SerialCommPort.cc

Go to the documentation of this file.

#include "SerialCommPort.h"
#include <sys/ioctl.h>
#include <errno.h>
#ifdef __APPLE__
#  include <IOKit/serial/ioss.h>
#endif
#ifdef __linux__
#  include <linux/serial.h>
#endif

#ifdef __CYGWIN__
// Cygwin doesn't provide cfmakeraw...
// this definition found in port of unix 'script' utility
// by Alan Evans (Alan_Evans AT iwv com), 2002-09-27
// http://marc.info/?l=cygwin&m=103314951904556&w=2
void cfmakeraw(struct termios *termios_p) {
  termios_p->c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
        |INLCR|IGNCR|ICRNL|IXON);
  termios_p->c_oflag &= ~OPOST;
  termios_p->c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
  termios_p->c_cflag &= ~(CSIZE|PARENB);
  termios_p->c_cflag |= CS8;
}
#endif

using namespace std;

const char * const SerialCommPort::parityNames[] = { "EVEN", "ODD", "NONE", NULL };
INSTANTIATE_NAMEDENUMERATION_STATICS(SerialCommPort::parity_t);

std::map<int,speed_t> SerialCommPort::bauds;

const std::string SerialCommPort::autoRegisterSerialCommPort = CommPort::getRegistry().registerType<SerialCommPort>("SerialCommPort");

void SerialCommPort::setupSerial() {
  if(fd<0)
    return;
  
  // ** first do a basic setup to initialize our access to the serial port **
  
  // get current termios structure (sys/termios.h)
  struct termios  theTermios;
  int ret = tcgetattr(fd, &theTermios);
  cfmakeraw(&theTermios);
  
  // We'll handle Darwin and Linux after we're done with termios settings
  // these platforms use a separate ioctl call to get non-standard baud rates
#ifndef __APPLE__
  std::map<int,speed_t>::const_iterator baudIt = bauds.find(baudRate);
#  ifdef __linux__
  // For linux, custom/non-standard speed requires B38400 baud be set here (wtf...)
  const speed_t TGTBAUD = baudIt==bauds.end() ? B38400 : baudIt->second;
#  else
  // Unknown platform: we'll just have to stick to cfsetspeed, which probably
  // doesn't handle non-standard rates, but worth a shot :(
  const speed_t TGTBAUD = baudIt==bauds.end() ? baudRate : baudIt->second;
#  endif
  ret = cfsetispeed(&theTermios, TGTBAUD);
  if(ret)
    dispError("cfsetispeed",ret,errno);
  ret = cfsetospeed(&theTermios, TGTBAUD);
  if(ret)
    dispError("cfsetospeed",ret,errno);
#endif
  
  // turn on READ and ignore modem control lines
  theTermios.c_cflag |= CREAD | CLOCAL;
  //theTermios.c_cflag = CIGNORE;
  
  switch (dataBits) {
    case 5:   theTermios.c_cflag |= CS5;    break;
    case 6:   theTermios.c_cflag |= CS6;    break;
    case 7:   theTermios.c_cflag |= CS7;    break;
    case 8:   theTermios.c_cflag |= CS8;    break;
    default: std::cerr << "SerialCommPort: bad DataBits value " << dataBits << std::endl; 
  }
  
  // stop bit(s)?
  if(stopBits==1u)
    theTermios.c_cflag &= ~CSTOPB;
  else if(stopBits==2u)
    theTermios.c_cflag |= CSTOPB;
  else
    std::cerr << "SerialCommPort: bad StopBits value " << stopBits << std::endl; 
  
  // parity?
  switch(parity) {
    case EVEN:
      theTermios.c_cflag |= PARENB; theTermios.c_cflag &= ~PARODD; break;
    case ODD:
      theTermios.c_cflag |= PARENB; theTermios.c_cflag |= PARODD; break;
    case NONE:
      theTermios.c_cflag &= ~PARENB; break;
  }
  // default no flow control:
  theTermios.c_iflag &= ~(IXON | IXOFF);
  theTermios.c_cflag &= ~CRTSCTS;
  
  // apply our settings
  ret = tcsetattr(fd, TCSAFLUSH, &theTermios);
  //ret = ioctl(fd, TIOCSETA, &theTermios); // alternative ?
  if (ret)
    dispError("tcsetattr(TCSAFLUSH)",ret,errno);
  
#ifdef __APPLE__
  // this allows higher (non-standard) baud rates, apparently not supported (on darwin) via termios
  const int TGTBAUD = baudRate;
  ret = ioctl(fd, IOSSIOSPEED, &TGTBAUD); // as opposed to setting it in theTermios ?
  if (ret)
    dispError("ioctl(IOSSIOSPEED)",ret,errno);
#endif

#ifdef __linux__
  if(baudIt==bauds.end()) {
    serial_struct sserial;
    ret = ioctl(fd, TIOCGSERIAL, &sserial);
    if(ret)
      dispError("ioctl(TIOCGSERIAL)",ret,errno);
    else {
      // if we're using a custom speed, set the bit, otherwise clear it
      if(baudIt==bauds.end())
        sserial.flags |= ASYNC_SPD_CUST;
      else
        sserial.flags &= ~ASYNC_SPD_MASK;
      // always request low-latency though (appears to be default anyway)
      sserial.flags |= ASYNC_LOW_LATENCY;
      sserial.custom_divisor = (int)(sserial.baud_base / (float)baudRate + .5);
      ret = ioctl(fd, TIOCSSERIAL, &sserial);
      if(ret)
        dispError("ioctl(TIOCSSERIAL)",ret,errno);
    }
  }
#endif
  
  // this part doesn't seem to be necessary, but better safe than sorry...
  int modem;
  ret = ioctl(fd, TIOCMGET, &modem);
  if (ret!=0) {
    //int err = errno;
    //std::cerr << "Warning: ioctl(TIOCMGET) returned errno " << err << " (" << strerror(err) << ")" << endl;
  } else {
    modem |= TIOCM_DTR;
    ret = ioctl(fd, TIOCMSET, &modem);
    if (ret)
      dispError("ioctl(TIOCMSET)",ret,errno);
  }
  
  // this works on linux, but won't let you set custom speeds on OS X
  // best to leave blank unless you really need it
  if(sttyConfig.size()>0) {
    // ** do additional setup by calling out to stty **
  #ifdef __linux__
    std::string cmd="stty -F "+path+" "+sttyConfig;
  #else /* assume BSD style... use a -f instead of -F (...sigh...) */
    std::string cmd="stty -f "+path+" "+sttyConfig;
  #endif
    switch(::system(cmd.c_str())) {
      case 0:
        break; // good!
      case -1:
        perror("Warning: SerialCommPort could not make system call to stty"); break;
      case 127:
        std::cerr << "Warning: SerialCommPort could not make system call to stty: no shell found" << std::endl; break;
      default:
        std::cerr << "Warning: SerialCommPort stty reported error on configuration string: " << sttyConfig << std::endl; break;
    }
  }
}

void SerialCommPort::dispError(const char* where, int ret, int err) {
  std::cerr << where << " returned " << ret << " (errno " << err << ": " << strerror(err) << ")" << std::endl;
}

void SerialCommPort::initBauds() {
#ifdef B0
  bauds[0]=B0;
#endif
#ifdef B50
  bauds[50]=B50;
#endif
#ifdef B75
  bauds[75]=B75;
#endif
#ifdef B110
  bauds[110]=B110;
#endif
#ifdef B134
  bauds[134]=B134;
#endif
#ifdef B150
  bauds[150]=B150;
#endif
#ifdef B200
  bauds[200]=B200;
#endif
#ifdef B300
  bauds[300]=B300;
#endif
#ifdef B600
  bauds[600]=B600;
#endif
#ifdef B1200
  bauds[1200]=B1200;
#endif
#ifdef B1200
  bauds[1200]=B1200;
#endif
#ifdef B1800
  bauds[1800]=B1800;
#endif
#ifdef B2400
  bauds[2400]=B2400;
#endif
#ifdef B4800
  bauds[4800]=B4800;
#endif
#ifdef B9600
  bauds[9600]=B9600;
#endif
#ifdef B19200
  bauds[19200]=B19200;
#endif
#ifdef B38400
  bauds[38400]=B38400;
#endif
#ifdef B57600
  bauds[57600]=B57600;
#endif
#ifdef B76800
  bauds[76800]=B76800;
#endif
#ifdef B115200
  bauds[115200]=B115200;
#endif
#ifdef B153600
  bauds[153600]=B153600;
#endif
#ifdef B230400
  bauds[230400]=B230400;
#endif
#ifdef B307200
  bauds[307200]=B307200;
#endif
#ifdef B460800
  bauds[460800]=B460800;
#endif
#ifdef B500000
  bauds[500000]=B500000;
#endif
#ifdef B576000
  bauds[576000]=B576000;
#endif
#ifdef B921600
  bauds[921600]=B921600;
#endif
#ifdef B1000000
  bauds[1000000]=B1000000;
#endif
#ifdef B1152000
  bauds[1152000]=B1152000;
#endif
#ifdef B1500000
  bauds[1500000]=B1500000;
#endif
#ifdef B2000000
  bauds[2000000]=B2000000;
#endif
#ifdef B2500000
  bauds[2500000]=B2500000;
#endif
#ifdef B3000000
  bauds[3000000]=B3000000;
#endif
#ifdef B3500000
  bauds[3500000]=B3500000;
#endif
#ifdef B4000000
  bauds[4000000]=B4000000;
#endif
}

/*! @file
 * @brief 
 * @author Ethan Tira-Thompson (ejt) (Creator)
 */