linux_termios.c

   1 /*
   2  * This file is part of the libserialport project.
   3  *
   4  * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Lesser General Public License as
   8  * published by the Free Software Foundation, either version 3 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * At the time of writing, glibc does not support the Linux kernel interfaces
  22  * for setting non-standard baud rates and flow control. We therefore have to
  23  * prepare the correct ioctls ourselves, for which we need the declarations in
  24  * linux/termios.h.
  25  *
  26  * We can't include linux/termios.h in serialport.c however, because its
  27  * contents conflict with the termios.h provided by glibc. So this file exists
  28  * to isolate the bits of code which use the kernel termios declarations.
  29  *
  30  * The details vary by architecture. Some architectures have c_ispeed/c_ospeed
  31  * in struct termios, accessed with TCSETS/TCGETS. Others have these fields in
  32  * struct termios2, accessed with TCSETS2/TCGETS2. Some architectures have the
  33  * TCSETX/TCGETX ioctls used with struct termiox, others do not.
  34  */
  35
  36 #ifdef __linux__
  37
  38 #include <linux/termios.h>
  39 #include "linux_termios.h"
  40
  41 int get_termios_get_ioctl(void)
  42 {
  43 #ifdef HAVE_TERMIOS2
  44         return TCGETS2;
  45 #else
  46         return TCGETS;
  47 #endif
  48 }
  49
  50 int get_termios_set_ioctl(void)
  51 {
  52 #ifdef HAVE_TERMIOS2
  53         return TCSETS2;
  54 #else
  55         return TCSETS;
  56 #endif
  57 }
  58
  59 int get_termios_size(void)
  60 {
  61 #ifdef HAVE_TERMIOS2
  62         return sizeof(struct termios2);
  63 #else
  64         return sizeof(struct termios);
  65 #endif
  66 }
  67
  68 int get_termios_speed(void *data)
  69 {
  70 #ifdef HAVE_TERMIOS2
  71         struct termios2 *term = (struct termios2 *) data;
  72 #else
  73         struct termios *term = (struct termios *) data;
  74 #endif
  75         if (term->c_ispeed != term->c_ospeed)
  76                 return -1;
  77         else
  78                 return term->c_ispeed;
  79 }
  80
  81 void set_termios_speed(void *data, int speed)
  82 {
  83 #ifdef HAVE_TERMIOS2
  84         struct termios2 *term = (struct termios2 *) data;
  85 #else
  86         struct termios *term = (struct termios *) data;
  87 #endif
  88         term->c_cflag &= ~CBAUD;
  89         term->c_cflag |= BOTHER;
  90         term->c_ispeed = term->c_ospeed = speed;
  91 }
  92
  93 #ifdef HAVE_TERMIOX
  94 int get_termiox_size(void)
  95 {
  96         return sizeof(struct termiox);
  97 }
  98
  99 int get_termiox_flow(void *data)
 100 {
 101         struct termiox *termx = (struct termiox *) data;
 102         int flags = 0;
 103
 104         if (termx->x_cflag & RTSXOFF)
 105                 flags |= RTS_FLOW;
 106         if (termx->x_cflag & CTSXON)
 107                 flags |= CTS_FLOW;
 108         if (termx->x_cflag & DTRXOFF)
 109                 flags |= DTR_FLOW;
 110         if (termx->x_cflag & DSRXON)
 111                 flags |= DSR_FLOW;
 112
 113         return flags;
 114 }
 115
 116 void set_termiox_flow(void *data, int flags)
 117 {
 118         struct termiox *termx = (struct termiox *) data;
 119
 120         termx->x_cflag &= ~(RTSXOFF | CTSXON | DTRXOFF | DSRXON);
 121
 122         if (flags & RTS_FLOW)
 123                 termx->x_cflag |= RTSXOFF;
 124         if (flags & CTS_FLOW)
 125                 termx->x_cflag |= CTSXON;
 126         if (flags & DTR_FLOW)
 127                 termx->x_cflag |= DTRXOFF;
 128         if (flags & DSR_FLOW)
 129                 termx->x_cflag |= DSRXON;
 130 }
 131 #endif
 132
 133 #endif