Re: [PATCH 4/4] arm64: dts: mediatek: mt8186: Wire up GPU voltage/frequency scaling

[AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>]

Il 07/06/23 11:06, Chen-Yu Tsai ha scritto:
> Add the GPU's OPP table. This is from the downstream ChromeOS kernel,
> adapted to the new upstream opp-supported-hw binning format. Also add
> dynamic-power-coefficient for the GPU.
> 
> Also add label for mfg1 power domain. This is to be used at the board
> level to add a regulator supply for the power domain.
> 
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
> ---
>   arch/arm64/boot/dts/mediatek/mt8186.dtsi | 140 ++++++++++++++++++++++-
>   1 file changed, 139 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/mediatek/mt8186.dtsi b/arch/arm64/boot/dts/mediatek/mt8186.dtsi
> index c58d7eb87b1d..a34489e27cd4 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8186.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8186.dtsi
> @@ -695,6 +695,142 @@ clk32k: oscillator-32k {
>   		clock-output-names = "clk32k";
>   	};
>   
> +	gpu_opp_table: opp-table-gpu {
> +		compatible = "operating-points-v2";
> +
> +		opp-299000000 {
> +			opp-hz = /bits/ 64 <299000000>;
> +			opp-microvolt = <612500>;
> +			opp-supported-hw = <0x38>;

For all of the OPPs that are supposed to be supported by all speed-bins, you don't
need to restrict them to all "known" bins.

Please change opp-supported-hw from <0x38> to <0xff>, which literally means
just "applies to all revisions".

> +		};


..snip...

> +
> +		opp-900000000-3 {

What about calling those like "opp-900000000-bin3"?
Makes it clear that it's tied to what MediaTek calls a speedbin "3" (as we're
interpreting the values in the nvmem driver to make them compatible with the
opp-supported-hw's expectations).

Cheers,
Angelo