[alsa-devel] How to select input from muxer in front of SSI on i.MX6

Nicolin Chen nicoleotsuka at gmail.com
Fri Sep 19 19:52:06 CEST 2014


CCed Mark and Liam.

On Fri, Sep 19, 2014 at 05:18:08PM +0200, Jean-Michel Hautbois wrote:
> Hi,
> 
> I am now working on making my audio path working completely.
> And I get some difficulties to write a DT for my needs.
> I join a picture which is not the reality but a simplified version of the board.
> 
> I have a FPGA between my codecs and my i.MX6. This FPGA is responsible
> of lots of things, and in particular of muxing signals.
> I can program it in order to get the audio signal I want on the SSI I
> want (so sgtl5000 can ben on SSI1 or SSI2 or both). This path is not a
> single codec, but a multiple codec one.
> So I can have on SSI1 LineIn from sgtl5000 or audio from hdmi (adv7611).
> 
> I don't know how to write it in DT, regarding audmux for instance, and
> the sound{} node...
> And I don't know how to drive all these peripherals (from arecord, I
> wish I have hw:0,0 is LineIn, hw:0;1 is HDMI, etc.).

This looks like a DPCM (Documentation/sound/alsa/soc/DPCM.txt) to me.

I'm not sure how to write a DT for DPCM either. But it seems that you
might need a specific machine driver (guessing).

I saw Morimoto-san plans to add DPCM into Simple Card, but not sure
when they will finish it. Otherwise, you may use Simple Card while
following their defined DT formats.

Nicolin


More information about the Alsa-devel mailing list