On Wed, Oct 24, 2012 at 6:57 PM, Felipe Balbi [off-list ref] wrote:

On Wed, Oct 24, 2012 at 09:18:01AM -0700, Dmitry Torokhov wrote:

quoted

OK, so with drivers/base/, have you considered doing default pinctrl
selection in bus's probe() methods? Yo would select the default
configuration before starting probing the device and maybe select idle
when probe fails or device is unbound? That would still keep the link
between device object and pinctrl and there less busses than device
drivers out there.

it starts to become confusing after a while. I mean, there's a reason
why all drivers explictly call pm_runtim_enable(), right ?

From a first thought, one could think of just yanking that into bus'
probe() as you may suggest, but sometimes the device is already enabled,
so we need extra tricks:

pm_runtime_set_active();
pm_runtime_enable();
pm_runtime_get();

the same could happen with pinctrl eventually. What if a device needs to
do something else (an errata fix as an example) before requesting
pinctrl's default state ?

I can confirm this. Just the ordering between enabling/disabling
resources like clock/pins/powerdomain screw things up for us
and even if we can surely centralize parts of this code as such
into the drivers/base or pm_* namespace we would still need
explicit calls from the driver.

I'm thinking that maybe the best helpers are actually static
inline functions in the <linux/pinctrl/consumer.h> header
rather than moving anything into drivers/base/* if the
code duplication is the real problem.

Yours,
Linus Walleij