Re: [PATCH v9 3/4] dt-bindings: ethernet-phy: add optional brr-mode flag

[Andrew Lunn]

On Fri, Jun 21, 2024 at 01:26:32PM +0200, Kamil Horák (2N) wrote:
> There is a group of PHY chips supporting BroadR-Reach link modes in
> a manner allowing for more or less identical register usage as standard
> Clause 22 PHY.
> These chips support standard Ethernet link modes as well, however, the
> circuitry is mutually exclusive and cannot be auto-detected.
> The link modes in question are 100Base-T1 as defined in IEEE802.3bw,
> based on Broadcom's 1BR-100 link mode, and newly defined 10Base-T1BRR
> (1BR-10 in Broadcom documents).
> 
> Add optional brr-mode flag to switch the PHY to BroadR-Reach mode.
> 
> Signed-off-by: Kamil Horák (2N) <kamilh@xxxxxxxx>
> Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/net/ethernet-phy.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> index 8fb2a6ee7e5b..0353ef98f2e1 100644
> --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
> @@ -93,6 +93,13 @@ properties:
>        the turn around line low at end of the control phase of the
>        MDIO transaction.
>  
> +  brr-mode:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description:
> +      Request the PHY to operate in BroadR-Reach mode. This means the
> +      PHY will use the BroadR-Reach protocol to communicate with the other
> +      end of the link, including LDS auto-negotiation if applicable.

DT is supposed to describe hardware, not configuration. So i would
have a different description. Say that the coupling to the cable is
that for BroadR-Reach, not standard base-T.

The driver can then imply it needs to configure the hardware to
BroadR-Reach.

	Andrew