dt-bindings: power: supply: add cw2015_battery bindings

This patch adds the dts binding schema for the cw2015 fuel gauge.
Signed-off-by: NTobias Schramm <t.schramm@manjaro.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/power/supply/cw2015_battery.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/cw2015_battery.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Battery driver for CW2015 shuntless fuel gauge by CellWise.
+
+maintainers:
+  - Tobias Schramm <t.schramm@manjaro.org>
+
+description: |
+  The driver can utilize information from a simple-battery linked via a
+  phandle in monitored-battery. If specified the driver uses the
+  charge-full-design-microamp-hours property of the battery.
+
+properties:
+  compatible:
+    const: cellwise,cw2015
+
+  reg:
+    maxItems: 1
+
+  cellwise,battery-profile:
+    description: |
+      This property specifies characteristics of the battery used. The format
+      of this binary blob is kept secret by CellWise. The only way to obtain
+      it is to mail two batteries to a test facility of CellWise and receive
+      back a test report with the binary blob.
+    allOf:
+      - $ref: /schemas/types.yaml#definitions/uint8-array
+    items:
+      - minItems: 64
+        maxItems: 64
+
+  cellwise,monitor-interval-ms:
+    description:
+      Specifies the interval in milliseconds gauge values are polled at
+    minimum: 250
+
+  power-supplies:
+    description:
+      Specifies supplies used for charging the battery connected to this gauge
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/phandle-array
+      - minItems: 1
+        maxItems: 8 # Should be enough
+
+  monitored-battery:
+    description:
+      Specifies the phandle of a simple-battery connected to this gauge
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        cw2015@62 {
+            compatible = "cellwise,cw201x";
+            reg = <0x62>;
+            cellwise,battery-profile = /bits/ 8 <
+                0x17 0x67 0x80 0x73 0x6E 0x6C 0x6B 0x63
+                0x77 0x51 0x5C 0x58 0x50 0x4C 0x48 0x36
+                0x15 0x0C 0x0C 0x19 0x5B 0x7D 0x6F 0x69
+                0x69 0x5B 0x0C 0x29 0x20 0x40 0x52 0x59
+                0x57 0x56 0x54 0x4F 0x3B 0x1F 0x7F 0x17
+                0x06 0x1A 0x30 0x5A 0x85 0x93 0x96 0x2D
+                0x48 0x77 0x9C 0xB3 0x80 0x52 0x94 0xCB
+                0x2F 0x00 0x64 0xA5 0xB5 0x11 0xF0 0x11
+           >;
+           cellwise,monitor-interval-ms = <5000>;
+           monitored-battery = <&bat>;
+           power-supplies = <&mains_charger>, <&usb_charger>;
+       };
+    };
+