Hi Mark
48kHz ---> 48kHz 44.1kHz ---> [SRC] ---> [codec] 96kHz --->
I would like to confirm about this again.
If yes, and if I want to exchange rate from 96kHz -> 48kHz, I can use be->dai_link->be_hw_params_fixup() for 48kHz settings ?
That's the idea, yes.
I need to add DPCM support for above sample rate convert feature, and, I need it under DT. So, I need to add DPCM DT support as 1st step. Of course I want to add it on simple-card driver.
Q1 About DPCM, if my understanding was correct, the FE/BE for above feature will be like below. Here, CPU (= FE) can covert rate for codec (= BE). But, is it correct ? if not, what is the correct connection ?
FE: CPU <-> dummy BE: dummy <-> codec
Q2 This is extra question, but, if my understanding was correct, DPCM can use "single source (= CPU), multi sink (= codec)" playback ?
Q3. I know Lars-Peter pointed DT idea for DPCM via http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/media...
and, you and Jean-Francois discussed about it in Subject: Re: [alsa-devel] [PATCH] ASoC: generic: add generic compound card with DT support Date: Thu, 2 Jan 2014 13:44:37 +0100
But, it seems that there is no final agreement in ML ?
In my understanding, FE/BE connection is controlled by amixer, this means connection is not statically, but dynamically selected. (Or can we use statically linked FE/BE ?) I think, we can use above video-interfaces.txt idea for DT, but, not 100% good match for us ? Can you show me your DT binding idea for DPCM ? I can study it, and try to implement it.
Best regards --- Kuninori Morimoto