1 /* $NetBSD: refclock_hpgps.c,v 1.1.1.3 2013/12/27 23:30:59 christos Exp $ */ 2 3 /* 4 * refclock_hpgps - clock driver for HP 58503A GPS receiver 5 */ 6 7 #ifdef HAVE_CONFIG_H 8 # include <config.h> 9 #endif 10 11 #if defined(REFCLOCK) && defined(CLOCK_HPGPS) 12 13 #include "ntpd.h" 14 #include "ntp_io.h" 15 #include "ntp_refclock.h" 16 #include "ntp_stdlib.h" 17 18 #include <stdio.h> 19 #include <ctype.h> 20 21 /* Version 0.1 April 1, 1995 22 * 0.2 April 25, 1995 23 * tolerant of missing timecode response prompt and sends 24 * clear status if prompt indicates error; 25 * can use either local time or UTC from receiver; 26 * can get receiver status screen via flag4 27 * 28 * WARNING!: This driver is UNDER CONSTRUCTION 29 * Everything in here should be treated with suspicion. 30 * If it looks wrong, it probably is. 31 * 32 * Comments and/or questions to: Dave Vitanye 33 * Hewlett Packard Company 34 * dave@scd.hp.com 35 * (408) 553-2856 36 * 37 * Thanks to the author of the PST driver, which was the starting point for 38 * this one. 39 * 40 * This driver supports the HP 58503A Time and Frequency Reference Receiver. 41 * This receiver uses HP SmartClock (TM) to implement an Enhanced GPS receiver. 42 * The receiver accuracy when locked to GPS in normal operation is better 43 * than 1 usec. The accuracy when operating in holdover is typically better 44 * than 10 usec. per day. 45 * 46 * The same driver also handles the HP Z3801A which is available surplus 47 * from the cell phone industry. It's popular with hams. 48 * It needs a different line setup: 19200 baud, 7 data bits, odd parity 49 * That is selected by adding "mode 1" to the server line in ntp.conf 50 * HP Z3801A code from Jeff Mock added by Hal Murray, Sep 2005 51 * 52 * 53 * The receiver should be operated with factory default settings. 54 * Initial driver operation: expects the receiver to be already locked 55 * to GPS, configured and able to output timecode format 2 messages. 56 * 57 * The driver uses the poll sequence :PTIME:TCODE? to get a response from 58 * the receiver. The receiver responds with a timecode string of ASCII 59 * printing characters, followed by a <cr><lf>, followed by a prompt string 60 * issued by the receiver, in the following format: 61 * T#yyyymmddhhmmssMFLRVcc<cr><lf>scpi > 62 * 63 * The driver processes the response at the <cr> and <lf>, so what the 64 * driver sees is the prompt from the previous poll, followed by this 65 * timecode. The prompt from the current poll is (usually) left unread until 66 * the next poll. So (except on the very first poll) the driver sees this: 67 * 68 * scpi > T#yyyymmddhhmmssMFLRVcc<cr><lf> 69 * 70 * The T is the on-time character, at 980 msec. before the next 1PPS edge. 71 * The # is the timecode format type. We look for format 2. 72 * Without any of the CLK or PPS stuff, then, the receiver buffer timestamp 73 * at the <cr> is 24 characters later, which is about 25 msec. at 9600 bps, 74 * so the first approximation for fudge time1 is nominally -0.955 seconds. 75 * This number probably needs adjusting for each machine / OS type, so far: 76 * -0.955000 on an HP 9000 Model 712/80 HP-UX 9.05 77 * -0.953175 on an HP 9000 Model 370 HP-UX 9.10 78 * 79 * This receiver also provides a 1PPS signal, but I haven't figured out 80 * how to deal with any of the CLK or PPS stuff yet. Stay tuned. 81 * 82 */ 83 84 /* 85 * Fudge Factors 86 * 87 * Fudge time1 is used to accomodate the timecode serial interface adjustment. 88 * Fudge flag4 can be set to request a receiver status screen summary, which 89 * is recorded in the clockstats file. 90 */ 91 92 /* 93 * Interface definitions 94 */ 95 #define DEVICE "/dev/hpgps%d" /* device name and unit */ 96 #define SPEED232 B9600 /* uart speed (9600 baud) */ 97 #define SPEED232Z B19200 /* uart speed (19200 baud) */ 98 #define PRECISION (-10) /* precision assumed (about 1 ms) */ 99 #define REFID "GPS\0" /* reference ID */ 100 #define DESCRIPTION "HP 58503A GPS Time and Frequency Reference Receiver" 101 102 #define SMAX 23*80+1 /* for :SYSTEM:PRINT? status screen response */ 103 104 #define MTZONE 2 /* number of fields in timezone reply */ 105 #define MTCODET2 12 /* number of fields in timecode format T2 */ 106 #define NTCODET2 21 /* number of chars to checksum in format T2 */ 107 108 /* 109 * Tables to compute the day of year from yyyymmdd timecode. 110 * Viva la leap. 111 */ 112 static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 113 static int day2tab[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 114 115 /* 116 * Unit control structure 117 */ 118 struct hpgpsunit { 119 int pollcnt; /* poll message counter */ 120 int tzhour; /* timezone offset, hours */ 121 int tzminute; /* timezone offset, minutes */ 122 int linecnt; /* set for expected multiple line responses */ 123 char *lastptr; /* pointer to receiver response data */ 124 char statscrn[SMAX]; /* receiver status screen buffer */ 125 }; 126 127 /* 128 * Function prototypes 129 */ 130 static int hpgps_start (int, struct peer *); 131 static void hpgps_shutdown (int, struct peer *); 132 static void hpgps_receive (struct recvbuf *); 133 static void hpgps_poll (int, struct peer *); 134 135 /* 136 * Transfer vector 137 */ 138 struct refclock refclock_hpgps = { 139 hpgps_start, /* start up driver */ 140 hpgps_shutdown, /* shut down driver */ 141 hpgps_poll, /* transmit poll message */ 142 noentry, /* not used (old hpgps_control) */ 143 noentry, /* initialize driver */ 144 noentry, /* not used (old hpgps_buginfo) */ 145 NOFLAGS /* not used */ 146 }; 147 148 149 /* 150 * hpgps_start - open the devices and initialize data for processing 151 */ 152 static int 153 hpgps_start( 154 int unit, 155 struct peer *peer 156 ) 157 { 158 register struct hpgpsunit *up; 159 struct refclockproc *pp; 160 int fd; 161 int ldisc; 162 char device[20]; 163 164 /* 165 * Open serial port. Use CLK line discipline, if available. 166 * Default is HP 58503A, mode arg selects HP Z3801A 167 */ 168 snprintf(device, sizeof(device), DEVICE, unit); 169 ldisc = LDISC_CLK; 170 /* mode parameter to server config line shares ttl slot */ 171 if (1 == peer->ttl) 172 ldisc |= LDISC_7O1; 173 fd = refclock_open(device, SPEED232Z, ldisc); 174 if (fd <= 0) 175 return (0); 176 /* 177 * Allocate and initialize unit structure 178 */ 179 up = emalloc_zero(sizeof(*up)); 180 pp = peer->procptr; 181 pp->io.clock_recv = hpgps_receive; 182 pp->io.srcclock = peer; 183 pp->io.datalen = 0; 184 pp->io.fd = fd; 185 if (!io_addclock(&pp->io)) { 186 close(fd); 187 pp->io.fd = -1; 188 free(up); 189 return (0); 190 } 191 pp->unitptr = up; 192 193 /* 194 * Initialize miscellaneous variables 195 */ 196 peer->precision = PRECISION; 197 pp->clockdesc = DESCRIPTION; 198 memcpy((char *)&pp->refid, REFID, 4); 199 up->tzhour = 0; 200 up->tzminute = 0; 201 202 *up->statscrn = '\0'; 203 up->lastptr = up->statscrn; 204 up->pollcnt = 2; 205 206 /* 207 * Get the identifier string, which is logged but otherwise ignored, 208 * and get the local timezone information 209 */ 210 up->linecnt = 1; 211 if (write(pp->io.fd, "*IDN?\r:PTIME:TZONE?\r", 20) != 20) 212 refclock_report(peer, CEVNT_FAULT); 213 214 return (1); 215 } 216 217 218 /* 219 * hpgps_shutdown - shut down the clock 220 */ 221 static void 222 hpgps_shutdown( 223 int unit, 224 struct peer *peer 225 ) 226 { 227 register struct hpgpsunit *up; 228 struct refclockproc *pp; 229 230 pp = peer->procptr; 231 up = pp->unitptr; 232 if (-1 != pp->io.fd) 233 io_closeclock(&pp->io); 234 if (NULL != up) 235 free(up); 236 } 237 238 239 /* 240 * hpgps_receive - receive data from the serial interface 241 */ 242 static void 243 hpgps_receive( 244 struct recvbuf *rbufp 245 ) 246 { 247 register struct hpgpsunit *up; 248 struct refclockproc *pp; 249 struct peer *peer; 250 l_fp trtmp; 251 char tcodechar1; /* identifies timecode format */ 252 char tcodechar2; /* identifies timecode format */ 253 char timequal; /* time figure of merit: 0-9 */ 254 char freqqual; /* frequency figure of merit: 0-3 */ 255 char leapchar; /* leapsecond: + or 0 or - */ 256 char servchar; /* request for service: 0 = no, 1 = yes */ 257 char syncchar; /* time info is invalid: 0 = no, 1 = yes */ 258 short expectedsm; /* expected timecode byte checksum */ 259 short tcodechksm; /* computed timecode byte checksum */ 260 int i,m,n; 261 int month, day, lastday; 262 char *tcp; /* timecode pointer (skips over the prompt) */ 263 char prompt[BMAX]; /* prompt in response from receiver */ 264 265 /* 266 * Initialize pointers and read the receiver response 267 */ 268 peer = rbufp->recv_peer; 269 pp = peer->procptr; 270 up = pp->unitptr; 271 *pp->a_lastcode = '\0'; 272 pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp); 273 274 #ifdef DEBUG 275 if (debug) 276 printf("hpgps: lencode: %d timecode:%s\n", 277 pp->lencode, pp->a_lastcode); 278 #endif 279 280 /* 281 * If there's no characters in the reply, we can quit now 282 */ 283 if (pp->lencode == 0) 284 return; 285 286 /* 287 * If linecnt is greater than zero, we are getting information only, 288 * such as the receiver identification string or the receiver status 289 * screen, so put the receiver response at the end of the status 290 * screen buffer. When we have the last line, write the buffer to 291 * the clockstats file and return without further processing. 292 * 293 * If linecnt is zero, we are expecting either the timezone 294 * or a timecode. At this point, also write the response 295 * to the clockstats file, and go on to process the prompt (if any), 296 * timezone, or timecode and timestamp. 297 */ 298 299 300 if (up->linecnt-- > 0) { 301 if ((int)(pp->lencode + 2) <= (SMAX - (up->lastptr - up->statscrn))) { 302 *up->lastptr++ = '\n'; 303 memcpy(up->lastptr, pp->a_lastcode, pp->lencode); 304 up->lastptr += pp->lencode; 305 } 306 if (up->linecnt == 0) 307 record_clock_stats(&peer->srcadr, up->statscrn); 308 309 return; 310 } 311 312 record_clock_stats(&peer->srcadr, pp->a_lastcode); 313 pp->lastrec = trtmp; 314 315 up->lastptr = up->statscrn; 316 *up->lastptr = '\0'; 317 up->pollcnt = 2; 318 319 /* 320 * We get down to business: get a prompt if one is there, issue 321 * a clear status command if it contains an error indication. 322 * Next, check for either the timezone reply or the timecode reply 323 * and decode it. If we don't recognize the reply, or don't get the 324 * proper number of decoded fields, or get an out of range timezone, 325 * or if the timecode checksum is bad, then we declare bad format 326 * and exit. 327 * 328 * Timezone format (including nominal prompt): 329 * scpi > -H,-M<cr><lf> 330 * 331 * Timecode format (including nominal prompt): 332 * scpi > T2yyyymmddhhmmssMFLRVcc<cr><lf> 333 * 334 */ 335 336 strlcpy(prompt, pp->a_lastcode, sizeof(prompt)); 337 tcp = strrchr(pp->a_lastcode,'>'); 338 if (tcp == NULL) 339 tcp = pp->a_lastcode; 340 else 341 tcp++; 342 prompt[tcp - pp->a_lastcode] = '\0'; 343 while ((*tcp == ' ') || (*tcp == '\t')) tcp++; 344 345 /* 346 * deal with an error indication in the prompt here 347 */ 348 if (strrchr(prompt,'E') > strrchr(prompt,'s')){ 349 #ifdef DEBUG 350 if (debug) 351 printf("hpgps: error indicated in prompt: %s\n", prompt); 352 #endif 353 if (write(pp->io.fd, "*CLS\r\r", 6) != 6) 354 refclock_report(peer, CEVNT_FAULT); 355 } 356 357 /* 358 * make sure we got a timezone or timecode format and 359 * then process accordingly 360 */ 361 m = sscanf(tcp,"%c%c", &tcodechar1, &tcodechar2); 362 363 if (m != 2){ 364 #ifdef DEBUG 365 if (debug) 366 printf("hpgps: no format indicator\n"); 367 #endif 368 refclock_report(peer, CEVNT_BADREPLY); 369 return; 370 } 371 372 switch (tcodechar1) { 373 374 case '+': 375 case '-': 376 m = sscanf(tcp,"%d,%d", &up->tzhour, &up->tzminute); 377 if (m != MTZONE) { 378 #ifdef DEBUG 379 if (debug) 380 printf("hpgps: only %d fields recognized in timezone\n", m); 381 #endif 382 refclock_report(peer, CEVNT_BADREPLY); 383 return; 384 } 385 if ((up->tzhour < -12) || (up->tzhour > 13) || 386 (up->tzminute < -59) || (up->tzminute > 59)){ 387 #ifdef DEBUG 388 if (debug) 389 printf("hpgps: timezone %d, %d out of range\n", 390 up->tzhour, up->tzminute); 391 #endif 392 refclock_report(peer, CEVNT_BADREPLY); 393 return; 394 } 395 return; 396 397 case 'T': 398 break; 399 400 default: 401 #ifdef DEBUG 402 if (debug) 403 printf("hpgps: unrecognized reply format %c%c\n", 404 tcodechar1, tcodechar2); 405 #endif 406 refclock_report(peer, CEVNT_BADREPLY); 407 return; 408 } /* end of tcodechar1 switch */ 409 410 411 switch (tcodechar2) { 412 413 case '2': 414 m = sscanf(tcp,"%*c%*c%4d%2d%2d%2d%2d%2d%c%c%c%c%c%2hx", 415 &pp->year, &month, &day, &pp->hour, &pp->minute, &pp->second, 416 &timequal, &freqqual, &leapchar, &servchar, &syncchar, 417 &expectedsm); 418 n = NTCODET2; 419 420 if (m != MTCODET2){ 421 #ifdef DEBUG 422 if (debug) 423 printf("hpgps: only %d fields recognized in timecode\n", m); 424 #endif 425 refclock_report(peer, CEVNT_BADREPLY); 426 return; 427 } 428 break; 429 430 default: 431 #ifdef DEBUG 432 if (debug) 433 printf("hpgps: unrecognized timecode format %c%c\n", 434 tcodechar1, tcodechar2); 435 #endif 436 refclock_report(peer, CEVNT_BADREPLY); 437 return; 438 } /* end of tcodechar2 format switch */ 439 440 /* 441 * Compute and verify the checksum. 442 * Characters are summed starting at tcodechar1, ending at just 443 * before the expected checksum. Bail out if incorrect. 444 */ 445 tcodechksm = 0; 446 while (n-- > 0) tcodechksm += *tcp++; 447 tcodechksm &= 0x00ff; 448 449 if (tcodechksm != expectedsm) { 450 #ifdef DEBUG 451 if (debug) 452 printf("hpgps: checksum %2hX doesn't match %2hX expected\n", 453 tcodechksm, expectedsm); 454 #endif 455 refclock_report(peer, CEVNT_BADREPLY); 456 return; 457 } 458 459 /* 460 * Compute the day of year from the yyyymmdd format. 461 */ 462 if (month < 1 || month > 12 || day < 1) { 463 refclock_report(peer, CEVNT_BADTIME); 464 return; 465 } 466 467 if ( ! isleap_4(pp->year) ) { /* Y2KFixes */ 468 /* not a leap year */ 469 if (day > day1tab[month - 1]) { 470 refclock_report(peer, CEVNT_BADTIME); 471 return; 472 } 473 for (i = 0; i < month - 1; i++) day += day1tab[i]; 474 lastday = 365; 475 } else { 476 /* a leap year */ 477 if (day > day2tab[month - 1]) { 478 refclock_report(peer, CEVNT_BADTIME); 479 return; 480 } 481 for (i = 0; i < month - 1; i++) day += day2tab[i]; 482 lastday = 366; 483 } 484 485 /* 486 * Deal with the timezone offset here. The receiver timecode is in 487 * local time = UTC + :PTIME:TZONE, so SUBTRACT the timezone values. 488 * For example, Pacific Standard Time is -8 hours , 0 minutes. 489 * Deal with the underflows and overflows. 490 */ 491 pp->minute -= up->tzminute; 492 pp->hour -= up->tzhour; 493 494 if (pp->minute < 0) { 495 pp->minute += 60; 496 pp->hour--; 497 } 498 if (pp->minute > 59) { 499 pp->minute -= 60; 500 pp->hour++; 501 } 502 if (pp->hour < 0) { 503 pp->hour += 24; 504 day--; 505 if (day < 1) { 506 pp->year--; 507 if ( isleap_4(pp->year) ) /* Y2KFixes */ 508 day = 366; 509 else 510 day = 365; 511 } 512 } 513 514 if (pp->hour > 23) { 515 pp->hour -= 24; 516 day++; 517 if (day > lastday) { 518 pp->year++; 519 day = 1; 520 } 521 } 522 523 pp->day = day; 524 525 /* 526 * Decode the MFLRV indicators. 527 * NEED TO FIGURE OUT how to deal with the request for service, 528 * time quality, and frequency quality indicators some day. 529 */ 530 if (syncchar != '0') { 531 pp->leap = LEAP_NOTINSYNC; 532 } 533 else { 534 pp->leap = LEAP_NOWARNING; 535 switch (leapchar) { 536 537 case '0': 538 break; 539 540 /* See http://bugs.ntp.org/1090 541 * Ignore leap announcements unless June or December. 542 * Better would be to use :GPSTime? to find the month, 543 * but that seems too likely to introduce other bugs. 544 */ 545 case '+': 546 if ((month==6) || (month==12)) 547 pp->leap = LEAP_ADDSECOND; 548 break; 549 550 case '-': 551 if ((month==6) || (month==12)) 552 pp->leap = LEAP_DELSECOND; 553 break; 554 555 default: 556 #ifdef DEBUG 557 if (debug) 558 printf("hpgps: unrecognized leap indicator: %c\n", 559 leapchar); 560 #endif 561 refclock_report(peer, CEVNT_BADTIME); 562 return; 563 } /* end of leapchar switch */ 564 } 565 566 /* 567 * Process the new sample in the median filter and determine the 568 * reference clock offset and dispersion. We use lastrec as both 569 * the reference time and receive time in order to avoid being 570 * cute, like setting the reference time later than the receive 571 * time, which may cause a paranoid protocol module to chuck out 572 * the data. 573 */ 574 if (!refclock_process(pp)) { 575 refclock_report(peer, CEVNT_BADTIME); 576 return; 577 } 578 pp->lastref = pp->lastrec; 579 refclock_receive(peer); 580 581 /* 582 * If CLK_FLAG4 is set, ask for the status screen response. 583 */ 584 if (pp->sloppyclockflag & CLK_FLAG4){ 585 up->linecnt = 22; 586 if (write(pp->io.fd, ":SYSTEM:PRINT?\r", 15) != 15) 587 refclock_report(peer, CEVNT_FAULT); 588 } 589 } 590 591 592 /* 593 * hpgps_poll - called by the transmit procedure 594 */ 595 static void 596 hpgps_poll( 597 int unit, 598 struct peer *peer 599 ) 600 { 601 register struct hpgpsunit *up; 602 struct refclockproc *pp; 603 604 /* 605 * Time to poll the clock. The HP 58503A responds to a 606 * ":PTIME:TCODE?" by returning a timecode in the format specified 607 * above. If nothing is heard from the clock for two polls, 608 * declare a timeout and keep going. 609 */ 610 pp = peer->procptr; 611 up = pp->unitptr; 612 if (up->pollcnt == 0) 613 refclock_report(peer, CEVNT_TIMEOUT); 614 else 615 up->pollcnt--; 616 if (write(pp->io.fd, ":PTIME:TCODE?\r", 14) != 14) { 617 refclock_report(peer, CEVNT_FAULT); 618 } 619 else 620 pp->polls++; 621 } 622 623 #else 624 int refclock_hpgps_bs; 625 #endif /* REFCLOCK */ 626