arch/arm64/boot/dts/renesas/ulcb-audio-graph-card.dtsi

Source file repositories/reference/linux-study-clean/arch/arm64/boot/dts/renesas/ulcb-audio-graph-card.dtsi

File Facts

System
Linux kernel
Corpus path
arch/arm64/boot/dts/renesas/ulcb-audio-graph-card.dtsi
Extension
.dtsi
Size
1451 bytes
Lines
91
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: configuration, schema, or hardware description
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Device Tree for ULCB + Audio Graph Card
 *
 * Copyright (C) 2022 Renesas Electronics Corp.
 */

/*
 *	(A) CPU0 <-----> ak4613
 *	(B) CPU1  -----> HDMI
 *
 *	(A) aplay   -D plughw:0,0 xxx.wav
 *	(B) aplay   -D plughw:0,1 xxx.wav
 *
 *	(A) arecord -D plughw:0,0 xxx.wav
 */

/ {
	sound_card: sound {
		compatible = "audio-graph-card";
		label = "snd-ulcb";

		dais = <&snd_ulcb1 /* (A) CPU0 <-> ak4613 */
			&snd_ulcb2 /* (B) CPU1  -> HDMI   */
		>;
	};
};

&ak4613 {
	#sound-dai-cells = <0>;

	port {
		/*
		 * (A) CPU0 <-> ak4613
		 */
		ak4613_endpoint: endpoint {
			remote-endpoint = <&rsnd_for_ak4613>;
		};
	};
};

&hdmi0 {
	ports {
		port@2 {
			/*
			 * (B) CPU1 -> HDMI
			 */
			dw_hdmi0_snd_in: endpoint {
				remote-endpoint = <&rsnd_for_hdmi>;
			};
		};
	};
};

&rcar_sound {
	#address-cells = <1>;
	#size-cells = <0>;

	ports@0 {
		#address-cells = <1>;
		#size-cells = <0>;
		reg = <0>;

		snd_ulcb1: port@0 {
			/*
			 * (A) CPU0 <-> ak4613
			 */
			reg = <0>;
			rsnd_for_ak4613: endpoint {
				remote-endpoint = <&ak4613_endpoint>;

Annotation

Implementation Notes