[alsa-devel] Multiple codecs on one sound card for multi-channel sound card

[Caleb Crome]

Ah Ha!  thank you Arnaud!  I'll understand this stuff eventually.
I'll implement as you've shown and see how it goes.

I see that you have 'fsl,imx-audio-foo', using an SSI.  from what I
can see the SSIs only support channels_max=2.  How do you get
multi-channel TDM to work with the freescale SSI port?  I need to get
this TDM working on both TI & Freescale, and the freescale has been
quite problematic because the multi-channel doesn't seem to be
supported in the driver.

I have just checked out and verified that

http://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/

sound/soc/fsl/*ssi*

all have channels_max = 2

We're very motivated to get this working on the freescale MX6, and
getting it to work sure does not seem as simple as changing 2 to a
bigger number :-)


Thanks,
  -Caleb


On Wed, Sep 16, 2015 at 2:57 AM, arnaud.mouiche at invoxia.com
<arnaud.mouiche at invoxia.com> wrote:
> Hello Caleb,
>
> Multi-codec support is now working fine the current linux releases.
> for previous releases, check if commit
>     [PATCH] ASoC: dapm: Don't add prefix to widget stream name
> is included. I remember this is the last required patch.
>
> After that, I don't know if the "simple-card" can be configured for multi
> codec support as you wish.
>
> On my side, I cooked a particular sound card for the purpose.
> here is some tips:
>
>
>     struct snd_soc_dai_link_component codecs[2];
>     struct snd_soc_codec_conf codecs_conf[2];
> [...]
>     for (num_codecs=0; num_codecs<2; num_codecs++) {
>         struct device_node *of_node;
>         of_node = of_parse_phandle(pdev->dev.of_node, "audio-codec",
> num_codecs);
>         if (!of_node) break;
>         data->codecs[num_codecs].of_node = of_node;
>         data->codecs[num_codecs].dai_name = "tlv320aic3x-foo";
>
>         /* add a "C2" name prefix for every control of the 2nd codec */
>         data->codecs_conf[num_codecs].of_node = of_node;
>         if (num_codecs == 1) {
>             data->codecs_conf[num_codecs].name_prefix = "C2";
>         }
>     }
> [...]
>     data->dai.codecs = data->codecs;
>     data->dai.num_codecs = num_codecs;
>     data->card.dai_link = &data->dai;
>     data->card.codec_conf = data->codecs_conf;
>     data->card.num_configs = num_codecs;
> [...]
>
>
> On DTS side, I have something like
>
>     sound at 0 {
>         compatible = "fsl,imx-audio-foo";
>         model = "foo-audio";
>         ssi-controller = <&ssi1>;
>
>         /*
>          * list phandles for the 2 codecs used in the same TDM network
>          */
>         audio-codec = <&codec1>, <&codec2>;
>
>         [...]
>
>     };
>
>
> You also need to have a particular hw_params() method to dispatch the TDM
> and sysclk configuration to your codecs, making the difference between your
> first codec (your bus master) and the others.
>
>
> Arnaud
>
>
> Le 15/09/2015 03:07, Caleb Crome a écrit :
>>
>> (re-sending hope it's not a duplicate -- I think I must have had HTML
>> in my previous email and it was ignored)
>>
>>   Hi all,
>>      What are the current best practices to specify multiple codecs on
>> one sound card, with all codecs sharing a single TDM bus?
>>
>>   I have a card with up to 32 TLV320AIC33 codecs on it.  For the
>> moment, we can limit the discussion to only 16 codecs, so we don't
>> have to get extra serializers involved...
>>
>>   I currently have something like this in my am335x-boneblack.dts file:
>>
>>   (i.e. attempting to set tdm slot width and num in the i2c codec)
>>
>>   but it doesn't seem to be picking up the fact that I want all the
>> codecs linked together as one.
>>
>>   (FYI, the first codec, i.e. tlv32aic3x_a should be the master, and
>> all others including the CPU will be slaves).
>>
>>   Thanks for any help!
>>
>>   BTW, I'm happy to use whatever kernel will support me with the
>> minimal amount of effort, currently using 4.1
>>
>>
>>
>> Thank you!
>>     -Caleb
>>
>> &i2c1 {
>>   ...
>> tlv320aic3x_a: tlv320aic3x at 18 {
>> #sound-dai-cells = <1>;
>> compatible = "ti,tlv320aic3x";
>> reg = <0x18>;
>> tdm-offset = <0>;
>> status = "okay";
>> };
>> tlv320aic3x_b: tlv320aic3x at 19 {
>> #sound-dai-cells = <1>;
>> compatible = "ti,tlv320aic3x";
>> reg = <0x19>;
>> tdm-offset = <32>;
>> status = "okay";
>> };
>> tlv320aic3x_c: tlv320aic3x at 1a {
>> #sound-dai-cells = <1>;
>> compatible = "ti,tlv320aic3x";
>> reg = <0x1a>;
>> tdm-offset = <64>;
>> status = "okay";
>> };
>> tlv320aic3x_d: tlv320aic3x at 1b {
>> #sound-dai-cells = <1>;
>> compatible = "ti,tlv320aic3x";
>> reg = <0x1b>;
>> tdm-offset = <96>;
>> status = "okay";
>> };
>> };
>>
>> &mcasp0 {
>> #sound-dai-cells = <0>;
>> pinctrl-names = "default";
>> pinctrl-0 = <&mcasp_0_pins_default>;
>> status = "okay";
>>
>> op-mode = <0>;          /* MCASP_IIS_MODE */
>> tdm-slots = <16>;
>> num-serializer = <16>;
>> serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
>> 0 0 1 2
>> 0 0 0 0
>> 0 0 0 0
>> 0 0 0 0
>>>
>>> ;
>>
>> tx-num-evt = <1>;
>> rx-num-evt = <1>;
>> };
>>
>> / {
>> sound {
>> compatible = "simple-audio-card";
>> simple-audio-card,name = "puppy-audio";
>> simple-audio-card,mclk-fs = <256>;
>> system-clock-frequency = <12288000>;
>> status = "okay";
>> simple-audio-card,bitclock-master = <&tlv320aic3x_a>;
>>        simple-audio-card,frame-master    = <&tlv320aic3x_a>;
>> simple-audio-card,widgets =
>> "Line", "Line Out",
>> "Line", "Line In";
>> simple-audio-card,routing =
>> "Line Out",       "HPLOUT",
>> "Line Out",       "HPROUT",
>> "Line In",        "LINE1L",
>> "Line In",        "LINE1R";
>>
>> simple-audio-card,dai-link at 0 {
>> format = "left_j";
>> cpu {
>> sound-dai = <&mcasp0>;
>> };
>> codec {
>> sound-dai = <&tlv320aic3x_a 0>;
>> dai-tdm-slot-num = <0>;
>> dai-tdm-slot-width = <16>;
>> };
>> };
>> /**** The stuff below doesn't work -- I can't figure out how to get
>> the name_prefixes set
>>   on each codec... .How do I set up so that each codec gets its own name
>> prfix
>> and so that the soc core thinks all codecs are on the same DAI?
>> **** */
>>
>> // simple-audio-card,dai-link at 1 {
>> // format = "left_j";
>> // cpu {
>> // sound-dai = <&mcasp0>;
>> // };
>> // codec {
>> // sound-dai = <&tlv320aic3x_b 0>;
>> // dai-tdm-slot-num = <2>;
>> // dai-tdm-slot-width = <16>;
>> // };
>> // };
>> // simple-audio-card,dai-link at 2 {
>> // format = "left_j";
>> // cpu {
>> // sound-dai = <&mcasp0>;
>> // };
>> // codec {
>> // sound-dai = <&tlv320aic3x_c>;
>> // dai-tdm-slot-num = <4>;
>> // dai-tdm-slot-width = <16>;
>> // };
>> // };
>> // simple-audio-card,dai-link at 3 {
>> // format = "left_j";
>> // cpu {
>> // sound-dai = <&mcasp0>;
>> // };
>> // codec {
>> // sound-dai = <&tlv320aic3x_d>;
>> // dai-tdm-slot-num = <6>;
>> // dai-tdm-slot-width = <16>;
>> // };
>> // };
>> };
>> };
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