Hi Mark

...

snd_soc_of_parse_tdm_slot() / snd_soc_dai_set_tdm_slot(). Is slot = 3 in this case ?

...

| |--- 2ch --> | | | CPU |--- 2ch --> | Codec | | |--- 2ch --> | | total 6ch

No, 6 - it's expected to be one slot per channel.

Thanks. We can have total channel number. Then do we have common DT settings/method to indicate below ? I guess we need this settings on both CPU/Codec.

6ch - 2ch x 3 - 6ch x 1 - ...

12ch - 4ch x 3 - 12ch x 1 - 8ch x 1 + 4ch x 1 - ...

Moreover, my IP can output 6ch x 1 sound via 8ch wide (= with empty 2ch). I guess I need this settings on both CPU/Codec too. Do we have common settings/method ?

Hi Mark

...

snd_soc_of_parse_tdm_slot() / snd_soc_dai_set_tdm_slot(). Is slot = 3 in this case ?

...

| |--- 2ch --> | | | CPU |--- 2ch --> | Codec | | |--- 2ch --> | | total 6ch

No, 6 - it's expected to be one slot per channel.

Thanks. We can have total channel number. Then do we have common DT settings/method to indicate below ? I guess we need this settings on both CPU/Codec.

6ch - 2ch x 3 - 6ch x 1 - ...

12ch - 4ch x 3 - 12ch x 1 - 8ch x 1 + 4ch x 1 - ...

Moreover, my IP can output 6ch x 1 sound via 8ch wide (= with empty 2ch). I guess I need this settings on both CPU/Codec too. Do we have common settings/method ?

Hi Mark

...

snd_soc_of_parse_tdm_slot() / snd_soc_dai_set_tdm_slot(). Is slot = 3 in this case ?

...

| |--- 2ch --> | | | CPU |--- 2ch --> | Codec | | |--- 2ch --> | | total 6ch

No, 6 - it's expected to be one slot per channel.

Thanks. We can have total channel number. Then do we have common DT settings/method to indicate below ? I guess we need this settings on both CPU/Codec.

6ch - 2ch x 3 - 6ch x 1 - ...

12ch - 4ch x 3 - 12ch x 1 - 8ch x 1 + 4ch x 1 - ...

Moreover, my IP can output 6ch x 1 sound via 8ch wide (= with empty 2ch). I guess I need this settings on both CPU/Codec too. Do we have common settings/method ?

Hi Mark

Thank you for your help. But I still want to ask about TDM settings

...

Thanks. We can have total channel number. Then do we have common DT settings/method to indicate below ?

There's some stuff already supported for simple-card - see snd_soc_of_parse_tdm_slot(). This won't cover all uses but it should be good for simple uses.

In my check, it is caring about - tdm slot : total channel number - tdm slot width : bit width for each channel (?) - tdm tx/rx mask : active slot (?)

tx/rx mask seems care about active/non-active. We can use it if it sends 6ch sound by using 8ch slot (?).

But it doesn't care about dai connection (?) (= I mean 6ch x 1 or 2ch x 3 etc) "simple card" should be simple, but CPU/Codec need this "dai connection" information ? Otherwise, my CPU/Codec can't setup for TDM (= 6ch x 1 or 2ch x 3 etc). I guess this can be common method, but what do you think ?

And this snd_soc_of_parse_tdm_slot() is called under asoc_simple_card_sub_parse_of(). This means DT is like this ?

sound { compatible = "simple-audio-card"; ...

cpu { sound-dai = <&xxx>; dai-tdm-slot-xxx = <xx>; dai-tdm-slot-xxx = <xx>; }; codec { sound-dai = <&xxx>; dai-tdm-slot-xxx = <xx>; dai-tdm-slot-xxx = <xx>; }; };

But I wonder it should be this ?

sound { compatible = "simple-audio-card"; ...

dai-tdm-slot-xxx = <xx>; dai-tdm-slot-xxx = <xx>;

cpu { sound-dai = <&xxx>; }; codec { sound-dai = <&xxx>; }; };

In my check this "dai-tdm-slot-xxx" is implemented, but no one is using ? ${LINUX}/Documentation/devicetree/bindings/sound/st,sti-asoc-card.txt is including dai-tdm-slot-width, but it seems it is ignored today ?

I would like to expand dai-tdm-slot-xxx 1) use common settings for both CPU/Codec 2) add dai connect information

Best regards --- Kuninori Morimoto

On Fri, Nov 27, 2015 at 08:55:01AM +0000, Kuninori Morimoto wrote:

If my understanding was correct, tdm_slots is not enough for me. Because my CPU/Codec needs to know 6ch by (6ch) or (2ch + 2ch + 2ch) (My CPU can output both style) How to select this ?

I think we'd currently expect the three two channel interfaces to appear as separate DAIs with their own TDM slots, though with routing within the CPU you could just always configure them as a single DAI and then let the choice of connection to the front end DAIs select what gets routed out.