1/* 2 * refclock_wwvb - clock driver for Spectracom WWVB and GPS receivers 3 */ 4 5#ifdef HAVE_CONFIG_H 6#include <config.h> 7#endif 8 9#if defined(REFCLOCK) && defined(CLOCK_SPECTRACOM) 10 11#include "ntpd.h" 12#include "ntp_io.h" 13#include "ntp_refclock.h" 14#include "ntp_calendar.h" 15#include "ntp_stdlib.h" 16 17#include <stdio.h> 18#include <ctype.h> 19 20#ifdef HAVE_PPSAPI 21#include "ppsapi_timepps.h" 22#include "refclock_atom.h" 23#endif /* HAVE_PPSAPI */ 24 25/* 26 * This driver supports the Spectracom Model 8170 and Netclock/2 WWVB 27 * Synchronized Clocks and the Netclock/GPS Master Clock. Both the WWVB 28 * and GPS clocks have proven reliable sources of time; however, the 29 * WWVB clocks have proven vulnerable to high ambient conductive RF 30 * interference. The claimed accuracy of the WWVB clocks is 100 us 31 * relative to the broadcast signal, while the claimed accuracy of the 32 * GPS clock is 50 ns; however, in most cases the actual accuracy is 33 * limited by the resolution of the timecode and the latencies of the 34 * serial interface and operating system. 35 * 36 * The WWVB and GPS clocks should be configured for 24-hour display, 37 * AUTO DST off, time zone 0 (UTC), data format 0 or 2 (see below) and 38 * baud rate 9600. If the clock is to used as the source for the IRIG 39 * Audio Decoder (refclock_irig.c in this distribution), it should be 40 * configured for AM IRIG output and IRIG format 1 (IRIG B with 41 * signature control). The GPS clock can be configured either to respond 42 * to a 'T' poll character or left running continuously. 43 * 44 * There are two timecode formats used by these clocks. Format 0, which 45 * is available with both the Netclock/2 and 8170, and format 2, which 46 * is available only with the Netclock/2, specially modified 8170 and 47 * GPS. 48 * 49 * Format 0 (22 ASCII printing characters): 50 * 51 * <cr><lf>i ddd hh:mm:ss TZ=zz<cr><lf> 52 * 53 * on-time = first <cr> 54 * hh:mm:ss = hours, minutes, seconds 55 * i = synchronization flag (' ' = in synch, '?' = out of synch) 56 * 57 * The alarm condition is indicated by other than ' ' at a, which occurs 58 * during initial synchronization and when received signal is lost for 59 * about ten hours. 60 * 61 * Format 2 (24 ASCII printing characters): 62 * 63 * <cr><lf>iqyy ddd hh:mm:ss.fff ld 64 * 65 * on-time = <cr> 66 * i = synchronization flag (' ' = in synch, '?' = out of synch) 67 * q = quality indicator (' ' = locked, 'A'...'D' = unlocked) 68 * yy = year (as broadcast) 69 * ddd = day of year 70 * hh:mm:ss.fff = hours, minutes, seconds, milliseconds 71 * 72 * The alarm condition is indicated by other than ' ' at a, which occurs 73 * during initial synchronization and when received signal is lost for 74 * about ten hours. The unlock condition is indicated by other than ' ' 75 * at q. 76 * 77 * The q is normally ' ' when the time error is less than 1 ms and a 78 * character in the set 'A'...'D' when the time error is less than 10, 79 * 100, 500 and greater than 500 ms respectively. The l is normally ' ', 80 * but is set to 'L' early in the month of an upcoming UTC leap second 81 * and reset to ' ' on the first day of the following month. The d is 82 * set to 'S' for standard time 'I' on the day preceding a switch to 83 * daylight time, 'D' for daylight time and 'O' on the day preceding a 84 * switch to standard time. The start bit of the first <cr> is 85 * synchronized to the indicated time as returned. 86 * 87 * This driver does not need to be told which format is in use - it 88 * figures out which one from the length of the message. The driver 89 * makes no attempt to correct for the intrinsic jitter of the radio 90 * itself, which is a known problem with the older radios. 91 * 92 * PPS Signal Processing 93 * 94 * When PPS signal processing is enabled, and when the system clock has 95 * been set by this or another driver and the PPS signal offset is 96 * within 0.4 s of the system clock offset, the PPS signal replaces the 97 * timecode for as long as the PPS signal is active. If for some reason 98 * the PPS signal fails for one or more poll intervals, the driver 99 * reverts to the timecode. If the timecode fails for one or more poll 100 * intervals, the PPS signal is disconnected. 101 * 102 * Fudge Factors 103 * 104 * This driver can retrieve a table of quality data maintained 105 * internally by the Netclock/2 clock. If flag4 of the fudge 106 * configuration command is set to 1, the driver will retrieve this 107 * table and write it to the clockstats file when the first timecode 108 * message of a new day is received. 109 * 110 * PPS calibration fudge time 1: format 0 .003134, format 2 .004034 111 */ 112/* 113 * Interface definitions 114 */ 115#define DEVICE "/dev/wwvb%d" /* device name and unit */ 116#define SPEED232 B9600 /* uart speed (9600 baud) */ 117#define PRECISION (-13) /* precision assumed (about 100 us) */ 118#define PPS_PRECISION (-13) /* precision assumed (about 100 us) */ 119#define REFID "WWVB" /* reference ID */ 120#define DESCRIPTION "Spectracom WWVB/GPS Receiver" /* WRU */ 121 122#define LENWWVB0 22 /* format 0 timecode length */ 123#define LENWWVB1 22 /* format 1 timecode length */ 124#define LENWWVB2 24 /* format 2 timecode length */ 125#define LENWWVB3 29 /* format 3 timecode length */ 126#define MONLIN 15 /* number of monitoring lines */ 127 128/* 129 * WWVB unit control structure 130 */ 131struct wwvbunit { 132#ifdef HAVE_PPSAPI 133 struct refclock_atom atom; /* PPSAPI structure */ 134 int ppsapi_tried; /* attempt PPSAPI once */ 135 int ppsapi_lit; /* time_pps_create() worked */ 136 int tcount; /* timecode sample counter */ 137 int pcount; /* PPS sample counter */ 138#endif /* HAVE_PPSAPI */ 139 l_fp laststamp; /* last receive timestamp */ 140 u_char lasthour; /* last hour (for monitor) */ 141 u_char linect; /* count ignored lines (for monitor */ 142}; 143 144/* 145 * Function prototypes 146 */ 147static int wwvb_start (int, struct peer *); 148static void wwvb_shutdown (int, struct peer *); 149static void wwvb_receive (struct recvbuf *); 150static void wwvb_poll (int, struct peer *); 151static void wwvb_timer (int, struct peer *); 152#ifdef HAVE_PPSAPI 153static void wwvb_control (int, struct refclockstat *, 154 struct refclockstat *, struct peer *); 155#define WWVB_CONTROL wwvb_control 156#else 157#define WWVB_CONTROL noentry 158#endif /* HAVE_PPSAPI */ 159 160/* 161 * Transfer vector 162 */ 163struct refclock refclock_wwvb = { 164 wwvb_start, /* start up driver */ 165 wwvb_shutdown, /* shut down driver */ 166 wwvb_poll, /* transmit poll message */ 167 WWVB_CONTROL, /* fudge set/change notification */ 168 noentry, /* initialize driver (not used) */ 169 noentry, /* not used (old wwvb_buginfo) */ 170 wwvb_timer /* called once per second */ 171}; 172 173 174/* 175 * wwvb_start - open the devices and initialize data for processing 176 */ 177static int 178wwvb_start( 179 int unit, 180 struct peer *peer 181 ) 182{ 183 register struct wwvbunit *up; 184 struct refclockproc *pp; 185 int fd; 186 char device[20]; 187 188 /* 189 * Open serial port. Use CLK line discipline, if available. 190 */ 191 sprintf(device, DEVICE, unit); 192 if (-1 == (fd = refclock_open(device, SPEED232, LDISC_CLK))) 193 return (0); 194 195 /* 196 * Allocate and initialize unit structure 197 */ 198 up = (struct wwvbunit *)emalloc(sizeof(struct wwvbunit)); 199 memset((char *)up, 0, sizeof(struct wwvbunit)); 200 pp = peer->procptr; 201 pp->unitptr = (caddr_t)up; 202 pp->io.clock_recv = wwvb_receive; 203 pp->io.srcclock = (caddr_t)peer; 204 pp->io.datalen = 0; 205 pp->io.fd = fd; 206 if (!io_addclock(&pp->io)) { 207 close(fd); 208 free(up); 209 return (0); 210 } 211 212 /* 213 * Initialize miscellaneous variables 214 */ 215 peer->precision = PRECISION; 216 pp->clockdesc = DESCRIPTION; 217 memcpy((char *)&pp->refid, REFID, 4); 218 return (1); 219} 220 221 222/* 223 * wwvb_shutdown - shut down the clock 224 */ 225static void 226wwvb_shutdown( 227 int unit, 228 struct peer *peer 229 ) 230{ 231 register struct wwvbunit *up; 232 struct refclockproc *pp; 233 234 pp = peer->procptr; 235 up = (struct wwvbunit *)pp->unitptr; 236 io_closeclock(&pp->io); 237 free(up); 238} 239 240 241/* 242 * wwvb_receive - receive data from the serial interface 243 */ 244static void 245wwvb_receive( 246 struct recvbuf *rbufp 247 ) 248{ 249 struct wwvbunit *up; 250 struct refclockproc *pp; 251 struct peer *peer; 252 253 l_fp trtmp; /* arrival timestamp */ 254 int tz; /* time zone */ 255 int day, month; /* ddd conversion */ 256 int temp; /* int temp */ 257 char syncchar; /* synchronization indicator */ 258 char qualchar; /* quality indicator */ 259 char leapchar; /* leap indicator */ 260 char dstchar; /* daylight/standard indicator */ 261 char tmpchar; /* trashbin */ 262 263 /* 264 * Initialize pointers and read the timecode and timestamp 265 */ 266 peer = (struct peer *)rbufp->recv_srcclock; 267 pp = peer->procptr; 268 up = (struct wwvbunit *)pp->unitptr; 269 temp = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp); 270 271 /* 272 * Note we get a buffer and timestamp for both a <cr> and <lf>, 273 * but only the <cr> timestamp is retained. Note: in format 0 on 274 * a Netclock/2 or upgraded 8170 the start bit is delayed 100 275 * +-50 us relative to the pps; however, on an unmodified 8170 276 * the start bit can be delayed up to 10 ms. In format 2 the 277 * reading precision is only to the millisecond. Thus, unless 278 * you have a PPS gadget and don't have to have the year, format 279 * 0 provides the lowest jitter. 280 */ 281 if (temp == 0) { 282 up->laststamp = trtmp; 283 return; 284 } 285 pp->lencode = temp; 286 pp->lastrec = up->laststamp; 287 288 /* 289 * We get down to business, check the timecode format and decode 290 * its contents. This code uses the timecode length to determine 291 * format 0, 2 or 3. If the timecode has invalid length or is 292 * not in proper format, we declare bad format and exit. 293 */ 294 syncchar = qualchar = leapchar = dstchar = ' '; 295 tz = 0; 296 switch (pp->lencode) { 297 298 case LENWWVB0: 299 300 /* 301 * Timecode format 0: "I ddd hh:mm:ss DTZ=nn" 302 */ 303 if (sscanf(pp->a_lastcode, 304 "%c %3d %2d:%2d:%2d%c%cTZ=%2d", 305 &syncchar, &pp->day, &pp->hour, &pp->minute, 306 &pp->second, &tmpchar, &dstchar, &tz) == 8) 307 pp->nsec = 0; 308 break; 309 310 case LENWWVB2: 311 312 /* 313 * Timecode format 2: "IQyy ddd hh:mm:ss.mmm LD" */ 314 if (sscanf(pp->a_lastcode, 315 "%c%c %2d %3d %2d:%2d:%2d.%3ld %c", 316 &syncchar, &qualchar, &pp->year, &pp->day, 317 &pp->hour, &pp->minute, &pp->second, &pp->nsec, 318 &leapchar) == 9) 319 pp->nsec *= 1000000; 320 break; 321 322 case LENWWVB3: 323 324 /* 325 * Timecode format 3: "0003I yyyymmdd hhmmss+0000SL#" 326 */ 327 if (sscanf(pp->a_lastcode, 328 "0003%c %4d%2d%2d %2d%2d%2d+0000%c%c", 329 &syncchar, &pp->year, &month, &day, &pp->hour, 330 &pp->minute, &pp->second, &dstchar, &leapchar) == 8) 331 { 332 pp->day = ymd2yd(pp->year, month, day); 333 pp->nsec = 0; 334 break; 335 } 336 337 default: 338 339 /* 340 * Unknown format: If dumping internal table, record 341 * stats; otherwise, declare bad format. 342 */ 343 if (up->linect > 0) { 344 up->linect--; 345 record_clock_stats(&peer->srcadr, 346 pp->a_lastcode); 347 } else { 348 refclock_report(peer, CEVNT_BADREPLY); 349 } 350 return; 351 } 352 353 /* 354 * Decode synchronization, quality and leap characters. If 355 * unsynchronized, set the leap bits accordingly and exit. 356 * Otherwise, set the leap bits according to the leap character. 357 * Once synchronized, the dispersion depends only on the 358 * quality character. 359 */ 360 switch (qualchar) { 361 362 case ' ': 363 pp->disp = .001; 364 pp->lastref = pp->lastrec; 365 break; 366 367 case 'A': 368 pp->disp = .01; 369 break; 370 371 case 'B': 372 pp->disp = .1; 373 break; 374 375 case 'C': 376 pp->disp = .5; 377 break; 378 379 case 'D': 380 pp->disp = MAXDISPERSE; 381 break; 382 383 default: 384 pp->disp = MAXDISPERSE; 385 refclock_report(peer, CEVNT_BADREPLY); 386 break; 387 } 388 if (syncchar != ' ') 389 pp->leap = LEAP_NOTINSYNC; 390 else if (leapchar == 'L') 391 pp->leap = LEAP_ADDSECOND; 392 else 393 pp->leap = LEAP_NOWARNING; 394 395 /* 396 * Process the new sample in the median filter and determine the 397 * timecode timestamp, but only if the PPS is not in control. 398 */ 399#ifdef HAVE_PPSAPI 400 up->tcount++; 401 if (peer->flags & FLAG_PPS) 402 return; 403 404#endif /* HAVE_PPSAPI */ 405 if (!refclock_process_f(pp, pp->fudgetime2)) 406 refclock_report(peer, CEVNT_BADTIME); 407} 408 409 410/* 411 * wwvb_timer - called once per second by the transmit procedure 412 */ 413static void 414wwvb_timer( 415 int unit, 416 struct peer *peer 417 ) 418{ 419 register struct wwvbunit *up; 420 struct refclockproc *pp; 421 char pollchar; /* character sent to clock */ 422 423 /* 424 * Time to poll the clock. The Spectracom clock responds to a 425 * 'T' by returning a timecode in the format(s) specified above. 426 * Note there is no checking on state, since this may not be the 427 * only customer reading the clock. Only one customer need poll 428 * the clock; all others just listen in. 429 */ 430 pp = peer->procptr; 431 up = (struct wwvbunit *)pp->unitptr; 432 if (up->linect > 0) 433 pollchar = 'R'; 434 else 435 pollchar = 'T'; 436 if (write(pp->io.fd, &pollchar, 1) != 1) 437 refclock_report(peer, CEVNT_FAULT); 438#ifdef HAVE_PPSAPI 439 if (up->ppsapi_lit && 440 refclock_pps(peer, &up->atom, pp->sloppyclockflag) > 0) { 441 up->pcount++, 442 peer->flags |= FLAG_PPS; 443 peer->precision = PPS_PRECISION; 444 } 445#endif /* HAVE_PPSAPI */ 446} 447 448 449/* 450 * wwvb_poll - called by the transmit procedure 451 */ 452static void 453wwvb_poll( 454 int unit, 455 struct peer *peer 456 ) 457{ 458 register struct wwvbunit *up; 459 struct refclockproc *pp; 460 461 /* 462 * Sweep up the samples received since the last poll. If none 463 * are received, declare a timeout and keep going. 464 */ 465 pp = peer->procptr; 466 up = (struct wwvbunit *)pp->unitptr; 467 pp->polls++; 468 469 /* 470 * If the monitor flag is set (flag4), we dump the internal 471 * quality table at the first timecode beginning the day. 472 */ 473 if (pp->sloppyclockflag & CLK_FLAG4 && pp->hour < 474 (int)up->lasthour) 475 up->linect = MONLIN; 476 up->lasthour = (u_char)pp->hour; 477 478 /* 479 * Process median filter samples. If none received, declare a 480 * timeout and keep going. 481 */ 482#ifdef HAVE_PPSAPI 483 if (up->pcount == 0) { 484 peer->flags &= ~FLAG_PPS; 485 peer->precision = PRECISION; 486 } 487 if (up->tcount == 0) { 488 pp->coderecv = pp->codeproc; 489 refclock_report(peer, CEVNT_TIMEOUT); 490 return; 491 } 492 up->pcount = up->tcount = 0; 493#else /* HAVE_PPSAPI */ 494 if (pp->coderecv == pp->codeproc) { 495 refclock_report(peer, CEVNT_TIMEOUT); 496 return; 497 } 498#endif /* HAVE_PPSAPI */ 499 refclock_receive(peer); 500 record_clock_stats(&peer->srcadr, pp->a_lastcode); 501#ifdef DEBUG 502 if (debug) 503 printf("wwvb: timecode %d %s\n", pp->lencode, 504 pp->a_lastcode); 505#endif 506} 507 508 509/* 510 * wwvb_control - fudge parameters have been set or changed 511 */ 512#ifdef HAVE_PPSAPI 513static void 514wwvb_control( 515 int unit, 516 struct refclockstat *in_st, 517 struct refclockstat *out_st, 518 struct peer *peer 519 ) 520{ 521 register struct wwvbunit *up; 522 struct refclockproc *pp; 523 524 pp = peer->procptr; 525 up = (struct wwvbunit *)pp->unitptr; 526 527 if (!(pp->sloppyclockflag & CLK_FLAG1)) { 528 if (!up->ppsapi_tried) 529 return; 530 up->ppsapi_tried = 0; 531 if (!up->ppsapi_lit) 532 return; 533 peer->flags &= ~FLAG_PPS; 534 peer->precision = PRECISION; 535 time_pps_destroy(up->atom.handle); 536 up->atom.handle = 0; 537 up->ppsapi_lit = 0; 538 return; 539 } 540 541 if (up->ppsapi_tried) 542 return; 543 /* 544 * Light up the PPSAPI interface. 545 */ 546 up->ppsapi_tried = 1; 547 if (refclock_ppsapi(pp->io.fd, &up->atom)) { 548 up->ppsapi_lit = 1; 549 return; 550 } 551 552 NLOG(NLOG_CLOCKINFO) 553 msyslog(LOG_WARNING, "%s flag1 1 but PPSAPI fails", 554 refnumtoa(&peer->srcadr)); 555} 556#endif /* HAVE_PPSAPI */ 557 558#else 559int refclock_wwvb_bs; 560#endif /* REFCLOCK */ 561