Re: [PATCH v5 1/9] dt-bindings: mmc: spacemit,sdhci: add pinctrl support for voltage switching

Ulf Hansson
2026-03-31T10:59:13Z

On Tue, 31 Mar 2026 at 08:48, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On Mon, Mar 30, 2026 at 10:38:02AM +0200, Iker Pedrosa wrote:
> > Document pinctrl properties to support voltage-dependent pin
> > configuration switching for UHS-I SD card modes.
> >
> > Add optional pinctrl-names property with two states:
> > - "default": For 3.3V operation with standard drive strength
> > - "state_uhs": For 1.8V operation with optimized drive strength
> >
> > These pinctrl states allow the SDHCI driver to coordinate voltage
> > switching with pin configuration changes, ensuring proper signal
> > integrity during UHS-I mode transitions.
> >
> > Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
> > ---
> > .../devicetree/bindings/mmc/spacemit,sdhci.yaml | 17 +++++++++++++++++
> > 1 file changed, 17 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
> > index 9a055d963a7f0cdba4741c1e3e7269688dcd5f45..201ab97f0e88376a4680dcca7917e8b3172bd84a 100644
> > --- a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
> > @@ -44,6 +44,20 @@ properties:
> > - const: axi
> > - const: sdh
> >
> > + pinctrl-names:
> > + minItems: 1
> > + maxItems: 2
> > + items:
> > + enum:
>
> No, that's not enum but list. Look here:
>
> > + - default
> > + - state_uhs
>
> Instead: uhs

While I agree that "uhs" would be better, we have tried to stick with
"state_uhs" for legacy and consistency reasons with other mmc
controllers.

No strong opinion though, what do you think?

[...]

Kind regards
Uffe