On 09-01-2024 07:47, Kuninori Morimoto wrote:
/-----> codec1 endpoint
/
CPU endpoint \
\-----> codec2 endpoint
It sounds "Single CPU - Mult Codec" connection, and if my understanding
was correct, current ASoC is not supporting it so far.
Yes, this is a typical TDM use case.
__soc_pcm_hw_params() call in soc-pcm.c loops over all CODECs for a
given rtd. So is there something else you are referring to which makes
ASoC core doesn't work?
But dummy CPU with Multi-CPU/Codec connection helps you ?
I'm not 100% sure though...
See
${LINUX}/sound/soc/generic/audio-graph-card2-custom-sample.dtsi
DT looks like
[Multi-CPU/Codec]
+-+ +-+
cpu <--| |<-@--------->| |-> codec1
dummy <--| | | |-> codec2
+-+ +-+
Use Multi-CPU/Codec connection with dummy.
audio-graph-card2 {
compatible = "audio-graph-card2";
links = <&mcpu>;
multi {
ports@0 {
/* [Multi-CPU] */
mcpu: port@0 { mcpu0_ep: endpoint { remote-endpoint = <&mcodec0_ep>; }; };
port@1 { mcpu1_ep: endpoint { remote-endpoint = <&cpu_ep>; }; };
port@2 { mcpu2_ep: endpoint { remote-endpoint = <&dummy_ep>; }; };
};
/* [Multi-Codec] */
ports@1 {
port@0 { mcodec0_ep: endpoint { remote-endpoint = <&mcpu0_ep>; }; };
port@1 { mcodec1_ep: endpoint { remote-endpoint = <&codec1_ep>; }; };
port@2 { mcodec2_ep: endpoint { remote-endpoint = <&codec2_ep>; }; };
};
};
};
test_cpu {
compatible = "test-cpu";
port { dummy_ep: endpoint { remote-endpoint = <&mcpu2_ep>; }; };
};
I looked at the 1:N (Semi-Multi) example in the references you shared.
Seems like this is broken into multiple 1:1 links. Is this correct
understanding?
Also the binding properties of "audio-graph-card2" seem to be different
from "audio-graph-card". I am looking at a simpler extension of existing
bindings for Tegra audio without having to re-write the whole bindings.
If "remote-endpoint" can take phandle array it would be simpler from DT
point of view.
