Re: [PATCH v2 2/2] dt-bindings: net: adi,adin: document LP Termination property

Nuno Sá
2026-01-07T10:25:03Z

On Sat, 2025-12-27 at 13:29 +0100, Krzysztof Kozlowski wrote:
> On Mon, Dec 22, 2025 at 05:21:05PM -0500, Osose Itua wrote:
> > Add "adi,low-cmode-impedance" boolean property which, when present,
> > configures the PHY for the lowest common-mode impedance on the receive
> > pair for 100BASE-TX operation.
> >
> > Signed-off-by: Osose Itua <osose.itua@savoirfairelinux.com>
> > ---
> >  Documentation/devicetree/bindings/net/adi,adin.yaml | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/net/adi,adin.yaml
> > b/Documentation/devicetree/bindings/net/adi,adin.yaml
> > index c425a9f1886d..d3c8c5cc4bb1 100644
> > --- a/Documentation/devicetree/bindings/net/adi,adin.yaml
> > +++ b/Documentation/devicetree/bindings/net/adi,adin.yaml
> > @@ -52,6 +52,12 @@ properties:
> >      description: Enable 25MHz reference clock output on CLK25_REF pin.
> >      type: boolean
> >
> > +  adi,low-cmode-impedance:
> > +    description: |
> > +      Ability to configure for the lowest common-mode impedance on the
>
> Either this is ability or you configure the PHY, as written in commit
> msg. The latter suggests that's a SW property, not hardware, thus not
> for bindings.
>

Looking at the datasheet this looks like a system level decision. With the above
it seems we'll actually use more power and it is suited for designs where there is
common-mode noise reaching the phy. So it feels like something we would put in DT...

But I agree the commit message (and maybe the property description) should
be better in reflecting why this is used rather than just saying what are we enabling.

- Nuno Sá