[RFC 1/3] pinctrl: add a driver for the OMAP pinmux

[Linus Walleij]

On Tue, Nov 22, 2011 at 6:54 PM, Tony Lindgren <tony at atomide.com> wrote:

> Note that with device tree things get simpler for muxing as we can
> get rid of the hardcoded grouping of pins in mux drivers. Instead of
> hardcoded pingroups, the groups can be created dynamically based on
> what the driver DT entries have.

Yes, I know too little about DT to figure out how these should
come in.

> The reason why we want to avoid hardcoded pin groups is because trying
> to map all the pad combinations in the pinmux driver is not a scalable
> way to go. And it's not even possible at least on omaps because of the
> huge number of combinations with alternative pins and multiple packages.

Yes, that's a solid case!

> FYI I'm playing with a DT based pinmux-simple.c driver that should
> be pretty generic and work for all kinds of hardware hopefully.

I love it.

> It will be few days before I can post anything though, there are
> some pinctrl fwk issues to deal with first. Like the hardcoded
> pinmux_maps that assumes that dev entries are static. This means
> that multiple instances of pinmux drivers won't work..

I'm not following, but I guess I will understand when I see the
patches. The idea behind the current map concept is that you
get either a string or struct device * to identify the pin controller
and mapped device, that's as far as I thought it out, sorry for
any inherent limitations, they're not intentional...

Thanks,
Linus Walleij