> I will check with the xpcs maintainer how can we add indirect access > to the xpcs module. https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c#L449 It creates a regmap for the memory range. On top of that it creates an MDIO bus. You can then access the PCS in the normal way. Andrew