Subject: Re: [PATCH net-next v5 10/12] dt-bindings: net: dsa: lantiq,gswip: add support for MaxLinear GSW1xx switches

From: Rob Herring <[email-masked]>
Date: Thu, 30 Oct 2025 19:35:40 -0500

On Thu, Oct 30, 2025 at 11:29:50AM +0000, Daniel Golle wrote:
> Extend the Lantiq GSWIP device tree binding to also cover MaxLinear
> GSW1xx switches which are based on the same hardware IP but connected
> via MDIO instead of being memory-mapped.
> 
> Add compatible strings for MaxLinear GSW120, GSW125, GSW140, GSW141,
> and GSW145 switches and adjust the schema to handle the different
> connection methods with conditional properties.
> 
> Add MaxLinear GSW125 example showing MDIO-connected configuration.
> 
> Signed-off-by: Daniel Golle <[email-masked]>
> ---
> v5:
>  * drop maxlinear,rx-inverted from example
> 
> v4:
>  * drop maxlinear,rx-inverted and maxlinear,tx-inverted properties for
>    now in favor of upcoming generic properties
> 
> v3:
>  * add maxlinear,rx-inverted and maxlinear,tx-inverted properties
> 
> v2:
>  * remove git conflict left-overs which somehow creeped in
>  * indent example with 4 spaces instead of tabs
> 
>  .../bindings/net/dsa/lantiq,gswip.yaml        | 266 +++++++++++++-----
>  1 file changed, 193 insertions(+), 73 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml b/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml
> index ab3ee4ecd938..ee42c2e099e2 100644
> --- a/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml
> +++ b/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml
> @@ -4,7 +4,12 @@
>  $id: http://devicetree.org/schemas/net/dsa/lantiq,gswip.yaml#
>  $schema: http://devicetree.org/meta-schemas/core.yaml#
>  
> -title: Lantiq GSWIP Ethernet switches
> +title: Lantiq GSWIP and MaxLinear GSW1xx Ethernet switches
> +
> +description:
> +  Lantiq GSWIP and MaxLinear GSW1xx switches share the same hardware IP.
> +  Lantiq switches are embedded in SoCs and accessed via memory-mapped I/O,
> +  while MaxLinear switches are standalone ICs connected via MDIO.
>  
>  $ref: dsa.yaml#
>  
> @@ -37,6 +42,100 @@ patternProperties:
>                Configure the RMII reference clock to be a clock output
>                rather than an input. Only applicable for RMII mode.
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - lantiq,xrx200-gswip
> +              - lantiq,xrx300-gswip
> +              - lantiq,xrx330-gswip
> +    then:
> +      properties:
> +        reg:
> +          minItems: 3
> +          maxItems: 3
> +          description: Memory-mapped register regions (switch, mdio, mii)
> +        reg-names:
> +          items:
> +            - const: switch
> +            - const: mdio
> +            - const: mii
> +        mdio:
> +          $ref: /schemas/net/mdio.yaml#
> +          unevaluatedProperties: false
> +
> +          properties:
> +            compatible:
> +              const: lantiq,xrx200-mdio
> +
> +          required:
> +            - compatible
> +        gphy-fw:
> +          type: object
> +          properties:
> +            '#address-cells':
> +              const: 1
> +
> +            '#size-cells':
> +              const: 0
> +
> +            compatible:
> +              items:
> +                - enum:
> +                    - lantiq,xrx200-gphy-fw
> +                    - lantiq,xrx300-gphy-fw
> +                    - lantiq,xrx330-gphy-fw
> +                - const: lantiq,gphy-fw
> +
> +            lantiq,rcu:
> +              $ref: /schemas/types.yaml#/definitions/phandle
> +              description: phandle to the RCU syscon
> +
> +          patternProperties:
> +            "^gphy@[0-9a-f]{1,2}$":
> +              type: object
> +
> +              additionalProperties: false
> +
> +              properties:
> +                reg:
> +                  minimum: 0
> +                  maximum: 255
> +                  description:
> +                    Offset of the GPHY firmware register in the RCU register
> +                    range
> +
> +                resets:
> +                  items:
> +                    - description: GPHY reset line
> +
> +                reset-names:
> +                  items:
> +                    - const: gphy
> +
> +              required:
> +                - reg
> +
> +          required:
> +            - compatible
> +            - lantiq,rcu
> +
> +          additionalProperties: false
> +      required:
> +        - reg-names
> +    else:
> +      properties:
> +        reg:
> +          maxItems: 1
> +          description: MDIO bus address
> +        reg-names: false
> +        gphy-fw: false
> +        mdio:
> +          $ref: /schemas/net/mdio.yaml#
> +          unevaluatedProperties: false
> +
>  maintainers:
>    - Hauke Mehrtens <[email-masked]>
>  
> @@ -46,78 +145,11 @@ properties:
>        - lantiq,xrx200-gswip
>        - lantiq,xrx300-gswip
>        - lantiq,xrx330-gswip
> -
> -  reg:
> -    minItems: 3
> -    maxItems: 3
> -
> -  reg-names:
> -    items:
> -      - const: switch
> -      - const: mdio
> -      - const: mii
> -
> -  mdio:
> -    $ref: /schemas/net/mdio.yaml#
> -    unevaluatedProperties: false
> -
> -    properties:
> -      compatible:
> -        const: lantiq,xrx200-mdio
> -
> -    required:
> -      - compatible
> -
> -  gphy-fw:
> -    type: object
> -    properties:
> -      '#address-cells':
> -        const: 1
> -
> -      '#size-cells':
> -        const: 0
> -
> -      compatible:
> -        items:
> -          - enum:
> -              - lantiq,xrx200-gphy-fw
> -              - lantiq,xrx300-gphy-fw
> -              - lantiq,xrx330-gphy-fw
> -          - const: lantiq,gphy-fw
> -
> -      lantiq,rcu:
> -        $ref: /schemas/types.yaml#/definitions/phandle
> -        description: phandle to the RCU syscon
> -
> -    patternProperties:
> -      "^gphy@[0-9a-f]{1,2}$":
> -        type: object
> -
> -        additionalProperties: false
> -
> -        properties:
> -          reg:
> -            minimum: 0
> -            maximum: 255
> -            description:
> -              Offset of the GPHY firmware register in the RCU register range
> -
> -          resets:
> -            items:
> -              - description: GPHY reset line
> -
> -          reset-names:
> -            items:
> -              - const: gphy
> -
> -        required:
> -          - reg
> -
> -    required:
> -      - compatible
> -      - lantiq,rcu

All this should remain rather than being under an if/then schema. If you 
need something so different, then it should probably be a separate 
schema file. If there's some common parts, then a common schema shared 
between 2 or more specific bindings.

Rob