[alsa-devel] [PATCH 0/4] ASoC: add graph base connection on simple-card

[Kuninori Morimoto]

Hi Jean

Thank you for your kindly explanation.

> When the cards are defined from a graph of ports, the CPU/CODEC drivers
> do not need to know about this graph if they use a fixed numbering of
> their DAIs (I think this is the case of all existing drivers but the
> ones in my system). There is no useful information for these drivers
> in the DT, so, they don't need any change when moving to a graph of
> ports.
> 
> Such a move is done first in the DT by removing the simple-card node
> and replacing the previous 'dai-link' definitions by couples of ports
> in the CPU (audio controller) and in the CODEC device nodes.
> 
> The previous DAI properties (tdm-slots, clocks...) must also be moved
> to the graph (ports of the graph links). As nothing exists about these
> port properties in the DT documentation, they must be added.
> 
> The previous global (simple-)card properties (widgets, routing..) must
> also be moved. Where? Simply to the main audio controller node.
> They could be named 'audio-xxx' or included in an audio container.
> 
> Now, let's talk about the code. As there is no simple-card device to
> create the card, an other piece of code must do the job.
> The simplest way to run it is to put it in the audio controller:
> when the audio controller scans the DT, it sees the card definitions
> (audio-xxx' or audio container), so, it has all elements to create the
> card.
> This card is as generic as the simple-card, so it could be in the
> sound/soc core.
> 
> So, in brief again: when using a full graph style card:
> - there is no change in the CPU/CODEC drivers,
> - there is no simple-card,
> - the 'audio-graph-card's are created by the audio controllers which
>   run a generic code.

I could understand your idea,
and had read previous some discussions.
I would like to have it on upstream too.
Can you show me about your plan for next step ?