[alsa-devel] [PATCH 8/8] ASoC: add snd-soc-dummy DT support

Kuninori Morimoto kuninori.morimoto.gx at gmail.com
Thu Aug 28 02:33:55 CEST 2014


Hi Lars

Thank you for your comment

> > 	sound {
> > 		compatible = "simple-audio-card";
> >
> > 		/* FrontEnd */
> > 		simple-audio-card,dai-link at 0 {
> > 			...
> > 			format = "left_j";
> > 			remote = <&endpoint>;
> >
> > 			cpu {
> > 				sound-dai = <&rcar_sound 0>;
> > 			};
> > 			codec { /* dummy */ };
> > 		};
> >
> > 		/* BackEnd */
> > 		endpoint: simple-audio-card,dai-link at 1 {
> > 			...
> > 			format = "left_j";
> >
> > 			cpu { /* dummy */ };
> > 			codec1: codec {
> > 				sound-dai = <&ak4643>;
> > 			};
> > 		};
> > 	};
> 
> When you try to come up with with a binding try to completely ignore that 
> something call DPCM exists. The binding is supposed to describe the hardware 
> and how the different hardware components are interconnected. So try to come 
> up with a binding that accurately describes the hardware connections. Once 
> that is done try to map the binding onto the existing software framework. 
> The last step may require some adjustments to the framework.

Now, my system is working well with simple-card by this

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

		cpu {
			sound-dai = <&rcar_sound 0>;
		};
		codec {
			sound-dai = <&ak4643>;
		};
	};

The reason why I'm tring to support DPCM on simple-card is "sampling rate convert".
My rcar_sound can convert sampling rate, and I tried to add this feature as
rcar_sound property.
But, Mark rejected and requests me to use DPCM for it,
since it can be common featrue.
Current existing simple-card can't use it, and I'm tring.
But, am I misunderstanding ?

Best regards
---
Kuninori Morimoto


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