usb: typec: fusb302: Improve suspend/resume handling

usb: typec: fusb302: Improve suspend/resume handling

Remove the code which avoids doing i2c-transfers while our parent
i2c-adapter may be suspended by busy-waiting for our resume handler
to be called.

Instead move the interrupt handling from a threaded interrupt handler
to a work-queue and install a non-threaded interrupt handler which
normally queues the new interrupt handling work directly.

When our suspend handler gets called we set a flag which makes the new
non-threaded interrupt handler skip queueing the work before our parent
i2c-adapter is ready, instead the new non-threaded handler will record an
interrupt has happened during suspend and then our resume handler will
queue the work (at which point our parent will be ready).

Note normally i2c drivers solve the problem of not being able to access
the i2c bus until the i2c-controller is resumed by simply disabling their
irq from the suspend handler and re-enabling it on resume.

That is not possible with the fusb302 since the irq is a wakeup source
(it must be a wakeup source so that we can do PD negotiation when a
charger gets plugged in while suspended).

Besides avoiding the ugly busy-wait, this also fixes the following errors
which were logged by the busy-wait code when woken from suspend by plugging
in a Type-C device:

fusb302: i2c: pm suspend, retry 1 / 10
fusb302: i2c: pm suspend, retry 2 / 10
etc.

This commit also changes the devm_request_irq to a regular request_irq
+ free_irq, so that the work can be properly stopped. While at it also
properly disable the wake setting on the irq and also properly stop the
delayed work for bcl handling.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>