Bluetooth: Interleaved discovery support

This patch adds interleaved discovery support to MGMT Start
Discovery command.

In case interleaved discovery is not supported (not a dual mode
device), we perform BR/EDR or LE-only discovery according to the
device capabilities.
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>

include/net/bluetooth/hci_core.h

@@ -716,6 +716,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
 #define lmp_ssp_capable(dev)       ((dev)->features[6] & LMP_SIMPLE_PAIR)
 #define lmp_no_flush_capable(dev)  ((dev)->features[6] & LMP_NO_FLUSH)
 #define lmp_le_capable(dev)        ((dev)->features[4] & LMP_LE)
+#define lmp_bredr_capable(dev)     (!((dev)->features[4] & LMP_NO_BREDR))
 
 /* ----- Extended LMP capabilities ----- */
 #define lmp_host_le_capable(dev)   ((dev)->host_features[0] & LMP_HOST_LE)
@@ -1019,6 +1020,7 @@ int mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 int mgmt_start_discovery_failed(struct hci_dev *hdev, u8 status);
 int mgmt_stop_discovery_failed(struct hci_dev *hdev, u8 status);
 int mgmt_discovering(struct hci_dev *hdev, u8 discovering);
+int mgmt_interleaved_discovery(struct hci_dev *hdev);
 int mgmt_device_blocked(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 int mgmt_device_unblocked(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 

net/bluetooth/hci_event.c

@@ -1090,11 +1090,16 @@ static void hci_cc_le_set_scan_enable(struct hci_dev *hdev,
 
 		clear_bit(HCI_LE_SCAN, &hdev->dev_flags);
 
+		schedule_delayed_work(&hdev->adv_work, ADV_CLEAR_TIMEOUT);
+
+		if (hdev->discovery.type == DISCOV_TYPE_INTERLEAVED) {
+			mgmt_interleaved_discovery(hdev);
+		} else {
 			hci_dev_lock(hdev);
 			hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
 			hci_dev_unlock(hdev);
+		}
 
-		schedule_delayed_work(&hdev->adv_work, ADV_CLEAR_TIMEOUT);
 		break;
 
 	default:

net/bluetooth/mgmt.c

@@ -108,8 +108,10 @@ static const u16 mgmt_events[] = {
 #define LE_SCAN_WIN			0x12
 #define LE_SCAN_INT			0x12
 #define LE_SCAN_TIMEOUT_LE_ONLY		10240	/* TGAP(gen_disc_scan_min) */
+#define LE_SCAN_TIMEOUT_BREDR_LE	5120	/* TGAP(100)/2 */
 
 #define INQUIRY_LEN_BREDR		0x08	/* TGAP(100) */
+#define INQUIRY_LEN_BREDR_LE		0x04	/* TGAP(100)/2 */
 
 #define SERVICE_CACHE_TIMEOUT (5 * 1000)
 
@@ -2153,6 +2155,46 @@ static int remove_remote_oob_data(struct sock *sk, u16 index,
 	return err;
 }
 
+static int discovery(struct hci_dev *hdev)
+{
+	int err;
+
+	if (lmp_host_le_capable(hdev)) {
+		if (lmp_bredr_capable(hdev)) {
+			err = hci_le_scan(hdev, LE_SCAN_TYPE,
+						LE_SCAN_INT, LE_SCAN_WIN,
+						LE_SCAN_TIMEOUT_BREDR_LE);
+		} else {
+			hdev->discovery.type = DISCOV_TYPE_LE;
+			err = hci_le_scan(hdev, LE_SCAN_TYPE,
+						LE_SCAN_INT, LE_SCAN_WIN,
+						LE_SCAN_TIMEOUT_LE_ONLY);
+		}
+	} else {
+		hdev->discovery.type = DISCOV_TYPE_BREDR;
+		err = hci_do_inquiry(hdev, INQUIRY_LEN_BREDR);
+	}
+
+	return err;
+}
+
+int mgmt_interleaved_discovery(struct hci_dev *hdev)
+{
+	int err;
+
+	BT_DBG("%s", hdev->name);
+
+	hci_dev_lock(hdev);
+
+	err = hci_do_inquiry(hdev, INQUIRY_LEN_BREDR_LE);
+	if (err < 0)
+		hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
+
+	hci_dev_unlock(hdev);
+
+	return err;
+}
+
 static int start_discovery(struct sock *sk, u16 index,
 						void *data, u16 len)
 {
@@ -2196,7 +2238,6 @@ static int start_discovery(struct sock *sk, u16 index,
 
 	switch (hdev->discovery.type) {
 	case DISCOV_TYPE_BREDR:
-	case DISCOV_TYPE_INTERLEAVED:
 		err = hci_do_inquiry(hdev, INQUIRY_LEN_BREDR);
 		break;
 
@@ -2205,6 +2246,10 @@ static int start_discovery(struct sock *sk, u16 index,
 					LE_SCAN_WIN, LE_SCAN_TIMEOUT_LE_ONLY);
 		break;
 
+	case DISCOV_TYPE_INTERLEAVED:
+		err = discovery(hdev);
+		break;
+
 	default:
 		err = -EINVAL;
 	}