On Tue, Jun 4, 2013 at 8:15 PM, Kevin Hilman [off-list ref] wrote:

[Me]

quoted

I think this will save a *lot* of identical code in all the
drivers, that will just have to call
pinctrl_select_pm_sleep(), pinctrl_select_pm_default()
pinctrl_select_pm_idle() instead of all the complex code.

This is what I planned to do but never got around to.

What about taking it one tiny step further, and having it done by the PM
core itself?

Maybe so, but atleast currently we cannot do it
exclusively in the PM core.

We have things like what you find in
drivers/tty/serial/amba-pl011.c
where pl011_shutdown() puts the pins into sleep mode
on unused TTYs.

The same applies to any unused ports like that, we're
thinking of a way to sleep pins for unused I2C hosts
for example.

And that works fine also on systems that does not
enable CONFIG_PM (so the pin control subsystem
is completely orthogonal). But maybe that is
complicating things? I was just thinking it was a bit
thick to require everything and its dog to make a
complete transition to (runtime)PM.

Yours,
Linus Walleij