Hello Morimoto-san,

On Mon, Nov 20, 2023 at 6:36 AM Kuninori Morimoto kuninori.morimoto.gx@renesas.com wrote:

Hi Daniel, Mark

...

We can specify DAI id using reg property. When dts node has only 1 DAI simple-card always assumes that DAI id is 0.

But this is not correct in the case of SOF for example which adds DAIs staticaly (See definition of snd_soc_dai_driver in sound/soc/sof/imx/imx8m.c)

(snip)

...

• args.args_count = (of_graph_get_endpoint_count(node) > 1);
  

• args.args_count = (of_graph_get_endpoint_count(node) >= 1);
  

If my understanding was correct, for example you want to use 2nd DAI but your DT has only 1 port (thus, it is using reg property) ?

Yes.

Current simple utils is assuming (1) DT has all DAI settings, (2) having reg property is option.

But current DT requests reg property. So maybe it is good time to remove non-reg-property support ?

I have no problem removing non-reg-property support. This will work for me. Will later send a patch.

I want to understand how current non-reg-property support works.

I'm looking at commit 73b17f1a65c881fc ("SoC: simple-card-utils: support snd_soc_get_dai_id()").

So, the reg property was introduced for cases where we can have ports of different types? E.g In the case of HDMI we can have Audio ports and Video ports? And we need reg property in order to get the correct DAI id?

I don't understand how DAI id is currently computed if we don't have the reg property and also we have Non HDMI sound case:

Here is the code:

» /* » * Non HDMI sound case, counting port/endpoint on its DT » * is enough. Let's count it. » */ » i = 0; » id = -1; » for_each_endpoint_of_node(node, endpoint) { » » if (endpoint == ep) » » » id = i; » » i++; » }

» of_node_put(node);

So, this code assumes that the DAI id is exactly the number of the port, right? But this is wrong if we have a component (port) with multiple DAIs attached.

Daniel.

On Tue, Nov 21, 2023 at 1:04 AM Kuninori Morimoto kuninori.morimoto.gx@renesas.com wrote:

Hi Daniel, Mark

...

...

...

• args.args_count = (of_graph_get_endpoint_count(node) > 1);
  

• args.args_count = (of_graph_get_endpoint_count(node) >= 1);
  

If my understanding was correct, for example you want to use 2nd DAI but your DT has only 1 port (thus, it is using reg property) ?

Yes.

But hmm... in your case, you need to setup 2ports, and use 2nd port is assumed approach. Why you don't setup full port ? Do you have some reason ??

I'm not sure I understand what is a full port setup. But let me describe my scenario so that we have a common ground.

I want to use audio-graph-card2 machine driver to setup Sound Open Firrmware cards.

Here we start with a normal link with the following components:

Component 0 (DAI) : 3b6e8000.dsp (See sound/soc/sof/core.c: 280) -> for imx8m this has 3 statically defined DAIs See sound/soc/sof/imx/imx8m.c:

static struct snd_soc_dai_driver imx8m_dai[] = { { // DAI with index 0 » .name = "sai1", }, { // DAI with index 1 » .name = "sai3", }, { / // DAI with index 2 » .name = "micfil", }, };

Component 1 (Codec): wm8960-hifi -> with 1 DAI

static struct snd_soc_dai_driver wm8960_dai = { » .name = "wm8960-hifi", };

Now, I want to write a DTS description where my DAI link uses Component 0 (CPU) (with its DAI index 1) connected with Component 1 (codec) (with its DAI index 0).

So, for this I use the following dts snippet:

sof-sound-wm8960 { » » compatible = "audio-graph-card2"; » » links = <&cpu>; }

dsp: dsp@3b6e8000 { cpu: port@1 { » » reg = <1>; » » cpu_ep: endpoint { remote-endpoint = <&codec_ep>; }; » }; }

wm8960 {

» port { » » codec_ep: endpoint { remote-endpoint = <&cpu_ep>; }; » }; }

So, property reg = <1> refferes to DAI with index 1 associated with component DSP.

On Wed, Nov 22, 2023 at 5:39 AM Kuninori Morimoto kuninori.morimoto.gx@renesas.com wrote:

Hi Daniel

...

...

But hmm... in your case, you need to setup 2ports, and use 2nd port is assumed approach. Why you don't setup full port ? Do you have some reason ??

(snip)

...

Now, I want to write a DTS description where my DAI link uses Component 0 (CPU) (with its DAI index 1) connected with Component 1 (codec) (with its DAI index 0).

Thank you for indicating your DTS.

So in imx8m_dai case, it has total 3 DAIs, and you want to use reg = 1. In such case, your DTS need to have like below, if my understanding was correct.

    dsp: dsp@3b6e8000 {
            ports {
                         port@0 { reg = <0>;         endpoint { /* not used */ };  };
                    cpu: port@1 { reg = <1>; cpu_ep: endpoint { remote-endpoint = <xxx>; }; };
                         port@2 { reg = <2>;         endpoint { /* not used */ };  };
            };
    };

This works! Thanks. I didn't know that you can leave an endpoint unused :).

So please ignore my initial patch then.