dt-bindings: sound: Add TLV320ADCx140 dt bindings

Add dt bindings for the TLV320ADCx140 Burr-Brown ADC.
The initial support is for the following:

TLV320ADC3140 - http://www.ti.com/lit/gpn/tlv320adc3140
TLV320ADC5140 - http://www.ti.com/lit/gpn/tlv320adc5140
TLV320ADC6140 - http://www.ti.com/lit/gpn/tlv320adc6140Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200220210759.31466-2-dmurphy@ti.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/tlv320adcx140.yaml

+# SPDX-License-Identifier: (GPL-2.0+ OR BSD-2-Clause)
+# Copyright (C) 2019 Texas Instruments Incorporated
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/tlv320adcx140.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments TLV320ADCX140 Quad Channel Analog-to-Digital Converter
+
+maintainers:
+  - Dan Murphy <dmurphy@ti.com>
+
+description: |
+  The TLV320ADCX140 are multichannel (4-ch analog recording or 8-ch digital
+  PDM microphones recording), high-performance audio, analog-to-digital
+  converter (ADC) with analog inputs supporting up to 2V RMS. The TLV320ADCX140
+  family supports line and  microphone Inputs, and offers a programmable
+  microphone bias or supply voltage generation.
+
+  Specifications can be found at:
+    http://www.ti.com/lit/ds/symlink/tlv320adc3140.pdf
+    http://www.ti.com/lit/ds/symlink/tlv320adc5140.pdf
+    http://www.ti.com/lit/ds/symlink/tlv320adc6140.pdf
+
+properties:
+  compatible:
+    oneOf:
+      - const: ti,tlv320adc3140
+      - const: ti,tlv320adc5140
+      - const: ti,tlv320adc6140
+
+  reg:
+    maxItems: 1
+    description: |
+       I2C addresss of the device can be one of these 0x4c, 0x4d, 0x4e or 0x4f
+
+  reset-gpios:
+    description: |
+       GPIO used for hardware reset.
+
+  areg-supply:
+      description: |
+       Regulator with AVDD at 3.3V.  If not defined then the internal regulator
+       is enabled.
+
+  ti,mic-bias-source:
+    description: |
+       Indicates the source for MIC Bias.
+       0 - Mic bias is set to VREF
+       1 - Mic bias is set to VREF × 1.096
+       6 - Mic bias is set to AVDD
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+      - enum: [0, 1, 6]
+
+  ti,vref-source:
+    description: |
+       Indicates the source for MIC Bias.
+       0 - Set VREF to 2.75V
+       1 - Set VREF to 2.5V
+       2 - Set VREF to 1.375V
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+      - enum: [0, 1, 2]
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    i2c0 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      codec: codec@4c {
+        compatible = "ti,tlv320adc5140";
+        reg = <0x4c>;
+        ti,use-internal-areg;
+        ti,mic-bias-source = <6>;
+        reset-gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
+      };
+    };