/*
* Open the serial port.
* Return -1 on error.
*/
int serial_open (const char *devname, int baud_rate, int timeout)
{
#if defined(__WIN32__) || defined(WIN32)
DCB new_mode;
COMMTIMEOUTS ctmo;
#else
struct termios new_mode;
unsigned int ctl;
int rv;
#endif
timeout_msec = timeout;
#if defined(__WIN32__) || defined(WIN32)
/* Check for the Windows device syntax and bend a DOS device
* into that syntax to allow higher COM numbers than 9
*/
if (devname[0] != '\\') {
// Prepend device prefix: COM23 -> \\.\COM23
char *buf = alloca(5 + strlen(devname));
if (! buf) {
fprintf (stderr, "%s: Out of memory\n", devname);
return -1;
}
strcpy(buf, "\\\\.\\");
strcat(buf, devname);
devname = buf;
}
/* Open port */
fd = CreateFile (devname, GENERIC_READ | GENERIC_WRITE,
0, 0, OPEN_EXISTING, 0, 0);
if (fd == INVALID_HANDLE_VALUE) {
fprintf (stderr, "%s: Cannot open\n", devname);
return -1;
}
/* Set serial attributes */
memset (&saved_mode, 0, sizeof(saved_mode));
if (! GetCommState (fd, &saved_mode)) {
fprintf (stderr, "%s: Cannot get state\n", devname);
return -1;
}
new_mode = saved_mode;
new_mode.BaudRate = baud_rate;
new_mode.ByteSize = 8;
new_mode.StopBits = ONESTOPBIT;
new_mode.Parity = 0;
new_mode.fParity = FALSE;
new_mode.fOutX = FALSE;
new_mode.fInX = FALSE;
new_mode.fOutxCtsFlow = FALSE;
new_mode.fOutxDsrFlow = FALSE;
new_mode.fRtsControl = RTS_CONTROL_ENABLE;
new_mode.fNull = FALSE;
new_mode.fAbortOnError = FALSE;
new_mode.fBinary = TRUE;
if (! SetCommState (fd, &new_mode)) {
fprintf (stderr, "%s: Cannot set state\n", devname);
return -1;
}
memset (&ctmo, 0, sizeof(ctmo));
ctmo.ReadIntervalTimeout = 0;
ctmo.ReadTotalTimeoutMultiplier = 0;
ctmo.ReadTotalTimeoutConstant = timeout_msec;
if (! SetCommTimeouts (fd, &ctmo)) {
fprintf (stderr, "%s: Cannot set timeouts\n", devname);
return -1;
}
#else
/* Encode baud rate. */
int baud_code = baud_encode (baud_rate);
if (baud_code < 0) {
fprintf (stderr, "%s: Bad baud rate %d\n", devname, baud_rate);
return -1;
}
/* Open port */
fd = open (devname, O_RDWR | O_NOCTTY | O_NONBLOCK);
if (fd < 0) {
perror (devname);
return -1;
}
/* Set serial attributes */
memset (&saved_mode, 0, sizeof(saved_mode));
tcgetattr (fd, &saved_mode);
/* 8n1, ignore parity */
memset (&new_mode, 0, sizeof(new_mode));
new_mode.c_cflag = CS8 | CLOCAL | CREAD;
new_mode.c_iflag = IGNBRK;
new_mode.c_oflag = 0;
new_mode.c_lflag = 0;
new_mode.c_cc[VTIME] = 0;
new_mode.c_cc[VMIN] = 1;
cfsetispeed (&new_mode, baud_code);
cfsetospeed (&new_mode, baud_code);
tcflush (fd, TCIFLUSH);
tcsetattr (fd, TCSANOW, &new_mode);
/* Clear O_NONBLOCK flag. */
int flags = fcntl (fd, F_GETFL, 0);
if (flags >= 0)
fcntl (fd, F_SETFL, flags & ~O_NONBLOCK);
rv = ioctl(fd, TIOCMGET, &ctl);
if (rv < 0) {
perror("ioctl(\"TIOCMGET\")");
return -1;
}
ctl &= ~(TIOCM_DTR | TIOCM_RTS);
rv = ioctl(fd, TIOCMSET, &ctl);
if (rv < 0) {
perror("ioctl(\"TIOCMSET\")");
return -1;
}
usleep(250*1000);
ctl |= (TIOCM_DTR | TIOCM_RTS);
rv = ioctl(fd, TIOCMSET, &ctl);
if (rv < 0) {
perror("ioctl(\"TIOCMSET\")");
return -1;
}
usleep(50*1000);
#endif
return 0;
}
/*
* Open the serial port.
* Return -1 on error.
*/
int serial_open(const char *devname, int baud_rate)
{
#if defined(__WIN32__) || defined(WIN32)
DCB new_mode;
COMMTIMEOUTS ctmo;
#else
struct termios new_mode;
#endif
#if defined(__WIN32__) || defined(WIN32)
/* Open port */
fd = CreateFile(devname, GENERIC_READ | GENERIC_WRITE,
0, 0, OPEN_EXISTING, 0, 0);
if (fd == INVALID_HANDLE_VALUE) {
fprintf(stderr, "%s: Cannot open\n", devname);
return -1;
}
/* Set serial attributes */
memset(&saved_mode, 0, sizeof(saved_mode));
if (! GetCommState(fd, &saved_mode)) {
fprintf(stderr, "%s: Cannot get state\n", devname);
return -1;
}
new_mode = saved_mode;
new_mode.BaudRate = baud_rate;
new_mode.ByteSize = 8;
new_mode.StopBits = ONESTOPBIT;
new_mode.Parity = 0;
new_mode.fParity = FALSE;
new_mode.fOutX = FALSE;
new_mode.fInX = FALSE;
new_mode.fOutxCtsFlow = FALSE;
new_mode.fOutxDsrFlow = FALSE;
new_mode.fRtsControl = RTS_CONTROL_ENABLE;
new_mode.fNull = FALSE;
new_mode.fAbortOnError = FALSE;
new_mode.fBinary = TRUE;
if (! SetCommState(fd, &new_mode)) {
fprintf(stderr, "%s: Cannot set state\n", devname);
return -1;
}
memset(&ctmo, 0, sizeof(ctmo));
ctmo.ReadIntervalTimeout = 0;
ctmo.ReadTotalTimeoutMultiplier = 0;
ctmo.ReadTotalTimeoutConstant = 5000;
if (! SetCommTimeouts(fd, &ctmo)) {
fprintf(stderr, "%s: Cannot set timeouts\n", devname);
return -1;
}
#else
/* Encode baud rate. */
int baud_code = baud_encode(baud_rate);
if (baud_code < 0) {
fprintf(stderr, "%s: Bad baud rate %d\n", devname, baud_rate);
return -1;
}
/* Open port */
fd = open(devname, O_RDWR | O_NOCTTY | O_NONBLOCK);
if (fd < 0) {
perror(devname);
return -1;
}
/* Set serial attributes */
memset(&saved_mode, 0, sizeof(saved_mode));
tcgetattr(fd, &saved_mode);
/* 8n1, ignore parity */
memset(&new_mode, 0, sizeof(new_mode));
new_mode.c_cflag = CS8 | CLOCAL | CREAD;
new_mode.c_iflag = IGNBRK;
new_mode.c_oflag = 0;
new_mode.c_lflag = 0;
new_mode.c_cc[VTIME] = 0;
new_mode.c_cc[VMIN] = 1;
cfsetispeed(&new_mode, baud_code);
cfsetospeed(&new_mode, baud_code);
tcflush(fd, TCIFLUSH);
tcsetattr(fd, TCSANOW, &new_mode);
/* Clear O_NONBLOCK flag. */
int flags = fcntl(fd, F_GETFL, 0);
if (flags >= 0)
fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
#endif
return 0;
}
/*
* Check whether the given speed in bits per second
* is supported by the system.
* Return 0 when not supported.
*/
int serial_speed_valid (int bps)
{
return baud_encode (bps) > 0;
}
