dt-bindings: power: Add the bindings for the bq2515x family of chargers.

The BQ2515X family of devices are highly integrated battery management
ICs that integrate the most common functions for wearable devices
namely a charger, an output voltage rail, ADC for battery and system
monitoring, and a push-button controller.

Datasheets:
http://www.ti.com/lit/ds/symlink/bq25150.pdf
http://www.ti.com/lit/ds/symlink/bq25155.pdfReviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ricardo Rivera-Matos <r-rivera-matos@ti.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/power/supply/bq2515x.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (C) 2020 Texas Instruments Incorporated
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/power/supply/bq2515x.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: TI bq2515x 500-mA Linear charger family
+
+maintainers:
+  - Dan Murphy <dmurphy@ti.com>
+  - Ricardo Rivera-Matos <r-rivera-matos@ti.com>
+
+description: |
+  The BQ2515x family is a highly integrated battery charge management IC that
+  integrates the most common functions for wearable devices, namely a charger,
+  an output voltage rail, ADC for battery and system monitoring, and
+  push-button controller.
+
+  Specifications about the charger can be found at:
+    http://www.ti.com/lit/ds/symlink/bq25150.pdf
+    http://www.ti.com/lit/ds/symlink/bq25155.pdf
+
+properties:
+  compatible:
+    enum:
+      - ti,bq25150
+      - ti,bq25155
+
+  reg:
+    maxItems: 1
+    description: I2C address of the charger.
+
+  ac-detect-gpios:
+    description: |
+       GPIO used for connecting the bq2515x device PG (AC Detect)
+       pin.
+    maxItems: 1
+
+  reset-gpios:
+    description: GPIO used for hardware reset.
+    maxItems: 1
+
+  powerdown-gpios:
+    description: GPIO used for low power mode of IC.
+    maxItems: 1
+
+  charge-enable-gpios:
+    description: GPIO used to turn on and off charging.
+    maxItems: 1
+
+  input-current-limit-microamp:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Maximum input current in micro Amps.
+    minimum: 50000
+    maximum: 500000
+
+  monitored-battery:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: phandle to the battery node being monitored
+
+required:
+  - compatible
+  - reg
+  - monitored-battery
+
+additionalProperties: false
+
+examples:
+  - |
+    bat: battery {
+      compatible = "simple-battery";
+      constant-charge-current-max-microamp = <50000>;
+      precharge-current-microamp = <2500>;
+      constant-charge-voltage-max-microvolt = <4000000>;
+    };
+    #include <dt-bindings/gpio/gpio.h>
+    i2c0 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      bq25150: charger@6b {
+        compatible = "ti,bq25150";
+        reg = <0x6b>;
+        monitored-battery = <&bat>;
+        input-current-limit-microamp = <100000>;
+
+        ac-detect-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+        reset-gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
+        powerdown-gpios = <&gpio0 15 GPIO_ACTIVE_HIGH>;
+        charge-enable-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+      };
+    };