[U-Boot] [PATCH v2 2/8] mxs: Fix PULLUP/NOPULL definitions

[Michael Heimpold]

Hi Fabio,

> On mx23 and mx28 the pullup bits are defined as:
> 
> - 0: Enable the internal pad keeper 
> - 1: Disable the internal pad keeper
> 
> Fix the definitions as they are currently the opposite.

Sorry, but I think this is not correct. Please have a look
at the reference manual for i.MX28 page 786:
It seems that some pins have an internal pullup, but other
pins "only" have the internal keeper you mentioned.

Quote from :
bank 0 pin 24: "Set this bit to one to _enable_ the internal pullup..."
bank 0 pin 25: "Set this bit to one to _disable_ the internal keeper..."

So I think the current implementation is correct.

However, if you are trying to enable a pullup for a pin which does not
have this function (e.g. because the hardware guys trimmed the BOM
and did not spend an external pullup) you are actually disabling the
keeper which makes the situation even worse in some situations.

I'm still wondering what an ideal solution could be...

Best regards,
Michael