Streamline Nanostack interface initialisation

Can unify quite a log of the setup here, and that would be useful to
allow initialisation other than in "connect".

features/nanostack/mbed-mesh-api/mbed-mesh-api/LoWPANNDInterface.h

@@ -37,9 +37,10 @@ public:
      */
     LoWPANNDInterface(NanostackRfPhy *phy) : MeshInterfaceNanostack(phy) { }
 
-    virtual int connect();
-    virtual int disconnect();
     bool getRouterIpAddress(char *address, int8_t len);
+protected:
+    Nanostack::LoWPANNDInterface *get_interface() const;
+    virtual nsapi_error_t do_initialize();
 };
 
 #endif

features/nanostack/mbed-mesh-api/mbed-mesh-api/MeshInterfaceNanostack.h

@@ -67,6 +67,18 @@ protected:
 
 class InterfaceNanostack : public virtual NetworkInterface {
 public:
+    /** Start the interface
+     *
+     *  @return     0 on success, negative error code on failure
+     */
+    virtual nsapi_error_t connect();
+
+    /** Stop the interface
+     *
+     *  @return     0 on success, negative error code on failure
+     */
+    virtual nsapi_error_t disconnect();
+
     /** Get the internally stored IP address
     /return     IP address of the interface or null if not yet connected
     */
@@ -109,6 +121,7 @@ protected:
     InterfaceNanostack();
     virtual Nanostack *get_stack(void);
     Nanostack::Interface *get_interface() const { return _interface; }
+    virtual nsapi_error_t do_initialize() = 0;
 
     Nanostack::Interface *_interface;
 

features/nanostack/mbed-mesh-api/mbed-mesh-api/NanostackEthernetInterface.h

@@ -49,20 +49,9 @@ public:
 
     nsapi_error_t initialize(NanostackEthernetPhy *phy);
 
-    /** Start the interface
-     *
-     *  @return     0 on success, negative on failure
-     */
-    virtual nsapi_error_t connect();
-
-    /** Stop the interface
-     *
-     *  @return     0 on success, negative on failure
-     */
-    virtual nsapi_error_t disconnect();
-
 protected:
     Nanostack::EthernetInterface *get_interface() const { return static_cast<Nanostack::EthernetInterface *>(_interface); }
+    virtual nsapi_error_t do_initialize();
 
 };
 

features/nanostack/mbed-mesh-api/mbed-mesh-api/ThreadInterface.h

@@ -62,10 +62,9 @@ public:
 
     mesh_error_t device_pskd_set(const char *pskd);
 
-    virtual int connect();
-    virtual int disconnect();
 protected:
     Nanostack::ThreadInterface *get_interface() const;
+    virtual nsapi_error_t do_initialize();
 };
 
 #endif // THREADINTERFACE_H

features/nanostack/mbed-mesh-api/source/LoWPANNDInterface.cpp

@@ -27,7 +27,12 @@ private:
     mesh_error_t mesh_disconnect();
 };
 
-int LoWPANNDInterface::connect()
+Nanostack::LoWPANNDInterface *LoWPANNDInterface::get_interface() const
+{
+    return static_cast<Nanostack::LoWPANNDInterface*>(_interface);
+}
+
+nsapi_error_t LoWPANNDInterface::do_initialize()
 {
     if (!_interface) {
         _interface = new (nothrow) Nanostack::LoWPANNDInterface(*_phy);
@@ -36,9 +41,7 @@ int LoWPANNDInterface::connect()
         }
         _interface->attach(_connection_status_cb);
     }
-
-    return _interface->bringup(false, NULL, NULL, NULL, IPV6_STACK, _blocking);
-
+    return NSAPI_ERROR_OK;
 }
 
 nsapi_error_t Nanostack::LoWPANNDInterface::bringup(bool dhcp, const char *ip,
@@ -84,11 +87,6 @@ nsapi_error_t Nanostack::LoWPANNDInterface::bringup(bool dhcp, const char *ip,
 
 }
 
-int LoWPANNDInterface::disconnect()
-{
-    return _interface->bringdown();
-}
-
 nsapi_error_t Nanostack::LoWPANNDInterface::bringdown()
 {
     NanostackLockGuard lock;

features/nanostack/mbed-mesh-api/source/MeshInterfaceNanostack.cpp

@@ -82,6 +82,24 @@ InterfaceNanostack::InterfaceNanostack()
     // Nothing to do
 }
 
+int InterfaceNanostack::connect()
+{
+    nsapi_error_t error = do_initialize();
+    if (error) {
+        return error;
+    }
+
+    return _interface->bringup(false, NULL, NULL, NULL, IPV6_STACK, _blocking);
+}
+
+int InterfaceNanostack::disconnect()
+{
+    if (!_interface) {
+        return NSAPI_ERROR_NO_CONNECTION;
+    }
+    return _interface->bringdown();
+}
+
 nsapi_error_t MeshInterfaceNanostack::initialize(NanostackRfPhy *phy)
 {
     if (_phy) {

features/nanostack/mbed-mesh-api/source/NanostackEthernetInterface.cpp

@@ -87,12 +87,12 @@ nsapi_error_t Nanostack::EthernetInterface::bringup(bool dhcp, const char *ip,
     return 0;
 }
 
-int NanostackEthernetInterface::connect()
+nsapi_error_t NanostackEthernetInterface::do_initialize()
 {
     if (!_interface) {
         return NSAPI_ERROR_PARAMETER;
     }
-    return _interface->bringup(false, NULL, NULL, NULL, IPV6_STACK, _blocking);
+    return NSAPI_ERROR_OK;
 }
 
 nsapi_error_t Nanostack::EthernetInterface::bringdown()
@@ -100,12 +100,3 @@ nsapi_error_t Nanostack::EthernetInterface::bringdown()
     enet_tasklet_disconnect();
     return 0;
 }
-
-
-int NanostackEthernetInterface::disconnect()
-{
-    if (!_interface) {
-        return NSAPI_ERROR_NO_CONNECTION;
-    }
-    return _interface->bringdown();
-}

features/nanostack/mbed-mesh-api/source/ThreadInterface.cpp

@@ -76,7 +76,7 @@ Nanostack::ThreadInterface *ThreadInterface::get_interface() const
     return static_cast<Nanostack::ThreadInterface*>(_interface);
 }
 
-int ThreadInterface::connect()
+nsapi_error_t ThreadInterface::do_initialize()
 {
     if (!_interface) {
         _interface = new (nothrow) Nanostack::ThreadInterface(*_phy);
@@ -85,8 +85,7 @@ int ThreadInterface::connect()
         }
         _interface->attach(_connection_status_cb);
     }
-
-    return _interface->bringup(false, NULL, NULL, NULL, IPV6_STACK, _blocking);
+    return NSAPI_ERROR_OK;
 }
 
 nsapi_error_t Nanostack::ThreadInterface::bringup(bool dhcp, const char *ip,
@@ -146,11 +145,6 @@ nsapi_error_t Nanostack::ThreadInterface::bringup(bool dhcp, const char *ip,
     return 0;
 }
 
-int ThreadInterface::disconnect()
-{
-    return _interface->bringdown();
-}
-
 nsapi_error_t Nanostack::ThreadInterface::bringdown()
 {
     nanostack_lock();