support/serial.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2
   3 /* serial port functions
   4  *
   5  * Author: Chris Toshok <toshok@ximian.com>
   6  */
   7
   8 #include <termios.h>
   9 #include <unistd.h>
  10 #include <fcntl.h>
  11 #include <string.h>
  12 #include <errno.h>
  13 #if defined(__APPLE__)
  14 #include "fakepoll.h"
  15 #else
  16 #include <sys/poll.h>
  17 #endif
  18 #include <sys/ioctl.h>
  19
  20 #include <glib.h>
  21
  22 /* This is for FIONREAD on solaris */
  23 #if defined(sun)
  24 #include <sys/filio.h>
  25 #endif
  26
  27 /* sys/time.h (for timeval) is required when using osx 10.3 (but not 10.4) */
  28 #ifdef __APPLE__
  29 #include <sys/time.h>
  30 #endif
  31
  32 /* This is a copy of System.IO.Ports.Handshake */
  33 typedef enum {
  34         NoneHandshake = 0,
  35         XOnXOff = 1,
  36         RequestToSend = 2,
  37         RequestToSendXOnXOff = 3
  38 } MonoHandshake;
  39
  40 /* This is a copy of System.IO.Ports.Parity */
  41 typedef enum {
  42         NoneParity = 0,
  43         Odd = 1,
  44         Even = 2,
  45         Mark = 3,
  46         Space = 4
  47 } MonoParity;
  48
  49 /* This is a copy of System.IO.Ports.StopBits */
  50 typedef enum {
  51         NoneStopBits = 0,
  52         One = 1,
  53         Two = 2,
  54         OnePointFive = 3
  55 } MonoStopBits;
  56
  57 /* This is a copy of System.IO.Ports.SerialSignal */
  58 typedef enum {
  59         NoneSignal,
  60         Cd = 1, /* Carrier detect */
  61         Cts = 2, /* Clear to send */
  62         Dsr = 4, /* Data set ready */
  63         Dtr = 8, /* Data terminal ready */
  64         Rts = 16  /* Request to send */
  65 } MonoSerialSignal;
  66
  67 /*
  68  * Silence the compiler, we do not need these prototypes to be public, since these are only
  69  * used by P/Invoke
  70  */
  71
  72 int              open_serial (char *devfile);
  73 int              close_serial (int unix_fd);
  74 guint32          read_serial (int fd, guchar *buffer, int offset, int count);
  75 int              write_serial (int fd, guchar *buffer, int offset, int count, int timeout);
  76 int              discard_buffer (int fd, gboolean input);
  77 gint32           get_bytes_in_buffer (int fd, gboolean input);
  78 gboolean         is_baud_rate_legal (int baud_rate);
  79 int              setup_baud_rate (int baud_rate);
  80 gboolean         set_attributes (int fd, int baud_rate, MonoParity parity, int dataBits, MonoStopBits stopBits, MonoHandshake handshake);
  81 MonoSerialSignal get_signals (int fd, gint32 *error);
  82 gint32           set_signal (int fd, MonoSerialSignal signal, gboolean value);
  83 int              breakprop (int fd);
  84 gboolean         poll_serial (int fd, gint32 *error, int timeout);
  85 void            *list_serial_devices (void);
  86
  87 int
  88 open_serial (char *devfile)
  89 {
  90         int fd;
  91         fd = open (devfile, O_RDWR | O_NOCTTY | O_NONBLOCK);
  92
  93         return fd;
  94 }
  95
  96 int
  97 close_serial (int unix_fd)
  98 {
  99         // Linus writes: do not retry close after EINTR
 100         return close (unix_fd);
 101 }
 102
 103 guint32
 104 read_serial (int fd, guchar *buffer, int offset, int count)
 105 {
 106         guint32 n;
 107
 108         n = read (fd, buffer + offset, count);
 109
 110         return (guint32) n;
 111 }
 112
 113 int
 114 write_serial (int fd, guchar *buffer, int offset, int count, int timeout)
 115 {
 116         struct pollfd pinfo;
 117         guint32 n;
 118
 119         pinfo.fd = fd;
 120         pinfo.events = POLLOUT;
 121         pinfo.revents = POLLOUT;
 122
 123         n = count;
 124
 125         while (n > 0)
 126         {
 127                 ssize_t t;
 128
 129                 if (timeout != 0) {
 130                         int c;
 131
 132                         while ((c = poll (&pinfo, 1, timeout)) == -1 && errno == EINTR)
 133                                 ;
 134                         if (c == -1)
 135                                 return -1;
 136                 }
 137
 138                 do {
 139                         t = write (fd, buffer + offset, n);
 140                 } while (t == -1 && errno == EINTR);
 141
 142                 if (t < 0)
 143                         return -1;
 144
 145                 offset += t;
 146                 n -= t;
 147         }
 148
 149         return 0;
 150 }
 151
 152 int
 153 discard_buffer (int fd, gboolean input)
 154 {
 155         return tcflush(fd, input ? TCIFLUSH : TCOFLUSH);
 156 }
 157
 158 gint32
 159 get_bytes_in_buffer (int fd, gboolean input)
 160 {
 161         gint32 retval;
 162
 163         if (ioctl (fd, input ? FIONREAD : TIOCOUTQ, &retval) == -1) {
 164                 return -1;
 165         }
 166
 167         return retval;
 168 }
 169
 170 gboolean
 171 is_baud_rate_legal (int baud_rate)
 172 {
 173         return setup_baud_rate (baud_rate) != -1;
 174 }
 175
 176 int
 177 setup_baud_rate (int baud_rate)
 178 {
 179         switch (baud_rate)
 180         {
 181 /*Some values are not defined on OSX and *BSD */
 182 #if defined(B921600)
 183         case 921600:
 184             baud_rate = B921600;
 185             break;
 186 #endif
 187 #if defined(B460800)
 188         case 460800:
 189             baud_rate = B460800;
 190             break;
 191 #endif
 192         case 230400:
 193             baud_rate = B230400;
 194             break;
 195         case 115200:
 196             baud_rate = B115200;
 197             break;
 198         case 57600:
 199             baud_rate = B57600;
 200             break;
 201         case 38400:
 202             baud_rate = B38400;
 203             break;
 204         case 19200:
 205             baud_rate = B19200;
 206             break;
 207         case 9600:
 208                 baud_rate = B9600;
 209                 break;
 210         case 4800:
 211             baud_rate = B4800;
 212                 break;
 213         case 2400:
 214             baud_rate = B2400;
 215                 break;
 216         case 1800:
 217             baud_rate = B1800;
 218                 break;
 219         case 1200:
 220             baud_rate = B1200;
 221                 break;
 222         case 600:
 223             baud_rate = B600;
 224             break;
 225         case 300:
 226             baud_rate = B300;
 227             break;
 228         case 200:
 229             baud_rate = B200;
 230             break;
 231         case 150:
 232             baud_rate = B150;
 233             break;
 234         case 134:
 235             baud_rate = B134;
 236             break;
 237         case 110:
 238             baud_rate = B110;
 239             break;
 240         case 75:
 241             baud_rate = B75;
 242             break;
 243         case 50:
 244         case 0:
 245         default:
 246             baud_rate = -1;
 247                 break;
 248         }
 249         return baud_rate;
 250 }
 251
 252 gboolean
 253 set_attributes (int fd, int baud_rate, MonoParity parity, int dataBits, MonoStopBits stopBits, MonoHandshake handshake)
 254 {
 255         struct termios newtio;
 256
 257         if (tcgetattr (fd, &newtio) == -1)
 258                 return FALSE;
 259
 260         newtio.c_cflag |=  (CLOCAL | CREAD);
 261         newtio.c_lflag &= ~(ICANON | ECHO | ECHOE | ECHOK | ECHONL | ISIG | IEXTEN );
 262         newtio.c_oflag &= ~(OPOST);
 263         newtio.c_iflag = IGNBRK;
 264
 265         /* setup baudrate */
 266         baud_rate = setup_baud_rate (baud_rate);
 267
 268         /* char lenght */
 269         newtio.c_cflag &= ~CSIZE;
 270         switch (dataBits)
 271         {
 272         case 5:
 273             newtio.c_cflag |= CS5;
 274             break;
 275         case 6:
 276             newtio.c_cflag |= CS6;
 277             break;
 278         case 7:
 279             newtio.c_cflag |= CS7;
 280             break;
 281         case 8:
 282         default:
 283                 newtio.c_cflag |= CS8;
 284                 break;
 285         }
 286
 287         /* stopbits */
 288         switch (stopBits)
 289         {
 290         case NoneStopBits:
 291                 /* Unhandled */
 292                 break;
 293         case One: /* One */
 294                 /* do nothing, the default is one stop bit */
 295             newtio.c_cflag &= ~CSTOPB;
 296                 break;
 297         case Two: /* Two */
 298                 newtio.c_cflag |= CSTOPB;
 299                 break;
 300         case OnePointFive: /* OnePointFive */
 301                 /* XXX unhandled */
 302                 break;
 303         }
 304
 305         /* parity */
 306         newtio.c_iflag &= ~(INPCK | ISTRIP );
 307
 308         switch (parity)
 309         {
 310         case NoneParity: /* None */
 311             newtio.c_cflag &= ~(PARENB | PARODD);
 312             break;
 313
 314         case Odd: /* Odd */
 315             newtio.c_cflag |= PARENB | PARODD;
 316             break;
 317
 318         case Even: /* Even */
 319             newtio.c_cflag &= ~(PARODD);
 320             newtio.c_cflag |= (PARENB);
 321             break;
 322
 323         case Mark: /* Mark */
 324             /* XXX unhandled */
 325             break;
 326         case Space: /* Space */
 327             /* XXX unhandled */
 328             break;
 329         }
 330
 331         newtio.c_iflag &= ~(IXOFF | IXON);
 332 #ifdef CRTSCTS
 333         newtio.c_cflag &= ~CRTSCTS;
 334 #endif /* def CRTSCTS */
 335
 336         switch (handshake)
 337         {
 338         case NoneHandshake: /* None */
 339                 /* do nothing */
 340                 break;
 341         case RequestToSend: /* RequestToSend (RTS) */
 342 #ifdef CRTSCTS
 343                 newtio.c_cflag |= CRTSCTS;
 344 #endif /* def CRTSCTS */
 345                 break;
 346         case RequestToSendXOnXOff: /* RequestToSendXOnXOff (RTS + XON/XOFF) */
 347 #ifdef CRTSCTS
 348                 newtio.c_cflag |= CRTSCTS;
 349 #endif /* def CRTSCTS */
 350                 /* fall through */
 351         case XOnXOff: /* XOnXOff */
 352             newtio.c_iflag |= IXOFF | IXON;
 353                 break;
 354         }
 355
 356         if (cfsetospeed (&newtio, baud_rate) < 0 || cfsetispeed (&newtio, baud_rate) < 0 ||
 357             tcsetattr (fd, TCSANOW, &newtio) < 0)
 358         {
 359                 return FALSE;
 360         }
 361         else
 362         {
 363         return TRUE;
 364         }
 365 }
 366
 367
 368 static gint32
 369 get_signal_code (MonoSerialSignal signal)
 370 {
 371         switch (signal) {
 372                 case Cd:
 373                         return TIOCM_CAR;
 374                 case Cts:
 375                         return TIOCM_CTS;
 376                 case Dsr:
 377                         return TIOCM_DSR;
 378                 case Dtr:
 379                         return TIOCM_DTR;
 380                 case Rts:
 381                         return TIOCM_RTS;
 382                 default:
 383                         return 0;
 384         }
 385
 386         /* Not reached */
 387         return 0;
 388 }
 389
 390 static MonoSerialSignal
 391 get_mono_signal_codes (int signals)
 392 {
 393         MonoSerialSignal retval = NoneSignal;
 394
 395         if ((signals & TIOCM_CAR) != 0)
 396                 retval |= Cd;
 397         if ((signals & TIOCM_CTS) != 0)
 398                 retval |= Cts;
 399         if ((signals & TIOCM_DSR) != 0)
 400                 retval |= Dsr;
 401         if ((signals & TIOCM_DTR) != 0)
 402                 retval |= Dtr;
 403         if ((signals & TIOCM_RTS) != 0)
 404                 retval |= Rts;
 405
 406         return retval;
 407 }
 408
 409 MonoSerialSignal
 410 get_signals (int fd, gint32 *error)
 411 {
 412         int signals;
 413
 414         *error = 0;
 415
 416         if (ioctl (fd, TIOCMGET, &signals) == -1) {
 417                 *error = -1;
 418                 return NoneSignal;
 419         }
 420
 421         return get_mono_signal_codes (signals);
 422 }
 423
 424 gint32
 425 set_signal (int fd, MonoSerialSignal signal, gboolean value)
 426 {
 427         int signals, expected, activated;
 428
 429         expected = get_signal_code (signal);
 430         if (ioctl (fd, TIOCMGET, &signals) == -1)
 431                 return -1;
 432
 433         activated = (signals & expected) != 0;
 434         if (activated == value) /* Already set */
 435                 return 1;
 436
 437         if (value)
 438                 signals |= expected;
 439         else
 440                 signals &= ~expected;
 441
 442         if (ioctl (fd, TIOCMSET, &signals) == -1)
 443                 return -1;
 444
 445         return 1;
 446 }
 447
 448 int
 449 breakprop (int fd)
 450 {
 451         return tcsendbreak (fd, 0);
 452 }
 453
 454 gboolean
 455 poll_serial (int fd, gint32 *error, int timeout)
 456 {
 457         struct pollfd pinfo;
 458
 459         *error = 0;
 460
 461         pinfo.fd = fd;
 462         pinfo.events = POLLIN;
 463         pinfo.revents = 0;
 464
 465         while (poll (&pinfo, 1, timeout) == -1 && errno == EINTR) {
 466                 /* EINTR is an OK condition, we should not throw in the upper layer an IOException */
 467                 if (errno != EINTR){
 468                         *error = -1;
 469                         return FALSE;
 470                 }
 471         }
 472
 473         return (pinfo.revents & POLLIN) != 0 ? 1 : 0;
 474 }
 475
 476 /*
 477  * mono internals should not be used here.
 478  * this serial stuff needs to be implemented with icalls.
 479  * make this at least compile until the code is moved elsewhere
 480  * defined(linux) is wrong, too
 481  */
 482 void*
 483 list_serial_devices (void)
 484 {
 485         return NULL;
 486 }
 487
 488 #if 0
 489 MonoArray *
 490 list_serial_devices (void)
 491 {
 492         MonoArray *array;
 493 #if defined(linux)
 494         /* Linux serial files are of the form ttyS[0-9]+ */
 495         GSList *l, *list = NULL;
 496         GDir* dir = g_dir_open ("/dev", 0, NULL);
 497         const char *filename;
 498         int i = 0;
 499
 500         while ((filename = g_dir_read_name (dir))) {
 501                 if (filename) {
 502                         if (!strncmp (filename, "ttyS", 4))
 503                                 list = g_slist_append (list, g_strconcat ("/dev/", filename, NULL));
 504                 }
 505         }
 506
 507         g_dir_close (dir);
 508
 509         array = mono_array_new (mono_domain_get (), mono_get_string_class (), g_slist_length (list));
 510         for (l = list; l; l = l->next) {
 511                 mono_array_set (array, gpointer, i++, mono_string_new (mono_domain_get (), (char*)l->data));
 512                 g_free (l->data);
 513         }
 514
 515         g_slist_free (list);
 516
 517 #else
 518 #warning "list_serial_devices isn't ported to this OS"
 519 #endif
 520
 521         return array;
 522 }
 523 #endif
 524