net: phy: Dealing with 88e1543 dual-port mode

[Andrew Lunn]

Hi Maxime

> The way this works is that the PHY is internally configured by chaining
> 2 internal PHYs back to back. One PHY deals with the Host interface and
> is configured as an SGMII to QSGMII converter (the QSGMII is only used
> from within the PHY), and the other PHY acts as the Media-side PHY,
> configured in QSGMII to auto-media (RJ45 or Fiber (SFP)) :
> 
>                 +- 88e1543 -----------------------+
> +-----+         | +--------+          +--------+  |  /-- Copper (RJ45)
> |     |--SGMII----| Port 0 |--QSGMII--| Port 1 |----<
> |     |         | +--------+          +--------+  |  \--- Fiber
> | MAC |         |                                 |
> |     |         | +--------+          +--------+  |  /-- Copper (RJ45)
> |     |--SGMII----| Port 2 |--QSGMII--| Port 3 |----<
> +-----+         | +--------+          +--------+  |  \-- Fiber
>                 +---------------------------------+

Does this mean you need a dual port MAC as well?

Do we need to configure the MUX in the MAC?

	  Andrew