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

[Fabio Estevam]

Hi Michael,

On Thu, May 2, 2013 at 3:44 PM, Michael Heimpold <mhei at heimpold.de> wrote:

> 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.

Ok, I see.

mx23 does not have the "Set this bit to one to _enable_ the internal
pullup" option.

>
> 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...

So I plan to keep mx28 bits untouched and do the reverse definition
only for mx23:

#if defined CONFIG_MX28
#define PAD_PULLUP		1
#define PAD_NOPULL		0
#else
#define PAD_PULLUP		0
#define PAD_NOPULL		1
#endif