Re: [PATCH] pwm-pca9685: Allow any of the 16 PWMs to be used as a GPIO

[Clemens Gruber <clemens.gruber@pqgruber.com>]

On Thu, Oct 20, 2016 at 02:51:44PM +0200, Thierry Reding wrote:
> I'm reluctant to add this to the PWM core because it's effectively
> duplicating something for which a proper subsystem already exists.
> 
> If adding pinmux is considered overkill, maybe doing so needs to be
> simplified. Surely if this is applicable to more than one PWM controller
> some helpers could be extracted to make it easier to add.
> 
> But if it isn't generally useful I don't think it makes sense to add it
> to the PWM core either. So I think our choices here are to register via
> pinmux and in the process add helpers to make that easier (remove the
> overkill) or to keep this to the driver until we start seeing a pattern
> emerge.

But the fact that this one pwm chip bypasses PWM control and acts as a
GPO is an implementation detail of the chip, this feature is helpful for
other PWM chips too, as long as they don't toggle.
Would this really be a good fit in the pinmux subsystem?

I really like the idea of Mika to add a gpio_set callback in pwm_ops and
let the pwm core export a GPIO chip. For now we could add this callback
only to the pwm-pca9685 driver but others could opt-in if needed.

But the initial patch from Mika is fine too, in my opinion.

Regards,
Clemens