Re: [PATCH] ARM: OMAP: mux: add config for 16xx SPI pins

[Mark Howell <mhowell@northlink.com>]

Mark Howell wrote:
> This patch adds pin mux info for the SPI master/slave interface on 
> OMAP16xx. Data from OMAP 1611/1612 TRM and errata. Works for me on my
>  1611/H2 with current git kernel.
> 

I have since spent some lab time with a scope and figured out that I
misunderstood the pull-up config bits in the mux definition structure
(they are inverted vs. what is actually written to the pull-up control 
registers). The patch I posted before works, but it can be better.

I'll post a patch to set better default values for 16xx SPI pin mux
after I get a little more lab time. I don't think this is a burning
issue for anyone 'cept me, since eons had passed without anyone spec'ing
these pins for 16xx SPI anyway :-)

But this brings up a question... there are some other pins where I'm
suspicious of the default pull-up config in mux.c, such as for the
u-wire interface. Won't there be a bit of a power penalty for turning on
pull-up or pull-down when it isn't necessary? Is there some established 
opinion or practice in this group regarding pin mux pull-up config to 
which I can refer?

Cheers,

Mark.