Re: [PATCH net-next v11 1/7] dt-bindings: phy: document the serdes PHY on sa8255p

[Geert Uytterhoeven]

Hi Bartosz,

On Mon, 29 Jun 2026 at 16:07, Bartosz Golaszewski <brgl@xxxxxxxxxx> wrote:
> On Mon, 29 Jun 2026 15:51:31 +0200, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> said:
> > On Mon, 29 Jun 2026 at 13:29, Bartosz Golaszewski
> > <bartosz.golaszewski@xxxxxxxxxxxxxxxx> wrote:
> >> Describe the SGMII/SerDes PHY present on the Qualcomm sa8255p platforms.
> >> This is essentially the same hardware as sa8775p rev3 but the PHY is
> >> managed by firmware over SCMI.
> >
> > So why can't it be reuse the DT bindings, and be compatible with
> > qcom,sa8775p-dwmac-sgmii-phy?
> >
> >> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
> >
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/phy/qcom,sa8255p-dwmac-sgmii-phy.yaml
> >
> >> +  power-domains:
> >> +    maxItems: 1
> >> +
> >> +  power-domain-names:
> >> +    items:
> >> +      - const: serdes
> >
> >> +examples:
> >> +  - |
> >> +    phy@8901000 {
> >> +        compatible = "qcom,sa8255p-dwmac-sgmii-phy";
> >> +        reg = <0x08901000 0xe10>;
> >> +        #phy-cells = <0>;
> >> +        power-domains = <&scmi7_dvfs 0>;
> >> +        power-domain-names = "serdes";
> >
> > Ah, this uses power-domains, while the existing bindings for
> > qcom,sa8775p-dwmac-sgmii-phy use a clock.
> > I guess the clock is the correct hardware description?
> >
> > Adding to my list of examples for backing a hardware-to-SCMI remapping
> > driver...
> >
>
> Russell King asked me to put the PHY logic for SCMI pm domains into the PHY
> driver instead of the MAC driver where it was previously. Instead of cramming
> both HLOS and firmware handling into the same driver, I figured it makes more
> sense to have a dedicated, cleaner driver as the two share very little code (if
> any).

I think you are mixing up DT bindings and driver implementation?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds