[PATCH] arm64: dts: rockchip: Fix vdd_gpu voltage constraints on PinePhone Pro

[Dragan Simic]

The regulator-{min,max}-microvolt values for the vdd_gpu regulator in the
PinePhone Pro device dts file are too restrictive, which prevents the highest
GPU OPP from being used, slowing the GPU down unnecessarily.  Let's fix that
by making the regulator-{min,max}-microvolt values less strict, using the
voltage range that the Silergy SYR838 chip used for the vdd_gpu regulator is
actually capable of producing. [1][2]

This also eliminates the following error messages from the kernel log:

  core: _opp_supported_by_regulators: OPP minuV: 1100000 maxuV: 1150000, not supported by regulator
  panfrost ff9a0000.gpu: _opp_add: OPP not supported by regulators (800000000)

These changes to the regulator-{min,max}-microvolt values make the PinePhone
Pro device dts consistent with the dts files for other Rockchip RK3399-based
boards and devices.  It's possible to be more strict here, by specifying the
regulator-{min,max}-microvolt values that don't go outside of what the GPU
actually may use, as the consumer of the vdd_gpu regulator, but those changes
are left for a later directory-wide regulator cleanup.

[1] https://files.pine64.org/doc/PinePhonePro/PinephonePro-Schematic-V1.0-20211127.pdf
[2] https://www.t-firefly.com/download/Firefly-RK3399/docs/Chip%20Specifications/DC-DC_SYR837_838.pdf

Fixes: 78a21c7d5952 ("arm64: dts: rockchip: Add initial support for Pine64 PinePhone Pro")
Cc: stable at vger.kernel.org
Signed-off-by: Dragan Simic <dsimic at manjaro.org>
---
 arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
index 1a44582a49fb..956d64f5b271 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
@@ -410,8 +410,8 @@ vdd_gpu: regulator at 41 {
 		pinctrl-names = "default";
 		pinctrl-0 = <&vsel2_pin>;
 		regulator-name = "vdd_gpu";
-		regulator-min-microvolt = <875000>;
-		regulator-max-microvolt = <975000>;
+		regulator-min-microvolt = <712500>;
+		regulator-max-microvolt = <1500000>;
 		regulator-ramp-delay = <1000>;
 		regulator-always-on;
 		regulator-boot-on;