In a custom board based on P1020RDB, eTsec3 is set in SGMII mode, so beside eTSEC2, there are two Ethernet interfaces in SGMII mode and naturally eTSEC1 in RGMII mode. Two interfaces are connected to a Gigabit SGMII/SERDES 4-port Ethernet switch on the board, and eTSEC1 to a Vitesse PHY. eTSEC1 works fine, but I could not find an appropriate configuration to be put in device tree (.dts) file for two other SGMII interfaces. When I use p1020rdb.dts which has at least eTSEC2 in SGMII mode, Linux does not detect any eth interface on eTSEC2 (it detects only one for eTSEC1). I appreciate if you could advise me how the .dts file should be modified.
Note that a difference between P1020RDB configuration for eTSEC2 in SGMII board and our board is that in the former, eTSEC is connected to an SGMII PHY, but in our board to an SGMII/Serdes 4-port Ethernet switch. I am not sure if a driver should be installed for the Ethernet switch.
Thank you for your support.