configured
by firmware, with values provided by MediaTek: 8000 uV/us for Vbcpu, and
4500 uV/us for Vlcpu and Vgpu.

Fixes: 3183cb62b033 ("arm64: dts: mediatek: asurada: Add SPMI regulators")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
Patch created with LLM. Values were translated from raw register values
by MediaTek.
---
 arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
index d1993b80f9ce..43286241cd22 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
@@ -1812,6 +1812,7 @@ mt6315_6_vbuck1: vbuck1 {
 				regulator-min-microvolt = <400000>;
 				regulator-max-microvolt = <1193750>;
 				regulator-enable-ramp-delay = <256>;
+				regulator-ramp-delay = <8000>;
 				regulator-allowed-modes = <0 1 2>;
 				regulator-always-on;
 			};
@@ -1821,6 +1822,7 @@ mt6315_6_vbuck3: vbuck3 {
 				regulator-min-microvolt = <400000>;
 				regulator-max-microvolt = <1193750>;
 				regulator-enable-ramp-delay = <256>;
+				regulator-ramp-delay = <4500>;
 				regulator-allowed-modes = <0 1 2>;
 				regulator-always-on;
 			};
@@ -1841,6 +1843,7 @@ mt6315_7_vbuck1: vbuck1 {
 				regulator-min-microvolt = <400000>;
 				regulator-max-microvolt = <800000>;
 				regulator-enable-ramp-delay = <256>;
+				regulator-ramp-delay = <4500>;
 				regulator-allowed-modes = <0 1 2>;
 				regulator-coupled-with = <&mt6359_vsram_others_ldo_reg>;
 				regulator-coupled-max-spread = <10000>;
-- 
2.56.0.317.g454f8302e1-goog

[PATCH 2/3] arm64: dts: mediatek: mt8195-cherry: Fix ramp-delay for Vgpu

[Chen-Yu Tsai]

On Cherry, the MT6315 PMIC at USID 0x7 powering Vgpu has its slew rate
configured by firmware to 4500 uV/us, rather than the 6250 uV/us
currently specified in the device tree.

Since regulator-ramp-delay is specified in uV/us, specifying a higher
slew rate than what the PMIC actually uses results in an underestimated
voltage ramp time, risking GPU undervoltage when switching to higher
operating points.

Update regulator-ramp-delay on mt6315_7_vbuck1 to 4500 to match the
configured slew rate provided by MediaTek. (Vbcpu on USID 0x6 is
configured to 6250 uV/us and needs no change.)

Fixes: 260c04d425eb ("arm64: dts: mediatek: cherry: Enable MT6315 regulators on SPMI bus")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
Patch created with LLM. Values were translated from raw register values
by MediaTek.
---
 arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
index f23a0c7aa87e..81628d8a4b0e 100644
--- a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
@@ -1596,7 +1596,7 @@ mt6315_7_vbuck1: vbuck1 {
 				regulator-min-microvolt = <400000>;
 				regulator-max-microvolt = <1193750>;
 				regulator-enable-ramp-delay = <256>;
-				regulator-ramp-delay = <6250>;
+				regulator-ramp-delay = <4500>;
 				regulator-allowed-modes = <0 1 2>;
 			};
 		};
-- 
2.56.0.317.g454f8302e1-goog

[PATCH 3/3] arm64: dts: mediatek: mt8186-corsola-voltorb: Add MT6319 ramp-delay

[Chen-Yu Tsai]

On Voltorb and Squirtle, the MT6319 buck1 regulator supplying the big
CPU cluster is missing the regulator-ramp-delay property. Without the
slew rate specified, voltage increases may not have settled before
switching the big CPU cluster to higher operating points, risking
undervoltage crashes.

Firmware configures the MT6319 slew rate on these designs to 6250 uV/us,
with the value provided by MediaTek. Add regulator-ramp-delay = <6250>
to mt6319_buck1.

Fixes: 321ad586e607 ("arm64: dts: mediatek: Add MT8186 Voltorb Chromebooks")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
Patch created with LLM. Values were translated from raw register values
by MediaTek.
---
 arch/arm64/boot/dts/mediatek/mt8186-corsola-voltorb.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8186-corsola-voltorb.dtsi b/arch/arm64/boot/dts/mediatek/mt8186-corsola-voltorb.dtsi
index 0250b4eeadd4..2ec343f49da3 100644
--- a/arch/arm64/boot/dts/mediatek/mt8186-corsola-voltorb.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8186-corsola-voltorb.dtsi
@@ -84,6 +84,7 @@ mt6319_buck1: vbuck1 {
 					regulator-min-microvolt = <600000>;
 					regulator-max-microvolt = <1193750>;
 					regulator-enable-ramp-delay = <256>;
+					regulator-ramp-delay = <6250>;
 					regulator-allowed-modes = <0 1 2>;
 					regulator-always-on;
 			};
-- 
2.56.0.317.g454f8302e1-goog