Messages in this thread Patch in this message | | | From | Chen-Yu Tsai <> | Date | Thu, 2 Mar 2023 18:03:08 +0800 | Subject | Re: [PATCH v4 12/19] arm64: dts: mediatek: mt8192-asurada: Couple VGPU and VSRAM_OTHER regulators |
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On Wed, Mar 1, 2023 at 5:55 PM AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> wrote: > > 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@collabora.com> > --- > 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>;
Looking again at the downstream OPP table, it seems there's no voltage difference requirement. It only needs V_SRAM >= V_GPU. Same applies to MT8195. Looks like only MT8183 and MT8186 need V_SRAM - V_GPU >= 10000.
Would setting max-spread to 0 work? I ask because with both regulator's maximum voltage set to 0.8V, there's no way we can reach the highest OPP.
ChenYu
> +}; > + > &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 >
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