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 #include <linux/termios.h>
  37 #include "linux_termios.h"
  38
  39 int get_termios_get_ioctl(void)
  40 {
  41 #ifdef HAVE_TERMIOS2
  42         return TCGETS2;
  43 #else
  44         return TCGETS;
  45 #endif
  46 }
  47
  48 int get_termios_set_ioctl(void)
  49 {
  50 #ifdef HAVE_TERMIOS2
  51         return TCSETS2;
  52 #else
  53         return TCSETS;
  54 #endif
  55 }
  56
  57 int get_termios_size(void)
  58 {
  59 #ifdef HAVE_TERMIOS2
  60         return sizeof(struct termios2);
  61 #else
  62         return sizeof(struct termios);
  63 #endif
  64 }
  65
  66 #if defined(HAVE_TERMIOS_SPEED) || defined(HAVE_TERMIOS2_SPEED)
  67 int get_termios_speed(void *data)
  68 {
  69 #ifdef HAVE_TERMIOS2
  70         struct termios2 *term = (struct termios2 *) data;
  71 #else
  72         struct termios *term = (struct termios *) data;
  73 #endif
  74         if (term->c_ispeed != term->c_ospeed)
  75                 return -1;
  76         else
  77                 return term->c_ispeed;
  78 }
  79
  80 void set_termios_speed(void *data, int speed)
  81 {
  82 #ifdef HAVE_TERMIOS2
  83         struct termios2 *term = (struct termios2 *) data;
  84 #else
  85         struct termios *term = (struct termios *) data;
  86 #endif
  87         term->c_cflag &= ~CBAUD;
  88         term->c_cflag |= BOTHER;
  89         term->c_ispeed = term->c_ospeed = speed;
  90 }
  91 #endif
  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, int *rts, int *cts, int *dtr, int *dsr)
 100 {
 101         struct termiox *termx = (struct termiox *) data;
 102         int flags = 0;
 103
 104         *rts = (termx->x_cflag & RTSXOFF);
 105         *cts = (termx->x_cflag & CTSXON);
 106         *dtr = (termx->x_cflag & DTRXOFF);
 107         *dsr = (termx->x_cflag & DSRXON);
 108
 109         return flags;
 110 }
 111
 112 void set_termiox_flow(void *data, int rts, int cts, int dtr, int dsr)
 113 {
 114         struct termiox *termx = (struct termiox *) data;
 115
 116         termx->x_cflag &= ~(RTSXOFF | CTSXON | DTRXOFF | DSRXON);
 117
 118         if (rts)
 119                 termx->x_cflag |= RTSXOFF;
 120         if (cts)
 121                 termx->x_cflag |= CTSXON;
 122         if (dtr)
 123                 termx->x_cflag |= DTRXOFF;
 124         if (dsr)
 125                 termx->x_cflag |= DSRXON;
 126 }
 127 #endif