From b210d531724265b61ae85c467b677a8aca843ab4 Mon Sep 17 00:00:00 2001
From: Mariusz Skamra <mariusz.skamra@tieto.com>
Date: Mon, 13 Jul 2015 12:43:02 +0200
Subject: [PATCH] Bluetooth: Add initial auto connect support

Calling bt_conn_set_auto_conn one can decide if auto connect shall
be used. If so, everytime the connection is lost, passive scanning
will be enabled to listen for connectable advertisements from
remote device and re-establish the connection.

Auto connect can be disabled if one decide to disconnect from
this device using bt_disconnect or call bt_conn_set_auto_conn
with auto_conn flag set to false.

Change-Id: Ic9952e313cb8612ea6c72838be0755805daeffcf
Signed-off-by: Mariusz Skamra <mariusz.skamra@tieto.com>
---
 include/bluetooth/conn.h      | 16 ++++++++++++++++
 net/bluetooth/conn.c          |  9 +++++++++
 net/bluetooth/conn_internal.h |  6 ++++++
 net/bluetooth/hci_core.c      | 13 +++++++++++++
 4 files changed, 44 insertions(+)

diff --git a/include/bluetooth/conn.h b/include/bluetooth/conn.h
index a55219b9321..358503e263d 100644
--- a/include/bluetooth/conn.h
+++ b/include/bluetooth/conn.h
@@ -34,6 +34,8 @@
 #ifndef __BT_CONN_H
 #define __BT_CONN_H
 
+#include <stdbool.h>
+
 #include <bluetooth/hci.h>
 
 /** Opaque type representing a connection to a remote device */
@@ -93,4 +95,18 @@ struct bt_conn_cb {
  */
 void bt_conn_cb_register(struct bt_conn_cb *cb);
 
+/** @brief Automatically connect to remote device if it's in range.
+ *
+ *  This function enables/disables automatic connection initiation.
+ *  Everytime the device looses the connection with peer, this connection
+ *  will be re-established if connectable advertisement from peer is received.
+ *
+ *  @param conn Existing connection object.
+ *  @param auto_conn boolean value. If true, auto connect is enabled,
+ *  if false, auto connect is disabled.
+ *
+ *  @return none
+ */
+void bt_conn_set_auto_conn(struct bt_conn *conn, bool auto_conn);
+
 #endif /* __BT_CONN_H */
diff --git a/net/bluetooth/conn.c b/net/bluetooth/conn.c
index b563bf734d6..ff8d47cd685 100644
--- a/net/bluetooth/conn.c
+++ b/net/bluetooth/conn.c
@@ -465,3 +465,12 @@ int bt_security(struct bt_conn *conn, bt_security_t sec)
 
 	return bt_smp_send_pairing_req(conn);
 }
+
+void bt_conn_set_auto_conn(struct bt_conn *conn, bool auto_conn)
+{
+	if (auto_conn) {
+		atomic_set_bit(conn->flags, BT_CONN_AUTO_CONNECT);
+	} else {
+		atomic_clear_bit(conn->flags, BT_CONN_AUTO_CONNECT);
+	}
+}
diff --git a/net/bluetooth/conn_internal.h b/net/bluetooth/conn_internal.h
index 59bc71f0d00..4f8476d651a 100644
--- a/net/bluetooth/conn_internal.h
+++ b/net/bluetooth/conn_internal.h
@@ -48,10 +48,16 @@ struct bt_conn_l2cap {
 	uint8_t			ident;
 };
 
+/* bt_conn flags: the flags defined here represent connection parameters */
+enum {
+	BT_CONN_AUTO_CONNECT,
+};
+
 struct bt_conn {
 	struct bt_dev		*dev;
 	uint16_t		handle;
 	uint8_t			role;
+	atomic_t		flags[1];
 
 	bt_addr_le_t		src;
 	bt_addr_le_t		dst;
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 8bee8bfce07..1c7eb9f68d8 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -691,6 +691,12 @@ static void hci_disconn_complete(struct bt_buf *buf)
 
 	bt_conn_set_state(conn, BT_CONN_DISCONNECTED);
 	conn->handle = 0;
+
+	if (atomic_test_bit(conn->flags, BT_CONN_AUTO_CONNECT)) {
+		bt_conn_set_state(conn, BT_CONN_CONNECT_SCAN);
+		trigger_scan();
+	}
+
 	bt_conn_put(conn);
 
 	if (dev.adv_enable) {
@@ -1660,6 +1666,13 @@ int bt_disconnect(struct bt_conn *conn, uint8_t reason)
 	case BT_CONN_CONNECT:
 		return bt_hci_connect_le_cancel(conn);
 	case BT_CONN_CONNECTED:
+		/* Disconnection is initiated by us, so auto connection shall
+		 * be disabled. Otherwise the passive scan would be enabled
+		 * and we could send LE Create Connection as soon as the remote
+		 * starts advertising.
+		 */
+		bt_conn_set_auto_conn(conn, false);
+
 		return bt_hci_disconnect(conn, reason);
 	case BT_CONN_DISCONNECT:
 		return 0;