Bluetooth: Add HCIUARTSETFLAGS and HCIUARTGETFLAGS ioctls

This patch introduces two new ioctls: HCIUARTSETFLAGS and
HCIUARTGETFLAGS. The only flag available for now is HCI_UART_RAW_DEVICE
which allows to initialize a UART device into RAW mode from userspace.
This is particularly useful for experimenting with Bluetooth controllers
that don't yet have proper support in BlueZ.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index e8beffe..a57dbfc 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -395,6 +395,9 @@
 	if (!reset)
 		set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks);
 
+	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
+		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
+
 	if (hci_register_dev(hdev) < 0) {
 		BT_ERR("Can't register HCI device");
 		hci_free_dev(hdev);
@@ -475,6 +478,15 @@
 			return hu->hdev->id;
 		return -EUNATCH;
 
+	case HCIUARTSETFLAGS:
+		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
+			return -EBUSY;
+		hu->hdev_flags = arg;
+		break;
+
+	case HCIUARTGETFLAGS:
+		return hu->hdev_flags;
+
 	default:
 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
 		break;