Cellular: removed manual registering state.

Simplified state machine by removing manual registering state.
This was done as some modems did not have all the needed at commands
for checking the registered network. Some modem run out of memory as when
checking correct network there might be so many networks available.
Manual registration still works but it does not do any checks to which network
it's registered. Moved manual registering at command earlier in state machine so it forces
registering to a correct network. Internal refactor/fix, does not affect applications.

Author: Teppo Järvelin

UNITTESTS/features/cellular/framework/device/cellularstatemachine/cellularstatemachinetest.cpp

@@ -34,7 +34,6 @@ enum UT_CellularState {
     UT_STATE_DEVICE_READY,
     UT_STATE_SIM_PIN,
     UT_STATE_REGISTERING_NETWORK,
-    UT_STATE_MANUAL_REGISTERING_NETWORK,
     UT_STATE_ATTACHING_NETWORK,
     UT_STATE_MAX_FSM_STATE
 };
@@ -392,8 +391,8 @@ TEST_F(TestCellularStateMachine, test_run_to_state)
     ut.set_plmn("12345");
     ASSERT_EQ(NSAPI_ERROR_OK, ut.run_to_device_registered());
     (void)ut.get_current_status(current_state, target_state);
-    ASSERT_EQ(UT_STATE_MANUAL_REGISTERING_NETWORK, current_state);
-    ASSERT_EQ(UT_STATE_MANUAL_REGISTERING_NETWORK, target_state);
+    ASSERT_EQ(UT_STATE_REGISTERING_NETWORK, current_state);
+    ASSERT_EQ(UT_STATE_REGISTERING_NETWORK, target_state);
     ut.cellular_event_changed((nsapi_event_t)CellularRegistrationStatusChanged, (intptr_t)&data);
     ut.reset();
 

features/cellular/framework/AT/AT_CellularNetwork.cpp

@@ -171,7 +171,9 @@ void AT_CellularNetwork::read_reg_params_and_compare(RegistrationType type)
                     reg_params._status == RegisteredRoaming)) {
                 if (previous_registration_status == RegisteredHomeNetwork ||
                         previous_registration_status == RegisteredRoaming) {
-                    call_network_cb(NSAPI_STATUS_DISCONNECTED);
+                    if (type != C_REG) {// we are interested only if we drop from packet network
+                        _connection_status_cb(NSAPI_EVENT_CONNECTION_STATUS_CHANGE, NSAPI_STATUS_DISCONNECTED);
+                    }
                 }
             }
         }
@@ -267,6 +269,9 @@ nsapi_error_t AT_CellularNetwork::set_registration(const char *plmn)
         tr_debug("Manual network registration to %s", plmn);
         _at.cmd_start("AT+COPS=1,2,");
         _at.write_string(plmn);
+        if (_op_act != RAT_UNKNOWN) {
+            _at.write_int(_op_act);
+        }
         _at.cmd_stop_read_resp();
     }
 

features/cellular/framework/device/CellularStateMachine.cpp

@@ -48,8 +48,7 @@ CellularStateMachine::CellularStateMachine(CellularDevice &device, events::Event
     _cellularDevice(device), _state(STATE_INIT), _next_state(_state), _target_state(_state),
     _event_status_cb(0), _network(0), _queue(queue), _queue_thread(0), _sim_pin(0),
     _retry_count(0), _event_timeout(-1), _event_id(-1), _plmn(0), _command_success(false),
-    _plmn_network_found(false), _is_retry(false), _cb_data(), _current_event(NSAPI_EVENT_CONNECTION_STATUS_CHANGE),
-    _status(0)
+    _is_retry(false), _cb_data(), _current_event(NSAPI_EVENT_CONNECTION_STATUS_CHANGE), _status(0)
 {
 #if MBED_CONF_CELLULAR_RANDOM_MAX_START_DELAY == 0
     _start_time = 0;
@@ -83,7 +82,6 @@ void CellularStateMachine::reset()
     _state = STATE_INIT;
     _event_timeout = -1;
     _event_id = -1;
-    _plmn_network_found = false;
     _is_retry = false;
     _status = 0;
     _target_state = STATE_INIT;
@@ -161,15 +159,30 @@ bool CellularStateMachine::open_sim()
         }
     }
 
-    return state == CellularDevice::SimStateReady;
+    bool sim_ready = state == CellularDevice::SimStateReady;
+
+    if (sim_ready) {
+        // If plmn is set, we should it right after sim is opened so that registration is forced to correct network.
+        if (_plmn && strlen(_plmn)) {
+            _cb_data.error = _network->set_registration(_plmn);
+            tr_debug("STM: manual set_registration: %d, plmn: %s", _cb_data.error, _plmn);
+            if (_cb_data.error) {
+                return false;
+            }
+        }
+    }
+
+    return sim_ready;
 }
 
 bool CellularStateMachine::is_registered()
 {
     CellularNetwork::RegistrationStatus status;
     bool is_registered = false;
 
-    for (int type = 0; type < CellularNetwork::C_MAX; type++) {
+    // accept only CGREG/CEREG. CREG is for circuit switch network changed. If we accept CREG attach will fail if also
+    // CGREG/CEREG is not registered.
+    for (int type = 0; type < CellularNetwork::C_REG; type++) {
         if (get_network_registration((CellularNetwork::RegistrationType) type, status, is_registered)) {
             if (is_registered) {
                 break;
@@ -178,6 +191,11 @@ bool CellularStateMachine::is_registered()
     }
 
     _cb_data.status_data = status;
+    // in manual registering we are forcing registration to certain network so we don't accept active context or attached
+    // as indication that device is registered to correct network.
+    if (_plmn && strlen(_plmn)) {
+        return is_registered;
+    }
     return is_registered || _status;
 }
 
@@ -249,61 +267,13 @@ void CellularStateMachine::report_failure(const char *msg)
 const char *CellularStateMachine::get_state_string(CellularState state) const
 {
 #if MBED_CONF_MBED_TRACE_ENABLE
-    static const char *strings[STATE_MAX_FSM_STATE] = { "Init", "Power", "Device ready", "SIM pin", "Registering network", "Manual registering", "Attaching network"};
+    static const char *strings[STATE_MAX_FSM_STATE] = { "Init", "Power", "Device ready", "SIM pin", "Registering network", "Attaching network"};
     return strings[state];
 #else
     return NULL;
 #endif // #if MBED_CONF_MBED_TRACE_ENABLE
 }
 
-bool CellularStateMachine::is_registered_to_plmn()
-{
-    int format;
-    CellularNetwork::operator_t op;
-
-    _cb_data.error = _network->get_operator_params(format, op);
-    if (_cb_data.error == NSAPI_ERROR_OK) {
-        if (format == 2) {
-            // great, numeric format we can do comparison for that
-            if (strcmp(op.op_num, _plmn) == 0) {
-                return true;
-            }
-            return false;
-        }
-
-        // format was alpha, get operator names to do the comparing
-        CellularNetwork::operator_names_list names_list;
-        _cb_data.error = _network->get_operator_names(names_list);
-        if (_cb_data.error == NSAPI_ERROR_OK) {
-            CellularNetwork::operator_names_t *op_names = names_list.get_head();
-            bool found_match = false;
-            while (op_names) {
-                if (format == 0) {
-                    if (strcmp(op.op_long, op_names->alpha) == 0) {
-                        found_match = true;
-                    }
-                } else if (format == 1) {
-                    if (strcmp(op.op_short, op_names->alpha) == 0) {
-                        found_match = true;
-                    }
-                }
-
-                if (found_match) {
-                    if (strcmp(_plmn, op_names->numeric)) {
-                        names_list.delete_all();
-                        return true;
-                    }
-                    names_list.delete_all();
-                    return false;
-                }
-            }
-        }
-        names_list.delete_all();
-    }
-
-    return false;
-}
-
 void CellularStateMachine::enter_to_state(CellularState state)
 {
     _next_state = state;
@@ -378,6 +348,7 @@ bool CellularStateMachine::device_ready()
         _event_status_cb((nsapi_event_t)CellularDeviceReady, (intptr_t)&_cb_data);
     }
     _cellularDevice.set_ready_cb(0);
+
     return true;
 }
 
@@ -410,16 +381,15 @@ void CellularStateMachine::state_sim_pin()
     _cellularDevice.set_timeout(TIMEOUT_SIM_PIN);
     tr_info("Setup SIM (timeout %d s)", TIMEOUT_SIM_PIN / 1000);
     if (open_sim()) {
-
         bool success = false;
         for (int type = 0; type < CellularNetwork::C_MAX; type++) {
             _cb_data.error = _network->set_registration_urc((CellularNetwork::RegistrationType)type, true);
-            if (!_cb_data.error) {
+            if (!_cb_data.error && (type == CellularNetwork::C_EREG || type == CellularNetwork::C_GREG)) {
                 success = true;
             }
         }
         if (!success) {
-            tr_warn("Failed to set any URC's for registration");
+            tr_error("Failed to set CEREG/CGREG URC's for registration");
             retry_state_or_fail();
             return;
         }
@@ -428,16 +398,13 @@ void CellularStateMachine::state_sim_pin()
             tr_debug("Active context found.");
             _status |= ACTIVE_PDP_CONTEXT;
         }
-        CellularNetwork::AttachStatus status; // check if modem is already attached to a network
+        CellularNetwork::AttachStatus status = CellularNetwork::Detached; // check if modem is already attached to a network
         if (_network->get_attach(status) == NSAPI_ERROR_OK && status == CellularNetwork::Attached) {
             _status |= ATTACHED_TO_NETWORK;
             tr_debug("Cellular already attached.");
         }
-        if (_plmn) {
-            enter_to_state(STATE_MANUAL_REGISTERING_NETWORK);
-        } else {
-            enter_to_state(STATE_REGISTERING_NETWORK);
-        }
+
+        enter_to_state(STATE_REGISTERING_NETWORK);
     } else {
         retry_state_or_fail();
     }
@@ -448,44 +415,25 @@ void CellularStateMachine::state_registering()
     _cellularDevice.set_timeout(TIMEOUT_NETWORK);
     tr_info("Network registration (timeout %d s)", TIMEOUT_REGISTRATION / 1000);
     if (is_registered()) {
-        _cb_data.status_data = CellularNetwork::AlreadyRegistered;
+        if (_cb_data.status_data != CellularNetwork::RegisteredHomeNetwork &&
+                _cb_data.status_data != CellularNetwork::RegisteredRoaming && _status) {
+            // there was already activated context or attached to network, and registration status is not registered, set to already registered.
+            _cb_data.status_data = CellularNetwork::AlreadyRegistered;
+        }
         _cb_data.error = NSAPI_ERROR_OK;
         _event_status_cb(_current_event, (intptr_t)&_cb_data);
         // we are already registered, go to attach
         enter_to_state(STATE_ATTACHING_NETWORK);
     } else {
         _cellularDevice.set_timeout(TIMEOUT_REGISTRATION);
-        if (!_command_success) {
-            _cb_data.error = _network->set_registration();
+        if (!_command_success && !_plmn) { // don't call set_registration twice for manual registration
+            _cb_data.error = _network->set_registration(_plmn);
             _command_success = (_cb_data.error == NSAPI_ERROR_OK);
         }
         retry_state_or_fail();
     }
 }
 
-// only used when _plmn is set
-void CellularStateMachine::state_manual_registering_network()
-{
-    _cellularDevice.set_timeout(TIMEOUT_REGISTRATION);
-    tr_info("Manual registration %s (timeout %d s)", _plmn, TIMEOUT_REGISTRATION / 1000);
-    if (!_plmn_network_found) {
-        if (is_registered() && is_registered_to_plmn()) {
-            // we have to send registration changed event as network thinks that we are not registered even we have active PDP context
-            _cb_data.status_data = CellularNetwork::AlreadyRegistered;
-            _cb_data.error = NSAPI_ERROR_OK;
-            _event_status_cb(_current_event, (intptr_t)&_cb_data);
-            _plmn_network_found = true;
-            enter_to_state(STATE_ATTACHING_NETWORK);
-        } else {
-            if (!_command_success) {
-                _cb_data.error = _network->set_registration(_plmn);
-                _command_success = (_cb_data.error == NSAPI_ERROR_OK);
-            }
-            retry_state_or_fail();
-        }
-    }
-}
-
 void CellularStateMachine::state_attaching()
 {
     _cellularDevice.set_timeout(TIMEOUT_CONNECT);
@@ -523,13 +471,8 @@ void CellularStateMachine::continue_from_state(CellularState state)
 nsapi_error_t CellularStateMachine::run_to_state(CellularStateMachine::CellularState state)
 {
     _mutex.lock();
-
-    CellularState tmp_state = state;
-    if (_plmn && tmp_state == STATE_REGISTERING_NETWORK) {
-        tmp_state = STATE_MANUAL_REGISTERING_NETWORK;
-    }
     // call pre_event via queue so that it's in same thread and it's safe to decisions
-    int id = _queue.call_in(0, this, &CellularStateMachine::pre_event, tmp_state);
+    int id = _queue.call_in(0, this, &CellularStateMachine::pre_event, state);
     if (!id) {
         report_failure("Failed to call queue.");
         stop();
@@ -620,10 +563,6 @@ void CellularStateMachine::event()
             _current_event = (nsapi_event_t)CellularRegistrationStatusChanged;
             state_registering();
             break;
-        case STATE_MANUAL_REGISTERING_NETWORK:
-            _current_event = (nsapi_event_t)CellularRegistrationStatusChanged;
-            state_manual_registering_network();
-            break;
         case STATE_ATTACHING_NETWORK:
             _current_event = (nsapi_event_t)CellularAttachNetwork;
             state_attaching();
@@ -694,30 +633,23 @@ bool CellularStateMachine::check_is_target_reached()
 void CellularStateMachine::cellular_event_changed(nsapi_event_t ev, intptr_t ptr)
 {
     cell_callback_data_t *data = (cell_callback_data_t *)ptr;
-    if ((cellular_connection_status_t)ev == CellularRegistrationStatusChanged &&
-            (_state == STATE_REGISTERING_NETWORK || _state == STATE_MANUAL_REGISTERING_NETWORK)) {
+    if ((cellular_connection_status_t)ev == CellularRegistrationStatusChanged && _state == STATE_REGISTERING_NETWORK) {
         // expect packet data so only these states are valid
-        if ((data->status_data == CellularNetwork::RegisteredHomeNetwork || data->status_data == CellularNetwork::RegisteredRoaming) && data->error == NSAPI_ERROR_OK) {
-            if (_plmn) {
-                if (is_registered_to_plmn()) {
-                    if (!_plmn_network_found) {
-                        _plmn_network_found = true;
-                        _queue.cancel(_event_id);
-                        _is_retry = false;
-                        _event_id = -1;
-                        if (!check_is_target_reached()) {
-                            continue_from_state(STATE_ATTACHING_NETWORK);
-                        }
-                    }
-                }
-            } else {
+        CellularNetwork::registration_params_t reg_params;
+        nsapi_error_t err = _network->get_registration_params(reg_params);
+
+        if (err == NSAPI_ERROR_OK && (reg_params._type == CellularNetwork::C_EREG || reg_params._type == CellularNetwork::C_GREG)) {
+            if ((data->status_data == CellularNetwork::RegisteredHomeNetwork ||
+                    data->status_data == CellularNetwork::RegisteredRoaming) && data->error == NSAPI_ERROR_OK) {
                 _queue.cancel(_event_id);
                 _is_retry = false;
                 _event_id = -1;
                 if (!check_is_target_reached()) {
                     continue_from_state(STATE_ATTACHING_NETWORK);
                 }
             }
+        } else {
+            tr_debug("creg event, discard...");
         }
     }
 }

features/cellular/framework/device/CellularStateMachine.h

@@ -58,7 +58,6 @@ class CellularStateMachine {
         STATE_DEVICE_READY,
         STATE_SIM_PIN,
         STATE_REGISTERING_NETWORK,
-        STATE_MANUAL_REGISTERING_NETWORK,
         STATE_ATTACHING_NETWORK,
         STATE_MAX_FSM_STATE
     };
@@ -146,12 +145,10 @@ class CellularStateMachine {
     void state_device_ready();
     void state_sim_pin();
     void state_registering();
-    void state_manual_registering_network();
     void state_attaching();
     void enter_to_state(CellularState state);
     void retry_state_or_fail();
     void continue_from_state(CellularState state);
-    bool is_registered_to_plmn();
     void report_failure(const char *msg);
     void event();
     void device_ready_cb();
@@ -179,7 +176,6 @@ class CellularStateMachine {
     int _event_id;
     const char *_plmn;
     bool _command_success;
-    bool _plmn_network_found;
     bool _is_retry;
     cell_callback_data_t _cb_data;
     nsapi_event_t _current_event;