[PATCH 2/4] ASoC: dt-bindings: add ESS Technology ES9039Q2M

[Karl Asseily <karl@asseily.com>]

Add a binding for the ES9039Q2M, a 32-bit two-channel audio DAC with an
asynchronous sample rate converter.

The part selects between two control personalities with its MODE pin:
hardware mode, strapped by HW0/HW1/HW2 with no control bus at all, and
software mode over I2C or SPI. This binding describes software mode over
I2C, which MODE = GND selects.

Signed-off-by: Karl Asseily <karl@asseily.com>
---
 .../bindings/sound/ess,es9039q2m.yaml         | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/ess,es9039q2m.yaml

diff --git a/Documentation/devicetree/bindings/sound/ess,es9039q2m.yaml b/Documentation/devicetree/bindings/sound/ess,es9039q2m.yaml
new file mode 100644
index 00000000000..b52c4cc5304
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/ess,es9039q2m.yaml
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/ess,es9039q2m.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ESS Technology ES9039Q2M audio DAC
+
+maintainers:
+  - Karl Asseily <karl@asseily.com>
+
+description:
+  The ES9039Q2M is a 32-bit two-channel audio DAC supporting PCM to 768 kHz,
+  DSD64 to DSD1024, DoP and S/PDIF. It is controlled over I2C or SPI when the
+  MODE pin selects software mode; this binding covers the I2C interface. The
+  part contains an asynchronous sample rate converter, so the system clock need
+  not be synchronous with the audio bit or frame clocks.
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    const: ess,es9039q2m
+
+  reg:
+    description:
+      I2C address, selected by the ADDR0 and ADDR1 pins - 0x48, 0x49, 0x4a or
+      0x4b for GND/GND, GND/AVDD, AVDD/GND and AVDD/AVDD respectively.
+    enum: [ 0x48, 0x49, 0x4a, 0x4b ]
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: mclk
+
+  "#sound-dai-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - "#sound-dai-cells"
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        audio-codec@48 {
+            compatible = "ess,es9039q2m";
+            reg = <0x48>;
+            #sound-dai-cells = <0>;
+            clocks = <&dac_mclk>;
+            clock-names = "mclk";
+        };
+    };
-- 
2.34.1