[U-Boot] OMAP3 Beagle Pin Mux initialization issue

Albert ARIBAUD albert.aribaud at free.fr
Fri Feb 25 23:23:34 CET 2011


Le 25/02/2011 22:44, Bob Feretich a écrit :

> For the BeagleBoard, the pins of interest are the ones routed to the
> Expansion, J4, and J5 connectors. I am working with a local university.
> Students are building projects that interface to these connectors.
> Usually, the Linux boot delay is not a concern, but depending on the
> project, sometimes the pins need to be initialized before a "set time
> interval after power-on" expires (We can set the power-on reset delay to
> several hundreds milliseconds, but the time must be bounded.)

Can you not simply set this time high enough that the U-Boot script 
executes?

> By having the spot (beagle.c&  beagle.h) in u-boot, where we can add our
> I/O Pin Mux initialization code, we can satisfy the needs of a bounded
> I/O initialization time.

Out of sheer curiosity (I've done some lab teaching in assembly language 
and device control in a previous life), what are those IOs that have 
such a bounded set-up time relative to power-on in a university project? 
If you are willing to answer but find that's really not related to 
U-Boot, we can discuss this in private.

> Regards,
> Bob Feretich

Amicalement,
-- 
Albert.


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