RE: [PATCH v2 4/5] net: hpe: Add GXP UMAC Driver

From: Hawkins, Nick
Date: Wed Aug 09 2023 - 19:56:27 EST


> > > So what you call a PHY is probably a PCS. Please look at the API used
> > > in driver/net/pcs/. The real PHYs are external.
> >
> > I doubled checked the internal PHY is considered a PHY, but I believe
> > I can represent it as a PCS.

Hi Andrew,

Thank you for the additional information.

> Is there proper documentation somewhere? register set? Is there
> registers to kick off Base1000X/SGMII auto-neg? Somewhere to get the
> results of the auto-neg? Since this is Base1000X/SGMII you want to
> know if the link between it and the external PHY has established. And
> if there is not an external PHY, but an SFP, this auto neg is with the
> link peer, not the PHY. If it follows 802.3 clause 37, there should
> already be a lot of helper code for you. Is this is licensed core?

After discussing with the ASIC team:
The vendor IP in our ASIC performs a parallel GMII to serial SGMII
translation, including clock recovery and framing. It implements
the entire IEEE 802.3z PCS and is managed with a MCD/MDIO
serial interface. The SGMII interface connects to an external PHY
(and the external PHY is managed with a separate MDIO interface).

Thanks,

-Nick Hawkins