Cellular: add Callback functionality to CellularDevice.

features/cellular/framework/API/CellularDevice.h

@@ -20,6 +20,7 @@
 
 #include "CellularTargets.h"
 #include "CellularStateMachine.h"
+#include "Callback.h"
 
 namespace mbed {
 
@@ -145,6 +146,19 @@ public:
      */
     nsapi_error_t attach_to_network();
 
+    /** Register callback for status reporting.
+     *
+     *  The specified status callback function will be called on the network and cellular device status changes.
+     *  The parameters on the callback are the event type and event-type dependent reason parameter.
+     *
+     *  @remark  deleting CellularDevice/CellularContext in callback not allowed.
+     *  @remark  application should not attach to this function if using CellularContext::attach as it will contain the
+     *           same information.
+     *
+     *  @param status_cb The callback for status changes.
+     */
+    void attach(Callback<void(nsapi_event_t, intptr_t)> status_cb);
+
     /** Create new CellularNetwork interface.
      *
      *  @param fh    file handle used in communication to modem. Can be for example UART handle. If null then the default
@@ -258,6 +272,7 @@ private:
     char _sim_pin[MAX_PIN_SIZE + 1];
     char _plmn[MAX_PLMN_SIZE + 1];
     PlatformMutex _mutex;
+    Callback<void(nsapi_event_t, intptr_t)> _status_cb;
 };
 
 } // namespace mbed

features/cellular/framework/device/CellularDevice.cpp

@@ -51,7 +51,7 @@ MBED_WEAK CellularDevice *CellularDevice::get_default_instance()
 #endif // CELLULAR_DEVICE
 
 CellularDevice::CellularDevice(FileHandle *fh) : _network_ref_count(0), _sms_ref_count(0), _power_ref_count(0), _sim_ref_count(0),
-    _info_ref_count(0), _fh(fh), _queue(5 * EVENTS_EVENT_SIZE), _state_machine(0), _nw(0)
+    _info_ref_count(0), _fh(fh), _queue(5 * EVENTS_EVENT_SIZE), _state_machine(0), _nw(0), _status_cb(0)
 {
     set_sim_pin(NULL);
     set_plmn(NULL);
@@ -158,6 +158,11 @@ nsapi_error_t CellularDevice::start_state_machine(CellularStateMachine::Cellular
     return err;
 }
 
+void CellularDevice::attach(Callback<void(nsapi_event_t, intptr_t)> status_cb)
+{
+    _status_cb = status_cb;
+}
+
 void CellularDevice::cellular_callback(nsapi_event_t ev, intptr_t ptr)
 {
     if (ev >= NSAPI_EVENT_CELLULAR_STATUS_BASE && ev <= NSAPI_EVENT_CELLULAR_STATUS_END) {
@@ -200,6 +205,11 @@ void CellularDevice::cellular_callback(nsapi_event_t ev, intptr_t ptr)
         curr->cellular_callback(ev, ptr);
         curr = curr->_next;
     }
+
+    // forward to callback function if set by attach(...)
+    if (_status_cb) {
+        _status_cb(ev, ptr);
+    }
 }
 
 } // namespace mbed