Added Serial.baudRate() to get current baud rate

cores/esp8266/HardwareSerial.cpp

@@ -180,6 +180,13 @@ size_t HardwareSerial::write(uint8_t c)
     return 1;
 }
 
+int HardwareSerial::baudRate(void)
+{
+    // Null pointer on _uart is checked by SDK
+    return uart_get_baudrate(_uart);
+}
+
+
 HardwareSerial::operator bool() const
 {
     return _uart != 0;

cores/esp8266/HardwareSerial.h

@@ -133,6 +133,7 @@ class HardwareSerial: public Stream
     void setDebugOutput(bool);
     bool isTxEnabled(void);
     bool isRxEnabled(void);
+    int  baudRate(void);
 
 protected:
     int _uart_nr;

doc/reference.md

@@ -84,6 +84,21 @@ You also need to use `Serial.setDebugOutput(true)` to enable output from `printf
 
 Both `Serial` and `Serial1` objects support 5, 6, 7, 8 data bits, odd (O), even (E), and no (N) parity, and 1 or 2 stop bits. To set the desired mode, call `Serial.begin(baudrate, SERIAL_8N1)`, `Serial.begin(baudrate, SERIAL_6E2)`, etc.
 
+A new method has been implemented on both `Serial` and `Serial1` to get current baud rate setting. To get the current baud rate, call `Serial.baudRate()`, `Serial1.baudRate()`. Return a `int` of current speed. For example
+```cpp
+// Set Baud rate to 57600
+Serial.begin(57600);
+
+// Get current baud rate
+int br = Serial.baudRate();
+
+// Will print "Serial is 57600 bps"
+Serial.printf("Serial is %d bps", br);
+```
+
+I've done this also for official ESP8266 [Software Serial](https://github.com/esp8266/Arduino/blob/master/doc/libraries.md#softwareserial) library, see this [pull request](https://github.com/plerup/espsoftwareserial/pull/22).    
+Note that this implementation is **only for ESP8266 based boards**, and will not works with other Arduino boards.
+
 ## Progmem
 
 The Program memory features work much the same way as on a regular Arduino; placing read only data and strings in read only memory and freeing heap for your application.