dt-bindings: iio: dac: add docs for AXI DAC IP

This adds the bindings documentation for the Analog Devices AXI DAC IP
core.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240419-iio-backend-axi-dac-v4-6-5ca45b4de294@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/adi,axi-dac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AXI DAC IP core
+
+maintainers:
+  - Nuno Sa <nuno.sa@analog.com>
+
+description: |
+  Analog Devices Generic AXI DAC IP core for interfacing a DAC device
+  with a high speed serial (JESD204B/C) or source synchronous parallel
+  interface (LVDS/CMOS).
+  Usually, some other interface type (i.e SPI) is used as a control
+  interface for the actual DAC, while this IP core will interface
+  to the data-lines of the DAC and handle the streaming of data from
+  memory via DMA into the DAC.
+
+  https://wiki.analog.com/resources/fpga/docs/axi_dac_ip
+
+properties:
+  compatible:
+    enum:
+      - adi,axi-dac-9.1.b
+
+  reg:
+    maxItems: 1
+
+  dmas:
+    maxItems: 1
+
+  dma-names:
+    items:
+      - const: tx
+
+  clocks:
+    maxItems: 1
+
+  '#io-backend-cells':
+    const: 0
+
+required:
+  - compatible
+  - dmas
+  - reg
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    dac@44a00000 {
+        compatible = "adi,axi-dac-9.1.b";
+        reg = <0x44a00000 0x10000>;
+        dmas = <&tx_dma 0>;
+        dma-names = "tx";
+        #io-backend-cells = <0>;
+        clocks = <&axi_clk>;
+    };
+...

MAINTAINERS

@@ -1399,6 +1399,13 @@ F:	sound/soc/codecs/adav*
 F:	sound/soc/codecs/sigmadsp.*
 F:	sound/soc/codecs/ssm*
 
+ANALOG DEVICES INC AXI DAC DRIVER
+M:	Nuno Sa <nuno.sa@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml
+
 ANALOG DEVICES INC DMA DRIVERS
 M:	Lars-Peter Clausen <lars@metafoo.de>
 S:	Supported