[alsa-devel] [PATCH 1/2] ASoC: Add support for Conexant CX2072X CODEC

[Takashi Iwai]

On Wed, 08 May 2019 10:59:53 +0200,
Mark Brown wrote:
> 
> On Wed, May 08, 2019 at 10:16:06AM +0200, Takashi Iwai wrote:
> > Mark Brown wrote:
> 
> > > The GPIO/IRQ equivalence thing should just be a purely Linux internal
> > > thing - looking at the driver it appears that there's no need to look at
> > > the GPIO status, Linux can tell if something is plugged in purely by
> > > reading the chip registers so the jack status function could directly be
> > > the interrupt handler.
> 
> > But it can't see the button status or detect the headset type without
> > reading the codec's magic registers...  So some help from the codec
> > side is required, and the irq handler isn't in the codec side because
> 
> The whole thing should be in the CODEC side.
> 
> > there is no i2c irq assigned but only ACPI gpio, as far as I checked.
> 
> You can map through an ACPI GPIO to an interrupt without worrying about
> the fact that it's mapped as a GPIO in ACPI IIRC - if you can't there's
> lots of other drivers are going to have issues.

But what gives a benefit?  It needs more plumbing between codec and
machine driver.  The i2c probe doesn't give the irq, so you'd need and
extra stuff to enable the irq in a different route if you'd need to
implement the handler in the codec driver.

Actually, my latest patchset already eliminates the exported stuff by
moving to set_jack callback like some other drivers do.  If you have
an idea for further simplification / fixes, let me know.

I haven't submitted because of the merge window.  The patch is found
at topic/soc-cx2072x-5.2 branch, the commit is
  https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git/commit/?h=topic/soc-cx2072x-5.2&id=ca7f4eee5ecbefcf347f5a4984c0a17629360186


thanks,

Takashi