Re: More Generic Audio Graph Sound Card idea

On Tue, Oct 13, 2020 at 01:50:25PM +0900, Kuninori Morimoto wrote:

...

I'm thinking below style as new audio-graph-card2. It is not tricky, thus connection judgement for normal vs DSP is easy. Then, code can be more readable (= no guaranty :P) ?

I have proposed DPCM connection idea for audio-card2 before, and proposed Multi-CPU/Codec connection idea later. I'm not yet implemented these, but I want to merge / reuse these idea to keep simple code.

By this mail, I want to propose Codec2Codec idea. It is almost same idea with DPCM, Multi-CPU/Codec, and is last parts for missing feature.

I think this idea can be generic and easy to update in the future (if needed).

But, I want feedback, opinion. I wonder does it works for your use-case ?

-- Image ---

Codec2Codec

Codec1 <--> Codec2

-- DT Image --

+--+ => | |<--> Codec1 | |<--> Codec2 +--+

-- DT Sample --

sound { compatible = "audio-graph-card2";

dais = <&codec2codec>;

};

CODEC2CODEC { compatible = "audio-graph-card2-codec2codec";

ports {
	codec2codec: port@0 { fe_ep: endpoint { remote-endpoint = <&codec1_ep>; }; };
	             port@1 { be_ep: endpoint { remote-endpoint = <&codec2_ep>; }; };
};

};

I'm a bit confused about the use of FE and BE here since the two CODECs are peers rather than this being DPCM - I think that's just a bit cut'n'paste rather than anything else though? The other examples look sensible I think but this one feels odd.

-- Image ---

      *******

PCM0 <--> * * <--> DAI0: Codec Headset PCM1 <--> * * <--> DAI1: Codec Speakers PCM2 <--> * DSP * <--> DAI2: MODEM PCM3 <--> * * <--> DAI3: BT * * <--> DAI4: DMIC * * <--> DAI5: FM *******

DSP { compatible = "audio-graph-card2-dsp";

ports@0 {
	/* Front-End is pcm0_ep, Back-End is dummy */
	dsp_fe0: port@0 { dsp_fe0_ep: endpoint { remote-endpoint = <&pcm0_ep>; }; };
	         port@1 { };
};

I'm not clear why we need to represent the dummy port here?