Re: [RFC PATCH v2 net-next 13/15] dt-bindings: lynx-pcs: add properties for backplane mode

From: Krzysztof Kozlowski
Date: Sun Sep 24 2023 - 07:49:32 EST


On 23/09/2023 15:49, Vladimir Oltean wrote:
> When the Lynx PCS is deployed on a copper backplane link, it must be
> prepared to handle clause 73 autoneg and clause 72 link training, which
> it can do using a dedicated AN/LT block. The latter doesn't need to be
> described in the device tree, because it is discoverable from the SerDes
> lanes.
>
> The media type that is deployed on the link is not discoverable though,
> so the introduction of a fsl,backplane-mode boolean property appears
> necessary to determine whether the AN/LT block should be employed, or
> left bypassed.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> ---
> v1->v2: patch is new
>
> .../devicetree/bindings/net/pcs/fsl,lynx-pcs.yaml | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/net/pcs/fsl,lynx-pcs.yaml b/Documentation/devicetree/bindings/net/pcs/fsl,lynx-pcs.yaml
> index fbedf696c555..40fbcd80ee2a 100644
> --- a/Documentation/devicetree/bindings/net/pcs/fsl,lynx-pcs.yaml
> +++ b/Documentation/devicetree/bindings/net/pcs/fsl,lynx-pcs.yaml
> @@ -16,11 +16,24 @@ description: |
>
> properties:
> compatible:
> - const: fsl,lynx-pcs
> + enum:
> + - fsl,lx2160a-lynx-pcs
> + - fsl,lynx-pcs
>
> reg:
> maxItems: 1
>
> + phys:
> + maxItems: 4
> + description:
> + phandle for the SerDes lanes that act as PMA/PMD layer when the PCS is
> + part of a copper backplane PHY.
> +
> + fsl,backplane-mode:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description:
> + Indicates that the PCS is deployed over a copper backplane link.
> +

Please extend also existing example. If these do not apply to lynx-pcs,
then they should be disallowed in allOf:if:then.

Best regards,
Krzysztof