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 <config.h>
  37 #include <stdlib.h>
  38 #include <linux/termios.h>
  39 #include "linux_termios.h"
  40
  41 SP_PRIV unsigned long get_termios_get_ioctl(void)
  42 {
  43 #ifdef HAVE_STRUCT_TERMIOS2
  44         return TCGETS2;
  45 #else
  46         return TCGETS;
  47 #endif
  48 }
  49
  50 SP_PRIV unsigned long get_termios_set_ioctl(void)
  51 {
  52 #ifdef HAVE_STRUCT_TERMIOS2
  53         return TCSETS2;
  54 #else
  55         return TCSETS;
  56 #endif
  57 }
  58
  59 SP_PRIV size_t get_termios_size(void)
  60 {
  61 #ifdef HAVE_STRUCT_TERMIOS2
  62         return sizeof(struct termios2);
  63 #else
  64         return sizeof(struct termios);
  65 #endif
  66 }
  67
  68 #if (defined(HAVE_TERMIOS_SPEED) || defined(HAVE_TERMIOS2_SPEED)) && HAVE_DECL_BOTHER
  69 SP_PRIV int get_termios_speed(void *data)
  70 {
  71 #ifdef HAVE_STRUCT_TERMIOS2
  72         struct termios2 *term = (struct termios2 *) data;
  73 #else
  74         struct termios *term = (struct termios *) data;
  75 #endif
  76         if (term->c_ispeed != term->c_ospeed)
  77                 return -1;
  78         else
  79                 return term->c_ispeed;
  80 }
  81
  82 SP_PRIV void set_termios_speed(void *data, int speed)
  83 {
  84 #ifdef HAVE_STRUCT_TERMIOS2
  85         struct termios2 *term = (struct termios2 *) data;
  86 #else
  87         struct termios *term = (struct termios *) data;
  88 #endif
  89         term->c_cflag &= ~CBAUD;
  90         term->c_cflag |= BOTHER;
  91         term->c_ispeed = term->c_ospeed = speed;
  92 }
  93 #endif
  94
  95 #ifdef HAVE_STRUCT_TERMIOX
  96 SP_PRIV size_t get_termiox_size(void)
  97 {
  98         return sizeof(struct termiox);
  99 }
 100
 101 SP_PRIV int get_termiox_flow(void *data, int *rts, int *cts, int *dtr, int *dsr)
 102 {
 103         struct termiox *termx = (struct termiox *) data;
 104         int flags = 0;
 105
 106         *rts = (termx->x_cflag & RTSXOFF);
 107         *cts = (termx->x_cflag & CTSXON);
 108         *dtr = (termx->x_cflag & DTRXOFF);
 109         *dsr = (termx->x_cflag & DSRXON);
 110
 111         return flags;
 112 }
 113
 114 SP_PRIV void set_termiox_flow(void *data, int rts, int cts, int dtr, int dsr)
 115 {
 116         struct termiox *termx = (struct termiox *) data;
 117
 118         termx->x_cflag &= ~(RTSXOFF | CTSXON | DTRXOFF | DSRXON);
 119
 120         if (rts)
 121                 termx->x_cflag |= RTSXOFF;
 122         if (cts)
 123                 termx->x_cflag |= CTSXON;
 124         if (dtr)
 125                 termx->x_cflag |= DTRXOFF;
 126         if (dsr)
 127                 termx->x_cflag |= DSRXON;
 128 }
 129 #endif