Add a class for serial port communications

No win32 support yet

diff --git a/source/serial.cpp b/source/serial.cpp
new file mode 100644 (file)
index 0000000..e6eff51
--- /dev/null
+++ b/source/serial.cpp
@@ -0,0 +1,269 @@
+/* $Id$
+
+This file is part of libmspio
+Copyright © 2010 Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
+#include <termios.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <msp/strings/formatter.h>
+#include "except.h"
+#include "serial.h"
+
+using namespace std;
+
+namespace {
+
+using namespace Msp;
+using namespace Msp::IO;
+
+#ifndef WIN32
+void set_baud_rate(termios &t, unsigned baud)
+{
+       speed_t speed;
+       switch(baud)
+       {
+       case 0:      speed = B0; break;
+       case 50:     speed = B50; break;
+       case 75:     speed = B75; break;
+       case 110:    speed = B110; break;
+       case 134:    speed = B134; break;
+       case 150:    speed = B150; break;
+       case 200:    speed = B200; break;
+       case 300:    speed = B300; break;
+       case 600:    speed = B600; break;
+       case 1200:   speed = B1200; break;
+       case 1800:   speed = B1800; break;
+       case 2400:   speed = B2400; break;
+       case 4800:   speed = B4800; break;
+       case 9600:   speed = B9600; break;
+       case 19200:  speed = B19200; break;
+       case 38400:  speed = B38400; break;
+       case 57600:  speed = B57600; break;
+       case 115200: speed = B115200; break;
+       case 230400: speed = B230400; break;
+       default: throw InvalidParameterValue("Invalid baud rate");
+       }
+
+       cfsetospeed(&t, speed);
+       cfsetispeed(&t, speed);
+}
+
+void set_data_bits(termios &t, unsigned bits)
+{
+       tcflag_t flag;
+       switch(bits)
+       {
+       case 5: flag = CS5; break;
+       case 6: flag = CS6; break;
+       case 7: flag = CS7; break;
+       case 8: flag = CS8; break;
+       default: throw InvalidParameterValue("Invalid data bit count");
+       }
+
+       t.c_cflag = (t.c_cflag&~CSIZE)|flag;
+}
+
+void set_parity(termios &t, Serial::Parity par)
+{
+       tcflag_t flag;
+       switch(par)
+       {
+       case Serial::NONE: flag = 0; break;
+       case Serial::EVEN: flag = PARENB; break;
+       case Serial::ODD:  flag = PARENB|PARODD; break;
+       default: throw InvalidParameterValue("Invalid parity");
+       }
+
+       t.c_cflag = (t.c_cflag&~(PARENB|PARODD))|flag;
+}
+
+void set_stop_bits(termios &t, unsigned bits)
+{
+       tcflag_t flag;
+       switch(bits)
+       {
+       case 1: flag = 0; break;
+       case 2: flag = CSTOPB; break;
+       default: throw InvalidParameterValue("Invalid stop bit count");
+       }
+
+       t.c_cflag = (t.c_cflag&~CSTOPB)|flag;
+}
+#endif
+
+}
+
+
+namespace Msp {
+namespace IO {
+
+Serial::Serial(const string &descr)
+{
+       string::size_type comma = descr.find(',');
+       string port = descr.substr(0, comma);
+
+#ifndef WIN32
+       if(port.compare(0, 5, "/dev/"))
+               port = "/dev/"+port;
+
+       handle = open(port.c_str(), O_RDWR);
+       if(handle==-1)
+               throw SystemError(format("Can't open serial port '%s'", port), errno);
+       mode = M_READ|M_WRITE;
+
+       termios t;
+       tcgetattr(handle, &t);
+       t.c_lflag &= ~(ECHO|ICANON);
+       tcsetattr(handle, TCSADRAIN, &t);
+#else
+       throw Exception("Serial ports not supported in win32 yet");
+#endif
+
+       if(comma!=string::npos)
+       {
+               try
+               {
+                       set_parameters(descr.substr(comma+1));
+               }
+               catch(...)
+               {
+                       close();
+                       throw;
+               }
+       }
+
+       set_events(P_INPUT);
+}
+
+Serial::~Serial()
+{
+       close();
+}
+
+void Serial::set_block(bool b)
+{
+       if(b)
+               mode = mode|M_NONBLOCK;
+       else
+               mode = mode&~M_NONBLOCK;
+
+#ifndef WIN32
+       int flags = fcntl(handle, F_GETFD);
+       fcntl(handle, F_SETFL, (flags&O_NONBLOCK)|(b?0:O_NONBLOCK));
+#endif
+}
+
+void Serial::set_baud_rate(unsigned rate)
+{
+#ifndef WIN32
+       termios t;
+       tcgetattr(handle, &t);
+       ::set_baud_rate(t, rate);
+       tcsetattr(handle, TCSADRAIN, &t);
+#endif
+}
+
+void Serial::set_data_bits(unsigned bits)
+{
+#ifndef WIN32
+       termios t;
+       tcgetattr(handle, &t);
+       ::set_data_bits(t, bits);
+       tcsetattr(handle, TCSADRAIN, &t);
+#endif
+}
+
+void Serial::set_parity(Parity par)
+{
+#ifndef WIN32
+       termios t;
+       tcgetattr(handle, &t);
+       ::set_parity(t, par);
+       tcsetattr(handle, TCSADRAIN, &t);
+#endif
+}
+
+void Serial::set_stop_bits(unsigned bits)
+{
+#ifndef WIN32
+       termios t;
+       tcgetattr(handle, &t);
+       ::set_stop_bits(t, bits);
+       tcsetattr(handle, TCSADRAIN, &t);
+#endif
+}
+
+void Serial::set_parameters(const string &params)
+{
+       unsigned i;
+       for(i=0; i<params.size() && isdigit(params[i]); ++i) ;
+       if(i+4!=params.size() || params[i]!=',')
+               throw InvalidParameterValue("Invalid parameter string");
+       if(params[i+1]<'5' || params[i+1]>'8')
+               throw InvalidParameterValue("Invalid data bit count");
+       if(params[i+2]!='N' && params[i+2]!='E' && params[i+2]!='O')
+               throw InvalidParameterValue("Invalid parity");
+       if(params[i+3]!='1' && params[i+3]!='2')
+               throw InvalidParameterValue("Invalid stop bit count");
+
+#ifndef WIN32
+       termios t;
+       tcgetattr(handle, &t);
+       ::set_baud_rate(t, lexical_cast<unsigned>(params.substr(0, i)));
+       ::set_data_bits(t, params[i+1]-'0');
+       ::set_parity(t, (params[i+2]=='E' ? EVEN : params[i+2]=='O' ? ODD : NONE));
+       ::set_stop_bits(t, params[i+3]-'0');
+       tcsetattr(handle, TCSADRAIN, &t);
+#endif
+}
+
+void Serial::close()
+{
+#ifndef WIN32
+       ::close(handle);
+#endif
+}
+
+unsigned Serial::do_write(const char *buf, unsigned size)
+{
+       if(size==0)
+               return 0;
+
+#ifndef WIN32
+       int ret = ::write(handle, buf, size);
+       if(ret==-1)
+       {
+               if(errno==EAGAIN)
+                       return 0;
+               else
+                       throw SystemError("Writing to serial port failed", errno);
+       }
+#endif
+
+       return ret;
+}
+
+unsigned Serial::do_read(char *buf, unsigned size)
+{
+       if(size==0)
+               return 0;
+
+#ifndef WIN32
+       int ret = ::read(handle, buf, size);
+       if(ret==-1)
+       {
+               if(errno==EAGAIN)
+                       return 0;
+               else
+                       throw SystemError("Reading from serial port failed", errno);
+       }
+#endif
+
+       return ret;
+}
+
+} // namespace IO
+} // namespace Msp

diff --git a/source/serial.h b/source/serial.h
new file mode 100644 (file)
index 0000000..0e87361
--- /dev/null
+++ b/source/serial.h
@@ -0,0 +1,55 @@
+/* $Id$
+
+This file is part of libmspio
+Copyright © 2010 Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
+#ifndef MSP_IO_SERIAL_H_
+#define MSP_IO_SERIAL_H_
+
+#include "base.h"
+
+namespace Msp {
+namespace IO {
+
+class Serial: public Base
+{
+public:
+       enum Parity
+       {
+               NONE,
+               EVEN,
+               ODD
+       };
+
+private:
+       struct Private;
+
+       Handle handle;
+       Private *priv;
+
+public:
+       Serial(const std::string &);
+       virtual ~Serial();
+
+       virtual void set_block(bool);
+
+       void set_baud_rate(unsigned);
+       void set_data_bits(unsigned);
+       void set_parity(Parity);
+       void set_stop_bits(unsigned);
+       void set_parameters(const std::string &);
+
+       virtual Handle get_event_handle() { return handle; }
+
+private:
+       void close();
+       virtual unsigned do_write(const char *, unsigned);
+       virtual unsigned do_read(char *, unsigned);
+};
+
+} // namespace IO
+} // namespace Msp
+
+#endif