At present, there is support for single-port Ethernet modules, but there are some scenarios that require Ethernet daisy chains. I found a lot of information and found that the supported LAN8720 and LAN9303 are very similar. I hope the community can add the functions of the LAN9303 Ethernet chip.

it is very similar to the LAN8720. Only 1 register (that is used) is different - the PSCSR(PHY Special Control Status Register). Which, is still mostly the same. The only functional difference is in the function lan8720_negotiate, where it polls this PSCSC for a pscsr.auto_nego_done - which the LAN9303 does not have. So just edit out this check

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