iio: dac: Add AD5413 support

The AD5413 is a single-channel, 14-bit DAC with programmable current or
voltage output. It communicates via SPI at clock rates up to 50 MHz.

The output can be configured as either voltage or current and is available
on a single terminal.

Updates since v1:
- Fixed checkpatch issues (macro parentheses, line breaks)
- Adjusted reset/CRC handling logic as per review feedback
- Removed unused functions
- Updated YAML binding required fields format

Datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/ad5413.pdf

Signed-off-by: Bruce Tsao <[email protected]>

Author: BruceTsaoADI

Documentation/devicetree/bindings/iio/dac/adi,ad5413.yaml

@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/adi,ad5413.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD5413 DAC
+
+maintainers:
+  - Bruce Tsao <[email protected]>
+
+properties:
+  compatible:
+    const: adi,ad5413
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 50000000
+
+  reset-gpios: true
+
+  avdd-supply:
+    description: Analog positive supply (AVDD)
+
+  dvdd-supply:
+    description: Digital positive supply (DVDD)
+
+  avss-supply:
+    description: Analog negative supply (AVSS)
+
+  adi,range-microvolt:
+    description: Voltage output range <min, max> in microvolts
+    oneOf:
+      - items:
+          - const: -10500000
+          - const: 10500000
+      - items:
+          - const: -12600000
+          - const: 12600000
+
+  adi,range-microamp:
+    description: Current output range <min, max> in microamps
+    items:
+      - const: 0
+      - const: 24000
+
+  adi,slew-time-us:
+    description: Output digital slew control time in microseconds
+    minimum: 0
+    maximum: 1000000
+    default: 0
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+  - avdd-supply
+  - dvdd-supply
+  - avss-supply
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+  - oneOf:
+      - required: [adi,range-microamp]
+      - required: [adi,range-microvolt]
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        dac@0 {
+            compatible = "adi,ad5413";
+            reg = <0>;
+            spi-max-frequency = <1000000>;
+            reset-gpios = <&gpio 0 1>; /* 1 = active low */
+            avdd-supply = <&avdd>;
+            dvdd-supply = <&dvdd>;
+            avss-supply = <&avss>;
+            adi,range-microvolt = <(-10500000) 10500000>;
+            adi,slew-time-us = <125>;
+        };
+    };

drivers/iio/Kconfig.adi

@@ -96,6 +96,7 @@ config IIO_ALL_ADI_DRIVERS
 	imply AD5360
 	imply AD5380
 	imply AD5421
+	imply AD5413
 	imply AD5624R_SPI if SPI
 	imply AD3552R
 	imply AD3552R_HS

drivers/iio/dac/Kconfig

@@ -96,6 +96,16 @@ config AD5380
 	  To compile this driver as module choose M here: the module will be called
 	  ad5380.
 
+config AD5413
+	tristate "Analog Devices AD5413 DAC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Analog Devices AD5413 single channel
+	  Digital to Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5413.
+
 config AD5421
 	tristate "Analog Devices AD5421 DAC driver"
 	depends on SPI
@@ -597,5 +607,4 @@ config VF610_DAC
 
 	  This driver can also be built as a module. If so, the module will
 	  be called vf610_dac.
-
 endmenu

drivers/iio/dac/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_AD3552R) += ad3552r.o
 obj-$(CONFIG_AD5270) += ad5270.o
 obj-$(CONFIG_AD5360) += ad5360.o
 obj-$(CONFIG_AD5380) += ad5380.o
+obj-$(CONFIG_AD5413) += ad5413.o
 obj-$(CONFIG_AD5421) += ad5421.o
 obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
 obj-$(CONFIG_AD5064) += ad5064.o