dt-bindings: embedded-controller: Document Surface RT EC

Document Embedded Controller used in Microsoft Surface RT tablets for
monitoring battery properties and charger status.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260507134608.76222-2-clamor95@gmail.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/embedded-controller/microsoft,surface-rt-ec.yaml

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/embedded-controller/microsoft,surface-rt-ec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microsoft Surface RT fuel gauge and charger EC
+
+maintainers:
+  - Jonas Schwöbel <jonasschwoebel@yahoo.de>
+  - Svyatoslav Ryhel <clamor95@gmail.com>
+
+description:
+  An Embedded Controller used in Microsoft Surface RT for monitoring
+  battery properties and charger status.
+
+allOf:
+  - $ref: /schemas/power/supply/power-supply.yaml#
+
+properties:
+  compatible:
+    const: microsoft,surface-rt-ec
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  enable-gpios:
+    maxItems: 1
+
+  monitored-battery: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - enable-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        embedded-controller@a {
+            compatible = "microsoft,surface-rt-ec";
+            reg = <0x0a>;
+
+            interrupt-parent = <&gpio>;
+            interrupts = <74 IRQ_TYPE_EDGE_RISING>;
+
+            enable-gpios = <&gpio 88 GPIO_ACTIVE_HIGH>;
+            monitored-battery = <&battery>;
+        };
+    };
+...