RMII/SMI interface for dual LAN8720 PHY problem

[mariuszslonina]

Hello. I am try design PCB on iMX6Gcv2m05.

i need use both RMII interface but pins configure application reports that is impossible use SMI interface (mdc,mdio) because of pin conflict . only one can be used....

My PCB will work with LAN8720 PHY under LINUX.....

How to resolve this problem ?

[art]

As per the MDIO specification, a single MDIO interface can serve up to 32 PHYs, selected by unique individual addresses. So, the solution (also implemented on the i.MX6UL EVK board) is to assign an unique address to each PHY and use the MDIO interface of a single ENET controller to serve both PHYs.

Have a great day,
Artur

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[mariuszslonina]

Thank You very much for answer. so if I good understand following connection will be done

common  SMI interface shall be used for both PHY

separate  RMII interface shall be used for each PHY

each PHY shall be send different address  internal PHY register

each PHY shall be control by Reset pin, via  GPIO from I.mx device for establishes  PHY address...

please correct me is some are wrong.

Does Linux BSP have interface for multiply PHY address and support this solution? It will work this solution without some deep code modification ?

BR Mariusz.