dt-bindings: net: bluetooth: Add device tree bindings for QTI chip wcn3990

This patch enables regulators for the Qualcomm Bluetooth wcn3990
controller.
Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt

@@ -10,12 +10,25 @@ device the slave device is attached to.
 Required properties:
  - compatible: should contain one of the following:
    * "qcom,qca6174-bt"
+   * "qcom,wcn3990-bt"
+
+Optional properties for compatible string qcom,qca6174-bt:
 
-Optional properties:
  - enable-gpios: gpio specifier used to enable chip
  - clocks: clock provided to the controller (SUSCLK_32KHZ)
 
-Example:
+Required properties for compatible string qcom,wcn3990-bt:
+
+ - vddio-supply: VDD_IO supply regulator handle.
+ - vddxo-supply: VDD_XO supply regulator handle.
+ - vddrf-supply: VDD_RF supply regulator handle.
+ - vddch0-supply: VDD_CH0 supply regulator handle.
+
+Optional properties for compatible string qcom,wcn3990-bt:
+
+ - max-speed: see Documentation/devicetree/bindings/serial/slave-device.txt
+
+Examples:
 
 serial@7570000 {
 	label = "BT-UART";
@@ -28,3 +41,15 @@ serial@7570000 {
 		clocks = <&divclk4>;
 	};
 };
+
+serial@898000 {
+	bluetooth {
+		compatible = "qcom,wcn3990-bt";
+
+		vddio-supply = <&vreg_s4a_1p8>;
+		vddxo-supply = <&vreg_l7a_1p8>;
+		vddrf-supply = <&vreg_l17a_1p3>;
+		vddch0-supply = <&vreg_l25a_3p3>;
+		max-speed = <3200000>;
+	};
+};