Example #1
0
func (c *Connection) open() (err error) {
	c.file, err = os.OpenFile(c.Name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
	if err != nil {
		return err
	}

	fd, err := c.getFileDescriptor()
	if err != nil {
		c.file.Close()
		return err
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		c.file.Close()
		return err
	}

	// set the baud rate of the connection
	err = c.setBaudRate(c.Baud)
	if err != nil {
		c.file.Close()
		return err
	}

	// No timeout set directly on termios
	st.c_cc[C.VMIN] = 0
	st.c_cc[C.VTIME] = 0

	// Select local mode
	st.c_cflag |= (C.CLOCAL | C.CREAD)

	// Select raw mode
	st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
	st.c_oflag &= ^C.tcflag_t(C.OPOST)

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		c.file.Close()
		return err
	}

	r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
		uintptr(c.file.Fd()),
		uintptr(syscall.F_SETFL),
		uintptr(0))
	if e != 0 || r1 != 0 {
		s := fmt.Sprint("Clearing NONBLOCK syscall error:", e, r1)
		c.file.Close()
		return errors.New(s)
	}

	return nil
}
Example #2
0
func makeCAttributes(attr *Attributes) C.struct_termios {
	var cattr C.struct_termios
	cattr.c_iflag = C.tcflag_t(attr.Input)
	cattr.c_oflag = C.tcflag_t(attr.Output)
	cattr.c_cflag = C.tcflag_t(attr.Control)
	cattr.c_lflag = C.tcflag_t(attr.Local)
	for i := 0; i < C.NCCS; i++ {
		cattr.c_cc[i] = C.cc_t(attr.ControlChars[i])
	}
	return cattr
}
Example #3
0
func (s *Serial) SetStops(stops uint8) {
	if s.Opened {
		var tios C.struct_termios
		getTermios(s.f, &tios)
		if stops == 1 {
			tios.c_cflag &= C.tcflag_t(^uint16(C.CSTOPB))
		} else if stops == 2 {
			tios.c_cflag |= C.CSTOPB
		}
		setTermios(s.f, &tios)
	}
}
Example #4
0
func (s *Serial) SetParity(p string) {
	if s.Opened {
		var tios C.struct_termios
		getTermios(s.f, &tios)

		switch p {
		case "n":
			tios.c_cflag &= C.tcflag_t(^uint16(C.PARENB))
		case "o":
			tios.c_cflag |= C.PARENB | C.PARODD
		case "e":
			tios.c_cflag |= C.PARENB
			tios.c_cflag &= C.tcflag_t(^uint16(C.PARODD))
		}

		setTermios(s.f, &tios)
	}
}
Example #5
0
func (t *tScreen) termioInit() error {
	var e error
	var rv C.int
	var newtios C.struct_termios
	var fd C.int

	if t.in, e = os.OpenFile("/dev/tty", os.O_RDONLY, 0); e != nil {
		goto failed
	}
	if t.out, e = os.OpenFile("/dev/tty", os.O_WRONLY, 0); e != nil {
		goto failed
	}

	t.tiosp = &termiosPrivate{}

	fd = C.int(t.out.Fd())
	if rv, e = C.tcgetattr(fd, &t.tiosp.tios); rv != 0 {
		goto failed
	}
	t.baud = int(C.getbaud(&t.tiosp.tios))
	newtios = t.tiosp.tios
	newtios.c_iflag &^= C.IGNBRK | C.BRKINT | C.PARMRK |
		C.ISTRIP | C.INLCR | C.IGNCR |
		C.ICRNL | C.IXON
	newtios.c_oflag &^= C.OPOST
	newtios.c_lflag &^= C.ECHO | C.ECHONL | C.ICANON |
		C.ISIG | C.IEXTEN
	newtios.c_cflag &^= C.CSIZE | C.PARENB
	newtios.c_cflag |= C.CS8

	// We wake up at the earliest of 100 msec or when data is received.
	// We need to wake up frequently to permit us to exit cleanly and
	// close file descriptors on systems like Darwin, where close does
	// cause a wakeup.  (Probably we could reasonably increase this to
	// something like 1 sec or 500 msec.)
	newtios.c_cc[C.VMIN] = 0
	newtios.c_cc[C.VTIME] = 1

	if rv, e = C.tcsetattr(fd, C.TCSANOW|C.TCSAFLUSH, &newtios); rv != 0 {
		goto failed
	}

	signal.Notify(t.sigwinch, syscall.SIGWINCH)

	if w, h, e := t.getWinSize(); e == nil && w != 0 && h != 0 {
		t.w = w
		t.h = h
	}

	return nil

failed:
	if t.in != nil {
		t.in.Close()
	}
	if t.out != nil {
		t.out.Close()
	}
	return e
}
Example #6
0
func (s *Serial) SetBits(b uint8) {
	if s.Opened {
		switch b {
		case 8:
			b = C.CS8
		case 7:
			b = C.CS7
		case 6:
			b = C.CS6
		case 5:
			b = C.CS5
		default:
			b = 0
		}
		if b != 0 {
			var tios C.struct_termios
			getTermios(s.f, &tios)
			tios.c_cflag &= C.tcflag_t(^uint16(C.CSIZE))
			tios.c_cflag |= C.tcflag_t(b)
			setTermios(s.f, &tios)
		}
	}
}
Example #7
0
func (s *Serial) Open(name string) bool {
	if !s.Opened {
		var err error
		s.f, err = os.OpenFile(name, os.O_RDWR|syscall.O_NOCTTY|syscall.O_NDELAY|syscall.O_NONBLOCK, 0666)

		if err == nil {
			s.Name = name
			s.Opened = true

			var tios C.struct_termios
			getTermios(s.f, &tios)

			tios.c_cflag |= C.CLOCAL | C.CREAD
			tios.c_lflag &= C.tcflag_t(^uint16(C.ICANON | C.ECHO | C.ECHOE | C.ECHOK | C.ECHONL | C.ISIG | C.IEXTEN))
			tios.c_iflag &= C.tcflag_t(^uint16(C.BRKINT | C.ICRNL | C.INPCK | C.ISTRIP | C.IXON))
			tios.c_oflag &= C.tcflag_t(^uint16(C.OPOST))
			tios.c_cc[C.VMIN] = 1
			tios.c_cc[C.VTIME] = 0

			setTermios(s.f, &tios)
		}
	}
	return s.Opened
}
Example #8
0
func cTermios(goTerm *Termios) *C.struct_termios {
	var cTerm C.struct_termios

	cTerm.c_iflag = C.tcflag_t(goTerm.IFlag)
	cTerm.c_oflag = C.tcflag_t(goTerm.OFlag)
	cTerm.c_cflag = C.tcflag_t(goTerm.CFlag)
	cTerm.c_lflag = C.tcflag_t(goTerm.LFlag)
	for idx, ch := range goTerm.CC {
		cTerm.c_cc[idx] = C.cc_t(ch)
	}
	cTerm.c_ispeed = C.speed_t(goTerm.ISpeed)
	cTerm.c_ospeed = C.speed_t(goTerm.OSpeed)

	return &cTerm
}
Example #9
0
func openPort(name string, baud int, readTimeout time.Duration) (p *Port, err error) {
	f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
	if err != nil {
		return
	}

	fd := C.int(f.Fd())
	if C.isatty(fd) != 1 {
		f.Close()
		return nil, errors.New("File is not a tty")
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		f.Close()
		return nil, err
	}
	var speed C.speed_t
	switch baud {
	case 115200:
		speed = C.B115200
	case 57600:
		speed = C.B57600
	case 38400:
		speed = C.B38400
	case 19200:
		speed = C.B19200
	case 9600:
		speed = C.B9600
	case 4800:
		speed = C.B4800
	case 2400:
		speed = C.B2400
	default:
		f.Close()
		return nil, fmt.Errorf("Unknown baud rate %v", baud)
	}

	_, err = C.cfsetispeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}
	_, err = C.cfsetospeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}

	// Turn off break interrupts, CR->NL, Parity checks, strip, and IXON
	st.c_iflag &= ^C.tcflag_t(C.BRKINT | C.ICRNL | C.INPCK | C.ISTRIP | C.IXOFF | C.IXON | C.PARMRK)

	// Select local mode, turn off parity, set to 8 bits
	st.c_cflag &= ^C.tcflag_t(C.CSIZE | C.PARENB)
	st.c_cflag |= (C.CLOCAL | C.CREAD | C.CS8)

	// Select raw mode
	st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
	st.c_oflag &= ^C.tcflag_t(C.OPOST)

	// set blocking / non-blocking read
	/*
	*	http://man7.org/linux/man-pages/man3/termios.3.html
	* - Supports blocking read and read with timeout operations
	 */
	vmin, vtime := posixTimeoutValues(readTimeout)
	st.c_cc[C.VMIN] = C.cc_t(vmin)
	st.c_cc[C.VTIME] = C.cc_t(vtime)

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		f.Close()
		return nil, err
	}

	//fmt.Println("Tweaking", name)
	r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
		uintptr(f.Fd()),
		uintptr(syscall.F_SETFL),
		uintptr(0))
	if e != 0 || r1 != 0 {
		s := fmt.Sprint("Clearing NONBLOCK syscall error:", e, r1)
		f.Close()
		return nil, errors.New(s)
	}

	/*
				r1, _, e = syscall.Syscall(syscall.SYS_IOCTL,
			                uintptr(f.Fd()),
			                uintptr(0x80045402), // IOSSIOSPEED
			                uintptr(unsafe.Pointer(&baud)));
			        if e != 0 || r1 != 0 {
			                s := fmt.Sprint("Baudrate syscall error:", e, r1)
					f.Close()
		                        return nil, os.NewError(s)
				}
	*/

	return &Port{f: f}, nil
}
func openPort(name string, baud int) (rwc io.ReadWriteCloser, err error) {
	f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
	if err != nil {
		return
	}

	fd := C.int(f.Fd())
	if C.isatty(fd) != 1 {
		f.Close()
		return nil, errors.New("File is not a tty")
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		f.Close()
		return nil, err
	}
	var speed C.speed_t
	switch baud {
	case 115200:
		speed = C.B115200
	case 57600:
		speed = C.B57600
	case 38400:
		speed = C.B38400
	case 19200:
		speed = C.B19200
	case 9600:
		speed = C.B9600
	case 4800:
		speed = C.B4800
	case 2400:
		speed = C.B2400
	default:
		f.Close()
		return nil, fmt.Errorf("Unknown baud rate %v", baud)
	}

	_, err = C.cfsetispeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}
	_, err = C.cfsetospeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}

	// Select local mode
	st.c_cflag |= (C.CLOCAL | C.CREAD)

	// Select raw mode
	st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
	st.c_oflag &= ^C.tcflag_t(C.OPOST)

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		f.Close()
		return nil, err
	}

	//fmt.Println("Tweaking", name)
	r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
		uintptr(f.Fd()),
		uintptr(syscall.F_SETFL),
		uintptr(0))
	if e != 0 || r1 != 0 {
		s := fmt.Sprint("Clearing NONBLOCK syscall error:", e, r1)
		f.Close()
		return nil, errors.New(s)
	}

	/*
				r1, _, e = syscall.Syscall(syscall.SYS_IOCTL,
			                uintptr(f.Fd()),
			                uintptr(0x80045402), // IOSSIOSPEED
			                uintptr(unsafe.Pointer(&baud)));
			        if e != 0 || r1 != 0 {
			                s := fmt.Sprint("Baudrate syscall error:", e, r1)
					f.Close()
		                        return nil, os.NewError(s)
				}
	*/

	return f, nil
}
Example #11
0
func openPort(name string, c *Config) (rwc io.ReadWriteCloser, err error) {
	f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
	if err != nil {
		return
	}

	defer func() {
		if err != nil {
			f.Close()
		}
	}()

	fd := C.int(f.Fd())
	if C.isatty(fd) != 1 {
		return nil, errors.New("File is not a tty")
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		return nil, err
	}
	var speed C.speed_t
	switch c.Baud {
	case 115200:
		speed = C.B115200
	case 57600:
		speed = C.B57600
	case 38400:
		speed = C.B38400
	case 19200:
		speed = C.B19200
	case 9600:
		speed = C.B9600
	default:
		return nil, fmt.Errorf("Unknown baud rate %v", c.Baud)
	}

	_, err = C.cfsetispeed(&st, speed)
	if err != nil {
		return nil, err
	}
	_, err = C.cfsetospeed(&st, speed)
	if err != nil {
		return nil, err
	}

	// Select local mode
	st.c_cflag |= C.CLOCAL | C.CREAD

	// Select stop bits
	switch c.StopBits {
	case StopBits1:
		st.c_cflag &^= C.CSTOPB
	case StopBits2:
		st.c_cflag |= C.CSTOPB
	default:
		panic(c.StopBits)
	}

	// Select character size
	st.c_cflag &^= C.CSIZE
	switch c.Size {
	case Byte5:
		st.c_cflag |= C.CS5
	case Byte6:
		st.c_cflag |= C.CS6
	case Byte7:
		st.c_cflag |= C.CS7
	case Byte8:
		st.c_cflag |= C.CS8
	default:
		panic(c.Size)
	}

	// Select parity mode
	switch c.Parity {
	case ParityNone:
		st.c_cflag &^= C.PARENB
	case ParityEven:
		st.c_cflag |= C.PARENB
		st.c_cflag &^= C.PARODD
	case ParityOdd:
		st.c_cflag |= C.PARENB
		st.c_cflag |= C.PARODD
	default:
		panic(c.Parity)
	}

	// Select CRLF translation
	if c.CRLFTranslate {
		st.c_iflag |= C.ICRNL
	} else {
		st.c_iflag &^= C.ICRNL
	}

	// Select raw mode
	st.c_lflag &^= C.ICANON | C.ECHO | C.ECHOE | C.ISIG
	st.c_oflag &^= C.OPOST

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		return nil, err
	}

	//fmt.Println("Tweaking", name)
	r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
		uintptr(f.Fd()),
		uintptr(syscall.F_SETFL),
		uintptr(0))
	if e != 0 || r1 != 0 {
		s := fmt.Sprint("Clearing NONBLOCK syscall error:", e, r1)
		return nil, errors.New(s)
	}

	/*
				r1, _, e = syscall.Syscall(syscall.SYS_IOCTL,
			                uintptr(f.Fd()),
			                uintptr(0x80045402), // IOSSIOSPEED
			                uintptr(unsafe.Pointer(&baud)));
			        if e != 0 || r1 != 0 {
			                s := fmt.Sprint("Baudrate syscall error:", e, r1)
		                        return nil, os.NewError(s)
				}
	*/

	return f, nil
}
Example #12
0
func OpenPort(name string, baud int) (rwc io.ReadWriteCloser, err error) {
	f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
	if err != nil {
		return
	}

	fd := C.int(f.Fd())
	if C.isatty(fd) != 1 {
		f.Close()
		return nil, fmt.Errorf("[ERROR] not a tty/cu device")
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		f.Close()
		return nil, err
	}
	var speed C.speed_t
	switch baud {
	case 115200:
		speed = C.B115200
	case 57600:
		speed = C.B57600
	case 38400:
		speed = C.B38400
	case 19200:
		speed = C.B19200
	case 9600:
		speed = C.B9600
	default:
		f.Close()
		return nil, fmt.Errorf("Unknown baud rate %v", baud)
	}

	_, err = C.cfsetispeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}
	_, err = C.cfsetospeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}

	// Select local mode
	st.c_cflag |= (C.CLOCAL | C.CREAD)

	// Select raw mode
	st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
	st.c_oflag &= ^C.tcflag_t(C.OPOST)

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		f.Close()
		return nil, err
	}

	r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
		uintptr(f.Fd()),
		uintptr(syscall.F_SETFL),
		uintptr(0))
	if e != 0 || r1 != 0 {
		s := fmt.Sprint("[WARN] clearing NONBLOCK syscall error:", e, r1)
		f.Close()
		return nil, fmt.Errorf("%s", s)
	}

	return f, nil
}
Example #13
0
// Opens and returns a non-blocking serial port.
// The device, baud rate, and SerConf is specified.
//
// Example:  rs232.OpenPort("/dev/ttyS0", 115200, rs232.S_8N1)
func OpenPort(port string, baudRate int, serconf SerConf) (*SerialPort, error) {
	rv := &SerialPort{}
	f, err := os.OpenFile(port,
		syscall.O_RDWR|syscall.O_NOCTTY, 0666)
	if err != nil {
		return nil, err
	}
	rv.port = f

	fd := rv.port.Fd()

	var options C.struct_termios
	if C.tcgetattr(C.int(fd), &options) < 0 {
		defer f.Close()
		return nil, fmt.Errorf("tcgetattr failed")
	}

	if C.cfsetispeed(&options, baudConversion(baudRate)) < 0 {
		defer f.Close()
		return nil, fmt.Errorf("cfsetispeed failed")
	}
	if C.cfsetospeed(&options, baudConversion(baudRate)) < 0 {
		defer f.Close()
		return nil, fmt.Errorf("cfsetospeed failed")
	}
	switch serconf {
	case S_8N1:
		{
			options.c_cflag &^= C.PARENB
			options.c_cflag &^= C.CSTOPB
			options.c_cflag &^= C.CSIZE
			options.c_cflag |= C.CS8
		}
	case S_7E1:
		{
			options.c_cflag |= C.PARENB
			options.c_cflag &^= C.PARODD
			options.c_cflag &^= C.CSTOPB
			options.c_cflag &^= C.CSIZE
			options.c_cflag |= C.CS7
		}
	case S_7O1:
		{
			options.c_cflag |= C.PARENB
			options.c_cflag |= C.PARODD
			options.c_cflag &^= C.CSTOPB
			options.c_cflag &^= C.CSIZE
			options.c_cflag |= C.CS7
		}
	}
	// Local
	options.c_cflag |= (C.CLOCAL | C.CREAD)
	// no hardware flow control
	options.c_cflag &^= C.CRTSCTS
	// Don't EOF on a zero read, just block
	options.c_cc[C.VMIN] = 1

	if C.tcsetattr(C.int(fd), C.TCSANOW, &options) < 0 {
		defer f.Close()
		return nil, fmt.Errorf("tcsetattr failed")
	}

	return rv, nil
}
Example #14
0
// Opens and returns a non-blocking serial port.
// The device, baud rate, and SerConf is specified.
//
// Example:  rs232.OpenPort("/dev/ttyS0", 115200, rs232.S_8N1)
func OpenPort(port string, baudRate int, serconf SerConf) (rv SerialPort, err error) {
	f, open_err := os.OpenFile(port,
		syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NDELAY,
		0666)
	if open_err != nil {
		err = open_err
		return
	}
	rv.port = f

	fd := rv.port.Fd()

	var options C.struct_termios
	if C.tcgetattr(C.int(fd), &options) < 0 {
		panic("tcgetattr failed")
	}

	if C.cfsetispeed(&options, baudConversion(baudRate)) < 0 {
		panic("cfsetispeed failed")
	}
	if C.cfsetospeed(&options, baudConversion(baudRate)) < 0 {
		panic("cfsetospeed failed")
	}
	switch serconf {
	case S_8N1:
		{
			options.c_cflag &^= C.PARENB
			options.c_cflag &^= C.CSTOPB
			options.c_cflag &^= C.CSIZE
			options.c_cflag |= C.CS8
		}
	case S_7E1:
		{
			options.c_cflag |= C.PARENB
			options.c_cflag &^= C.PARODD
			options.c_cflag &^= C.CSTOPB
			options.c_cflag &^= C.CSIZE
			options.c_cflag |= C.CS7
		}
	case S_7O1:
		{
			options.c_cflag |= C.PARENB
			options.c_cflag |= C.PARODD
			options.c_cflag &^= C.CSTOPB
			options.c_cflag &^= C.CSIZE
			options.c_cflag |= C.CS7
		}
	}
	// Local
	options.c_cflag |= (C.CLOCAL | C.CREAD)
	// no hardware flow control
	options.c_cflag &^= C.CRTSCTS

	if C.tcsetattr(C.int(fd), C.TCSANOW, &options) < 0 {
		panic("tcsetattr failed")
	}

	if syscall.SetNonblock(int(fd), false) != nil {
		panic("Error disabling blocking")
	}

	return
}
Example #15
0
func openPort(name string, baud int) (rwc io.ReadWriteCloser, err error) {
	f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY, 0666)
	if err != nil {
		return
	}

	fd := C.int(f.Fd())
	if C.isatty(fd) != 1 {
		f.Close()
		return nil, errors.New("File is not a tty")
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		f.Close()
		return nil, err
	}
	var speed C.speed_t
	switch baud {
	case 115200:
		speed = C.B115200
	case 57600:
		speed = C.B57600
	case 38400:
		speed = C.B38400
	case 19200:
		speed = C.B19200
	case 9600:
		speed = C.B9600
	case 4800:
		speed = C.B4800
	case 2400:
		speed = C.B2400
	default:
		f.Close()
		return nil, fmt.Errorf("Unknown baud rate %v", baud)
	}

	_, err = C.cfsetispeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}
	_, err = C.cfsetospeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}

	// Select local mode
	st.c_cflag |= (C.CLOCAL | C.CREAD)

	// Select raw mode
	st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
	st.c_oflag &= ^C.tcflag_t(C.OPOST)

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		f.Close()
		return nil, err
	}

	return f, nil
}
Example #16
0
func openPort(name string, baud int, spec []byte, flow []bool) (rwc io.ReadWriteCloser, err error) {
	port := new(serialPort)

	f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
	if err != nil {
		return
	}

	fd := C.int(f.Fd())
	if C.isatty(fd) != 1 {
		f.Close()
		return nil, errors.New("File is not a tty")
	}

	var st C.struct_termios
	_, err = C.tcgetattr(fd, &st)
	if err != nil {
		f.Close()
		return nil, err
	}
	var speed C.speed_t
	switch baud {
	case 115200:
		speed = C.B115200
	case 57600:
		speed = C.B57600
	case 38400:
		speed = C.B38400
	case 19200:
		speed = C.B19200
	case 9600:
		speed = C.B9600
	default:
		f.Close()
		return nil, fmt.Errorf("Unknown baud rate %v", baud)
	}

	_, err = C.cfsetispeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}
	_, err = C.cfsetospeed(&st, speed)
	if err != nil {
		f.Close()
		return nil, err
	}

	// Select local mode
	st.c_cflag |= (C.CLOCAL | C.CREAD)

	// Select raw mode
	st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
	st.c_oflag &= ^C.tcflag_t(C.OPOST)

	// Flow control
	if flow[RTS_FLAG] {
		st.c_cflag |= C.tcflag_t(C.CRTSCTS)
	}
	if flow[XON_FLAG] {
		st.c_cflag |= C.tcflag_t(C.IXON | C.IXOFF | C.IXANY)
	}

	// Defaults to 8N1 if nothing valid is given
	byteSize := spec[0]
	parity := spec[1]
	stopBits := spec[2]

	switch byteSize {
	case byte(5):
		st.c_cflag |= C.tcflag_t(C.CS5)
		break
	case byte(6):
		st.c_cflag |= C.tcflag_t(C.CS6)
		break
	case byte(7):
		st.c_cflag |= C.tcflag_t(C.CS7)
		break
	case byte(8):
	default:
		st.c_cflag |= C.tcflag_t(C.CS8)
		break
	}
	switch parity {
	case PARITY_EVEN:
		st.c_cflag |= C.tcflag_t(C.PARENB)
		st.c_cflag &= ^C.tcflag_t(C.PARODD)
		break
	case PARITY_ODD:
		st.c_cflag |= C.tcflag_t(C.PARENB)
		st.c_cflag |= C.tcflag_t(C.PARODD)
		break
	case PARITY_NONE:
	default:
		st.c_cflag &= ^C.tcflag_t(C.PARENB)
		break
	}
	switch stopBits {
	case byte(2):
		st.c_cflag |= C.tcflag_t(C.CSTOPB)
		break
	case byte(1):
	default:
		st.c_cflag &= ^C.tcflag_t(C.CSTOPB)
		break
	}
	st.c_cflag &= ^C.tcflag_t(C.CSIZE)

	_, err = C.tcsetattr(fd, C.TCSANOW, &st)
	if err != nil {
		f.Close()
		return nil, err
	}

	//fmt.Println("Tweaking", name)
	r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
		uintptr(f.Fd()),
		uintptr(syscall.F_SETFL),
		uintptr(0))
	if e != 0 || r1 != 0 {
		s := fmt.Sprint("Clearing NONBLOCK syscall error:", e, r1)
		f.Close()
		return nil, errors.New(s)
	}

	/*
				r1, _, e = syscall.Syscall(syscall.SYS_IOCTL,
			                uintptr(f.Fd()),
			                uintptr(0x80045402), // IOSSIOSPEED
			                uintptr(unsafe.Pointer(&baud)));
			        if e != 0 || r1 != 0 {
			                s := fmt.Sprint("Baudrate syscall error:", e, r1)
					f.Close()
		                        return nil, os.NewError(s)
				}
	*/

	port.f = f

	return port, nil
}