misc/tty_lin_master/main.c

   1 /*
   2  * UART-LIN master implementation
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <unistd.h>
   8 #include <fcntl.h>
   9 #include <string.h>
  10 #include <termios.h>
  11 #include <stdint.h>
  12 #include <sys/ioctl.h>
  13 #include <linux/serial.h> /* struct struct_serial */
  14 #include <unistd.h>
  15 #include <fcntl.h>
  16 #include <time.h> /* clock_nanosleep */
  17 #include <getopt.h>
  18 #include "lin_common.h"
  19
  20 #define LIN_HDR_SIZE            2
  21
  22 struct sllin_tty {
  23         int tty_fd;
  24         struct termios tattr_orig;
  25         struct termios tattr;
  26         struct serial_struct sattr;
  27 };
  28
  29 struct sllin_tty sllin_tty_data;
  30
  31 struct sllin sllin_data = {
  32         .tty = &sllin_tty_data,
  33 };
  34
  35 /* ------------------------------------------------------------------------ */
  36 static void tty_reset_mode(struct sllin_tty *tty)
  37 {
  38         tcsetattr(tty->tty_fd, TCSANOW, &tty->tattr_orig);
  39 }
  40
  41 static int tty_set_baudrate(struct sllin_tty *tty, int baudrate)
  42 {
  43         /* Set "non-standard" baudrate in serial_struct struct */
  44         tty->sattr.flags &= (~ASYNC_SPD_MASK);
  45         tty->sattr.flags |= (ASYNC_SPD_CUST);
  46         tty->sattr.custom_divisor = (tty->sattr.baud_base + baudrate / 2) / baudrate;
  47         if (ioctl(tty->tty_fd, TIOCSSERIAL, &tty->sattr) < 0)
  48         {
  49                 perror("ioctl TIOCSSERIAL");
  50                 return -1;
  51         }
  52
  53 //      cfsetispeed(&tty->tattr, B38400);
  54 //      cfsetospeed(&tty->tattr, B38400);
  55 //
  56 //      if (tcsetattr(tty->tty_fd, TCSANOW, &tty->tattr) == -1) {
  57 //              perror("tcsetattr()");
  58 //              return -1;
  59 //      }
  60
  61         return 0;
  62 }
  63
  64 static int tty_set_mode(struct sllin_tty *tty, int baudrate)
  65 {
  66         if(!isatty(tty->tty_fd)) {
  67                 fprintf(stderr, "Not a terminal.\n");
  68                 return -1;
  69         }
  70
  71         /* Flush input and output queues. */
  72         if (tcflush(tty->tty_fd, TCIOFLUSH) != 0) {
  73                 perror("tcflush");
  74                 return -1;;
  75         }
  76
  77         /* Save settings for later restoring */
  78         tcgetattr(tty->tty_fd, &tty->tattr_orig);
  79
  80         /* Save settings into global variables for later use */
  81         if (tcgetattr(tty->tty_fd, &tty->tattr) < 0)
  82                 perror("tcgetattr");
  83
  84         if (ioctl(tty->tty_fd, TIOCGSERIAL, &tty->sattr) < 0)
  85                 perror("ioctl TIOCGSERIAL");
  86
  87         /* Set RAW mode */
  88 #if 0
  89         tty->tattr.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
  90                                 | INLCR | IGNCR | ICRNL | IXON);
  91         tty->tattr.c_oflag &= ~OPOST;
  92         tty->tattr.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
  93         tty->tattr.c_cflag &= ~(CSIZE | PARENB);
  94         tty->tattr.c_cflag |= CS8;
  95
  96         tty->tattr.c_cc[VMIN] = 1;
  97         tty->tattr.c_cc[VTIME] = 0;
  98 #else
  99         /* 8 data bits                  */
 100         /* Enable receiver              */
 101         /* Ignore CD (local connection) */
 102         tty->tattr.c_cflag = CS8 | CREAD | CLOCAL;
 103         tty->tattr.c_iflag = 0;
 104         tty->tattr.c_oflag = NL0 | CR0 | TAB0 | BS0 | VT0 | FF0;
 105         tty->tattr.c_lflag = 0;
 106
 107         tty->tattr.c_cc[VINTR]    = '\0';
 108         tty->tattr.c_cc[VQUIT]    = '\0';
 109         tty->tattr.c_cc[VERASE]   = '\0';
 110         tty->tattr.c_cc[VKILL]    = '\0';
 111         tty->tattr.c_cc[VEOF]     = '\0';
 112         tty->tattr.c_cc[VTIME]    = '\0';
 113         tty->tattr.c_cc[VMIN]     = 1;
 114         tty->tattr.c_cc[VSWTC]    = '\0';
 115         tty->tattr.c_cc[VSTART]   = '\0';
 116         tty->tattr.c_cc[VSTOP]    = '\0';
 117         tty->tattr.c_cc[VSUSP]    = '\0';
 118         tty->tattr.c_cc[VEOL]     = '\0';
 119         tty->tattr.c_cc[VREPRINT] = '\0';
 120         tty->tattr.c_cc[VDISCARD] = '\0';
 121         tty->tattr.c_cc[VWERASE]  = '\0';
 122         tty->tattr.c_cc[VLNEXT]   = '\0';
 123         tty->tattr.c_cc[VEOL2]    = '\0';
 124 #endif
 125
 126         /* Set TX, RX speed to 38400 -- this value allows
 127            to use custom speed in struct struct_serial */
 128         cfsetispeed(&tty->tattr, B38400);
 129         cfsetospeed(&tty->tattr, B38400);
 130
 131         if (tcsetattr(tty->tty_fd, TCSANOW, &tty->tattr) == -1) {
 132                 perror("tcsetattr()");
 133                 return -1;
 134         }
 135
 136         /* Set real speed */
 137         tty_set_baudrate(tty, baudrate);
 138
 139         return 0;
 140 }
 141
 142 /* ------------------------------------------------------------------------ */
 143
 144 int sllin_open(struct sllin *sl, const char *dev_fname, int baudrate)
 145 {
 146         int fd;
 147
 148         sl->lin_baud = baudrate;
 149
 150         /* Calculate baudrate for sending LIN break */
 151         sl->lin_break_baud = (sl->lin_baud * 2) / 3;
 152
 153         fd = open(dev_fname, O_RDWR);
 154         if (fd < 0) {
 155                 perror("open()");
 156                 return -1;
 157         }
 158         sl->tty->tty_fd = fd;
 159
 160         return tty_set_mode(sl->tty, sl->lin_baud);
 161 }
 162
 163 int sllin_close(struct sllin *sl)
 164 {
 165         tty_reset_mode(sl->tty);
 166         close(sl->tty->tty_fd);
 167         return 0;
 168 }
 169
 170 int send_header(struct sllin *sl, int lin_id)
 171 {
 172         int buff[3];
 173
 174         buff[0] = 0x00; /* Fake break */
 175         buff[1] = 0x55; /* Sync byte */
 176
 177         lin_id &= 0x3f;
 178         lin_id |= sllin_id_parity_table[lin_id];
 179         buff[2] = lin_id; /* LIN ID: 1 */
 180
 181         printf("send_header() invoked\n");
 182         tcflush(sl->tty->tty_fd, TCIOFLUSH);
 183
 184         /* Decrease speed to send BREAK
 185            (simulated with 0x00 data frame) */
 186         tty_set_baudrate(sl->tty, sl->lin_break_baud);
 187
 188         printf("Write break\n");
 189         write(sl->tty->tty_fd, &buff[0], 1); /* Write "break" */
 190 #if 0
 191         read(sl->tty->tty_fd, &buff[0], 1);
 192         printf("Break read\n");
 193 #else
 194         {
 195                 struct timespec sleep_time;
 196                 sleep_time.tv_sec = 0;
 197                 sleep_time.tv_nsec = ((1000000000ll * 11) / sl->lin_break_baud);
 198                 clock_nanosleep(CLOCK_MONOTONIC, 0, &sleep_time, NULL);
 199         }
 200 #endif
 201
 202         /* Restore "normal" speed */
 203         tty_set_baudrate(sl->tty, sl->lin_baud);
 204
 205         write(sl->tty->tty_fd, &buff[1], 1); /* Sync Byte Field */
 206         write(sl->tty->tty_fd, &buff[2], 1); /* PID -- Protected Identifier Field */
 207         return 0;
 208 }
 209
 210 int read_header(struct sllin *sl)
 211 {
 212         int p0, p1; /* Parity bits */
 213         int par_rec; /* Parity received as a part of a packet */
 214         int par_calc; /* Calculated parity */
 215         int received = 0;
 216         uint8_t buff[LIN_HDR_SIZE];
 217         memset(buff, '\0', sizeof(buff));
 218
 219         while (1) {
 220                 received = read(sl->tty->tty_fd, &buff[0], 1);
 221                 if (received == -1)
 222                         perror("read()");
 223
 224                 if (buff[0] != 0x55) /* Sync byte field */
 225                         continue;
 226
 227                 received = read(sl->tty->tty_fd, &buff[1], 1);
 228                 if (received == -1)
 229                         perror("read()");
 230                 else
 231                         break;
 232         }
 233
 234         p0 = (buff[1] ^ (buff[1] >> 1) ^ (buff[1] >> 2) ^ (buff[1] >> 4)) & 0x1;
 235         p1 = ~(((buff[1] >> 1) ^ (buff[1] >> 3) ^ (buff[1] >> 4) ^ (buff[1] >> 5))) & 0x1;
 236
 237         printf("%02X ", buff[0]);
 238         printf("%02X ", buff[1]);
 239
 240         par_rec = (buff[1] & 0xc0) >> 6;
 241         par_calc = p0 | (p1 << 1);
 242         printf("| LIN id: %02X ", buff[1] & 0x3f);
 243         //printf("| par_rec: %X; par_calc: %X ", par_rec, par_calc);
 244         if (par_rec == par_calc)
 245                 printf("| parity OK");
 246
 247         printf("\n");
 248
 249         return 0;
 250 }
 251
 252 int parse_arr(unsigned char *buff, const char *str, int len_max)
 253 {
 254         char *p;
 255         int len = 0;
 256
 257         do {
 258                 if (len >= len_max)
 259                         return -1;
 260
 261                 *buff = strtol(str, &p, 0);
 262                 if(str == p)
 263                         return -1;
 264
 265                 str = p;
 266
 267                 len++;
 268                 buff++;
 269         } while (*(str++) == ',');
 270
 271         if (*(--str) != '\0')
 272                 return -1;
 273
 274         return len;
 275 }
 276
 277 static void usage(void)
 278 {
 279         printf("Usage: lin_master <parameters>\n\n");
 280         printf("Mandatory parameters:\n");
 281         printf("  -d, --device <device>   Device name, e.g. /dev/ttyS0\n\n");
 282         printf("Optional parameters:\n");
 283         printf("  -B, --baud <baud>       LIN bus baudrate. Default value is 19200.\n");
 284         printf("                          Recommendet values are 2400, 9600, 19200\n");
 285         printf("  -i, --id <num>          LIN frame ID\n");
 286         printf("  -r, --response <num>    Values of data fields sent from slave task\n");
 287         printf("  -h, --help              Help, i.e. this screen\n");
 288 }
 289
 290 int main(int argc, char* argv[])
 291 {
 292         struct sllin *sl = &sllin_data;
 293
 294         static struct option long_opts[] = {
 295                 {"device"  , 1, 0, 'd'},
 296                 {"baud"    , 1, 0, 'B'},
 297                 {"id"      , 1, 0, 'i'},
 298                 {"response", 1, 0, 'r'},
 299                 {"help"    , 0, 0, 'h'},
 300                 {0, 0, 0, 0}
 301         };
 302         int opt;
 303         char *dev_fname = "";
 304         int lin_baudrate = 19200;
 305         int lin_id = 1;
 306         int resp_len = 0;
 307         unsigned char resp_data[SLLIN_DATA_MAX + 1];
 308         char *p;
 309
 310         while ((opt = getopt_long(argc, argv, "d:B:i:r:h", &long_opts[0], NULL)) != EOF) {
 311                 switch (opt) {
 312                         case 'd':
 313                                 dev_fname = optarg;
 314                                 break;
 315
 316                         case 'B':
 317                                 lin_baudrate = strtol(optarg, &p, 10);
 318                                 if ((p == optarg) || ((*p != '\0') && (*p != ' '))) {
 319                                         fprintf(stderr, "Baudrate format error\n");
 320                                         exit(EXIT_FAILURE);
 321                                 }
 322                                 break;
 323
 324                         case 'i':
 325                                 lin_id = strtol(optarg, &p, 0);
 326                                 if ((p == optarg) || ((*p != '\0') && (*p != ' '))) {
 327                                         fprintf(stderr, "LIN ID format error\n");
 328                                         exit(EXIT_FAILURE);
 329                                 }
 330                                 break;
 331
 332                         case 'r':
 333                                 resp_len = parse_arr(resp_data, optarg, SLLIN_DATA_MAX);
 334                                 if (resp_len < 0) {
 335                                         fprintf(stderr, "Response data format error\n");
 336                                         exit(EXIT_FAILURE);
 337                                 }
 338                                 break;
 339
 340                         case 'h':
 341                         default:
 342                                 usage();
 343                                 exit(opt == 'h' ? 0 : 1);
 344                                 break;
 345                 }
 346         }
 347
 348         if (optind < argc) {
 349                 usage();
 350                 //fprintf(stderr, "Expected argument after options\n");
 351                 exit(EXIT_FAILURE);
 352         }
 353
 354         /* Device name was not set by user */
 355         if (strlen(dev_fname) == 0) {
 356                 usage();
 357                 exit(EXIT_FAILURE);
 358         }
 359
 360         /* ----------------------------------- */
 361         if (sllin_open(sl, dev_fname, lin_baudrate) < 0) {
 362                 fprintf (stderr, "sllin_open open failed\n");
 363                 exit(EXIT_FAILURE);
 364         }
 365
 366         fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
 367         printf("Press enter to terminate.\n\n");
 368
 369
 370         while(1) {
 371                 char c;
 372
 373                 send_header(sl, lin_id);
 374                 sleep(1);
 375
 376                 if (read(fileno(stdin), &c, 1) > 0)
 377                         break;
 378         }
 379
 380         sllin_close(sl);
 381
 382         return EXIT_SUCCESS;
 383 }