Re: [PATCH net-next 1/3] dt-bindings: net: dsa: lantiq,gswip: reference common PHY properties

[Daniel Golle <daniel@makrotopia.org>]

On Wed, Jan 28, 2026 at 12:25:08AM +0200, Vladimir Oltean wrote:
> On Tue, Jan 27, 2026 at 10:10:58PM +0000, Daniel Golle wrote:
> > Taking a step back I noticed that we need to decide this also for
> > mt7530.
> > 
> > commit bde1ae2d52ab ("net: pcs: pcs-mtk-lynxi: pass SGMIISYS OF node to PCS")
> > currently doesn't pass any fwnode when creating the LynxI PCS.
> > > +               pcs = mtk_pcs_lynxi_create(priv->dev, NULL, regmap,
> > > +                                          MT7531_PHYA_CTRL_SIGNAL3);
> > 
> > However, each PCS does belong to a specific switch port, and it would be
> > advantegous and imho consistent to also assign the ports OF node to the
> > PCS, this would allow to configure the polarities also on the MT7530
> > SerDes ports.
> 
> mt753x_phylink_mac_select_pcs() returns either &priv->pcs[dp->index].pcs
> for TRGMII or priv->ports[dp->index].sgmii_pcs for the rest.
> 
> How would one know (generally speaking) if properties placed in the
> ethernet-port node are for the SGMII PCS or for the other one?

Because of the port number and a fixed assignment of possible external
interface types to each port: On MT7531, port 6 is always connected
to the SerDes PCS. On MT7531AE port 5 is another SerDes PCS, while
on MT7531BE port 5 is (the only) (T)RGMII interface.
So, just like with the MaxLinear GSW1xx port and PCS are tightly
tied together.