src/lib/platform/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 "../timeutils.h"
  36
  37 using namespace std;
  38 using namespace CEC;
  39
  40 void FormatWindowsError(int iErrorCode, string &strMessage)
  41 {
  42   if (iErrorCode != ERROR_SUCCESS)
  43   {
  44     char strAddMessage[1024];
  45     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, iErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), strAddMessage, 1024, NULL);
  46     strMessage.append(": ");
  47     strMessage.append(strAddMessage);
  48   }
  49 }
  50
  51 CSerialPort::CSerialPort(void) :
  52   m_handle(INVALID_HANDLE_VALUE),
  53   m_bIsOpen(false),
  54   m_iBaudrate(0),
  55   m_iDatabits(0),
  56   m_iStopbits(0),
  57   m_iParity(0)
  58 {
  59 }
  60
  61 CSerialPort::~CSerialPort(void)
  62 {
  63   Close();
  64 }
  65
  66 bool CSerialPort::Open(string name, int baudrate, int databits, int stopbits, int parity)
  67 {
  68   m_handle = CreateFile(name.c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
  69   if (m_handle == INVALID_HANDLE_VALUE)
  70   {
  71     m_error = "Unable to open COM port";
  72     FormatWindowsError(GetLastError(), m_error);
  73     return false;
  74   }
  75
  76   COMMCONFIG commConfig = {0};
  77   DWORD dwSize = sizeof(commConfig);
  78   commConfig.dwSize = dwSize;
  79   if (GetDefaultCommConfig(name.c_str(), &commConfig,&dwSize))
  80   {
  81     if (!SetCommConfig(m_handle, &commConfig,dwSize))
  82     {
  83       m_error = "unable to set default config";
  84       FormatWindowsError(GetLastError(), m_error);
  85     }
  86   }
  87   else
  88   {
  89     m_error = "unable to get default config";
  90     FormatWindowsError(GetLastError(), m_error);
  91   }
  92
  93   if (!SetupComm(m_handle, 64, 64))
  94   {
  95     m_error = "unable to set up the com port";
  96     FormatWindowsError(GetLastError(), m_error);
  97   }
  98
  99   m_iDatabits = databits;
 100   m_iStopbits = stopbits;
 101   m_iParity   = parity;
 102   if (!SetBaudRate(baudrate))
 103   {
 104     m_error = "unable to set baud rate";
 105     FormatWindowsError(GetLastError(), m_error);
 106     Close();
 107     return false;
 108   }
 109
 110   if (!SetTimeouts(false))
 111   {
 112     m_error = "unable to set timeouts";
 113     FormatWindowsError(GetLastError(), m_error);
 114     Close();
 115     return false;
 116   }
 117
 118   m_bIsOpen = true;
 119   return m_bIsOpen;
 120 }
 121
 122 bool CSerialPort::SetTimeouts(bool bBlocking)
 123 {
 124   if (m_handle == INVALID_HANDLE_VALUE)
 125           return false;
 126
 127   COMMTIMEOUTS cto;
 128   if (!GetCommTimeouts(m_handle, &cto))
 129   {
 130     m_error = "GetCommTimeouts failed";
 131     FormatWindowsError(GetLastError(), m_error);
 132     return false;
 133   }
 134
 135   if (bBlocking)
 136   {
 137     cto.ReadIntervalTimeout         = 0;
 138     cto.ReadTotalTimeoutConstant    = 0;
 139     cto.ReadTotalTimeoutMultiplier  = 0;
 140   }
 141   else
 142   {
 143     cto.ReadIntervalTimeout         = MAXDWORD;
 144     cto.ReadTotalTimeoutConstant    = 0;
 145     cto.ReadTotalTimeoutMultiplier  = 0;
 146   }
 147
 148   if (!SetCommTimeouts(m_handle, &cto))
 149   {
 150     m_error = "SetCommTimeouts failed";
 151     FormatWindowsError(GetLastError(), m_error);
 152     return false;
 153   }
 154
 155   return true;
 156 }
 157
 158 void CSerialPort::Close(void)
 159 {
 160   if (m_bIsOpen)
 161   {
 162     CloseHandle(m_handle);
 163     m_bIsOpen = false;
 164   }
 165 }
 166
 167 int CSerialPort::Write(uint8_t* data, int len)
 168 {
 169   DWORD iBytesWritten = 0;
 170   if (!m_bIsOpen)
 171     return -1;
 172
 173   if (!WriteFile(m_handle, data, len, &iBytesWritten, NULL))
 174   {
 175     m_error = "Error while writing to COM port";
 176     FormatWindowsError(GetLastError(), m_error);
 177     return -1;
 178   }
 179
 180   return (int) iBytesWritten;
 181 }
 182
 183 int CSerialPort::Read(uint8_t* data, int len, int iTimeoutMs /* = -1 */)
 184 {
 185   DWORD iBytesRead = 0;
 186   if (m_handle == 0)
 187   {
 188     m_error = "Error while reading from COM port: invalid handle";
 189     return -1;
 190   }
 191
 192   if(!ReadFile(m_handle, data, len, &iBytesRead, NULL) != 0)
 193   {
 194     m_error = "unable to read from device";
 195     FormatWindowsError(GetLastError(), m_error);
 196     iBytesRead = -1;
 197   }
 198
 199   return (int) iBytesRead;
 200 }
 201
 202 bool CSerialPort::SetBaudRate(int baudrate)
 203 {
 204   m_iBaudrate = baudrate;
 205
 206   DCB dcb;
 207   memset(&dcb,0,sizeof(dcb));
 208   dcb.DCBlength = sizeof(dcb);
 209   dcb.BaudRate      = IntToBaudrate(m_iBaudrate);
 210   dcb.fBinary       = true;
 211   dcb.fDtrControl   = DTR_CONTROL_DISABLE;
 212   dcb.fRtsControl   = RTS_CONTROL_DISABLE;
 213   dcb.fOutxCtsFlow  = false;
 214   dcb.fOutxDsrFlow  = false;
 215   dcb.fOutX         = false;
 216         dcb.fInX          = false;
 217   dcb.fAbortOnError = true;
 218
 219   if (m_iParity == PAR_NONE)
 220     dcb.Parity = NOPARITY;
 221   else if (m_iParity == PAR_EVEN)
 222     dcb.Parity = EVENPARITY;
 223   else
 224     dcb.Parity = ODDPARITY;
 225
 226   if (m_iStopbits == 2)
 227     dcb.StopBits = TWOSTOPBITS;
 228   else
 229     dcb.StopBits = ONESTOPBIT;
 230
 231   dcb.ByteSize = m_iDatabits;
 232
 233   if(!SetCommState(m_handle,&dcb))
 234   {
 235     m_error = "SetCommState failed";
 236     FormatWindowsError(GetLastError(), m_error);
 237     return false;
 238   }
 239
 240   return true;
 241 }
 242
 243 bool CSerialPort::IsOpen() const
 244 {
 245   return m_bIsOpen;
 246 }