Merge pull request #9473 from VeijoPesonen/feature-esp8266_reset_handling

ESP8266: treats reset-ready-message as OOB

Author: Cruz Monrreal

components/wifi/esp8266-driver/ESP8266/ESP8266.cpp

@@ -25,6 +25,7 @@
 #include "PinNames.h"
 #include "platform/Callback.h"
 #include "platform/mbed_error.h"
+#include "rtos/Kernel.h"
 
 #define TRACE_GROUP  "ESPA" // ESP8266 AT layer
 
@@ -51,6 +52,8 @@ ESP8266::ESP8266(PinName tx, PinName rx, bool debug, PinName rts, PinName cts)
       _sock_already(false),
       _closed(false),
       _busy(false),
+      _reset_check(_rmutex),
+      _reset_done(false),
       _conn_status(NSAPI_STATUS_DISCONNECTED)
 {
     _serial.set_baud(ESP8266_DEFAULT_BAUD_RATE);
@@ -71,6 +74,7 @@ ESP8266::ESP8266(PinName tx, PinName rx, bool debug, PinName rts, PinName cts)
     _parser.oob("UNLINK", callback(this, &ESP8266::_oob_socket_close_err));
     _parser.oob("ALREADY CONNECTED", callback(this, &ESP8266::_oob_conn_already));
     _parser.oob("ERROR", callback(this, &ESP8266::_oob_err));
+    _parser.oob("ready", callback(this, &ESP8266::_oob_ready));
     // Don't expect to find anything about the watchdog reset in official documentation
     //https://techtutorialsx.com/2017/01/21/esp8266-watchdog-functions/
     _parser.oob("wdt reset", callback(this, &ESP8266::_oob_watchdog_reset));
@@ -183,14 +187,17 @@ bool ESP8266::start_uart_hw_flow_ctrl(void)
     bool done = true;
 
 #if DEVICE_SERIAL_FC
+    _smutex.lock();
     if (_serial_rts != NC && _serial_cts != NC) {
-       // Start board's flow control
-        _serial.set_flow_control(SerialBase::RTSCTS, _serial_rts, _serial_cts);
-
         // Start ESP8266's flow control
         done = _parser.send("AT+UART_CUR=%u,8,1,0,3", ESP8266_DEFAULT_BAUD_RATE)
                && _parser.recv("OK\n");
 
+        if (done) {
+            // Start board's flow control
+             _serial.set_flow_control(SerialBase::RTSCTS, _serial_rts, _serial_cts);
+        }
+
     } else if (_serial_rts != NC) {
         _serial.set_flow_control(SerialBase::RTS, _serial_rts, NC);
 
@@ -203,7 +210,14 @@ bool ESP8266::start_uart_hw_flow_ctrl(void)
         done = _parser.send("AT+UART_CUR=%u,8,1,0,1", ESP8266_DEFAULT_BAUD_RATE)
                && _parser.recv("OK\n");
 
-        _serial.set_flow_control(SerialBase::CTS, NC, _serial_cts);
+        if (done) {
+            _serial.set_flow_control(SerialBase::CTS, NC, _serial_cts);
+        }
+    }
+    _smutex.unlock();
+
+    if (!done) {
+        tr_debug("Enable UART HW flow control: FAIL");
     }
 #else
     if (_serial_rts != NC || _serial_cts != NC) {
@@ -234,20 +248,35 @@ bool ESP8266::startup(int mode)
 
 bool ESP8266::reset(void)
 {
+    static const int ESP8266_BOOTTIME = 10000; // [ms]
     bool done = false;
 
     _smutex.lock();
-    set_timeout(ESP8266_CONNECT_TIMEOUT);
 
+    unsigned long int start_time = rtos::Kernel::get_ms_count();
+    _reset_done = false;
+    set_timeout(ESP8266_RECV_TIMEOUT);
     for (int i = 0; i < 2; i++) {
-        if (_parser.send("AT+RST")
-                && _parser.recv("OK\n")
-                && _parser.recv("ready")) {
-            done = true;
+        if (!_parser.send("AT+RST") || !_parser.recv("OK\n")) {
+            tr_debug("reset(): AT+RST failed or no response");
+            continue;
+        }
+
+        _rmutex.lock();
+        while ((rtos::Kernel::get_ms_count() - start_time < ESP8266_BOOTTIME) && !_reset_done) {
+            _process_oob(ESP8266_RECV_TIMEOUT, true); // UART mutex claimed -> need to check for OOBs ourselves
+            _reset_check.wait_for(100); // Arbitrary relatively short delay
+        }
+
+        done = _reset_done;
+        _rmutex.unlock();
+        if (done) {
             break;
         }
     }
 
+    tr_debug("reset(): done: %s", done ? "OK" : "FAIL");
+
     _clear_socket_packets(ESP8266_ALL_SOCKET_IDS);
     set_timeout();
     _smutex.unlock();
@@ -963,6 +992,25 @@ void ESP8266::_oob_watchdog_reset()
                "_oob_watchdog_reset() modem watchdog reset triggered\n");
 }
 
+void ESP8266::_oob_ready()
+{
+
+    _rmutex.lock();
+    _reset_done = true;
+    _reset_check.notify_all();
+    _rmutex.unlock();
+
+    for (int i = 0; i < SOCKET_COUNT; i++) {
+        _sock_i[i].open = false;
+    }
+
+    // Makes possible to reinitialize
+    _conn_status = NSAPI_STATUS_ERROR_UNSUPPORTED;
+    _conn_stat_cb();
+
+    tr_debug("_oob_reset(): reset detected");
+}
+
 void ESP8266::_oob_busy()
 {
     char status[5];

components/wifi/esp8266-driver/ESP8266/ESP8266.h

@@ -27,6 +27,7 @@
 #include "platform/ATCmdParser.h"
 #include "platform/Callback.h"
 #include "platform/mbed_error.h"
+#include "rtos/ConditionVariable.h"
 #include "rtos/Mutex.h"
 
 // Various timeouts for different ESP8266 operations
@@ -396,6 +397,7 @@ class ESP8266 {
     PinName _serial_rts;
     PinName _serial_cts;
     rtos::Mutex _smutex; // Protect serial port access
+    rtos::Mutex _rmutex; // Reset protection
 
     // AT Command Parser
     mbed::ATCmdParser _parser;
@@ -435,6 +437,7 @@ class ESP8266 {
     void _oob_watchdog_reset();
     void _oob_busy();
     void _oob_tcp_data_hdlr();
+    void _oob_ready();
 
     // OOB state variables
     int _connect_error;
@@ -444,6 +447,8 @@ class ESP8266 {
     bool _closed;
     bool _error;
     bool _busy;
+    rtos::ConditionVariable _reset_check;
+    bool _reset_done;
 
     // Modem's address info
     char _ip_buffer[16];

components/wifi/esp8266-driver/ESP8266Interface.cpp

@@ -71,7 +71,7 @@ ESP8266Interface::ESP8266Interface()
 
     _esp.sigio(this, &ESP8266Interface::event);
     _esp.set_timeout();
-    _esp.attach(this, &ESP8266Interface::update_conn_state_cb);
+    _esp.attach(this, &ESP8266Interface::refresh_conn_state_cb);
 
     for (int i = 0; i < ESP8266_SOCKET_COUNT; i++) {
         _sock_i[i].open = false;
@@ -102,7 +102,7 @@ ESP8266Interface::ESP8266Interface(PinName tx, PinName rx, bool debug, PinName r
 
     _esp.sigio(this, &ESP8266Interface::event);
     _esp.set_timeout();
-    _esp.attach(this, &ESP8266Interface::update_conn_state_cb);
+    _esp.attach(this, &ESP8266Interface::refresh_conn_state_cb);
 
     for (int i = 0; i < ESP8266_SOCKET_COUNT; i++) {
         _sock_i[i].open = false;
@@ -404,12 +404,7 @@ bool ESP8266Interface::_get_firmware_ok()
 nsapi_error_t ESP8266Interface::_init(void)
 {
     if (!_initialized) {
-        _hw_reset();
-
-        if (!_esp.at_available()) {
-            return NSAPI_ERROR_DEVICE_ERROR;
-        }
-        if (!_esp.reset()) {
+        if (_reset() != NSAPI_ERROR_OK) {
             return NSAPI_ERROR_DEVICE_ERROR;
         }
         if (!_esp.echo_off()) {
@@ -436,7 +431,7 @@ nsapi_error_t ESP8266Interface::_init(void)
     return NSAPI_ERROR_OK;
 }
 
-void ESP8266Interface::_hw_reset()
+nsapi_error_t ESP8266Interface::_reset()
 {
     if (_rst_pin.is_connected()) {
         _rst_pin.rst_assert();
@@ -445,7 +440,17 @@ void ESP8266Interface::_hw_reset()
         wait_ms(2); // Documentation says 200 us should have been enough, but experimentation shows that 1ms was not enough
         _esp.flush();
         _rst_pin.rst_deassert();
+    } else {
+        _esp.flush();
+        if (!_esp.at_available()) {
+            return NSAPI_ERROR_DEVICE_ERROR;
+        }
+        if (!_esp.reset()) {
+            return NSAPI_ERROR_DEVICE_ERROR;
+        }
     }
+
+    return _esp.at_available() ? NSAPI_ERROR_OK : NSAPI_ERROR_DEVICE_ERROR;
 }
 
 struct esp8266_socket {
@@ -577,6 +582,10 @@ int ESP8266Interface::socket_send(void *handle, const void *data, unsigned size)
         return NSAPI_ERROR_NO_SOCKET;
     }
 
+    if (!_sock_i[socket->id].open) {
+        return NSAPI_ERROR_CONNECTION_LOST;
+    }
+
     if (!size) {
         // Firmware limitation
         return socket->proto == NSAPI_TCP ? 0 : NSAPI_ERROR_UNSUPPORTED;
@@ -604,6 +613,10 @@ int ESP8266Interface::socket_recv(void *handle, void *data, unsigned size)
         return NSAPI_ERROR_NO_SOCKET;
     }
 
+    if (!_sock_i[socket->id].open) {
+        return NSAPI_ERROR_CONNECTION_LOST;
+    }
+
     int32_t recv;
     if (socket->proto == NSAPI_TCP) {
         recv = _esp.recv_tcp(socket->id, data, size);
@@ -768,15 +781,11 @@ WiFiInterface *WiFiInterface::get_default_instance()
 
 #endif
 
-void ESP8266Interface::update_conn_state_cb()
+void ESP8266Interface::refresh_conn_state_cb()
 {
     nsapi_connection_status_t prev_stat = _conn_stat;
     _conn_stat = _esp.connection_status();
 
-    if (prev_stat == _conn_stat) {
-        return;
-    }
-
     switch (_conn_stat) {
         // Doesn't require changes
         case NSAPI_STATUS_CONNECTING:
@@ -791,8 +800,18 @@ void ESP8266Interface::update_conn_state_cb()
         default:
             _initialized = false;
             _conn_stat = NSAPI_STATUS_DISCONNECTED;
+            for (int i = 0; i < ESP8266_SOCKET_COUNT; i++) {
+                _sock_i[i].open = false;
+                _sock_i[i].sport = 0;
+            }
     }
 
+    if (prev_stat == _conn_stat) {
+        return;
+    }
+
+    tr_debug("refresh_conn_state_cb(): changed to %d", _conn_stat);
+
     // Inform upper layers
     if (_conn_stat_cb) {
         _conn_stat_cb(NSAPI_EVENT_CONNECTION_STATUS_CHANGE, _conn_stat);

components/wifi/esp8266-driver/ESP8266Interface.h

@@ -328,7 +328,7 @@ class ESP8266Interface : public NetworkStack, public WiFiInterface {
 private:
     // AT layer
     ESP8266 _esp;
-    void update_conn_state_cb();
+    void refresh_conn_state_cb();
 
     // HW reset pin
     class ResetPin {
@@ -365,10 +365,10 @@ class ESP8266Interface : public NetworkStack, public WiFiInterface {
 
     // Driver's state
     int _initialized;
+    nsapi_error_t _connect_retval;
     bool _get_firmware_ok();
     nsapi_error_t _init(void);
-    void _hw_reset();
-    nsapi_error_t _connect_retval;
+    nsapi_error_t _reset();
 
     //sigio
     struct {