Bluetooth: BR/EDR: Add basic SCAN support

Adds capability to stack to make controller discoverable and
connectable.

Change-Id: Iffe380d2bde0c193f806b76cce3933914c9a4796
Signed-off-by: Arkadiusz Lichwa <arkadiusz.lichwa@tieto.com>

include/bluetooth/bluetooth.h

@@ -240,4 +240,32 @@ static inline int bt_addr_le_to_str(const bt_addr_le_t *addr, char *str,
 			addr->val[5], addr->val[4], addr->val[3],
 			addr->val[2], addr->val[1], addr->val[0], type);
 }
+
+#if defined(CONFIG_BLUETOOTH_BREDR)
+/** @brief Enable/disable set controller in discoverable state.
+ *
+ *  Allows make local controller to listen on INQUIRY SCAN channel and responds
+ *  to devices making general inquiry. To enable this state it's mandatory
+ *  to first be in connectable state.
+ *
+ *  @param enable Value allowing/disallowing controller to become discoverable.
+ *
+ *  @return Negative if fail set to requested state or requested state has been
+ *  already set. Zero if done successfully.
+ */
+int bt_bredr_set_discoverable(bool enable);
+
+/** @brief Enable/disable set controller in connectable state.
+ *
+ *  Allows make local controller to be connectable. It means the controller
+ *  start listen to devices requests on PAGE SCAN channel. If disabled also
+ *  resets discoverability if was set.
+ *
+ *  @param enable Value allowing/disallowing controller to be connectable.
+ *
+ *  @return Negative if fail set to requested state or requested state has been
+ *  already set. Zero if done successfully.
+ */
+int bt_bredr_set_connectable(bool enable);
+#endif
 #endif /* __BT_BLUETOOTH_H */

include/bluetooth/hci.h

@@ -122,6 +122,11 @@ struct bt_hci_cp_set_event_mask {
 
 #define BT_HCI_OP_RESET				BT_OP(BT_OGF_BASEBAND, 0x0003)
 
+#define BT_HCI_OP_WRITE_SCAN_ENABLE		BT_OP(BT_OGF_BASEBAND, 0x001a)
+#define BT_BREDR_SCAN_DISABLED			0x00
+#define BT_BREDR_SCAN_INQUIRY			0x01
+#define BT_BREDR_SCAN_PAGE			0x02
+
 #define BT_HCI_OP_SET_CTL_TO_HOST_FLOW		BT_OP(BT_OGF_BASEBAND, 0x0031)
 
 #define BT_HCI_OP_HOST_BUFFER_SIZE		BT_OP(BT_OGF_BASEBAND, 0x0033)

net/bluetooth/hci_core.c

@@ -2105,3 +2105,78 @@ struct net_buf *bt_buf_get_acl(void)
 	return NULL;
 #endif /* CONFIG_BLUETOOTH_CONN */
 }
+
+#if defined(CONFIG_BLUETOOTH_BREDR)
+static int bt_bredr_hci_write_scan(uint8_t scan)
+{
+	struct net_buf *buf;
+	int err;
+
+	BT_DBG("type %u", scan);
+
+	buf = bt_hci_cmd_create(BT_HCI_OP_WRITE_SCAN_ENABLE, 1);
+	if (!buf) {
+		return -ENOBUFS;
+	}
+
+	memcpy(net_buf_add(buf, 1), &scan, 1);
+
+	err = bt_hci_cmd_send_sync(BT_HCI_OP_WRITE_SCAN_ENABLE, buf, NULL);
+	if (err) {
+		return err;
+	}
+
+	if (scan & BT_BREDR_SCAN_INQUIRY) {
+		atomic_set_bit(bt_dev.flags, BT_DEV_ISCAN);
+	} else {
+		atomic_clear_bit(bt_dev.flags, BT_DEV_ISCAN);
+	}
+
+	if (scan & BT_BREDR_SCAN_PAGE) {
+		atomic_set_bit(bt_dev.flags, BT_DEV_PSCAN);
+	} else {
+		atomic_clear_bit(bt_dev.flags, BT_DEV_PSCAN);
+	}
+
+	return 0;
+}
+
+int bt_bredr_set_connectable(bool enable)
+{
+	if (enable) {
+		if (atomic_test_bit(bt_dev.flags, BT_DEV_PSCAN)) {
+			return -EALREADY;
+		} else {
+			return bt_bredr_hci_write_scan(BT_BREDR_SCAN_PAGE);
+		}
+	} else {
+		if (!atomic_test_bit(bt_dev.flags, BT_DEV_PSCAN)) {
+			return -EALREADY;
+		} else {
+			return bt_bredr_hci_write_scan(BT_BREDR_SCAN_DISABLED);
+		}
+	}
+}
+
+int bt_bredr_set_discoverable(bool enable)
+{
+	if (enable) {
+		if (atomic_test_bit(bt_dev.flags, BT_DEV_ISCAN)) {
+			return -EALREADY;
+		}
+
+		if (!atomic_test_bit(bt_dev.flags, BT_DEV_PSCAN)) {
+			return -EPERM;
+		}
+
+		return bt_bredr_hci_write_scan(BT_BREDR_SCAN_INQUIRY |
+					       BT_BREDR_SCAN_PAGE);
+	} else {
+		if (!atomic_test_bit(bt_dev.flags, BT_DEV_ISCAN)) {
+			return -EALREADY;
+		}
+
+		return bt_bredr_hci_write_scan(BT_BREDR_SCAN_PAGE);
+	}
+}
+#endif

net/bluetooth/hci_core.h

@@ -44,6 +44,8 @@ enum {
 
 	BT_DEV_SCANNING,
 	BT_DEV_SCAN_FILTER_DUP,
+	BT_DEV_ISCAN,
+	BT_DEV_PSCAN,
 };
 
 struct bt_dev_le {