Bluetooth: Add hci_do_le_scan()

This patch adds to hci_core the hci_do_le_scan function which
should be used to scan LE devices.

In order to enable LE scan, hci_do_le_scan() sends commands (Set
LE Scan Parameters and Set LE Scan Enable) to the controller and
waits for its results. If commands were executed successfully a
delayed work is scheduled to disable the ongoing scanning after
some amount of time. This function blocks.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 8971c18..97152d9 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1031,6 +1031,8 @@
 	__u8 status = *((__u8 *) skb->data);
 
 	BT_DBG("%s status 0x%x", hdev->name, status);
+
+	hci_req_complete(hdev, HCI_OP_LE_SET_SCAN_PARAM, status);
 }
 
 static void hci_cc_le_set_scan_enable(struct hci_dev *hdev,
@@ -1041,15 +1043,17 @@
 
 	BT_DBG("%s status 0x%x", hdev->name, status);
 
-	if (status)
-		return;
-
 	cp = hci_sent_cmd_data(hdev, HCI_OP_LE_SET_SCAN_ENABLE);
 	if (!cp)
 		return;
 
 	switch (cp->enable) {
 	case LE_SCANNING_ENABLED:
+		hci_req_complete(hdev, HCI_OP_LE_SET_SCAN_ENABLE, status);
+
+		if (status)
+			return;
+
 		set_bit(HCI_LE_SCAN, &hdev->dev_flags);
 
 		cancel_delayed_work_sync(&hdev->adv_work);
@@ -1061,6 +1065,9 @@
 		break;
 
 	case LE_SCANNING_DISABLED:
+		if (status)
+			return;
+
 		clear_bit(HCI_LE_SCAN, &hdev->dev_flags);
 
 		hci_dev_lock(hdev);