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 <stdlib.h>
  37 #include <linux/termios.h>
  38 #include "linux_termios.h"
  39
  40 SP_PRIV unsigned long get_termios_get_ioctl(void)
  41 {
  42 #ifdef HAVE_TERMIOS2
  43         return TCGETS2;
  44 #else
  45         return TCGETS;
  46 #endif
  47 }
  48
  49 SP_PRIV unsigned long get_termios_set_ioctl(void)
  50 {
  51 #ifdef HAVE_TERMIOS2
  52         return TCSETS2;
  53 #else
  54         return TCSETS;
  55 #endif
  56 }
  57
  58 SP_PRIV size_t get_termios_size(void)
  59 {
  60 #ifdef HAVE_TERMIOS2
  61         return sizeof(struct termios2);
  62 #else
  63         return sizeof(struct termios);
  64 #endif
  65 }
  66
  67 #if (defined(HAVE_TERMIOS_SPEED) || defined(HAVE_TERMIOS2_SPEED)) && defined(HAVE_BOTHER)
  68 SP_PRIV 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 SP_PRIV 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 #endif
  93
  94 #ifdef HAVE_TERMIOX
  95 SP_PRIV size_t get_termiox_size(void)
  96 {
  97         return sizeof(struct termiox);
  98 }
  99
 100 SP_PRIV int get_termiox_flow(void *data, int *rts, int *cts, int *dtr, int *dsr)
 101 {
 102         struct termiox *termx = (struct termiox *) data;
 103         int flags = 0;
 104
 105         *rts = (termx->x_cflag & RTSXOFF);
 106         *cts = (termx->x_cflag & CTSXON);
 107         *dtr = (termx->x_cflag & DTRXOFF);
 108         *dsr = (termx->x_cflag & DSRXON);
 109
 110         return flags;
 111 }
 112
 113 SP_PRIV void set_termiox_flow(void *data, int rts, int cts, int dtr, int dsr)
 114 {
 115         struct termiox *termx = (struct termiox *) data;
 116
 117         termx->x_cflag &= ~(RTSXOFF | CTSXON | DTRXOFF | DSRXON);
 118
 119         if (rts)
 120                 termx->x_cflag |= RTSXOFF;
 121         if (cts)
 122                 termx->x_cflag |= CTSXON;
 123         if (dtr)
 124                 termx->x_cflag |= DTRXOFF;
 125         if (dsr)
 126                 termx->x_cflag |= DSRXON;
 127 }
 128 #endif