Re: [PATCH 2/5] dt-bindings: net: add schema for NXP S32CC dwmac glue driver

[Andrew Lunn <andrew@lunn.ch>]

> > > +      - description: Main GMAC clock
> > > +      - description: Peripheral registers clock
> > > +      - description: Transmit SGMII clock
> > > +      - description: Transmit RGMII clock
> > > +      - description: Transmit RMII clock
> > > +      - description: Transmit MII clock
> > > +      - description: Receive SGMII clock
> > > +      - description: Receive RGMII clock
> > > +      - description: Receive RMII clock
> > > +      - description: Receive MII clock
> > > +      - description:
> > > +          PTP reference clock. This clock is used for programming the
> > > +          Timestamp Addend Register. If not passed then the system
> > > +          clock will be used.

> Not clear to me has been whether the PHY mode can be switched at runtime
> (like DPAA2 on Layerscape allows for SFPs) or whether this is fixed by board
> design.

Does the hardware support 1000BaseX? Often the hardware implementing
SGMII can also do 1000BaseX, since SGMII is an extended/hacked up
1000BaseX.

If you have an SFP connected to the SERDES, a fibre module will want
1000BaseX and a copper module will want SGMII. phylink will tell you
what phy-mode you need to use depending on what module is in the
socket. This however might be a mute point, since both of these are
probably using the SGMII clocks.

Of the other MII modes listed, it is very unlikely a runtime swap will
occur.

	Andrew