[PATCH v3] driver core / PM: Add PM domain callbacks for device setup/cleanup

"Rafael J. Wysocki" [off-list ref] writes:

From: Rafael J. Wysocki <redacted>

If PM domains are in use, it may be necessary to prepare the code
handling a PM domain for driver probing.  For example, in some
cases device drivers rely on the ability to power on the devices
with the help of the IO runtime PM framework and the PM domain
code needs to be ready for that.  Also, if that code has not been
fully initialized yet, the driver probing should be deferred.

Moreover, after the probing is complete, it may be necessary to
put the PM domain in question into the state reflecting the current
needs of the devices in it, for example, so that power is not drawn
in vain.  The same should be done after removing a driver from
a device, as the PM domain state may need to be changed to reflect
the new situation.

For these reasons, introduce new PM domain callbacks, ->activate,
->sync and ->dismiss called, respectively, before probing for a
device driver, after the probing has completed successfully and
if the probing has failed or the driver has been removed.

Signed-off-by: Rafael J. Wysocki <redacted>
---

One more update taking Dmitry's comments into account and fixing an
overoptimization bug spotted by Ulf.

And this actually contains the patch this time (clicked on "Send" too
early last time, sorry about that).

Reviewed-by: Kevin Hilman <redacted>

Unless I'm missing somthing, this along with the just the genpd part of
Russell's patch should then fix his problem as well.

Kevin