[PATCH v4 REPOST 18/20] gpio/omap: use pm-runtime framework

[DebBarma, Tarun Kanti]

Todd,
[...]
> > > omap_gpio_mod_init calls mpuio_init calls platform_driver_register
> > > which can't be called in an IRQs off and spinlocked atomic context,
> ...
> > I have isolated mpuio_init() from omap_gpio_mod_init().
> > mpuio_init() is now called once in omap_gpio_probe().
> 
> Looking at omap_gpio_mod_init() it seems like much of its processing
> could probably be done once at probe time (or at pm_runtime_get_sync
> time) as well, namely setting the IRQ enable masks.
This must be called at the beginning of bank access to get reset state.
Otherwise, it would contain settings related to previous bank access.

> 
> Ungating the interface clock, enabling wakeup, setting smart idle for
> the module, and enabling the (old-style) system clock seem like either
> one-time actions at probe, or a part of the pm_runtime_get_sync
> callback.
Yes... sysconfig related settings are done by hwmod framework.
Debounce clocks are enabled in callback.

> 
> Or is there some other reason these power management actions should be
> taken each time a GPIO is requested in the block (when none were
> previously requested), after the runtime PM get_sync callback, but
> not as part of the get_sync callback?  If so, what caused
> the smart idle setting to be lost, or the interface clock gated, if
> not the pm_runtime_put_sync?
I am not sure which smart idle setting you are referring to.
Most stuffs done in *_get_sync() callback can skip first time.
Omap_gpio_mod_init() does resetting irqenable settings to reset value.
This should not be part of callback.
--
Tarun
> 
> 
> Todd
> 
> > > The omap_gpio_mod_init may be unbalanced with the code performed below
> > > on last free of a GPIO for the bank?  If all GPIOs are freed and then
> > > a new GPIO used, does omap_gpio_mod_init do the right thing?  Need a
> > > separate flag to indicate whether one-time init has ever been
> > > performed, vs. needing runtime PM enable/disable?
> > With the above changes I am seeing omap_gpio_mod_init() is balanced.
> > Let me know if I am still missing something.
> > --
> > Tarun