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

[Chen-Yu Tsai]

On Thu, Jun 8, 2023 at 8:14 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxxxx>
> > ---
> >   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".

OK.

> > +             };
>
>
> ..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).

I thought that at first as well, but the bindings require the OPP node to
be named following '^opp(-?[0-9]+)*$':, so numbers only.

ChenYu