ASoC: ep93xx: Add I2S description

Add device tree bindings for Cirrus Logic EP93xx internal SoCs' I2S
controller.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230411165951.2335899-1-alexander.sverdlin@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/cirrus,ep9301-i2s.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/cirrus,ep9301-i2s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cirrus EP93xx I2S Controller
+
+description: |
+  The I2S controller is used to stream serial audio data between the external
+  I2S CODECs’, ADCs/DACs, and the ARM Core. The controller supports I2S, Left-
+  and Right-Justified DSP formats.
+
+maintainers:
+  - Alexander Sverdlin <alexander.sverdlin@gmail.com>
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    const: cirrus,ep9301-i2s
+
+  '#sound-dai-cells':
+    const: 0
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 3
+    maxItems: 3
+
+  clock-names:
+    items:
+      - const: mclk
+      - const: sclk
+      - const: lrclk
+
+required:
+  - compatible
+  - '#sound-dai-cells'
+  - reg
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    i2s: i2s@80820000 {
+        compatible = "cirrus,ep9301-i2s";
+        #sound-dai-cells = <0>;
+        reg = <0x80820000 0x100>;
+        interrupt-parent = <&vic1>;
+        interrupts = <28>;
+        clocks = <&syscon 29>,
+                 <&syscon 30>,
+                 <&syscon 31>;
+        clock-names = "mclk", "sclk", "lrclk";
+    };
+
+...

MAINTAINERS

@@ -2072,6 +2072,7 @@ M:	Alexander Sverdlin <alexander.sverdlin@gmail.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	Documentation/devicetree/bindings/iio/adc/cirrus,ep9301-adc.yaml
+F:	Documentation/devicetree/bindings/sound/cirrus,ep9301-*
 F:	arch/arm/boot/compressed/misc-ep93xx.h
 F:	arch/arm/mach-ep93xx/
 F:	drivers/iio/adc/ep93xx_adc.c