dt-bindings: iio: add AD74413R

The AD74412R and AD74413R are quad-channel, software configurable,
input/output solutions for building and process control applications.

They contain functionality for analog output, analog input, digital input,
resistance temperature detector, and thermocouple measurements integrated
into a single chip solution with an SPI interface.

The devices feature a 16-bit ADC and four configurable 13-bit DACs to
provide four configurable input/output channels and a suite of diagnostic
functions.

The AD74413R differentiates itself from the AD74412R by being
HART-compatible.

Signed-off-by: Cosmin Tanislav <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/addac/adi,ad74413r.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD74412R/AD74413R device
+
+maintainers:
+  - Cosmin Tanislav <[e-mail]>
+
+description: |
+  The AD74412R and AD74413R are quad-channel software configurable input/output
+  solutions for building and process control applications. They contain
+  functionality for analog output, analog input, digital input, resistance
+  temperature detector, and thermocouple measurements integrated
+  into a single chip solution with an SPI interface.
+  The devices feature a 16-bit ADC and four configurable 13-bit DACs to provide
+  four configurable input/output channels and a suite of diagnostic functions.
+  The AD74413R differentiates itself from the AD74412R by being HART-compatible.
+    https://www.analog.com/en/products/ad74412r.html
+    https://www.analog.com/en/products/ad74413r.html
+
+properties:
+  compatible:
+    enum:
+      - adi,ad74412r
+      - adi,ad74413r
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  spi-max-frequency:
+    maximum: 1000000
+
+  spi-cpol: true
+
+  interrupts:
+    maxItems: 1
+
+  refin-supply: true
+
+  shunt-resistor-micro-ohms:
+    description:
+      Shunt (sense) resistor value in micro-Ohms.
+    default: 100000000
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+  - spi-cpol
+  - refin-supply
+
+additionalProperties: false
+
+patternProperties:
+  "^channel@[0-3]$":
+    type: object
+    description: Represents the external channels which are connected to the device.
+
+    properties:
+      reg:
+        description: |
+          The channel number. It can have up to 4 channels numbered from 0 to 3.
+        minimum: 0
+        maximum: 3
+
+      adi,ch-func:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: |
+          Channel function.
+          HART functions are not supported on AD74412R.
+          0 - CH_FUNC_HIGH_IMPEDANCE
+          1 - CH_FUNC_VOLTAGE_OUTPUT
+          2 - CH_FUNC_CURRENT_OUTPUT
+          3 - CH_FUNC_VOLTAGE_INPUT
+          4 - CH_FUNC_CURRENT_INPUT_EXT_POWER
+          5 - CH_FUNC_CURRENT_INPUT_LOOP_POWER
+          6 - CH_FUNC_RESISTANCE_INPUT
+          7 - CH_FUNC_DIGITAL_INPUT_LOGIC
+          8 - CH_FUNC_DIGITAL_INPUT_LOOP_POWER
+          9 - CH_FUNC_CURRENT_INPUT_EXT_POWER_HART
+          10 - CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART
+        minimum: 0
+        maximum: 10
+        default: 0
+
+      adi,gpo-comparator:
+        type: boolean
+        description: |
+          Whether to configure GPO as a comparator or not.
+          When not configured as a comparator, the GPO will be treated as an
+          output-only GPIO.
+
+    required:
+      - reg
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/iio/addac/adi,ad74413r.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      cs-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
+      status = "okay";
+
+      ad74413r@0 {
+        compatible = "adi,ad74413r";
+        reg = <0>;
+        spi-max-frequency = <1000000>;
+        spi-cpol;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        interrupt-parent = <&gpio>;
+        interrupts = <26 IRQ_TYPE_EDGE_FALLING>;
+
+        refin-supply = <&ad74413r_refin>;
+
+        channel@0 {
+          reg = <0>;
+
+          adi,ch-func = <CH_FUNC_VOLTAGE_OUTPUT>;
+        };
+
+        channel@1 {
+          reg = <1>;
+
+          adi,ch-func = <CH_FUNC_CURRENT_OUTPUT>;
+        };
+
+        channel@2 {
+          reg = <2>;
+
+          adi,ch-func = <CH_FUNC_DIGITAL_INPUT_LOGIC>;
+          adi,gpo-comparator;
+        };
+
+        channel@3 {
+          reg = <3>;
+
+          adi,ch-func = <CH_FUNC_CURRENT_INPUT_EXT_POWER>;
+        };
+      };
+    };
+...

include/dt-bindings/iio/addac/adi,ad74413r.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _DT_BINDINGS_ADI_AD74413R_H
+#define _DT_BINDINGS_ADI_AD74413R_H
+
+#define CH_FUNC_HIGH_IMPEDANCE			0x0
+#define CH_FUNC_VOLTAGE_OUTPUT			0x1
+#define CH_FUNC_CURRENT_OUTPUT			0x2
+#define CH_FUNC_VOLTAGE_INPUT			0x3
+#define CH_FUNC_CURRENT_INPUT_EXT_POWER		0x4
+#define CH_FUNC_CURRENT_INPUT_LOOP_POWER	0x5
+#define CH_FUNC_RESISTANCE_INPUT		0x6
+#define CH_FUNC_DIGITAL_INPUT_LOGIC		0x7
+#define CH_FUNC_DIGITAL_INPUT_LOOP_POWER	0x8
+#define CH_FUNC_CURRENT_INPUT_EXT_POWER_HART	0x9
+#define CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART	0xA
+
+#define CH_FUNC_MIN	CH_FUNC_HIGH_IMPEDANCE
+#define CH_FUNC_MAX	CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART
+
+#endif /* _DT_BINDINGS_ADI_AD74413R_H */