Bluetooth: mgmt: Add device disconnect reason

MGMT_EV_DEVICE_DISCONNECTED will now expose the disconnection reason to
userland, distinguishing four possible values:

	0x00	Reason not known or unspecified
	0x01	Connection timeout
	0x02	Connection terminated by local host
	0x03	Connection terminated by remote host

Note that the local/remote distinction just determines which side
terminated the low-level connection, regardless of the disconnection of
the higher-level profiles.

This can sometimes be misleading and thus must be used with care. For
example, some hardware combinations would report a locally initiated
disconnection even if the user turned Bluetooth off in the remote side.

Signed-off-by: Mikel Astiz <mikel.astiz@bmw-carit.de>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index 4348ee8..1b48eff 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -405,7 +405,16 @@
 	__u8	eir[0];
 } __packed;
 
+#define MGMT_DEV_DISCONN_UNKNOWN	0x00
+#define MGMT_DEV_DISCONN_TIMEOUT	0x01
+#define MGMT_DEV_DISCONN_LOCAL_HOST	0x02
+#define MGMT_DEV_DISCONN_REMOTE		0x03
+
 #define MGMT_EV_DEVICE_DISCONNECTED	0x000C
+struct mgmt_ev_device_disconnected {
+	struct mgmt_addr_info addr;
+	__u8	reason;
+} __packed;
 
 #define MGMT_EV_CONNECT_FAILED		0x000D
 struct mgmt_ev_connect_failed {