Ah okay. I didn't consider the switch architecture where the data interface
of the PHY is connected to the switch, and the PHY management interface is
connected to the mdio bus that the switch is connected to.
The generic Linux architecture for PHYs and binding them to a MAC via
a phandle allows the PHY to be on any MDIO bus anywhere. DSA has some
additional shortcuts to support 1:1 mapping if the switch has its own
MDIO bus, without describing it in DT, but this is just in addition to
the generic code.
Not json-schema documentation, don't care about:
- ar9331.txt
- lan9303.txt
- lantiq-gswip.txt
- marvell.txt
The marvell switch can have up to 2 MDIO busses. If i remember
correctly, there is also one switch which has one MDIO bus per port.