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

From: Conor Dooley

Date: Mon Mar 02 2026 - 13:25:20 EST


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@xxxxxxxxx>
> ---
> 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.
pw-bot: changes-requested

Thanks,
Conor.

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