[nrf fromtree] Bluetooth: Add configuration to control the dynamic connection callbacks

This commit allows to the user to control the use or not of dynamic
connection callbacks.
The stack is not using the dynamic connection callbacks so they are
only needed if the applications want to use it.
Setting it to true for backwards compatibility.

With dynamic connection callbacks

           FLASH:      176600 B       512 KB     33.68%
             RAM:       27428 B        64 KB     41.85%
        IDT_LIST:          0 GB        32 KB      0.00%

Without dynamic connection callbacks

           FLASH:      176376 B       512 KB     33.64%
             RAM:       27428 B        64 KB     41.85%
        IDT_LIST:          0 GB        32 KB      0.00%

Signed-off-by: Yago Fontoura do Rosario <[email protected]>
(cherry picked from commit ca06a1d80da97c897c2ee7e786181ab9b7d6e830)
Signed-off-by: Sean Madigan <[email protected]>

Author: Yagoor

samples/bluetooth/central_hr/overlay-static_callbacks.conf

@@ -0,0 +1,2 @@
+# Disable connection dynamic callbacks
+CONFIG_BT_CONN_DYNAMIC_CALLBACKS=n

samples/bluetooth/central_hr/prj_minimal.conf

@@ -87,6 +87,7 @@ CONFIG_BT_GATT_SERVICE_CHANGED=n
 CONFIG_BT_GAP_PERIPHERAL_PREF_PARAMS=n
 CONFIG_BT_SETTINGS_CCC_LAZY_LOADING=y
 CONFIG_BT_HCI_VS=n
+CONFIG_BT_CONN_DYNAMIC_CALLBACKS=n
 
 # Disable Bluetooth controller features not needed
 CONFIG_BT_CTLR_PRIVACY=n

samples/bluetooth/peripheral_hr/overlay-static_callbacks.conf

@@ -0,0 +1,2 @@
+# Disable connection dynamic callbacks
+CONFIG_BT_CONN_DYNAMIC_CALLBACKS=n

samples/bluetooth/peripheral_hr/prj_minimal.conf

@@ -93,6 +93,7 @@ CONFIG_BT_GATT_SERVICE_CHANGED=n
 CONFIG_BT_GAP_PERIPHERAL_PREF_PARAMS=n
 CONFIG_BT_SETTINGS_CCC_LAZY_LOADING=y
 CONFIG_BT_HCI_VS=n
+CONFIG_BT_CONN_DYNAMIC_CALLBACKS=n
 
 # Disable Bluetooth controller features not needed
 CONFIG_BT_CTLR_PRIVACY=n

subsys/bluetooth/Kconfig

@@ -131,6 +131,16 @@ config BT_LE_EXTENDED_FEAT_SET
 	  Enable support for the LL Extended Feature Set feature.
 
 if BT_CONN
+config BT_CONN_DYNAMIC_CALLBACKS
+	bool "Dynamic connection callbacks"
+	default y
+	help
+	  Enable support for dynamic connection callbacks. This links in
+	  bt_conn_cb_register(). Disabling this config is safe. It will make
+	  uses of this and associated APIs fail to link. Note: Static registration
+	  through BT_CONN_CB_DEFINE() is always available and does not depend on
+	  this config.
+
 config BT_HCI_ACL_FLOW_CONTROL
 	bool "Controller to Host ACL flow control support"
 	# Enable if building a Host-only build