dt-bindings: hwmon: Add sample averaging properties for ADM1275

Add documentation of new properties for sample averaging in PMON_CONFIG
register.

New properties:
- adi,volt-curr-sample-average
- adi,power-sample-average

Signed-off-by: Potin Lai <potin.lai@quantatw.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220302123817.27025-3-potin.lai@quantatw.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml

@@ -37,6 +37,72 @@ properties:
     description:
       Shunt resistor value in micro-Ohm.
 
+  adi,volt-curr-sample-average:
+    description: |
+      Number of samples to be used to report voltage and current values.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [1, 2, 4, 8, 16, 32, 64, 128]
+
+  adi,power-sample-average:
+    description: |
+      Number of samples to be used to report power values.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [1, 2, 4, 8, 16, 32, 64, 128]
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,adm1075
+              - adi,adm1276
+    then:
+      properties:
+        adi,volt-curr-sample-average:
+          default: 128
+        adi,power-sample-average: false
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,adm1275
+    then:
+      properties:
+        adi,volt-curr-sample-average:
+          default: 16
+        adi,power-sample-average: false
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,adm1272
+    then:
+      properties:
+        adi,volt-curr-sample-average:
+          default: 128
+        adi,power-sample-average:
+          default: 128
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,adm1278
+              - adi,adm1293
+              - adi,adm1294
+    then:
+      properties:
+        adi,volt-curr-sample-average:
+          default: 128
+        adi,power-sample-average:
+          default: 1
+
 required:
   - compatible
   - reg
@@ -53,5 +119,7 @@ examples:
             compatible = "adi,adm1272";
             reg = <0x10>;
             shunt-resistor-micro-ohms = <500>;
+            adi,volt-curr-sample-average = <128>;
+            adi,power-sample-average = <128>;
         };
     };