[PATCH] dt-bindings: iio: adc: Add schema for AD7816/7/8 digital temperature sensor

[Taha Narimani <tahanarimani3443@gmail.com>]

Document the Analog Devices AD7816, AD7817, and AD7818 digital
temperature sensor and ADC bindings in YAML format.

This resolves the checkpatch.pl warnings regarding undocumented DT
compatible strings for 'adi,ad7816', 'adi,ad7817', and 'adi,ad7818'.

Signed-off-by: Taha Narimani <tahanarimani3443@gmail.com>

---
v2: Added conditional schema constraints for busy-gpios as suggested by Sashiko AI.
---
 .../bindings/iio/adc/adi,ad7816.yaml          | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml
new file mode 100644
index 0000000..74008c1
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7816.yaml
@@ -0,0 +1,87 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7816.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD7816/7/8 digital temperature sensor and ADC
+
+maintainers:
+  - Taha Narimani <tahanarimani3443@gmail.com>
+
+description: |
+  Analog Devices AD7816, AD7817, and AD7818 10-Bit temperature sensor and ADC.
+  The device communicates via an SPI interface.
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7816
+      - adi,ad7817
+      - adi,ad7818
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency: true
+
+  rdwr-gpios:
+    maxItems: 1
+    description: GPIO connected to the RD/WR pin.
+
+  convert-gpios:
+    maxItems: 1
+    description: GPIO connected to the CONVST (Convert Start) pin.
+
+  busy-gpios:
+    maxItems: 1
+    description: GPIO connected to the BUSY pin.
+
+  interrupts:
+    maxItems: 1
+    description: OTI (Over Temperature Indicator) interrupt.
+
+required:
+  - compatible
+  - reg
+  - rdwr-gpios
+  - convert-gpios
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ad7816
+              - adi,ad7817
+    then:
+      required:
+        - busy-gpios
+    else:
+      properties:
+        busy-gpios: false
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad7816";
+            reg = <0>;
+            spi-max-frequency = <1000000>;
+            rdwr-gpios = <&gpio 5 GPIO_ACTIVE_HIGH>;
+            convert-gpios = <&gpio 6 GPIO_ACTIVE_HIGH>;
+            busy-gpios = <&gpio 7 GPIO_ACTIVE_HIGH>;
+            interrupts = <20 IRQ_TYPE_LEVEL_LOW>;
+            interrupt-parent = <&gpio>;
+        };
+    };
-- 
2.53.0