dt-bindings: iio: adc: adding support for PAC193X

This is the device tree schema for iio driver for
Microchip PAC193X series of Power Monitors with Accumulator.
Signed-off-by: Marius Cristea <marius.cristea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240222164206.65700-2-marius.cristea@microchip.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/microchip,pac1934.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/microchip,pac1934.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PAC1934 Power Monitors with Accumulator
+
+maintainers:
+  - Marius Cristea <marius.cristea@microchip.com>
+
+description: |
+  This device is part of the Microchip family of Power Monitors with
+  Accumulator.
+  The datasheet for PAC1931, PAC1932, PAC1933 and PAC1934 can be found here:
+    https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/PAC1931-Family-Data-Sheet-DS20005850E.pdf
+
+properties:
+  compatible:
+    enum:
+      - microchip,pac1931
+      - microchip,pac1932
+      - microchip,pac1933
+      - microchip,pac1934
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  interrupts:
+    maxItems: 1
+
+  slow-io-gpios:
+    description:
+      A GPIO used to trigger a change is sampling rate (lowering the chip power
+      consumption). If configured in SLOW mode, if this pin is forced high,
+      sampling rate is forced to eight samples/second. When it is forced low,
+      the sampling rate is 1024 samples/second unless a different sample rate
+      has been programmed.
+
+patternProperties:
+  "^channel@[1-4]+$":
+    type: object
+    $ref: adc.yaml
+    description:
+      Represents the external channels which are connected to the ADC.
+
+    properties:
+      reg:
+        items:
+          minimum: 1
+          maximum: 4
+
+      shunt-resistor-micro-ohms:
+        description:
+          Value in micro Ohms of the shunt resistor connected between
+          the SENSE+ and SENSE- inputs, across which the current is measured.
+          Value is needed to compute the scaling of the measured current.
+
+    required:
+      - reg
+      - shunt-resistor-micro-ohms
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        power-monitor@10 {
+            compatible = "microchip,pac1934";
+            reg = <0x10>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            channel@1 {
+                reg = <0x1>;
+                shunt-resistor-micro-ohms = <24900000>;
+                label = "CPU";
+            };
+
+            channel@2 {
+                reg = <0x2>;
+                shunt-resistor-micro-ohms = <49900000>;
+                label = "GPU";
+            };
+
+            channel@3 {
+                reg = <0x3>;
+                shunt-resistor-micro-ohms = <75000000>;
+                label = "MEM";
+                bipolar;
+            };
+
+            channel@4 {
+                reg = <0x4>;
+                shunt-resistor-micro-ohms = <100000000>;
+                label = "NET";
+                bipolar;
+            };
+        };
+    };
+
+...