GSM: allow retry if connection fails

cores/arduino/mbed/connectivity/cellular/include/cellular/framework/API/CellularDevice.h

@@ -201,6 +201,17 @@ class CellularDevice {
      */
     virtual nsapi_error_t soft_power_off() = 0;
 
+    /** Resets the modem via AT command
+     *
+     *  @remark CellularStateMachine disconnect or destruct does not reset the modem,
+     *  but you need to do that yourself.
+     *
+     *  @pre You must call shutdown to prepare the modem for reset.
+     *
+     *  @return         NSAPI_ERROR_OK on success
+     */
+    virtual nsapi_error_t soft_reset() = 0;
+
     /** Open the SIM card by setting the pin code for SIM.
      *
      *  @param sim_pin  PIN for the SIM card

cores/arduino/mbed/connectivity/cellular/include/cellular/framework/AT/AT_CellularDevice.h

@@ -80,6 +80,8 @@ class AT_CellularDevice : public CellularDevice {
 
     virtual nsapi_error_t soft_power_off();
 
+    virtual nsapi_error_t soft_reset();
+
     virtual nsapi_error_t set_pin(const char *sim_pin);
 
     virtual nsapi_error_t get_sim_state(SimState &state);

cores/arduino/mbed/connectivity/drivers/cellular/GEMALTO/CINTERION/GEMALTO_CINTERION.h

@@ -55,6 +55,9 @@ class GEMALTO_CINTERION : public AT_CellularDevice {
 
 protected:
     virtual nsapi_error_t init();
+    virtual nsapi_error_t shutdown();
+    virtual nsapi_error_t soft_power_off();
+    virtual nsapi_error_t soft_reset();
 
 private:
     static Module _module;

cores/arduino/mbed/connectivity/drivers/cellular/GEMALTO/CINTERION/GEMALTO_CINTERION_CellularStack.h

@@ -43,6 +43,7 @@ class GEMALTO_CINTERION_CellularStack : public AT_CellularStack {
     void stopGNSS();
     void PSMEnable();
     void PSMDisable();
+    int ping(const char *host, int ttl);
 
 protected:
 

libraries/GSM/src/GSM.cpp

@@ -46,10 +46,28 @@ mbed::CellularDevice *mbed::CellularDevice::get_default_instance()
 
 int arduino::GSMClass::begin(const char* pin, const char* apn, const char* username, const char* password, RadioAccessTechnologyType rat, uint32_t band, bool restart) {
 
-  if (restart || isCmuxEnable()) {
-    reset();
+  /* Assume module is powered ON. Uncomment this line is you are using
+   * Edge Control without Arduino_ConnectionHandler
+   * #if defined (ARDUINO_EDGE_CONTROL)
+   *   pinMode(ON_MKR2, OUTPUT);
+   *   digitalWrite(ON_MKR2, HIGH);
+   * #endif
+   */
+
+  /* Ensure module is not under reset */
+  pinMode(MBED_CONF_GEMALTO_CINTERION_RST, OUTPUT);
+  digitalWrite(MBED_CONF_GEMALTO_CINTERION_RST, LOW);
+
+  /* Reset module if needed */
+  const bool emergencyReset = restart || isCmuxEnable();
+  DEBUG_INFO("Emergency reset %s", emergencyReset ? "enabled" : "disabled");
+  if (emergencyReset) {
+    hardwareReset();
   }
 
+  /* Create rising edge on pin ON */
+  on();
+
   if (!_context) {
     _context = mbed::CellularContext::get_default_instance();
   }
@@ -59,20 +77,18 @@ int arduino::GSMClass::begin(const char* pin, const char* apn, const char* usern
     return 0;
   }
 
-  pinMode(MBED_CONF_GEMALTO_CINTERION_ON, INPUT_PULLDOWN);
-
+#if defined(ARDUINO_PORTENTA_H7_M7) || defined(ARDUINO_PORTENTA_H7_M4)
+  /* This is needed to wakeup module if hw flow control is enabled */
   static mbed::DigitalOut rts(MBED_CONF_GEMALTO_CINTERION_RTS, 0);
+#endif
 
   _device = _context->get_device();
   _device->modem_debug_on(_at_debug);
 
-  if (!isReady()) {
-    DEBUG_ERROR("Cellular device not ready");
-    return 0;
-  }
-
+  DEBUG_INFO("CMUX %s", _cmuxGSMenable ? "enabled" : "disabled");
   _device->set_cmux_status_flag(_cmuxGSMenable);
   _device->set_retry_timeout_array(_retry_timeout, sizeof(_retry_timeout) / sizeof(_retry_timeout[0]));
+  _device->set_timeout(_timeout);
   _device->attach(mbed::callback(this, &GSMClass::onStatusChange));
   _device->init();
 
@@ -106,6 +122,10 @@ int arduino::GSMClass::begin(const char* pin, const char* apn, const char* usern
   return connect_status == NSAPI_ERROR_OK ? 1 : 0;
 }
 
+void arduino::GSMClass::setTimeout(unsigned long timeout) {
+  _timeout = timeout;
+}
+
 void arduino::GSMClass::enableCmux() {
   _cmuxGSMenable = true;
 }
@@ -115,13 +135,62 @@ bool arduino::GSMClass::isCmuxEnable() {
 }
 
 void arduino::GSMClass::end() {
+  if(_device) {
+    _device->shutdown();
+  }
+}
+
+void arduino::GSMClass::reset() {
+  if(_device) {
+    _device->soft_reset();
+  }
+}
+
+void arduino::GSMClass::off() {
+  if(_device) {
+    _device->soft_power_off();
+  }
+}
+
+int arduino::GSMClass::ping(const char* hostname, int ttl) {
+
+  mbed::GEMALTO_CINTERION_CellularStack* stack = (mbed::GEMALTO_CINTERION_CellularStack*)_context->get_stack();
+  if (!stack) {
+    return -1;
+  }
+  return stack->ping(hostname, ttl);
+}
+
+int arduino::GSMClass::ping(const String &hostname, int ttl)
+{
+  return ping(hostname.c_str(), ttl);
+}
 
+int arduino::GSMClass::ping(IPAddress ip, int ttl)
+{
+  String host;
+  host.reserve(15);
+
+  host += ip[0];
+  host += '.';
+  host += ip[1];
+  host += '.';
+  host += ip[2];
+  host += '.';
+  host += ip[3];
+
+  return ping(host, ttl);
 }
 
 int arduino::GSMClass::disconnect() {
-  if (_context) {
+  if (!_context) {
+    return 0;
+  }
+
+  if (_context->is_connected()) {
     return _context->disconnect();
   }
+
   return 0;
 }
 
@@ -158,34 +227,22 @@ NetworkInterface* arduino::GSMClass::getNetwork() {
   return _context;
 }
 
-void arduino::GSMClass::reset() {
+void arduino::GSMClass::hardwareReset() {
+  /* Reset logic is inverted */
   pinMode(MBED_CONF_GEMALTO_CINTERION_RST, OUTPUT);
   digitalWrite(MBED_CONF_GEMALTO_CINTERION_RST, HIGH);
   delay(800);
   digitalWrite(MBED_CONF_GEMALTO_CINTERION_RST, LOW);
+}
+
+void arduino::GSMClass::on() {
+  /* Module needs a rising edge to power on */
   pinMode(MBED_CONF_GEMALTO_CINTERION_ON, OUTPUT);
   digitalWrite(MBED_CONF_GEMALTO_CINTERION_ON, LOW);
   delay(1);
   digitalWrite(MBED_CONF_GEMALTO_CINTERION_ON, HIGH);
   delay(1);
 }
 
-bool arduino::GSMClass::isReady(const int timeout) {
-  if (!_device) {
-    DEBUG_ERROR("No device found");
-    return false;
-  }
-
-  const unsigned int start = millis();
-  while (_device->is_ready() != NSAPI_ERROR_OK) {
-
-    if (millis() - start > timeout) {
-      DEBUG_WARNING("Timeout waiting device ready");
-      return false;
-    }
-    delay(100);
-  }
-  return true;
-}
 
 arduino::GSMClass GSM;

libraries/GSM/src/GSM.h

@@ -75,30 +75,47 @@ class GSMClass : public MbedSocketClass {
       }
     }
 
-  /* Start GSM connection.
-     * Configure the credentials into the device.
-     *
-     * param pin: Pointer to the pin string.
-     * param apn: Pointer to the apn string.
-     * param username: Pointer to the username string.
-     * param password: Pointer to the password string.
-     * param rat: Radio Access Technology.
-     * 
-     * return: 0 in case of success, negative number in case of failure
-     */
-  int begin(const char* pin, const char* apn, const char* username, const char* password, RadioAccessTechnologyType rat = CATNB, uint32_t band = BAND_20, bool restart = true);
+  /*
+   * Start GSM connection. Configure the credentials into the device.
+   *
+   * param pin: Pointer to the pin string.
+   * param apn: Pointer to the apn string.
+   * param username: Pointer to the username string.
+   * param password: Pointer to the password string.
+   * param rat: Radio Access Technology.
+   *
+   * return: 0 in case of success, negative number in case of failure
+   */
+  int begin(const char* pin, const char* apn, const char* username, const char* password, RadioAccessTechnologyType rat = CATNB, uint32_t band = BAND_20, bool restart = false);
 
   /*
-     * Disconnect from the network
-     *
-     * return: one value of wl_status_t enum
-     */
+   * Disconnect from the network
+   *
+   * return: one value of wl_status_t enum
+   */
   int disconnect(void);
 
+  /*
+   * Reset internal state machine in order to be ready to reconnect again.
+   */
   void end(void);
 
-  unsigned long getTime();
+  /*
+   * Send AT+CFUN=1,1 command to trigger a software reset. To be called only after end();
+   */
+  void reset();
 
+  /*
+   * Send AT^SMSO="fast command to power off the modem. To be called only after end();
+   */
+  void off();
+
+  /*
+   * Change cellular state timeouts. Needs to be called before GSM.begin()
+   */
+  void setTimeout(unsigned long timeout);
+
+  unsigned long getTime();
   unsigned long getLocalTime();
 
   bool setTime(unsigned long const epoch, int const timezone = 0);
@@ -108,9 +125,9 @@ class GSMClass : public MbedSocketClass {
   void trace(Stream& stream);
   void setTraceLevel(int trace_level, bool timestamp = false, bool at_trace = false);
 #endif
-  int ping(const char* hostname, uint8_t ttl = 128);
-  int ping(const String& hostname, uint8_t ttl = 128);
-  int ping(IPAddress host, uint8_t ttl = 128);
+  int ping(const char* hostname, int ttl = 5000);
+  int ping(const String& hostname, int ttl = 5000);
+  int ping(IPAddress host, int ttl = 5000);
   bool isConnected();
 
   friend class GSMClient;
@@ -130,11 +147,12 @@ class GSMClass : public MbedSocketClass {
   mbed::CellularContext* _context = nullptr;
   mbed::CellularDevice* _device = nullptr;
   bool _at_debug = false;
+  unsigned long _timeout = 1000;
 
   /* Internal cellular state machine retries. Values are in seconds.
-   * This array also defines the maximum number of retries to 6
+   * This array also defines the maximum number of retries to CELLULAR_RETRY_ARRAY_SIZE
    */
-  const uint16_t _retry_timeout[6] = {1, 2, 4, 8, 16, 32};
+  const uint16_t _retry_timeout[CELLULAR_RETRY_ARRAY_SIZE] = {1, 2, 4, 8, 8, 8, 8, 8, 8, 8};
 
   static constexpr int RSSI_UNKNOWN = 99;
   static const char * const sim_state_str[];
@@ -149,8 +167,8 @@ class GSMClass : public MbedSocketClass {
   static const char * getRegistrationStateString(const mbed::CellularNetwork::RegistrationStatus state);
   void onStatusChange(nsapi_event_t ev, intptr_t in);
 
-  void reset();
-  bool isReady(const int timeout = 5000);
+  void hardwareReset();
+  void on();
 };
 
 }

libraries/GSM/src/GSMClient.h

@@ -26,9 +26,29 @@
 namespace arduino {
 
 class GSMClient : public AClient {
+private:
   NetworkInterface *getNetwork() {
     return GSM.getNetwork();
   }
+
+public:
+  size_t write(uint8_t b) {
+    int ret = 0;
+    do {
+      ret = client->write(b);
+      delay(0);
+    } while (ret == 0 && status());
+    return ret;
+  }
+
+  size_t write(const uint8_t *buf, size_t size) {
+    int ret = 0;
+    do {
+      ret = client->write(buf, size);
+      delay(0);
+    } while (ret == 0 && status());
+    return ret;
+  }
 };
 
 }

libraries/GSM/src/GSMSSLClient.h

@@ -32,6 +32,25 @@ class GSMSSLClient : public arduino::ASslClient {
   NetworkInterface *getNetwork() {
     return GSM.getNetwork();
   }
+
+public:
+  size_t write(uint8_t b) {
+    int ret = 0;
+    do {
+      ret = client->write(b);
+      delay(0);
+    } while (ret == 0 && status());
+    return ret;
+  }
+
+  size_t write(const uint8_t *buf, size_t size) {
+    int ret = 0;
+    do {
+      ret = client->write(buf, size);
+      delay(0);
+    } while (ret == 0 && status());
+    return ret;
+  }
 };
 
 }