/**
* Configures serial port to use raw 8-bit mode and given baud
* rate. This function also supports non-standard baud rates if the
* underlying hardware is capable. If it fails, -1 is returned and
* errno is set. Otherwise, zero is returned.
*/
int init_serial_port(int fd, int speed)
{
// Check if speed preset is found or do we need to set a custom speed
tcflag_t speed_preset = to_speed(speed);
if (speed_preset == B0) {
// Find current configuration
struct serial_struct serial;
if(ioctl(fd, TIOCGSERIAL, &serial) == -1) return -1;
serial.flags = (serial.flags & ~ASYNC_SPD_MASK) | ASYNC_SPD_CUST;
serial.custom_divisor = (serial.baud_base + (speed / 2)) / speed;
// Check that the serial timing error is no more than 2%
int real_speed = serial.baud_base / serial.custom_divisor;
if (real_speed < speed * 98 / 100 ||
real_speed > speed * 102 / 100) {
errno = ENOTSUP;
return -1;
}
// Activate
if(ioctl(fd, TIOCSSERIAL, &serial) == -1) return -1;
// Custom baudrate only works with this magic value
speed_preset = B38400;
}
// Start with raw values
struct termios term;
term.c_cflag = speed_preset | CS8 | CLOCAL | CREAD;
cfmakeraw(&term);
if (tcsetattr(fd,TCSANOW,&term) == -1) return -1;
return 0;
}
static int set_com_state(int fd, uart_com_state_t* com)
{
struct termios tio;
// read current state
if (tcgetattr(fd, &tio) < 0) {
DEBUGF("unable to read com state: %s", strerror(errno));
return -1;
}
// On Mac os X IOSSIOSPEED can be used to set "non-traditional baud rate"
// From "IOKit/serial/ioss.h"
cfsetispeed(&tio, to_speed(com->ibaud));
cfsetospeed(&tio, to_speed(com->obaud));
// update from state
switch(com->parity) {
case UART_PARITY_NONE:
tio.c_iflag &= ~PARMRK;
tio.c_cflag &= ~PARENB;
break;
case UART_PARITY_ODD: // odd
tio.c_iflag &= ~PARMRK;
tio.c_cflag |= PARODD;
tio.c_cflag |= PARENB;
break;
case UART_PARITY_EVEN: // even
tio.c_iflag &= ~PARMRK;
tio.c_cflag &= ~PARODD;
tio.c_cflag |= PARENB;
break;
case UART_PARITY_MARK: // mark (FIXME)
tio.c_iflag |= PARMRK;
tio.c_cflag |= PARENB;
break;
case UART_PARITY_SPACE: // space (FIXME)
tio.c_iflag &= ~PARMRK;
tio.c_cflag &= ~PARENB;
break;
default:
break;
}
if (com->stopb == 1)
tio.c_cflag &= ~CSTOPB;
else if (com->stopb == 2)
tio.c_cflag |= CSTOPB;
tio.c_cflag &= ~CSIZE;
switch(com->csize) {
case 5: tio.c_cflag |= CS5; break;
case 6: tio.c_cflag |= CS6; break;
case 7: tio.c_cflag |= CS7; break;
case 8: tio.c_cflag |= CS8; break;
default: break;
}
// Set the buffer number of bytes buffered before interrupt
if (com->bufsz > 255)
tio.c_cc[VMIN] = 255;
else
tio.c_cc[VMIN] = com->bufsz;
// Set the max time to buffer bytes
if (com->buftm > 25500) // 25500 ms = 25.5 sec
tio.c_cc[VTIME] = 255;
else
tio.c_cc[VTIME] = com->buftm / 100;
tio.c_cc[VSTART] = com->xonchar;
tio.c_cc[VSTOP] = com->xoffchar;
// input flow control
UPD_BIT(tio.c_iflag, IXOFF, (com->iflow & UART_SW));
#if defined(CRTS_IFLOW)
UPD_BIT(tio.c_cflag, CRTS_IFLOW, (com->iflow & UART_RTS));
#endif
#if defined(CDTR_IFLOW)
UPD_BIT(tio.c_cflag, CDTR_IFLOW, (com->iflow & UART_DTR));
#endif
// output flow control
UPD_BIT(tio.c_iflag, IXON, (com->oflow & UART_SW));
#if defined(CCTS_OFLOW)
UPD_BIT(tio.c_cflag, CCTS_OFLOW, (com->oflow & UART_CTS));
#endif
#if defined(CDSR_OFLOW)
UPD_BIT(tio.c_cflag, CDSR_OFLOW, (com->oflow & UART_DSR));
#endif
#if defined(CCAR_OFLOW)
UPD_BIT(tio.c_cflag, CCAR_OFLOW, (com->oflow & UART_CD));
#endif
#if defined(CRTSCTS)
if ((com->iflow & UART_RTS) && (com->oflow & UART_CTS))
tio.c_cflag |= CRTSCTS;
else if (!(com->iflow & UART_RTS) && !(com->oflow & UART_CTS))
tio.c_cflag &= ~CRTSCTS;
#endif
// ignore break condition
tio.c_iflag |= IGNBRK;
// local line + enable receiver
tio.c_cflag |= (CLOCAL | CREAD);
// raw input processing
tio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG | IEXTEN);
// no output processing
tio.c_oflag &= ~(OPOST);
// do NOT hangup-on-close, need? we keep one slave open
tio.c_cflag &= ~HUPCL;
tcflush(fd, TCIFLUSH);
return tcsetattr(fd, TCSANOW, &tio);
}
static int set_com_state(HANDLE fh, uart_com_state_t* com)
{
DCB dcb;
COMMTIMEOUTS tmo;
int baud;
memset(&dcb, 0, sizeof(dcb));
if (!GetCommState(fh, &dcb)) {
DEBUG_ERROR("GetCommState: error %d", GetLastError());
return -1;
}
baud = (com->ibaud > com->obaud) ? com->ibaud : com->obaud;
dcb.BaudRate = to_speed(baud);
switch(com->parity) {
case UART_PARITY_NONE:
dcb.fParity = FALSE;
dcb.Parity = NOPARITY;
break;
case UART_PARITY_ODD:
dcb.fParity = TRUE;
dcb.Parity = ODDPARITY;
break;
case UART_PARITY_EVEN:
dcb.fParity = TRUE;
dcb.Parity = EVENPARITY;
break;
case UART_PARITY_MARK:
dcb.fParity = TRUE;
dcb.Parity = MARKPARITY;
break;
case UART_PARITY_SPACE:
dcb.fParity = TRUE;
dcb.Parity = SPACEPARITY;
break;
default:
dcb.fParity = FALSE;
dcb.Parity = NOPARITY;
break;
}
if (com->stopb == 1)
dcb.StopBits = ONESTOPBIT;
else if (com->stopb == 2)
dcb.StopBits = TWOSTOPBITS;
else if (com->stopb == 3)
dcb.StopBits = ONE5STOPBITS;
dcb.ByteSize = com->csize;
dcb.XonChar = com->xonchar;
dcb.XoffChar = com->xoffchar;
// FIXME better flow handling!
// {flow,[xoff|dtr|rts],[xoff|cts|dsr]} ?
//
dcb.fInX = (com->iflow & UART_SW) != 0;
dcb.fDtrControl = (com->iflow & UART_DTR) != 0;
dcb.fRtsControl = (com->iflow & UART_RTS) != 0;
dcb.fOutX = (com->oflow & UART_SW) != 0;
dcb.fOutxCtsFlow = (com->oflow & UART_CTS) != 0;
dcb.fOutxDsrFlow = (com->oflow & UART_DSR) != 0;
dcb.fNull = FALSE;
dcb.DCBlength = sizeof(DCB);
if (!SetCommState(fh, &dcb)) {
DEBUG_ERROR("SetCommState: error %d", GetLastError());
return -1;
}
// Setup harware buffer and timers
if (com->bufsz > 255)
SetupComm(fh, 255, DEFAULT_OUT_QUEUE);
else
SetupComm(fh, com->bufsz, DEFAULT_OUT_QUEUE);
tmo.ReadIntervalTimeout = com->buftm;
tmo.ReadTotalTimeoutMultiplier = 0;
tmo.ReadTotalTimeoutConstant = 0;
tmo.WriteTotalTimeoutMultiplier = 0;
tmo.WriteTotalTimeoutConstant = 0;
if (!SetCommTimeouts(fh, &tmo)) {
DEBUG_ERROR("GetCommTimeouts: error %d", GetLastError());
return -1;
}
return 0;
}
