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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "chrome/browser/extensions/api/serial/serial_connection.h"
      6 
      7 #include <sys/ioctl.h>
      8 #include <termios.h>
      9 
     10 namespace extensions {
     11 
     12 bool SerialConnection::PostOpen() {
     13   struct termios options;
     14 
     15   // Start with existing options and modify.
     16   tcgetattr(file_, &options);
     17 
     18   // Bitrate (sometimes erroneously referred to as baud rate).
     19   if (bitrate_ >= 0) {
     20     int bitrate_opt_;
     21     switch (bitrate_) {
     22       case 0:
     23         bitrate_opt_ = B0;
     24         break;
     25       case 50:
     26         bitrate_opt_ = B50;
     27         break;
     28       case 75:
     29         bitrate_opt_ = B75;
     30         break;
     31       case 110:
     32         bitrate_opt_ = B110;
     33         break;
     34       case 134:
     35         bitrate_opt_ = B134;
     36         break;
     37       case 150:
     38         bitrate_opt_ = B150;
     39         break;
     40       case 200:
     41         bitrate_opt_ = B200;
     42         break;
     43       case 300:
     44         bitrate_opt_ = B300;
     45         break;
     46       case 600:
     47         bitrate_opt_ = B600;
     48         break;
     49       case 1200:
     50         bitrate_opt_ = B1200;
     51         break;
     52       case 1800:
     53         bitrate_opt_ = B1800;
     54         break;
     55       case 2400:
     56         bitrate_opt_ = B2400;
     57         break;
     58       case 4800:
     59         bitrate_opt_ = B4800;
     60         break;
     61       case 9600:
     62         bitrate_opt_ = B9600;
     63         break;
     64       case 19200:
     65         bitrate_opt_ = B19200;
     66         break;
     67       case 38400:
     68         bitrate_opt_ = B38400;
     69         break;
     70 #if defined(OS_POSIX) && !defined(OS_MACOSX)
     71       case 57600:
     72         bitrate_opt_ = B57600;
     73         break;
     74       case 115200:
     75         bitrate_opt_ = B115200;
     76         break;
     77       case 230400:
     78         bitrate_opt_ = B230400;
     79         break;
     80       case 460800:
     81         bitrate_opt_ = B460800;
     82         break;
     83       case 576000:
     84         bitrate_opt_ = B576000;
     85         break;
     86       case 921600:
     87         bitrate_opt_ = B921600;
     88         break;
     89       default:
     90         bitrate_opt_ = B9600;
     91 #else
     92 // MACOSX doesn't define constants bigger than 38400.
     93 // So if it is MACOSX and the value doesn't fit any of the defined constants
     94 // It will setup the bitrate with 'bitrate_' (just forwarding the value)
     95       default:
     96         bitrate_opt_ = bitrate_;
     97 #endif
     98     }
     99 
    100     cfsetispeed(&options, bitrate_opt_);
    101     cfsetospeed(&options, bitrate_opt_);
    102   }
    103 
    104   // 8N1
    105   options.c_cflag &= ~PARENB;
    106   options.c_cflag &= ~CSTOPB;
    107   options.c_cflag &= ~CSIZE;
    108   options.c_cflag |= CS8;
    109   options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
    110 
    111   // Enable receiver and set local mode
    112   // See http://www.easysw.com/~mike/serial/serial.html to understand.
    113   options.c_cflag |= (CLOCAL | CREAD);
    114 
    115   // Write the options.
    116   tcsetattr(file_, TCSANOW, &options);
    117 
    118   return true;
    119 }
    120 
    121 bool SerialConnection::GetControlSignals(ControlSignals &control_signals) {
    122   int status;
    123   if (ioctl(file_, TIOCMGET, &status) == 0) {
    124     control_signals.dcd = (status & TIOCM_CAR) != 0;
    125     control_signals.cts = (status & TIOCM_CTS) != 0;
    126     return true;
    127   }
    128   return false;
    129 }
    130 
    131 bool SerialConnection::SetControlSignals(
    132     const ControlSignals &control_signals) {
    133   int status;
    134 
    135   if (ioctl(file_, TIOCMGET, &status) != 0)
    136     return false;
    137 
    138   if (control_signals.should_set_dtr) {
    139     if (control_signals.dtr)
    140       status |= TIOCM_DTR;
    141     else
    142       status &= ~TIOCM_DTR;
    143   }
    144   if (control_signals.should_set_rts) {
    145     if (control_signals.rts)
    146       status |= TIOCM_RTS;
    147     else
    148       status &= ~TIOCM_RTS;
    149   }
    150 
    151   return ioctl(file_, TIOCMSET, &status) == 0;
    152 }
    153 
    154 std::string SerialConnection::MaybeFixUpPortName(
    155     const std::string &port_name) {
    156   return port_name;
    157 }
    158 
    159 }  // namespace extensions
    160