[PATCH v1 2/4] dt-bindings: pinctrl: aspeed: Add support for AST27xx

[Billy Tsai]

On Fri, Aug 29, 2025 at 03:30:28PM +0800, Billy Tsai wrote:
> > Add bindings for the pin controller found in the ASPEED AST27xx SoC.

> Please explain why you have defined 2 pin controllers and why they
> aren't compatible with each other.

I will add following description in next version of the patch:

"The ASPEED AST2700 SoC contains two separate pin controllers, each
managed by a distinct System Control Unit (SCU).
Because these two controllers have different register maps, control
different sets of pins, support different pin configuration options, and
implement different multi-function switch logic, they are not compatible.
Therefore, two separate device tree bindings,'aspeed,ast2700-soc0-pinctrl'
and 'aspeed,ast2700-soc1-pinctrl', are introduced."

>
> > Signed-off-by: Billy Tsai <billy_tsai at aspeedtech.com>
> > ---
> >  .../pinctrl/aspeed,ast2700-soc0-pinctrl.yaml  | 135 ++++++
> >  .../pinctrl/aspeed,ast2700-soc1-pinctrl.yaml  | 452 ++++++++++++++++++
> >  2 files changed, 587 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pinctrl/aspeed,ast2700-soc0-pinctrl.yaml
> >  create mode 100644 Documentation/devicetree/bindings/pinctrl/aspeed,ast2700-soc1-pinctrl.yaml
>
> > diff --git a/Documentation/devicetree/bindings/pinctrl/aspeed,ast2700-soc0-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/aspeed,ast2700-soc0-pinctrl.yaml
> > new file mode 100644
> > index 000000000000..8abdc2fe1d8b
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/aspeed,ast2700-soc0-pinctrl.yaml
> > @@ -0,0 +1,135 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pinctrl/aspeed,ast2700-soc0-pinctrl.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ASPEED AST2700 SoC0 Pin Controller
> > +
> > +maintainers:
> > +  - Billy Tsai <billy_tsai at aspeedtech.com>
> > +
> > +description: |+

> What's the '+' for?

I will remove it.

> > +  The pin controller node should be the child of a syscon node with the
> > +  required property:
> > +
> > +  - compatible: Should be one of the following:
> > +                "aspeed,ast2700-scu0", "syscon", "simple-mfd"

> This should be a schema in the aspeed,ast2700-scu0 binding, not a
> free-form text description.

> > +
> > +  Refer to the bindings described in
> > +  Documentation/devicetree/bindings/mfd/syscon.yaml

> That does not cover 'simple-mfd' cases.

I will remove the description about the parent node and simplify the description
as following:

"Bindings for the ASPEED AST2700 SoC0 Pin Controller."


> > +
> > +properties:
> > +  compatible:
> > +    const: aspeed,ast2700-soc0-pinctrl
> > +
> > +additionalProperties:
> > +  $ref: pinmux-node.yaml#
> > +  additionalProperties: false
> > +
> > +  properties:
> > +    function:
> > +      enum:
> > +        - EMMC
> > +        - VGADDC
> > +        - USB3A
> > +        - USB2A
> > +        - USB3B
> > +        - USB2B
> > +        - JTAG0
> > +        - PCIERC
> > +
> > +    groups:
> > +      enum:
> > +        - EMMCG1
> > +        - EMMCG4
> > +        - EMMCG8
> > +        - EMMCWPN
> > +        - EMMCCDN
> > +        - VGADDC
> > +        - USB3AXHD
> > +        - USB3AXHPD
> > +        - USB3AXH
> > +        - USB3AXHP
> > +        - USB3AXH2B
> > +        - USB3AXHP2B
> > +        - USB2AXHD1
> > +        - USB2AXHPD1
> > +        - USB2AD1
> > +        - USB2AXH
> > +        - USB2AXHP
> > +        - USB2AXH2B
> > +        - USB2AXHP2B
> > +        - USB2AHPD0
> > +        - USB2AD0
> > +        - USB2AH
> > +        - USB2AHP
> > +        - USB3BXHD
> > +        - USB3BXHPD
> > +        - USB3BXH
> > +        - USB3BXHP
> > +        - USB3BXH2A
> > +        - USB3BXHP2A
> > +        - USB2BXHD1
> > +        - USB2BXHPD1
> > +        - USB2BD1
> > +        - USB2BXH
> > +        - USB2BXHP
> > +        - USB2BXH2A
> > +        - USB2BXHP2A
> > +        - USB2BHPD0
> > +        - USB2BD0
> > +        - USB2BH
> > +        - USB2BHP
> > +        - JTAGM0
> > +        - PSP
> > +        - SSP
> > +        - TSP
> > +        - DDR
> > +        - USB3A
> > +        - USB3B
> > +        - PCIEA
> > +        - PCIEB
> > +        - PCIERC0PERST
> > +        - PCIERC1PERST
> > +
> > +    pins: true

> You need to define the type as string or uint32 is possible.

Ok, I will use the following to replace:
pins:
      $ref: /schemas/types.yaml#/definitions/string-array

> > +    drive-strength:
> > +      minimum: 0
> > +      maximum: 15
> > +
> > +allOf:
> > +  - $ref: pinctrl.yaml#
> > +
> > +required:
> > +  - compatible
> > +
> > +examples:
> > +  - |
> > +     / {
> > +          #address-cells = <2>;
> > +          #size-cells = <2>;
> > +          syscon0: syscon at 12c02000 {
> > +              compatible = "aspeed,ast2700-scu0", "syscon", "simple-mfd";

> Drop the example here and put a complete example in the schema for the
> syscon.

Ok, I will use the following example to replace:

pinctrl0: pinctrl{
        compatible = "aspeed,ast2700-soc0-pinctrl";

        pinctrl_emmc_default: emmc-default {
                function = "EMMC";
                groups = "EMMCG1";
        };

        pinctrl_emmcclk_driving: emmcclk-driving {
                pins = "AC14";
                drive-strength = <2>;
        };
};

Thanks

Best Regards,
Billy Tsai

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