Pinmux bindings proposal V2

[Tony Lindgren]

* Shawn Guo <shawn.guo at linaro.org> [120129 17:27]:
> On Fri, Jan 27, 2012 at 09:16:53AM -0800, Tony Lindgren wrote:
> ...
> > I guess the analog we should follow here is clk_get and clk_set_rate,
> > except we would have pinconf_set_state with predefined states.
> > 
> It seems working for cases that we only change pinconf but never pinmux
> for different configuration states.  But how would that work for cases
> that require mux change for different configuration states?

I don't see why we should not allow changing the mux state with pinconf
too, after all it's the mux/pin that's locked, not the functionality of
the pin.

An example of this would be remuxing a shared UART line between rx and
tx. Those kind of cases could be defined as PMX_DIRECTION_INPUT and
PMX_DIRECTION_OUTPUT so driver could call Linux generic functions for
those if implemented.

Regards,

Tony