[alsa-devel] [PATCH 1/3] ASoC: Add GPIO support for jack reporting interface

[Mark Brown]

On Sun, Mar 01, 2009 at 07:54:36PM -0600, Lopez Cruz, Misael wrote:

> detection/report. There can be a generic detection/report function
> for gpio, I was thinking in something like:

Yes, that's more or less much what I was looking for.

> > Some systems won't be able to use their speaker output while a
> > headphone is connected and so will want to make sure to update
> > both speaker and headphone when the headphone jack status
> > changes.

> Having a single/generic report function like shown above (as is) we
> can't handle that case.

Sure it can - remember that the DAPM updates are done separately to the 
detection and can be set to invert the status reported for the power.
The speaker won't be visible as a jack in a situation like this.

> Could we leave the actual implementation of this report function to
> the machine driver? Since the things being done in detection function
> are common (even if other status are wanted to be updated), then
> probably machine driver could define a specific function ("action")
> for doing extra tasks, it can be called from generic gpio detect
> function. Could it be a valid approach?

That sounds like adding a callback for power updates on the jack itself
to me (which isn't a bad idea), rather than changing the report function
of the jack detection method.  The need for machine-specific extra
actions probably isn't specific to jacks that are detected via GPIOs.