arm64: imx8mp: Read values from M24C32-D write-lockable page on DHCOM i.MX8MP

The new i.MX8M Plus DHCOM rev.200 is populated with M24C32-D EEPROM
that contains an additional write-lockable page called ID page, which
is populated with a structure containing ethernet MAC addresses, DH
item number and DH serial number.

Because the write-lockable page is not present on rev.100 i.MX8MP DHCOM
SoM, test whether EEPROM ID page exists by setting up the i2c driver.

There may be multiple EEPROMs with an ID page on this platform, always
use the first one. The evaluation of the EEPROM ID page is done in two
steps. First, the content is read and checked. This is done to cache
the content of the EEPROM ID page. Second, the content is extracted
from the EEPROM buffer by requesting it.

For the ethernet MAC address the i.MX8M Plus DHCOM currently supports
parsing address from multiple sources in the following priority order:

1) U-Boot environment 'ethaddr'/'eth1addr' environment variable
2) SoC OTP fuses
3) On-SoM EEPROM

Add support for parsing the content of this new EEPROM ID page and place
it between 2) and 3) on the priority list. The new entry is 2.5) On-SoM
EEPROM write-lockable page.

Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Marek Vasut <marex@denx.de>
4 files changed