add get line coding API()

Adafruit_USBD_CDC.cpp

@@ -67,6 +67,38 @@ void Adafruit_USBD_CDC::end(void)
   // nothing to do
 }
 
+uint32_t Adafruit_USBD_CDC::baud(void)
+{
+  cdc_line_coding_t coding;
+  tud_cdc_get_line_coding(&coding);
+
+  return coding.bit_rate;
+}
+
+uint8_t Adafruit_USBD_CDC::stopbits(void)
+{
+  cdc_line_coding_t coding;
+  tud_cdc_get_line_coding(&coding);
+
+  return coding.stop_bits;
+}
+
+uint8_t Adafruit_USBD_CDC::paritytype(void)
+{
+  cdc_line_coding_t coding;
+  tud_cdc_get_line_coding(&coding);
+
+  return coding.parity;
+}
+
+uint8_t Adafruit_USBD_CDC::numbits(void)
+{
+  cdc_line_coding_t coding;
+  tud_cdc_get_line_coding(&coding);
+
+  return coding.data_bits;
+}
+
 Adafruit_USBD_CDC::operator bool()
 {
   bool ret = tud_cdc_connected();

Adafruit_USBD_CDC.h

@@ -41,6 +41,12 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface
 	void begin(uint32_t baud, uint8_t config);
 	void end(void);
 
+	// return line coding set by host
+	uint32_t baud(void);
+	uint8_t  stopbits(void);
+	uint8_t  paritytype(void);
+	uint8_t  numbits(void);
+
 	virtual int    available(void);
 	virtual int    peek(void);
 	virtual int    read(void);