dt-bindings: net: bluetooth: nxp: Add support for power save feature using GPIO

This adds a new optional device tree property device-wakeup-gpios, which
specifies the GPIO connected to BT_WAKE_IN pin of the NXP chipset.

If this property is defined, the driver will use this GPIO for driving chip
into sleep/wakeup state, else use the UART break signal by default.

Signed-off-by: Neeraj Sanjay Kale <[email protected]>
Reviewed-by: Rob Herring (Arm) <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>

Author: NeerajSanjayKale

Documentation/devicetree/bindings/net/bluetooth/nxp,88w8987-bt.yaml

@@ -34,17 +34,25 @@ properties:
   firmware-name:
     maxItems: 1
 
+  device-wakeup-gpios:
+    maxItems: 1
+    description:
+      Host-To-Chip power save mechanism is driven by this GPIO
+      connected to BT_WAKE_IN pin of the NXP chipset.
+
 required:
   - compatible
 
 additionalProperties: false
 
 examples:
   - |
+    #include <dt-bindings/gpio/gpio.h>
     serial {
         bluetooth {
             compatible = "nxp,88w8987-bt";
             fw-init-baudrate = <3000000>;
             firmware-name = "uartuart8987_bt_v0.bin";
+            device-wakeup-gpios = <&gpio 11 GPIO_ACTIVE_HIGH>;
         };
     };