dt-bindings: iio: adc: add AD4695 and similar ADCs

Add device tree bindings for AD4695 and similar ADCs.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20240711-iio-adc-ad4695-v4-0-c31621113b57@baylibre.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/adi,ad4695.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad4695.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices Easy Drive Multiplexed SAR Analog to Digital Converters
+
+maintainers:
+  - Michael Hennerich <Michael.Hennerich@analog.com>
+  - Nuno Sá <nuno.sa@analog.com>
+
+description: |
+  A family of similar multi-channel analog to digital converters with SPI bus.
+
+  * https://www.analog.com/en/products/ad4695.html
+  * https://www.analog.com/en/products/ad4696.html
+  * https://www.analog.com/en/products/ad4697.html
+  * https://www.analog.com/en/products/ad4698.html
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - adi,ad4695
+      - adi,ad4696
+      - adi,ad4697
+      - adi,ad4698
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 80000000
+
+  spi-cpol: true
+  spi-cpha: true
+
+  spi-rx-bus-width:
+    minimum: 1
+    maximum: 4
+
+  avdd-supply:
+    description: Analog power supply.
+
+  vio-supply:
+    description: I/O pin power supply.
+
+  ldo-in-supply:
+    description: Internal LDO Input. Mutually exclusive with vdd-supply.
+
+  vdd-supply:
+    description: Core power supply. Mutually exclusive with ldo-in-supply.
+
+  ref-supply:
+    description:
+      External reference voltage. Mutually exclusive with refin-supply.
+
+  refin-supply:
+    description:
+      Internal reference buffer input. Mutually exclusive with ref-supply.
+
+  com-supply:
+    description: Common voltage supply for pseudo-differential analog inputs.
+
+  adi,no-ref-current-limit:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      When this flag is present, the REF Overvoltage Reduced Current protection
+      is disabled.
+
+  adi,no-ref-high-z:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Enable this flag if the ref-supply requires Reference Input High-Z Mode
+      to be disabled for proper operation.
+
+  cnv-gpios:
+    description: The Convert Input (CNV). If omitted, CNV is tied to SPI CS.
+    maxItems: 1
+
+  reset-gpios:
+    description: The Reset Input (RESET). Should be configured GPIO_ACTIVE_LOW.
+    maxItems: 1
+
+  interrupts:
+    minItems: 1
+    items:
+      - description: Signal coming from the BSY_ALT_GP0 pin (ALERT or BUSY).
+      - description: Signal coming from the GP2 pin (ALERT).
+      - description: Signal coming from the GP3 pin (BUSY).
+
+  interrupt-names:
+    minItems: 1
+    items:
+      - const: gp0
+      - const: gp2
+      - const: gp3
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+    description: |
+      The first cell is the GPn number: 0 to 3.
+      The second cell takes standard GPIO flags.
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^in(?:[13579]|1[135])-supply$":
+    description:
+      Optional voltage supply for odd numbered channels when they are used as
+      the negative input for a pseudo-differential channel.
+
+  "^channel@[0-9a-f]$":
+    type: object
+    $ref: adc.yaml
+    unevaluatedProperties: false
+    description:
+      Describes each individual channel. In addition the properties defined
+      below, bipolar from adc.yaml is also supported.
+
+    properties:
+      reg:
+        maximum: 15
+
+      common-mode-channel:
+        description:
+          Describes the common mode channel for single channels. 0xFF is REFGND
+          and OxFE is COM. Macros are available for these values in
+          dt-bindings/iio/adi,ad4695.h. Values 1 to 15 correspond to INx inputs.
+          Only odd numbered INx inputs can be used as common mode channels.
+        items:
+          enum: [1, 3, 5, 7, 9, 11, 13, 15, 0xFE, 0xFF]
+        default: 0xFF
+
+      adi,no-high-z:
+        $ref: /schemas/types.yaml#/definitions/flag
+        description:
+          Enable this flag if the input pin requires the Analog Input High-Z
+          Mode to be disabled for proper operation.
+
+    required:
+      - reg
+
+    allOf:
+      # bipolar mode can't be used with REFGND
+      - if:
+          properties:
+            common-mode-channel:
+              const: 0xFF
+        then:
+          properties:
+            bipolar: false
+
+required:
+  - compatible
+  - reg
+  - avdd-supply
+  - vio-supply
+
+allOf:
+  - oneOf:
+      - required:
+          - ldo-in-supply
+      - required:
+          - vdd-supply
+
+  - oneOf:
+      - required:
+          - ref-supply
+      - required:
+          - refin-supply
+
+  # the internal reference buffer always requires high-z mode
+  - if:
+      required:
+        - refin-supply
+    then:
+      properties:
+        adi,no-ref-high-z: false
+
+  # limit channels for 8-channel chips
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad4697
+              - adi,ad4698
+    then:
+      patternProperties:
+        "^in(?:9|1[135])-supply$": false
+        "^channel@[0-7]$":
+          properties:
+            reg:
+              maximum: 7
+            common-mode-channel:
+              items:
+                enum: [1, 3, 5, 7, 0xFE, 0xFF]
+        "^channel@[8-9a-f]$": false
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/iio/adi,ad4695.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad4695";
+            reg = <0>;
+            spi-cpol;
+            spi-cpha;
+            spi-max-frequency = <80000000>;
+            avdd-supply = <&power_supply>;
+            ldo-in-supply = <&power_supply>;
+            vio-supply = <&io_supply>;
+            refin-supply = <&supply_5V>;
+            com-supply = <&supply_2V5>;
+            in3-supply = <&supply_2V5>;
+            reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            /* Pseudo-differential channel between IN0 and REFGND. */
+            channel@0 {
+                reg = <0>;
+            };
+
+            /* Pseudo-differential channel between IN1 and COM. */
+            channel@1 {
+                reg = <1>;
+                common-mode-channel = <AD4695_COMMON_MODE_COM>;
+                bipolar;
+            };
+
+            /* Pseudo-differential channel between IN2 and IN3. */
+            channel@2 {
+                reg = <2>;
+                common-mode-channel = <3>;
+                bipolar;
+            };
+        };
+    };

MAINTAINERS

@@ -1223,6 +1223,16 @@ F:	Documentation/ABI/testing/sysfs-bus-iio-adc-ad4130
 F:	Documentation/devicetree/bindings/iio/adc/adi,ad4130.yaml
 F:	drivers/iio/adc/ad4130.c
 
+ANALOG DEVICES INC AD4695 DRIVER
+M:	Michael Hennerich <michael.hennerich@analog.com>
+M:	Nuno Sá <nuno.sa@analog.com>
+R:	David Lechner <dlechner@baylibre.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/adc/adi,ad4695.yaml
+F:	include/dt-bindings/iio/adi,ad4695.h
+
 ANALOG DEVICES INC AD7091R DRIVER
 M:	Marcelo Schmitt <marcelo.schmitt@analog.com>
 L:	linux-iio@vger.kernel.org

include/dt-bindings/iio/adi,ad4695.h

+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+
+#ifndef _DT_BINDINGS_ADI_AD4695_H
+#define _DT_BINDINGS_ADI_AD4695_H
+
+#define AD4695_COMMON_MODE_REFGND	0xFF
+#define AD4695_COMMON_MODE_COM		0xFE
+
+#endif /* _DT_BINDINGS_ADI_AD4695_H */