[U-Boot] smc911x runtime detection (was: TI: OMAP3: Overo Tobi ethernet support)

Olof Johansson olof at lixom.net
Sat Sep 26 23:09:23 CEST 2009


On Sat, Sep 26, 2009 at 09:02:33AM -0700, Ben Warren wrote:

> It is a good idea in principle, but just reading and expecting *something*
> is a fatal flaw.  I don't know about these ones in particular, but
> memory-mapped chips often have ID registers that are RO and have
> well-documented contents.  If somebody can find something like that here,
> let's do it.

Register at offset 0x50 should contain the Chip ID and revision (0x9211 <<
16 | <rev>). It should be a better base for auto-probe.

Actually, the driver already does check it (and verifies it against a
table of known chip revs). By moving that call sooner we can essentially
accomplish the same thing. It also makes sense to move some of the
printouts around to not mess up he probing printouts. I will post a v3
patch for this separately (it also contains the GPIO changes).

I do find the whole "one firmware config for all overo carriers" to be a
little hard to accomplish, since the OMAP gumstix + carrier really is what
is normally considered the "board". On the other hand, having one firmware
that boots on all possible versions is probably preferrably on some level.

For future carrier boards, having an I2C ID EEPROM or similar on there
might not be a bad idea. However, I can't figure out how to contact anyone at
Gumstix without posting on their web forum.

See patch separately.


-Olof


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