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

[Lars-Peter Clausen]

On 08/28/2014 02:33 AM, Kuninori Morimoto wrote:
>
> 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 ?

Is the sample rate converter a extra module, or is the sample rate converter 
just a feature of the I2S core?

- Lars