[U-Boot] [PATCH v6] Add support for the digsy MTC board.

Grzegorz Bernacki
2009-03-17T09:05:43Z

Wolfgang Denk wrote:
> Dear Grzegorz Bernacki,
>
> In message <49BA2C42.5080903@semihalf.com> you wrote:
>>> Is such a scenario (MAC address split across 2 different EEPROM
>>> devices) possible (and supported) on these systems?
>> I think it is possible, cause whole eeprom is threated as a one continuous
>> area. Moreover, this function is called only if ethaddr environment variable
>> is not set, so not very often. I don't think optimizing it is worth risk of
>> reading incorrect ethernet address.
>
> You mean, there is actually only *one* phyical EEPROM chip on the
> board? Then the I2C driver is supposed to support reading / writing
> accross page boundaries.
>

Yes, it is one physical chip divided into 4 blocks. The chip is organized
so that accessing different blocks requires using different i2c slave
addresses, effectively making the chip appear as several i2c slaves.
The logic to handle such addressing is already implemented in the eeprom
access functions in the common/cmd_eeprom.c. Next version of the patch
will just use that existing read method.

regards,
Grzesiek