dt-bindings: power: supply: Add STC3117 Fuel Gauge

The STC3117 provides a simple fuel gauge via I2C.
Add a DT schema to describe how to set it up in the device tree.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
Signed-off-by: Bhavin Sharma <bhavin.sharma@siliconsignals.io>
Link: https://lore.kernel.org/r/20241220084958.32367-2-bhavin.sharma@siliconsignals.io
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/power/supply/st,stc3117.yaml

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/st,stc3117.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics STC3117 Fuel Gauge Unit Power Supply
+
+maintainers:
+  - Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
+  - Bhavin Sharma <bhavin.sharma@siliconsignals.io>
+
+description: |
+  The STC3117 includes the STMicroelectronics OptimGauge algorithm.
+  It provides accurate battery state-of-charge (SOC) monitoring, tracks
+  battery parameter changes with operation conditions, temperature,
+  and aging, and allows the application to get a battery state-of-health
+  (SOH) indication.
+
+  An alarm output signals low SOC or low voltage conditions and also
+  indicates fault conditions like a missing or swapped battery.
+
+  Datasheet is available at
+  https://www.st.com/resource/en/datasheet/stc3117.pdf
+
+allOf:
+  - $ref: power-supply.yaml#
+
+properties:
+  compatible:
+    enum:
+      - st,stc3117
+
+  reg:
+    maxItems: 1
+
+  monitored-battery:
+    description: |
+      The fuel gauge uses the following battery properties:
+      - charge-full-design-microamp-hours
+      - voltage-min-design-microvolt
+      - voltage-max-design-microvolt
+
+  shunt-resistor-micro-ohms:
+    description: Current sense resistor
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - monitored-battery
+  - shunt-resistor-micro-ohms
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      battery@70 {
+        compatible = "st,stc3117";
+        reg = <0x70>;
+        interrupt-parent = <&gpio0>;
+        interrupts = <31 IRQ_TYPE_LEVEL_LOW>;
+        monitored-battery = <&bat>;
+        shunt-resistor-micro-ohms = <10000>;
+      };
+    };