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";
		routing = "codec Playback", "DAI0 Playback",
			  "codec Playback", "DAI1 Playback",
			  "DAI0 Capture",   "codec Capture";

		dais = <&cpu_port0
			&cpu_port1>;
	};

	audio-codec {
		...

		audio-graph-card,prefix = "codec";
		audio-graph-card,convert-rate = <48000>;
		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";
					...
				};
			};
		};
	};