Kernel-4.18.0-80.el8_audio-graph-scu-car

Audio-Graph-SCU-Card:

Audio-Graph-SCU-Card is “Audio-Graph-Card” + “ALSA DPCM”.

It is based on common bindings for device graphs.
see ${LINUX}/Documentation/devicetree/bindings/graph.txt

Basically, Audio-Graph-SCU-Card property is same as
Simple-Card / Simple-SCU-Card / Audio-Graph-Card.
see ${LINUX}/Documentation/devicetree/bindings/sound/simple-card.txt
${LINUX}/Documentation/devicetree/bindings/sound/simple-scu-card.txt
${LINUX}/Documentation/devicetree/bindings/sound/audio-graph-card.txt

Below are same as Simple-Card / Audio-Graph-Card.

• label
• dai-format
• frame-master
• bitclock-master
• bitclock-inversion
• frame-inversion
• dai-tdm-slot-num
• dai-tdm-slot-width
• clocks / system-clock-frequency

Below are same as Simple-SCU-Card.

• convert-rate
• convert-channels
• prefix
• routing

Required properties:

• compatible : “audio-graph-scu-card”;
• dais : list of CPU DAI port{s}

Example 1. Sampling Rate Conversion

sound_card {
    compatible = "audio-graph-scu-card";

    label = "sound-card";
    prefix = "codec";
    routing = "codec Playback", "DAI0 Playback",
          "DAI0 Capture",   "codec Capture";
    convert-rate = <48000>;

    dais = <&cpu_port>;
};

audio-codec {
    ...

    port {
        codec_endpoint: endpoint {
            remote-endpoint = <&cpu_endpoint>;
        };
    };
};

dai-controller {
    ...
    cpu_port: port {
        cpu_endpoint: endpoint {
            remote-endpoint = <&codec_endpoint>;

            dai-format = "left_j";
            ...
        };
    };
};

Example 2. 2 CPU 1 Codec (Mixing)

sound_card {
    compatible = "audio-graph-scu-card";

    label = "sound-card";
    prefix = "codec";
    routing = "codec Playback", "DAI0 Playback",
          "codec Playback", "DAI1 Playback",
          "DAI0 Capture",   "codec Capture";
    convert-rate = <48000>;

    dais = <&cpu_port0
        &cpu_port1>;
};

audio-codec {
    ...

    port {
        codec_endpoint0: endpoint {
            remote-endpoint = <&cpu_endpoint0>;
        };
        codec_endpoint1: endpoint {
            remote-endpoint = <&cpu_endpoint1>;
        };
    };
};

dai-controller {
    ...
    ports {
        cpu_port0: port {
            cpu_endpoint0: endpoint {
                remote-endpoint = <&codec_endpoint0>;

                dai-format = "left_j";
                ...
            };
        };
        cpu_port1: port {
            cpu_endpoint1: endpoint {
                remote-endpoint = <&codec_endpoint1>;

                dai-format = "left_j";
                ...
            };
        };
    };
};