src/lib/libPlatform/windows/serialport.cpp

   1 /*
   2  * This file is part of the libCEC(R) library.
   3  *
   4  * libCEC(R) is Copyright (C) 2011 Pulse-Eight Limited.  All rights reserved.
   5  * libCEC(R) is an original work, containing original code.
   6  *
   7  * libCEC(R) is a trademark of Pulse-Eight Limited.
   8  *
   9  * This program is dual-licensed; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  *
  23  *
  24  * Alternatively, you can license this library under a commercial license,
  25  * please contact Pulse-Eight Licensing for more information.
  26  *
  27  * For more information contact:
  28  * Pulse-Eight Licensing       <license@pulse-eight.com>
  29  *     http://www.pulse-eight.com/
  30  *     http://www.pulse-eight.net/
  31  */
  32
  33 #include "../serialport.h"
  34 #include "../baudrate.h"
  35 #include "../../util/timeutils.h"
  36
  37 using namespace std;
  38
  39 void FormatWindowsError(int iErrorCode, string &strMessage)
  40 {
  41   if (iErrorCode != ERROR_SUCCESS)
  42   {
  43     char strAddMessage[1024];
  44     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, iErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), strAddMessage, 1024, NULL);
  45     strMessage.append(": ");
  46     strMessage.append(strAddMessage);
  47   }
  48 }
  49
  50 CSerialPort::CSerialPort(void) :
  51   m_handle(INVALID_HANDLE_VALUE),
  52   m_bIsOpen(false),
  53   m_iBaudrate(0),
  54   m_iDatabits(0),
  55   m_iStopbits(0),
  56   m_iParity(0)
  57 {
  58 }
  59
  60 CSerialPort::~CSerialPort(void)
  61 {
  62   Close();
  63 }
  64
  65 bool CSerialPort::Open(string name, int baudrate, int databits, int stopbits, int parity)
  66 {
  67   m_handle = CreateFile(name.c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
  68   if (m_handle == INVALID_HANDLE_VALUE)
  69   {
  70     m_error = "Unable to open COM port";
  71     FormatWindowsError(GetLastError(), m_error);
  72     return false;
  73   }
  74
  75   COMMCONFIG commConfig = {0};
  76   DWORD dwSize = sizeof(commConfig);
  77   commConfig.dwSize = dwSize;
  78   if (GetDefaultCommConfig(name.c_str(), &commConfig,&dwSize))
  79   {
  80     if (!SetCommConfig(m_handle, &commConfig,dwSize))
  81     {
  82       m_error = "unable to set default config";
  83       FormatWindowsError(GetLastError(), m_error);
  84     }
  85   }
  86   else
  87   {
  88     m_error = "unable to get default config";
  89     FormatWindowsError(GetLastError(), m_error);
  90   }
  91
  92   if (!SetupComm(m_handle, 64, 64))
  93   {
  94     m_error = "unable to set up the com port";
  95     FormatWindowsError(GetLastError(), m_error);
  96   }
  97
  98   m_iDatabits = databits;
  99   m_iStopbits = stopbits;
 100   m_iParity   = parity;
 101   if (!SetBaudRate(baudrate))
 102   {
 103     m_error = "unable to set baud rate";
 104     FormatWindowsError(GetLastError(), m_error);
 105     Close();
 106     return false;
 107   }
 108
 109   if (!SetTimeouts(false))
 110   {
 111     m_error = "unable to set timeouts";
 112     FormatWindowsError(GetLastError(), m_error);
 113     Close();
 114     return false;
 115   }
 116
 117   m_bIsOpen = true;
 118   return m_bIsOpen;
 119 }
 120
 121 bool CSerialPort::SetTimeouts(bool bBlocking)
 122 {
 123   if (m_handle == INVALID_HANDLE_VALUE)
 124           return false;
 125
 126   COMMTIMEOUTS cto;
 127   if (!GetCommTimeouts(m_handle, &cto))
 128   {
 129     m_error = "GetCommTimeouts failed";
 130     FormatWindowsError(GetLastError(), m_error);
 131     return false;
 132   }
 133
 134   if (bBlocking)
 135   {
 136     cto.ReadIntervalTimeout         = 0;
 137     cto.ReadTotalTimeoutConstant    = 0;
 138     cto.ReadTotalTimeoutMultiplier  = 0;
 139   }
 140   else
 141   {
 142     cto.ReadIntervalTimeout         = MAXDWORD;
 143     cto.ReadTotalTimeoutConstant    = 0;
 144     cto.ReadTotalTimeoutMultiplier  = 0;
 145   }
 146
 147   if (!SetCommTimeouts(m_handle, &cto))
 148   {
 149     m_error = "SetCommTimeouts failed";
 150     FormatWindowsError(GetLastError(), m_error);
 151     return false;
 152   }
 153
 154   return true;
 155 }
 156
 157 void CSerialPort::Close(void)
 158 {
 159   if (m_bIsOpen)
 160   {
 161     CloseHandle(m_handle);
 162     m_bIsOpen = false;
 163   }
 164 }
 165
 166 int CSerialPort::Write(uint8_t* data, int len)
 167 {
 168   DWORD iBytesWritten = 0;
 169   if (!m_bIsOpen)
 170     return -1;
 171
 172   if (!WriteFile(m_handle, data, len, &iBytesWritten, NULL))
 173   {
 174     m_error = "Error while writing to COM port";
 175     FormatWindowsError(GetLastError(), m_error);
 176     return -1;
 177   }
 178
 179   return (int) iBytesWritten;
 180 }
 181
 182 int CSerialPort::Read(uint8_t* data, int len, int iTimeoutMs /* = -1 */)
 183 {
 184   DWORD iBytesRead = 0;
 185   if (m_handle == 0)
 186   {
 187     m_error = "Error while reading from COM port: invalid handle";
 188     return -1;
 189   }
 190
 191   if(!ReadFile(m_handle, data, len, &iBytesRead, NULL) != 0)
 192   {
 193     m_error = "unable to read from device";
 194     FormatWindowsError(GetLastError(), m_error);
 195     iBytesRead = -1;
 196   }
 197
 198   return (int) iBytesRead;
 199 }
 200
 201 bool CSerialPort::SetBaudRate(int baudrate)
 202 {
 203   m_iBaudrate = baudrate;
 204
 205   DCB dcb;
 206   memset(&dcb,0,sizeof(dcb));
 207   dcb.DCBlength = sizeof(dcb);
 208   dcb.BaudRate      = IntToRate(m_iBaudrate);
 209   dcb.fBinary       = true;
 210   dcb.fDtrControl   = DTR_CONTROL_DISABLE;
 211   dcb.fRtsControl   = RTS_CONTROL_DISABLE;
 212   dcb.fOutxCtsFlow  = false;
 213   dcb.fOutxDsrFlow  = false;
 214   dcb.fOutX         = false;
 215         dcb.fInX          = false;
 216   dcb.fAbortOnError = true;
 217
 218   if (m_iParity == PAR_NONE)
 219     dcb.Parity = NOPARITY;
 220   else if (m_iParity == PAR_EVEN)
 221     dcb.Parity = EVENPARITY;
 222   else
 223     dcb.Parity = ODDPARITY;
 224
 225   if (m_iStopbits == 2)
 226     dcb.StopBits = TWOSTOPBITS;
 227   else
 228     dcb.StopBits = ONESTOPBIT;
 229
 230   dcb.ByteSize = m_iDatabits;
 231
 232   if(!SetCommState(m_handle,&dcb))
 233   {
 234     m_error = "SetCommState failed";
 235     FormatWindowsError(GetLastError(), m_error);
 236     return false;
 237   }
 238
 239   return true;
 240 }