ASoC: meson: aiu: add audio output dt-bindings

Add the dt-bindings and documentation of the AIU audio controller.
This component provides most of the audio outputs found on the Amlogic
Gx SoC family.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20200213155159.3235792-4-jbrunet@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/amlogic,aiu.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/amlogic,aiu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic AIU audio output controller
+
+maintainers:
+  - Jerome Brunet <jbrunet@baylibre.com>
+
+properties:
+  $nodename:
+    pattern: "^audio-controller@.*"
+
+  "#sound-dai-cells":
+    const: 2
+
+  compatible:
+    items:
+      - enum:
+        - amlogic,aiu-gxbb
+        - amlogic,aiu-gxl
+      - const:
+          amlogic,aiu
+
+  clocks:
+    items:
+      - description: AIU peripheral clock
+      - description: I2S peripheral clock
+      - description: I2S output clock
+      - description: I2S master clock
+      - description: I2S mixer clock
+      - description: SPDIF peripheral clock
+      - description: SPDIF output clock
+      - description: SPDIF master clock
+      - description: SPDIF master clock multiplexer
+
+  clock-names:
+    items:
+      - const: pclk
+      - const: i2s_pclk
+      - const: i2s_aoclk
+      - const: i2s_mclk
+      - const: i2s_mixer
+      - const: spdif_pclk
+      - const: spdif_aoclk
+      - const: spdif_mclk
+      - const: spdif_mclk_sel
+
+  interrupts:
+    items:
+      - description: I2S interrupt line
+      - description: SPDIF interrupt line
+
+  interrupt-names:
+    items:
+      - const: i2s
+      - const: spdif
+
+  reg:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - "#sound-dai-cells"
+  - compatible
+  - clocks
+  - clock-names
+  - interrupts
+  - interrupt-names
+  - reg
+  - resets
+
+examples:
+  - |
+    #include <dt-bindings/clock/gxbb-clkc.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/reset/amlogic,meson-gxbb-reset.h>
+
+    aiu: audio-controller@5400 {
+        compatible = "amlogic,aiu-gxl", "amlogic,aiu";
+        #sound-dai-cells = <2>;
+        reg = <0x0 0x5400 0x0 0x2ac>;
+        interrupts = <GIC_SPI 48 IRQ_TYPE_EDGE_RISING>,
+                     <GIC_SPI 50 IRQ_TYPE_EDGE_RISING>;
+        interrupt-names = "i2s", "spdif";
+        clocks = <&clkc CLKID_AIU_GLUE>,
+                 <&clkc CLKID_I2S_OUT>,
+                 <&clkc CLKID_AOCLK_GATE>,
+                 <&clkc CLKID_CTS_AMCLK>,
+                 <&clkc CLKID_MIXER_IFACE>,
+                 <&clkc CLKID_IEC958>,
+                 <&clkc CLKID_IEC958_GATE>,
+                 <&clkc CLKID_CTS_MCLK_I958>,
+                 <&clkc CLKID_CTS_I958>;
+        clock-names = "pclk",
+                      "i2s_pclk",
+                      "i2s_aoclk",
+                      "i2s_mclk",
+                      "i2s_mixer",
+                      "spdif_pclk",
+                      "spdif_aoclk",
+                      "spdif_mclk",
+                      "spdif_mclk_sel";
+        resets = <&reset RESET_AIU>;
+    };
+

include/dt-bindings/sound/meson-aiu.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DT_MESON_AIU_H
+#define __DT_MESON_AIU_H
+
+#define AIU_CPU			0
+#define AIU_HDMI		1
+#define AIU_ACODEC		2
+
+#define CPU_I2S_FIFO		0
+#define CPU_SPDIF_FIFO		1
+#define CPU_I2S_ENCODER		2
+#define CPU_SPDIF_ENCODER	3
+
+#define CTRL_I2S		0
+#define CTRL_PCM		1
+#define CTRL_OUT		2
+
+#endif /* __DT_MESON_AIU_H */