4 files changed, 94 insertions, 2 deletions

diff --git a/cores/arduino/CDC.cpp b/cores/arduino/CDC.cpp
index 7c7eacf..7168408 100644
--- a/cores/arduino/CDC.cpp
+++ b/cores/arduino/CDC.cpp
@@ -18,6 +18,7 @@
 
 #include "USBAPI.h"
 #include <avr/wdt.h>
+#include <util/atomic.h>
 
 #if defined(USBCON)
 
@@ -31,6 +32,7 @@ typedef struct
 } LineInfo;
 
 static volatile LineInfo _usbLineInfo = { 57600, 0x00, 0x00, 0x00, 0x00 };
+static volatile int32_t breakValue = -1;
 
 #define WEAK __attribute__ ((weak))
 
@@ -75,6 +77,11 @@ bool CDC_Setup(USBSetup& setup)
 
 	if (REQUEST_HOSTTODEVICE_CLASS_INTERFACE == requestType)
 	{
+		if (CDC_SEND_BREAK == r)
+		{
+			breakValue = ((uint16_t)setup.wValueH << 8) | setup.wValueL;
+		}
+
 		if (CDC_SET_LINE_CODING == r)
 		{
 			USB_RecvControl((void*)&_usbLineInfo,7);
@@ -173,6 +180,11 @@ int Serial_::read(void)
 	return USB_Recv(CDC_RX);
 }
 
+int Serial_::availableForWrite(void)
+{
+	return USB_SendSpace(CDC_TX);
+}
+
 void Serial_::flush(void)
 {
 	USB_Flush(CDC_TX);
@@ -222,6 +234,44 @@ Serial_::operator bool() {
 	return result;
 }
 
+unsigned long Serial_::baud() {
+	// Disable interrupts while reading a multi-byte value
+	ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+		return _usbLineInfo.dwDTERate;
+	}
+}
+
+uint8_t Serial_::stopbits() {
+	return _usbLineInfo.bCharFormat;
+}
+
+uint8_t Serial_::paritytype() {
+	return _usbLineInfo.bParityType;
+}
+
+uint8_t Serial_::numbits() {
+	return _usbLineInfo.bDataBits;
+}
+
+bool Serial_::dtr() {
+	return _usbLineInfo.lineState & 0x1;
+}
+
+bool Serial_::rts() {
+	return _usbLineInfo.lineState & 0x2;
+}
+
+int32_t Serial_::readBreak() {
+	int32_t ret;
+	// Disable IRQs while reading and clearing breakValue to make
+	// sure we don't overwrite a value just set by the ISR.
+	ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+		ret = breakValue;
+		breakValue = -1;
+	}
+	return ret;
+}
+
 Serial_ Serial;
 
 #endif /* if defined(USBCON) */
diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index a2029a8..5cd89e5 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -138,8 +138,7 @@ void HardwareSerial::begin(unsigned long baud, byte config)
 void HardwareSerial::end()
 {
   // wait for transmission of outgoing data
-  while (_tx_buffer_head != _tx_buffer_tail)
-    ;
+  flush();
 
   cbi(*_ucsrb, RXEN0);
   cbi(*_ucsrb, TXEN0);
diff --git a/cores/arduino/USBAPI.h b/cores/arduino/USBAPI.h
index 7f468a6..4072772 100644
--- a/cores/arduino/USBAPI.h
+++ b/cores/arduino/USBAPI.h
@@ -98,6 +98,7 @@ public:
 	virtual int available(void);
 	virtual int peek(void);
 	virtual int read(void);
+	int availableForWrite(void);
 	virtual void flush(void);
 	virtual size_t write(uint8_t);
 	virtual size_t write(const uint8_t*, size_t);
@@ -107,6 +108,46 @@ public:
 	volatile uint8_t _rx_buffer_head;
 	volatile uint8_t _rx_buffer_tail;
 	unsigned char _rx_buffer[SERIAL_BUFFER_SIZE];
+
+	// This method allows processing "SEND_BREAK" requests sent by
+	// the USB host. Those requests indicate that the host wants to
+	// send a BREAK signal and are accompanied by a single uint16_t
+	// value, specifying the duration of the break. The value 0
+	// means to end any current break, while the value 0xffff means
+	// to start an indefinite break.
+	// readBreak() will return the value of the most recent break
+	// request, but will return it at most once, returning -1 when
+	// readBreak() is called again (until another break request is
+	// received, which is again returned once).
+	// This also mean that if two break requests are received
+	// without readBreak() being called in between, the value of the
+	// first request is lost.
+	// Note that the value returned is a long, so it can return
+	// 0-0xffff as well as -1.
+	int32_t readBreak();
+
+	// These return the settings specified by the USB host for the
+	// serial port. These aren't really used, but are offered here
+	// in case a sketch wants to act on these settings.
+	uint32_t baud();
+	uint8_t stopbits();
+	uint8_t paritytype();
+	uint8_t numbits();
+	bool dtr();
+	bool rts();
+	enum {
+		ONE_STOP_BIT = 0,
+		ONE_AND_HALF_STOP_BIT = 1,
+		TWO_STOP_BITS = 2,
+	};
+	enum {
+		NO_PARITY = 0,
+		ODD_PARITY = 1,
+		EVEN_PARITY = 2,
+		MARK_PARITY = 3,
+		SPACE_PARITY = 4,
+	};
+
 };
 extern Serial_ Serial;
 
@@ -154,6 +195,7 @@ int USB_SendControl(uint8_t flags, const void* d, int len);
 int USB_RecvControl(void* d, int len);
 
 uint8_t	USB_Available(uint8_t ep);
+uint8_t USB_SendSpace(uint8_t ep);
 int USB_Send(uint8_t ep, const void* data, int len);	// blocking
 int USB_Recv(uint8_t ep, void* data, int len);		// non-blocking
 int USB_Recv(uint8_t ep);							// non-blocking
diff --git a/cores/arduino/USBCore.h b/cores/arduino/USBCore.h
index 66f8c05..eaeecef 100644
--- a/cores/arduino/USBCore.h
+++ b/cores/arduino/USBCore.h
@@ -57,6 +57,7 @@
 #define CDC_SET_LINE_CODING			0x20
 #define CDC_GET_LINE_CODING			0x21
 #define CDC_SET_CONTROL_LINE_STATE	0x22
+#define CDC_SEND_BREAK				0x23
 
 #define MSC_RESET					0xFF
 #define MSC_GET_MAX_LUN				0xFE