arm64: dts: meson: add audio playback to rbox-pro

Add initial support limited to HDMI i2s and SPDIF (LPCM).
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20210914151631.2841-1-christianshewitt@gmail.com

arch/arm64/boot/dts/amlogic/meson-gxm-rbox-pro.dts

@@ -14,6 +14,7 @@
 /dts-v1/;
 
 #include "meson-gxm.dtsi"
+#include <dt-bindings/sound/meson-aiu.h>
 
 / {
 	compatible = "kingnovel,r-box-pro", "amlogic,s912", "amlogic,meson-gxm";
@@ -33,6 +34,13 @@ memory@0 {
 		reg = <0x0 0x0 0x0 0x80000000>; /* 2 GiB or 3 GiB */
 	};
 
+	spdif_dit: audio-codec-0 {
+		#sound-dai-cells = <0>;
+		compatible = "linux,spdif-dit";
+		status = "okay";
+		sound-name-prefix = "DIT";
+	};
+
 	leds {
 		compatible = "gpio-leds";
 
@@ -90,6 +98,59 @@ sdio_pwrseq: sdio-pwrseq {
 		clocks = <&wifi32k>;
 		clock-names = "ext_clock";
 	};
+
+	sound {
+		compatible = "amlogic,gx-sound-card";
+		model = "RBOX-PRO";
+		assigned-clocks = <&clkc CLKID_MPLL0>,
+				  <&clkc CLKID_MPLL1>,
+				  <&clkc CLKID_MPLL2>;
+		assigned-clock-parents = <0>, <0>, <0>;
+		assigned-clock-rates = <294912000>,
+				       <270950400>,
+				       <393216000>;
+		status = "okay";
+
+		dai-link-0 {
+			sound-dai = <&aiu AIU_CPU CPU_I2S_FIFO>;
+		};
+
+		dai-link-1 {
+			sound-dai = <&aiu AIU_CPU CPU_SPDIF_FIFO>;
+		};
+
+		dai-link-2 {
+			sound-dai = <&aiu AIU_CPU CPU_I2S_ENCODER>;
+			dai-format = "i2s";
+			mclk-fs = <256>;
+
+			codec-0 {
+				sound-dai = <&aiu AIU_HDMI CTRL_I2S>;
+			};
+		};
+
+		dai-link-3 {
+			sound-dai = <&aiu AIU_CPU CPU_SPDIF_ENCODER>;
+
+			codec-0 {
+				sound-dai = <&spdif_dit>;
+			};
+		};
+
+		dai-link-4 {
+			sound-dai = <&aiu AIU_HDMI CTRL_OUT>;
+
+			codec-0 {
+				sound-dai = <&hdmi_tx>;
+			};
+		};
+	};
+};
+
+&aiu {
+	status = "okay";
+	pinctrl-0 = <&spdif_out_h_pins>;
+	pinctrl-names = "default";
 };
 
 &ethmac {