Re: [PATCH 01/10] dt-bindings: mmc: spacemit,sdhci: add AIB voltage switching registers

Yixun Lan
2026-03-02T22:38:05Z

Hi Iker, Conor,

On 18:25 Mon 02 Mar , Conor Dooley wrote:
> On Mon, Mar 02, 2026 at 04:13:22PM +0100, Iker Pedrosa wrote:
> > Add SpacemiT K1 AIB register properties for UHS voltage switching
> > support:
> >
> > - spacemit,aib-mmc1-io-reg: AIB MMC1 IO register address for voltage
> > switching
> > - spacemit,apbc-asfar-reg: APBC ASFAR register address for AIB access
> > - spacemit,apbc-assar-reg: APBC ASSAR register address for AIB access
> >
> > These properties enable the driver to perform voltage switching between
> > 3.3V and 1.8V required for UHS SD card modes.
> >
> > Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
> > ---
> > Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml | 15 +++++++++++++++
> > 1 file changed, 15 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
> > index 13d9382058fbc1c12be1024d1c550f04a825673c..4d6590aa8262009b6e5697a04b45cf3736c0fa42 100644
> > --- a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
> > @@ -32,6 +32,18 @@ properties:
> > - const: core
> > - const: io
> >
> > + spacemit,aib-mmc1-io-reg:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description: AIB MMC1 IO register address for voltage switching
> > +
> > + spacemit,apbc-asfar-reg:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description: APBC ASFAR register address for AIB access
> > +
> > + spacemit,apbc-assar-reg:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description: APBC ASSAR register address for AIB access
> > +
> > required:
> > - compatible
> > - reg
> > @@ -50,4 +62,7 @@ examples:
> > interrupt-parent = <&plic>;
> > clocks = <&clk_apmu 10>, <&clk_apmu 13>;
> > clock-names = "core", "io";
> > + spacemit,aib-mmc1-io-reg = <0xd401e81c>;
>
> This looks very very wrong to me. This is part of the pinctrl
> reservation:
> pinctrl: pinctrl@d401e000 {
> compatible = "spacemit,k1-pinctrl";
> reg = <0x0 0xd401e000 0x0 0x1000>;
> clocks = <&syscon_apbc CLK_AIB>,
> <&syscon_apbc CLK_AIB_BUS>;
> clock-names = "func", "bus";
> spacemit,apbc = <&syscon_apbc>;
> };
> so if you need to change something here, you need to do it via pinctrl.
>
> > + spacemit,apbc-asfar-reg = <0xd4015050>;
> > + spacemit,apbc-assar-reg = <0xd4015054>;
>
> These two are the apbc syscon:
> syscon_apbc: system-controller@d4015000 {
> compatible = "spacemit,k1-syscon-apbc";
> reg = <0x0 0xd4015000 0x0 0x1000>;
> clocks = <&osc_32k>, <&vctcxo_1m>, <&vctcxo_3m>,
> <&vctcxo_24m>;
> clock-names = "osc", "vctcxo_1m", "vctcxo_3m",
> "vctcxo_24m";
> #clock-cells = <1>;
> #reset-cells = <1>;
> };
> so add a phandle to the syscon (like the pinctrl currently has) and
> access these via its regmap. What you've got here is a non-runner,
> sorry.

We've gained this support in pinctrl which already accepted in mainline,
it's done as Conor suggested here, so you can drop these properties along
with the patch [5/10], see

https://lore.kernel.org/all/20260108-kx-pinctrl-aib-io-pwr-domain-v2-0-6bcb46146e53@linux.spacemit.com/

> pw-bot: changes-requested
>
> Thanks,
> Conor.

--
Yixun Lan (dlan)