Bluetooth: Add default wakeup callback for HCI UART driver

Bluetooth HCI devices indicate if they are able to wakeup in the wakeup
callback since 'commit 4539ca67 ("Bluetooth: Rename driver
.prevent_wake to .wakeup")'. This patch adds a default wakeup callback
for Bluetooth HCI UAR devices. It assumes Bluetooth HCI UART devices are
wakeable for backward compatibility. For those who need a customized
behavior, one can override it before calling hci_uart_register_device().

Fixes: 4539ca67 ("Bluetooth: Rename driver .prevent_wake to .wakeup")
Signed-off-by: Ying Hsu <yinghsu@chromium.org>
Reviewed-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/hci_serdev.c

@@ -231,6 +231,15 @@ static int hci_uart_setup(struct hci_dev *hdev)
 	return 0;
 }
 
+/* Check if the device is wakeable */
+static bool hci_uart_wakeup(struct hci_dev *hdev)
+{
+	/* HCI UART devices are assumed to be wakeable by default.
+	 * Implement wakeup callback to override this behavior.
+	 */
+	return true;
+}
+
 /** hci_uart_write_wakeup - transmit buffer wakeup
  * @serdev: serial device
  *
@@ -342,6 +351,8 @@ int hci_uart_register_device(struct hci_uart *hu,
 	hdev->flush = hci_uart_flush;
 	hdev->send  = hci_uart_send_frame;
 	hdev->setup = hci_uart_setup;
+	if (!hdev->wakeup)
+		hdev->wakeup = hci_uart_wakeup;
 	SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
 
 	if (test_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &hu->flags))