RE: [PATCH 4/7] dt-bindings: firmware: arm,scmi: support pinctrl protocol

Peng Fan <peng.fan@xxxxxxx> · Sat, 16 Dec 2023 04:44:38 +0000

Hi Rob,

> Subject: Re: [PATCH 4/7] dt-bindings: firmware: arm,scmi: support pinctrl
> protocol
> 
> On Fri, Dec 15, 2023 at 07:56:32PM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > Add SCMI v3.2 pinctrl protocol bindings and example.
> >
> > Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> > ---
> >  .../devicetree/bindings/firmware/arm,scmi.yaml     | 99
> ++++++++++++++++++++++
> >  1 file changed, 99 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > index 4591523b51a0..bfd2b6a89979 100644
> > --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > @@ -247,6 +247,85 @@ properties:
> >        reg:
> >          const: 0x18
> >
> > +  protocol@19:
> > +    type: object
> > +    allOf:
> > +      - $ref: '#/$defs/protocol-node'
> > +      - $ref: /schemas/pinctrl/pinctrl.yaml
> > +      - if:
> > +          properties:
> > +            compatible:
> > +              const: fsl,imx95-scmi-pinctrl
> > +        then:
> > +          patternProperties:
> > +            "grp$": false
> > +            "-pins$": true
> > +        else:
> > +          patternProperties:
> > +            "grp$": false
> > +            "-pins$": true
> > +    unevaluatedProperties: false
> 
> This will not scale if each vendor adds to arm,scmi.yaml. You need to move
> this to its own file. That can have a ref to
> /schemas/firmware/arm,scmi.yaml#/$defs/protocol-node.
> 
> Here you can just say compatible is "fsl,imx95-scmi-pinctrl" and
> 'additionalProperties: true'.

Do you have an example for this? I am not able write a correct
one to pass the dt check.
      - if:                                                                                         
          properties:                                                                               
            compatible:                                                                             
              const: fsl,imx95-scmi-pinctrl                                                         
        then:                                                                                       
          properties:                                                                               
            additionalProperties: true

.......
      compatible: true

And in fsl,imx95-scmi-pinctrl.yaml

allOf:                                                                                              
  - $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'                                    

properties:                                                                                         
  reg:                                                                                              
    const: 0x19                                                                                     

  compatible:                                                                                       
    const: fsl,imx95-scmi-pinctrl                                                                   

patternProperties:                                                                                  
  'grp$':                                                                                           
    type: object                                                                                    
    description:                                                                                    
      Pinctrl node's client devices use subnodes for desired pin configuration.                     
      Client device subnodes use below standard properties.                                         

    properties:                                                                                     
      fsl,pins:                                                                                     
        description:      

.....
> 
> > +
> > +    properties:
> > +      reg:
> > +        const: 0x19
> > +
> > +      '#pinctrl-cells':
> > +        const: 0
> 
> Generally not used if 0.

Will drop this property.

> 
> > +
> > +      compatible:
> > +        const: fsl,imx95-scmi-pinctrl
> > +
> > +    patternProperties:
> > +      '-pins$':
> > +        type: object
> > +        allOf:
> > +          - $ref: /schemas/pinctrl/pincfg-node.yaml#
> > +          - $ref: /schemas/pinctrl/pinmux-node.yaml#
> > +        unevaluatedProperties: false
> > +
> > +        description:
> > +          A pin multiplexing sub-node describe how to configure a
> > +          set of pins is some desired function.
> > +          A single sub-node may define several pin configurations.
> > +          This sub-node is using default pinctrl bindings to configure
> > +          pin multiplexing and using SCMI protocol to apply specified
> > +          configuration using SCMI protocol.
> > +
> > +      'grp$':
> > +        type: object
> > +        description:
> > +          Pinctrl node's client devices use subnodes for desired pin
> configuration.
> > +          Client device subnodes use below standard properties.
> > +
> > +        properties:
> > +          fsl,pins:
> > +            description:
> > +              each entry consists of 6 integers and represents the mux and
> config
> > +              setting for one pin. The first 5 integers <mux_reg conf_reg
> input_reg
> > +              mux_val input_val> are specified using a PIN_FUNC_ID macro,
> which can
> > +              be found in <arch/arm64/boot/dts/freescale/imx95-pinfunc.h>.
> The last
> > +              integer CONFIG is the pad setting value like pull-up on this pin.
> Please
> > +              refer to i.MX95 Plus Reference Manual for detailed CONFIG
> settings.
> > +            $ref: /schemas/types.yaml#/definitions/uint32-matrix
> > +            items:
> > +              items:
> > +                - description: |
> > +                    "mux_reg" indicates the offset of mux register.
> > +                - description: |
> > +                    "conf_reg" indicates the offset of pad configuration register.
> > +                - description: |
> > +                    "input_reg" indicates the offset of select input register.
> > +                - description: |
> > +                    "mux_val" indicates the mux value to be applied.
> > +                - description: |
> > +                    "input_val" indicates the select input value to be applied.
> > +                - description: |
> > +                    "pad_setting" indicates the pad configuration value to be
> applied.
> > +
> > +    required:
> > +      - reg
> > +
> >  additionalProperties: false
> >
> >  $defs:
> > @@ -401,6 +480,26 @@ examples:
> >              scmi_powercap: protocol@18 {
> >                  reg = <0x18>;
> >              };
> > +
> > +            scmi_pinctrl: protocol@19 {
> > +                reg = <0x19>;
> > +                #pinctrl-cells = <0>;
> 
> Missing compatible. Schema should catch that...

Only i.MX need compatible here.

Thanks,
Peng.

> 
> > +
> > +                i2c2-pins {
> > +                    groups = "i2c2_a", "i2c2_b";
> > +                    function = "i2c2";
> > +                };
> > +
> > +                mdio-pins {
> > +                    groups = "avb_mdio";
> > +                    drive-strength = <24>;
> > +                };
> > +
> > +                keys_pins: keys-pins {
> > +                    pins = "GP_5_17", "GP_5_20", "GP_5_22", "GP_2_1";
> > +                    bias-pull-up;
> > +                };
> > +            };
> >          };
> >      };
> >
> >
> > --
> > 2.37.1
> >