Bluetooth: Add shutdown callback before closing the device

This callback allows a vendor to send the vendor specific commands
before cloing the hci interface.
Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -373,6 +373,7 @@ struct hci_dev {
 	int (*close)(struct hci_dev *hdev);
 	int (*flush)(struct hci_dev *hdev);
 	int (*setup)(struct hci_dev *hdev);
+	int (*shutdown)(struct hci_dev *hdev);
 	int (*send)(struct hci_dev *hdev, struct sk_buff *skb);
 	void (*notify)(struct hci_dev *hdev, unsigned int evt);
 	void (*hw_error)(struct hci_dev *hdev, u8 code);

net/bluetooth/hci_core.c

@@ -1591,6 +1591,12 @@ static int hci_dev_do_close(struct hci_dev *hdev)
 {
 	BT_DBG("%s %p", hdev->name, hdev);
 
+	if (!test_bit(HCI_UNREGISTER, &hdev->dev_flags)) {
+		/* Execute vendor specific shutdown routine */
+		if (hdev->shutdown)
+			hdev->shutdown(hdev);
+	}
+
 	cancel_delayed_work(&hdev->power_off);
 
 	hci_req_cancel(hdev, ENODEV);