On Mon, Oct 24, 2011 at 11:20 AM, Mike Frysinger [off-list ref] wrote:

but the question here is about pinctrl. ?does userspace really need to
manipulate the pinmapping ? ?if we agree on that, then the question is
on the userspace interface.

assuming we want this, i can't see the performance argument being made
here for pinctrl. ?which means doing a sysfs interface here like we
already have with GPIO makes the most sense. ?GPIO deals in "binary"
data for the most part (reading/writing 0/1 ints) so the string-based
sysfs parsing is a bit weird, but pinctrl deals with strings
everywhere for selecting mapping groups, so sysfs is the natural
answer.

Hm now I feel I start to agree with you and come back to my
original proposition to do pinctrl in sysfs after all.

I wonder how soon we have a practical use case for this.
We do have this hacked-up driver in ux500:
http://git.linaro.org/gitweb?p=bsp/st-ericsson/linux-3.0-ux500.git;a=tree;f=drivers/staging/ab5500_sim;hb=HEAD

This controls a lot of SIM card pins from userspace...

Yours,
Linus Walleij