Hi Rob, On Saturday, 6 September 2025 01:26:57 Central European Summer Time Rob Herring wrote: > On Fri, Sep 05, 2025 at 12:22:57PM +0200, Nicolas Frattaroli wrote: > > The Mali-based GPU on the MediaTek MT8196 SoC is shackled to its concept > > of "MFlexGraphics", which in this iteration includes an embedded MCU > > that needs to be poked to power on the GPU, and is in charge of > > controlling all the clocks and regulators. > > > > In return, it lets us omit the OPP tables from the device tree, as those > > can now be enumerated at runtime from the MCU. > > > > Add the mediatek,mt8196-mali compatible, and a performance-controller > > property which points to a node representing such setups. It's required > > on mt8196 devices. > > > > Signed-off-by: Nicolas Frattaroli <nicolas.frattar...@collabora.com> > > --- > > .../bindings/gpu/arm,mali-valhall-csf.yaml | 36 > > +++++++++++++++++++++- > > 1 file changed, 35 insertions(+), 1 deletion(-) > > > > diff --git > > a/Documentation/devicetree/bindings/gpu/arm,mali-valhall-csf.yaml > > b/Documentation/devicetree/bindings/gpu/arm,mali-valhall-csf.yaml > > index > > a5b4e00217587c5d1f889094e2fff7b76e6148eb..6df802e900b744d226395c29f8d87fb6d3282d26 > > 100644 > > --- a/Documentation/devicetree/bindings/gpu/arm,mali-valhall-csf.yaml > > +++ b/Documentation/devicetree/bindings/gpu/arm,mali-valhall-csf.yaml > > @@ -19,6 +19,7 @@ properties: > > - items: > > - enum: > > - rockchip,rk3588-mali > > + - mediatek,mt8196-mali > > - const: arm,mali-valhall-csf # Mali Valhall GPU > > model/revision is fully discoverable > > > > reg: > > @@ -53,6 +54,13 @@ properties: > > opp-table: > > type: object > > > > + performance-controller: > > + $ref: /schemas/types.yaml#/definitions/phandle > > + description: > > + A phandle of a device that controls this GPU's power and frequency, > > + if any. If present, this is usually in the form of some specialised > > + embedded MCU. > > We already abuse power-domains binding with both power and performance. > There's a performance-domain binding too, but only used on one platform > for CPUs (Mediatek too IIRC). Or perhaps you could just point to an > empty OPP table. I don't think you have anything new here, so don't > invent something new.
Oops, yeah, I forgot about performance-domain already existing. I agree that it looks like a good fit; iirc I initially disregarded it because I thought it was an actual heterogenous core cpufreq-y thing I'd be overloading with new meaning, but I see now that this is not so, and aside from mediatek, Apple appears to be the only user. Thanks for the fast review. Kind regards, Nicolas Frattaroli > > Rob >
