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

[Jean-Michel Hautbois]

Hi Mark,

2014-09-24 10:21 GMT+02:00 Mark Brown <broonie at kernel.org>:
> On Tue, Sep 23, 2014 at 08:11:27AM +0200, Jean-Michel Hautbois wrote:
>> Le 23 sept. 2014 03:51, "Mark Brown" <broonie at kernel.org> a écrit :
>
>> > Depending on what the system looks like it's not at all clear that there
>> > should be any visibility at all of DPCM in the DT - it's a detail of how
>> > Linux is implemented at the end of the day.
>
>> So this should definitely be implemented directly in a specific driver for
>> my FPGA which is a DPCM right ?
>
> No, that's really not what DPCM is all about...  if this is a physically
> separate device that's not got direct memory access it's probably more
> appropriate to represent as a CODEC.  I was CCed in part way so don't
> entirely know.

OK, sorry for my late answer, but I was on a lot of things at the same time :/.
Well, here is a tentative to explain what I want to do :
http://paste.kde.org/pwijzty2p
The objective is to develop the "Mux I²S" part, as this is in fact a
FPGA with I²C registers which tell which input should go on which
output.

I am reading Alsa docs, in order to fully understand what should be
done, but it seems that this is nothing more than a simple codec with
no effect on audio parameters... It should be visible in alsa mixer
though, in order to drive the inputs from user space easily.

I hope this is clearer...
Thanks !
JM