Bluetooth: Add BT_CHANNEL_POLICY socket option

Allow control of AMP functionality on L2CAP sockets. By default,
connections will be restricted to BR/EDR.  Manipulating the
BT_CHANNEL_POLICY option allows for channels to be moved to or created
on AMP controllers.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

include/net/bluetooth/bluetooth.h

@@ -77,6 +77,33 @@ struct bt_power {
 #define BT_POWER_FORCE_ACTIVE_OFF 0
 #define BT_POWER_FORCE_ACTIVE_ON  1
 
+#define BT_CHANNEL_POLICY	10
+
+/* BR/EDR only (default policy)
+ *   AMP controllers cannot be used.
+ *   Channel move requests from the remote device are denied.
+ *   If the L2CAP channel is currently using AMP, move the channel to BR/EDR.
+ */
+#define BT_CHANNEL_POLICY_BREDR_ONLY		0
+
+/* BR/EDR Preferred
+ *   Allow use of AMP controllers.
+ *   If the L2CAP channel is currently on AMP, move it to BR/EDR.
+ *   Channel move requests from the remote device are allowed.
+ */
+#define BT_CHANNEL_POLICY_BREDR_PREFERRED	1
+
+/* AMP Preferred
+ *   Allow use of AMP controllers
+ *   If the L2CAP channel is currently on BR/EDR and AMP controller
+ *     resources are available, initiate a channel move to AMP.
+ *   Channel move requests from the remote device are allowed.
+ *   If the L2CAP socket has not been connected yet, try to create
+ *     and configure the channel directly on an AMP controller rather
+ *     than BR/EDR.
+ */
+#define BT_CHANNEL_POLICY_AMP_PREFERRED		2
+
 __attribute__((format (printf, 2, 3)))
 int bt_printk(const char *level, const char *fmt, ...);