mdw@git.distorted.org.uk Git - jog/blob - tx-serial-unix.c

   1 /* -*-c-*-
   2  *
   3  * $Id: tx-serial-unix.c,v 1.2 2002/01/30 09:24:24 mdw Exp $
   4  *
   5  * Unix/POSIX serial transport
   6  *
   7  * (c) 2001 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Jog: Programming for a jogging machine.
  13  *
  14  * Jog is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * Jog is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with Jog; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: tx-serial-unix.c,v $
  32  * Revision 1.2  2002/01/30 09:24:24  mdw
  33  * Restructure for new transport configuration interface.
  34  *
  35  * Revision 1.1  2002/01/25 19:34:45  mdw
  36  * Initial revision
  37  *
  38  */
  39
  40 /*----- Header files ------------------------------------------------------*/
  41
  42 #include <assert.h>
  43 #include <errno.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47
  48 #include <sys/types.h>
  49 #include <termios.h>
  50 #include <unistd.h>
  51 #include <fcntl.h>
  52
  53 #include <mLib/darray.h>
  54 #include <mLib/fdflags.h>
  55 #include <mLib/sub.h>
  56
  57 #include "err.h"
  58 #include "serial.h"
  59 #include "txport.h"
  60
  61 #ifndef O_NOCTTY
  62 #  define O_NOCTTY 0
  63 #endif
  64
  65 /*----- Data structures ---------------------------------------------------*/
  66
  67 typedef struct txsu {
  68   txport tx;                            /* Transport base */
  69   struct txsu *next, **prev;            /* Chain of serial transports */
  70   int fd;                               /* File descriptor */
  71   serial_config sc;                     /* Internal serial config */
  72   struct termios ta, old_ta;            /* External serial configs */
  73 } txsu;
  74
  75 /*----- Static variables --------------------------------------------------*/
  76
  77 struct baudmap { unsigned long baud; unsigned long magic; };
  78
  79 static const struct baudmap baudmap[] = {
  80 #ifdef B50
  81   {     50,     B50 },
  82 #endif
  83 #ifdef B75
  84   {     75,     B75 },
  85 #endif
  86 #ifdef B110
  87   {    110,    B110 },
  88 #endif
  89 #ifdef B134
  90   {    134,    B134 },
  91 #endif
  92 #ifdef B150
  93   {    150,    B150 },
  94 #endif
  95 #ifdef B200
  96   {    200,    B200 },
  97 #endif
  98 #ifdef B300
  99   {    300,    B300 },
 100 #endif
 101 #ifdef B600
 102   {    600,    B600 },
 103 #endif
 104 #ifdef B1200
 105   {   1200,   B1200 },
 106 #endif
 107 #ifdef B1800
 108   {   1800,   B1800 },
 109 #endif
 110 #ifdef B2400
 111   {   2400,   B2400 },
 112 #endif
 113 #ifdef B4800
 114   {   4800,   B4800 },
 115 #endif
 116 #ifdef B9600
 117   {   9600,   B9600 },
 118 #endif
 119 #ifdef B19200
 120   {  19200,  B19200 },
 121 #endif
 122 #ifdef B38400
 123   {  38400,  B38400 },
 124 #endif
 125 #ifdef B57600
 126   {  57600,  B57600 },
 127 #endif
 128 #ifdef B115200
 129   { 115200, B115200 },
 130 #endif
 131 #ifdef B230400
 132   { 230400, B230400 },
 133 #endif
 134   {      0,       0 }
 135 };
 136
 137 static unsigned long csize[] = { CS5, CS6, CS7, CS8 };
 138
 139 static txsu *active = 0;
 140
 141 /*----- Main code ---------------------------------------------------------*/
 142
 143 /* --- @txsu_shutdown@ --- *
 144  *
 145  * Arguments:   ---
 146  *
 147  * Returns:     ---
 148  *
 149  * Use:         Restores terminal settings on exit.
 150  */
 151
 152 void txsu_shutdown(void)
 153 {
 154   txsu *tx;
 155
 156   for (tx = active; tx; tx = tx->next)
 157     tcsetattr(tx->fd, TCSAFLUSH, &tx->old_ta);
 158 }
 159
 160 /* --- @setconfig@ --- *
 161  *
 162  * Arguments:   @txsu *tx@ = pointer to serial transport
 163  *              @serial_config *sc@ = pointer to configuration to set
 164  *
 165  * Returns:     Zero if OK, nonzero on error.
 166  *
 167  * Use:         Updates the external configuration from an internal
 168  *              representation.
 169  */
 170
 171 static int setconfig(txsu *tx, serial_config *sc)
 172 {
 173   struct termios *ta = &tx->ta;
 174   const struct baudmap *b;
 175
 176   for (b = baudmap; b->baud && b->baud != sc->baud; b++)
 177     ;
 178   if (!b->baud ||
 179       sc->wordlen < 5 || sc->wordlen > 8 ||
 180       sc->stopbits < 1 || sc->stopbits > 2) {
 181     err_report(ERR_TXPORT, ERRTX_CONFIG, 0, "bad serial configuration");
 182     return (-1);
 183   }
 184
 185   ta->c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL);
 186   ta->c_oflag &= ~OPOST;
 187   ta->c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
 188   ta->c_cc[VMIN] = 1;
 189   ta->c_cc[VTIME] = 0;
 190
 191   cfsetospeed(ta, b->magic);
 192   cfsetispeed(ta, b->magic);
 193   ta->c_cflag = (ta->c_cflag & ~CSIZE) | csize[sc->wordlen - 5];
 194   switch (sc->parity) {
 195     case PARITY_NONE: ta->c_cflag &= ~PARENB; break;
 196     case PARITY_ODD:  ta->c_cflag |= PARENB | PARODD; break;
 197     case PARITY_EVEN: ta->c_cflag |= PARENB; ta->c_cflag &= ~PARODD; break;
 198   }
 199   switch (sc->stopbits) {
 200     case 1: ta->c_cflag &= ~CSTOPB; break;
 201     case 2: ta->c_cflag |= CSTOPB; break;
 202   }
 203
 204   switch (sc->flow) {
 205     case FLOW_NONE:
 206       ta->c_cflag &= ~CRTSCTS;
 207       ta->c_iflag &= ~(IXON | IXOFF);
 208       break;
 209     case FLOW_XONXOFF:
 210       ta->c_cflag &= ~CRTSCTS;
 211       ta->c_iflag |= IXON | IXOFF;
 212       break;
 213     case FLOW_RTSCTS:
 214       ta->c_cflag |= CRTSCTS;
 215       ta->c_iflag &= ~(IXON | IXOFF);
 216       break;
 217   }
 218
 219   if (tcsetattr(tx->fd, TCSAFLUSH, ta)) {
 220     err_report(ERR_TXPORT, ERRTX_CREATE, errno,
 221                "couldn't set terminal attributes: %s", strerror(errno));
 222     return (-1);
 223   }
 224
 225   tx->sc = *sc;
 226   return (0);
 227 }
 228
 229 /* --- @txsu_create@ --- *
 230  *
 231  * Arguments:   @const char *file@ = filename for serial port
 232  *
 233  * Returns:     Pointer to created transport block.
 234  *
 235  * Use:         Creates a serial port transport.
 236  */
 237
 238 txport *txsu_create(const char *file)
 239 {
 240   txsu *tx = CREATE(txsu);
 241   serial_config sc = SERIAL_INIT;
 242
 243   if ((tx->fd = open(file, O_RDWR | O_NOCTTY | O_NONBLOCK)) < 0) {
 244     err_report(ERR_TXPORT, ERRTX_CREATE, errno,
 245                "couldn't open device `%s': %s", file, strerror(errno));
 246     goto fail_0;
 247   }
 248   if (fdflags(tx->fd, O_NONBLOCK, 0, 0, 0)) {
 249     err_report(ERR_TXPORT, ERRTX_CREATE, errno,
 250                "fcntl(clear O_NONBLOCK): %s", file, strerror(errno));
 251     goto fail_1;
 252   }
 253
 254   if (tcgetattr(tx->fd, &tx->old_ta)) {
 255     err_report(ERR_TXPORT, ERRTX_CREATE, errno,
 256                "couldn't get terminal attributes: %s", strerror(errno));
 257     goto fail_1;
 258   }
 259   tx->ta = tx->old_ta;
 260   if (setconfig(tx, &sc))
 261     goto fail_1;
 262
 263   tx->next = active;
 264   tx->prev = &active;
 265   active = tx;
 266   return (&tx->tx);
 267
 268   /* --- Tidy up because it all went horribly wrong --- */
 269
 270 fail_1:
 271   close(tx->fd);
 272 fail_0:
 273   DESTROY(tx);
 274   return (0);
 275 }
 276
 277 /* --- @txsu_configure@ --- *
 278  *
 279  * Arguments:   @txport *txg@ = pointer to transport block
 280  *              @const char *k@ = configuration keyword
 281  *              @const char *v@ = value
 282  *
 283  * Returns:     Nonzero if handled, zero otherwise.
 284  *
 285  * Use:         Configures a serial port.
 286  */
 287
 288 int txsu_configure(txport *txg, const char *k, const char *v)
 289 {
 290   txsu *tx = (txsu *)txg;
 291   serial_config sc = tx->sc;
 292
 293   if (!v) {
 294     err_report(ERR_TXPORT, ERRTX_CONFIG, 0,
 295                "syntax error in serial config `%s'", k);
 296     return (-1);
 297   }
 298   if (serial_parse(&sc, k, v)) {
 299     err_report(ERR_TXPORT, ERRTX_CONFIG, 0,
 300                "syntax error in serial config `%s=%s'", k, v);
 301     return (-1);
 302   }
 303   if (setconfig(tx, &sc))
 304     return (-1);
 305   return (1);
 306 }
 307
 308 /* --- @txsu_write@ --- *
 309  *
 310  * Arguments:   @txport *txg@ = pointer to transport context
 311  *              @const void *p@ = pointer to buffer
 312  *              @size_t sz@ = size of the buffer
 313  *
 314  * Returns:     Number of bytes written, or @-1@ on error.
 315  *
 316  * Use:         Writes data to a transport.
 317  */
 318
 319 ssize_t txsu_write(txport *txg, const void *p, size_t sz)
 320 {
 321   txsu *tx = (txsu *)txg;
 322
 323   return (write(tx->fd, p, sz));
 324 }
 325
 326 /* --- @txsu_fetch@ --- *
 327  *
 328  * Arguments:   @void *txv@ = pointer to transport context
 329  *
 330  * Returns:     Nothing of interest.
 331  *
 332  * Use:         Thread to fetch data from a serial port.
 333  */
 334
 335 void *txsu_fetch(void *txv)
 336 {
 337   txsu *tx = txv;
 338   unsigned char buf[BUFSIZ];
 339   ssize_t n;
 340   int e;
 341
 342   /* --- Read data while it arrives --- */
 343
 344   for (;;) {
 345     n = read(tx->fd, buf, sizeof(buf));
 346     if (n < 0) {
 347       err_report(ERR_TXPORT, ERRTX_READ, errno,
 348                  "error reading from serial port: %s", strerror(errno));
 349       break;
 350     }
 351 #ifdef TERMINAL_EOF
 352     if (!n) break;
 353 #else
 354     if (!n) continue;
 355 #endif
 356     if ((e = pthread_mutex_lock(&tx->tx.mx)) != 0) {
 357       err_report(ERR_TXPORT, ERRTX_READ, e,
 358                  "error locking mutex: %s", strerror(e));
 359       break;
 360     }
 361     DA_ENSURE(&tx->tx.buf, n);
 362     memcpy(DA(&tx->tx.buf) + DA_LEN(&tx->tx.buf), buf, n);
 363     DA_EXTEND(&tx->tx.buf, n);
 364     pthread_cond_signal(&tx->tx.cv);
 365     pthread_mutex_unlock(&tx->tx.mx);
 366   }
 367
 368   /* --- Deal with crapness --- */
 369
 370   e = pthread_mutex_lock(&tx->tx.mx);
 371   tx->tx.s = TX_CLOSE;
 372   pthread_cond_signal(&tx->tx.cv);
 373   pthread_mutex_unlock(&tx->tx.mx);
 374   return (0);
 375 }
 376
 377 /* --- @txsu_destroy@ --- *
 378  *
 379  * Arguments:   @txport *txg@ = pointer to transport context
 380  *
 381  * Returns:     ---
 382  *
 383  * Use:         Destroys a serial port transport.
 384  */
 385
 386 void txsu_destroy(txport *txg)
 387 {
 388   txsu *tx = (txsu *)txg;
 389
 390   tcsetattr(tx->fd, TCSAFLUSH, &tx->old_ta);
 391   close(tx->fd);
 392   *tx->prev = tx->next;
 393   if (tx->next)
 394     tx->next->prev = tx->prev;
 395   DESTROY(tx);
 396 }
 397
 398 /*----- That's all, folks -------------------------------------------------*/