topic Does iMX7D ENET2 support MII interface? in i.MX Processors

Does iMX7D ENET2 support MII interface?

ponomarev_ke — Thu, 24 Jun 2021 11:20:41 GMT

I need some clarification about ENET2 in iMX7D processor. We made a custom baseboard for Colibri iMX7D 1GB module, where we connect second Ethernet controller (ENET2) to KSZ8041MLL through MII interface. Now I had a problem with this interface, Linux correctly identify PHY through MDC/MDIO pins and load KSZ8041 driver, I see clock on ENET2_TX_CLK and ENET2_RX_CLK, but I can't see signals in data lines with oscilloscope. I played several days with dts file, but didn't solve the problem (dts file attached to this post)

So I decided to check information in Reference manual and found some strange thing. Table 11.1 in RM describes the external signals of ENET, and for signals RGMII2_RD[0:3], RGMII2_RX_CTL, RGMII2_TD[0:3], RGMII2_TX_CTL there is no MII interface in "Mode" column.

Does it mean, that ENET2 doesn't support MII Interface? Or I just made a mistake in my dts file?

Best regards

Konstantin Ponomarev

Re: Does iMX7D ENET2 support MII interface?

igorpadykov — Fri, 25 Jun 2021 00:30:14 GMT

Hi Konstantin

probably you used old Manual, latest has ENET2 description:

i.MX 7Dual Applications Processor Reference Manual

Best regards
igor

Re: Does iMX7D ENET2 support MII interface?

ponomarev_ke — Fri, 25 Jun 2021 02:51:57 GMT

Hi, Igor

I use the same manual as you offered

Best regards

Konstantin Ponomarev

Re: Does iMX7D ENET2 support MII interface?

igorpadykov — Fri, 25 Jun 2021 06:00:10 GMT

Best regards
igor

Re: Does iMX7D ENET2 support MII interface?

ponomarev_ke — Mon, 28 Jun 2021 10:36:47 GMT

Finally, I have solved the problem. There was a mistake in my dts file.

I attached the correct dts file to this reply, maybe somebody found it useful.