[alsa-devel] ASOC, SPDIF and AC97

Mark Brown broonie at opensource.wolfsonmicro.com
Wed May 28 12:14:30 CEST 2008

On Tue, May 27, 2008 at 02:16:54PM -0400, Jon Smirl wrote:

> I'm having trouble with SPDIF. I can make two devices like this in the
> codec file. But how do I get the SPDIF device hooked up to the right
> AC97 slot, 10/11? Are any of the ASOC codecs implementing SPDIF?

None that I know of implementing SPDIF (or at least, none with driver
support for it) but it might be worth taking a look at the PXA2xx AC97
controller support - it implements supports for AC97 timeslots beyond
the base playback and record channels.

Briefly, the approach is to provide a DAI in the AC97 controller driver
which handles the relevant AC97 timeslots and a DAI in the CODEC driver
which does the CODEC side of things then match the two together.

> I also see that the STAC9766 is missing an ac97_patch. From my reading
> of the datasheet it needs somethings fixed up.

> Does the ac97 support belong in the PCI directory? It took me a while
> to locate it while working on ASOC. With a model more like ASOC
> codecs, the AC97 patches could be pushed into the codec files.

The ASoC AC97 support doesn't use the AC97 patch infrastructure at all -
it's completely independent so things are pretty much as you describe,
everything is in the CODEC drivers.

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