Re: [PATCH net-next v3 3/5] dt-bindings: net: dp83867: make exclusivity explicit

[Andrew Lunn]

On Fri, Nov 06, 2026 at 08:47:27AM +0100, Steffen Trumtrar wrote:
> The io_impedance_ctrl nvmem cell and the properties
> ti,{min,max}-output-impedance are mutually exclusive, as noted in the
> ti,max-output-impedance description.
> 
> As this is only stated in the description and not made explicit in the
> schema, the binding checker will not catch if this condition is ignored.
> 
> Make it explicit in the schema that only one of them can be used. With
> that, drop the note, which also described a precedence for device trees
> that the schema now rejects.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/net/ti,dp83867.yaml | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/ti,dp83867.yaml b/Documentation/devicetree/bindings/net/ti,dp83867.yaml
> index 2cd8311ece5e..833540743bdf 100644
> --- a/Documentation/devicetree/bindings/net/ti,dp83867.yaml
> +++ b/Documentation/devicetree/bindings/net/ti,dp83867.yaml
> @@ -7,9 +7,6 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
>  
>  title: TI DP83867 ethernet PHY
>  
> -allOf:
> -  - $ref: ethernet-phy.yaml#
> -
>  # only the PHY ID, not every PHY with the c22 fallback
>  select:
>    properties:
> @@ -67,11 +64,6 @@ properties:
>      description: |
>        MAC Interface Impedance control to set the programmable output impedance
>        to a maximum value (70 ohms).
> -      Note: Specifying an io_impedance_ctrl nvmem cell or one of the
> -        ti,min-output-impedance, ti,max-output-impedance properties
> -        are mutually exclusive. If more than one is present, an nvmem
> -        cell takes precedence over ti,max-output-impedance, which in
> -        turn takes precedence over ti,min-output-impedance.
>  
>    tx-fifo-depth:
>      $ref: /schemas/types.yaml#/definitions/uint32
> @@ -133,6 +125,15 @@ properties:
>        Transmitt FIFO depth- see dt-bindings/net/ti-dp83867.h for applicable
>        values.
>  
> +allOf:
> +  - $ref: ethernet-phy.yaml#
> +  - not:
> +      required: [nvmem-cells, "ti,min-output-impedance"]
> +  - not:
> +      required: [nvmem-cells, "ti,max-output-impedance"]
> +  - not:
> +      required: ["ti,min-output-impedance", "ti,max-output-impedance"]

This is not very readable or obvious. So i suggest keeping the text,
and moving it here.

    Andrew