[alsa-devel] Counting links in simple-card

[Daniel Baluta]

On Wed, Oct 9, 2019 at 3:18 AM Kuninori Morimoto
<kuninori.morimoto.gx at renesas.com> wrote:
>
>
> Hi Daniel
>
> > >      * ex1)
> > >      * CPU0 --- Codec0
> > >      * CPU1 --- Codec1
> > >      * CPU2 -----/
> > >      * CPU3 --- Codec2
> > >      *
> > >      *    => 5 links = 2xCPU-Codec + 2xCPU-dummy + 1xdummy-Codec
> > >      *    => 7 DAIs  = 4xCPU + 3xCodec
> > >      *    => 1 ccnf  = 1xdummy-Codec
> > >
> > >
> > > So, I don't understand exactly how did you get the formula for links. AFAICT
> > > there should be 3 x CPU-Codec + 1 x CPU-dummy.
>
> CPU1/CPU2 and Codec1 are using DPCM.
> Thus, it is...
>
>  2xCPU-Codec:
>         CPU0 - Codec0
>         CPU3 - Codec2
>
>  2xCPU-dummy:
>         CPU1 - dummy
>         CPU2 - dummy
>
>  1xdummy-Codec:
>         dummy - Codec1

One more question: How would you describe in the DTS this scenario. Is
this, correct?

machine_drv {
        compatible = "simple-card";

        simple-audio-card,dai-link at 0 {
           cpu {
                  sound-dai=<&cpu0>;
           }
           codec {
                 sound-dai=<&Codec0>;
           }
       }

simple-audio-card,dai-link at 1 {
           cpu {
                  sound-dai=<&cpu3>;
           }
           codec {
                 sound-dai=<&Codec2>;
           }
       }


simple-audio-card,dai-link at 2 {
           cpu {
                  sound-dai=<&cpu1>;
           }
       }



simple-audio-card,dai-link at 3 {
           cpu {
                  sound-dai=<&cpu2>;
           }
       }

simple-audio-card,dai-link at 4{
           cpu {
                  sound-dai=<&Codec1>;
           }
       }
};