i.MX7 read MAC address via NVMEM driver

GeoffBenn · ‎10-07-2020

We are trying to read the MAC address on an i.MX7.

We've enabled the NVMEM driver.

Then hexdump results in an invalid argument as follows:

# hexdump /sys/bus/platform/drivers/imx_ocotp/30350000.ocotp-ctrl/imx-ocotp0/subsystem/devices/imx-ocotp0/nvmem

hexdump: /sys/bus/platform/drivers/imx_ocotp/30350000.ocotp-ctrl/imx-ocotp0/subsystem/devices/imx-ocotp0/nvmem: Invalid argument

0000000 0103 a003 886a 8ebf 0297 0000

000000c

# hexdump /sys/devices/platform/soc/30000000.aips-bus/30350000.ocotp-ctrl/imx-ocotp0/nvmem

hexdump: /sys/devices/platform/soc/30000000.aips-bus/30350000.ocotp-ctrl/imx-ocotp0/nvmem: Invalid argument

0000000 0103 a003 886a 8ebf 0297 0000

000000c

Note that at the moment the MAC address is unset, and will be set in due course.

igorpadykov · ‎10-07-2020

Hi GeoffBenn

one can look at similar example on

Best regards
igor

GeoffBenn · ‎10-09-2020

Thanks Igor,

Yes, I had seen that, including the successful hexdump.

However, isn't that patch adding "write" functionality, and we arent even getting as far as reading.

The link is broken, but by copying the displayed text, and pasting that it works.

The headline is i.MX8, thought it does also mention imx7s:

Tested imx8mm-evk, imx7s-warp7

I understood that they were quite different...?

Regards,

Geoff

igorpadykov · ‎10-09-2020

Hi Geoff

>I understood that they were quite different...?

it is the same, for example one can look at:

ocotp: ocotp-ctrl@30350000 {
compatible = "fsl,imx8mq-ocotp", "fsl,imx7d-ocotp", "syscon";

Different in i.MX8, i.MX8X families.