1 /* $NetBSD: refclock_hpgps.c,v 1.3 2015/07/10 14:20:33 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 speed, 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 speed = SPEED232; 171 /* mode parameter to server config line shares ttl slot */ 172 if (1 == peer->ttl) { 173 ldisc |= LDISC_7O1; 174 speed = SPEED232Z; 175 } 176 fd = refclock_open(device, speed, ldisc); 177 if (fd <= 0) 178 return (0); 179 /* 180 * Allocate and initialize unit structure 181 */ 182 up = emalloc_zero(sizeof(*up)); 183 pp = peer->procptr; 184 pp->io.clock_recv = hpgps_receive; 185 pp->io.srcclock = peer; 186 pp->io.datalen = 0; 187 pp->io.fd = fd; 188 if (!io_addclock(&pp->io)) { 189 close(fd); 190 pp->io.fd = -1; 191 free(up); 192 return (0); 193 } 194 pp->unitptr = up; 195 196 /* 197 * Initialize miscellaneous variables 198 */ 199 peer->precision = PRECISION; 200 pp->clockdesc = DESCRIPTION; 201 memcpy((char *)&pp->refid, REFID, 4); 202 up->tzhour = 0; 203 up->tzminute = 0; 204 205 *up->statscrn = '\0'; 206 up->lastptr = up->statscrn; 207 up->pollcnt = 2; 208 209 /* 210 * Get the identifier string, which is logged but otherwise ignored, 211 * and get the local timezone information 212 */ 213 up->linecnt = 1; 214 if (write(pp->io.fd, "*IDN?\r:PTIME:TZONE?\r", 20) != 20) 215 refclock_report(peer, CEVNT_FAULT); 216 217 return (1); 218 } 219 220 221 /* 222 * hpgps_shutdown - shut down the clock 223 */ 224 static void 225 hpgps_shutdown( 226 int unit, 227 struct peer *peer 228 ) 229 { 230 register struct hpgpsunit *up; 231 struct refclockproc *pp; 232 233 pp = peer->procptr; 234 up = pp->unitptr; 235 if (-1 != pp->io.fd) 236 io_closeclock(&pp->io); 237 if (NULL != up) 238 free(up); 239 } 240 241 242 /* 243 * hpgps_receive - receive data from the serial interface 244 */ 245 static void 246 hpgps_receive( 247 struct recvbuf *rbufp 248 ) 249 { 250 register struct hpgpsunit *up; 251 struct refclockproc *pp; 252 struct peer *peer; 253 l_fp trtmp; 254 char tcodechar1; /* identifies timecode format */ 255 char tcodechar2; /* identifies timecode format */ 256 char timequal; /* time figure of merit: 0-9 */ 257 char freqqual; /* frequency figure of merit: 0-3 */ 258 char leapchar; /* leapsecond: + or 0 or - */ 259 char servchar; /* request for service: 0 = no, 1 = yes */ 260 char syncchar; /* time info is invalid: 0 = no, 1 = yes */ 261 short expectedsm; /* expected timecode byte checksum */ 262 short tcodechksm; /* computed timecode byte checksum */ 263 int i,m,n; 264 int month, day, lastday; 265 char *tcp; /* timecode pointer (skips over the prompt) */ 266 char prompt[BMAX]; /* prompt in response from receiver */ 267 268 /* 269 * Initialize pointers and read the receiver response 270 */ 271 peer = rbufp->recv_peer; 272 pp = peer->procptr; 273 up = pp->unitptr; 274 *pp->a_lastcode = '\0'; 275 pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp); 276 277 #ifdef DEBUG 278 if (debug) 279 printf("hpgps: lencode: %d timecode:%s\n", 280 pp->lencode, pp->a_lastcode); 281 #endif 282 283 /* 284 * If there's no characters in the reply, we can quit now 285 */ 286 if (pp->lencode == 0) 287 return; 288 289 /* 290 * If linecnt is greater than zero, we are getting information only, 291 * such as the receiver identification string or the receiver status 292 * screen, so put the receiver response at the end of the status 293 * screen buffer. When we have the last line, write the buffer to 294 * the clockstats file and return without further processing. 295 * 296 * If linecnt is zero, we are expecting either the timezone 297 * or a timecode. At this point, also write the response 298 * to the clockstats file, and go on to process the prompt (if any), 299 * timezone, or timecode and timestamp. 300 */ 301 302 303 if (up->linecnt-- > 0) { 304 if ((int)(pp->lencode + 2) <= (SMAX - (up->lastptr - up->statscrn))) { 305 *up->lastptr++ = '\n'; 306 memcpy(up->lastptr, pp->a_lastcode, pp->lencode); 307 up->lastptr += pp->lencode; 308 } 309 if (up->linecnt == 0) 310 record_clock_stats(&peer->srcadr, up->statscrn); 311 312 return; 313 } 314 315 record_clock_stats(&peer->srcadr, pp->a_lastcode); 316 pp->lastrec = trtmp; 317 318 up->lastptr = up->statscrn; 319 *up->lastptr = '\0'; 320 up->pollcnt = 2; 321 322 /* 323 * We get down to business: get a prompt if one is there, issue 324 * a clear status command if it contains an error indication. 325 * Next, check for either the timezone reply or the timecode reply 326 * and decode it. If we don't recognize the reply, or don't get the 327 * proper number of decoded fields, or get an out of range timezone, 328 * or if the timecode checksum is bad, then we declare bad format 329 * and exit. 330 * 331 * Timezone format (including nominal prompt): 332 * scpi > -H,-M<cr><lf> 333 * 334 * Timecode format (including nominal prompt): 335 * scpi > T2yyyymmddhhmmssMFLRVcc<cr><lf> 336 * 337 */ 338 339 strlcpy(prompt, pp->a_lastcode, sizeof(prompt)); 340 tcp = strrchr(pp->a_lastcode,'>'); 341 if (tcp == NULL) 342 tcp = pp->a_lastcode; 343 else 344 tcp++; 345 prompt[tcp - pp->a_lastcode] = '\0'; 346 while ((*tcp == ' ') || (*tcp == '\t')) tcp++; 347 348 /* 349 * deal with an error indication in the prompt here 350 */ 351 if (strrchr(prompt,'E') > strrchr(prompt,'s')){ 352 #ifdef DEBUG 353 if (debug) 354 printf("hpgps: error indicated in prompt: %s\n", prompt); 355 #endif 356 if (write(pp->io.fd, "*CLS\r\r", 6) != 6) 357 refclock_report(peer, CEVNT_FAULT); 358 } 359 360 /* 361 * make sure we got a timezone or timecode format and 362 * then process accordingly 363 */ 364 m = sscanf(tcp,"%c%c", &tcodechar1, &tcodechar2); 365 366 if (m != 2){ 367 #ifdef DEBUG 368 if (debug) 369 printf("hpgps: no format indicator\n"); 370 #endif 371 refclock_report(peer, CEVNT_BADREPLY); 372 return; 373 } 374 375 switch (tcodechar1) { 376 377 case '+': 378 case '-': 379 m = sscanf(tcp,"%d,%d", &up->tzhour, &up->tzminute); 380 if (m != MTZONE) { 381 #ifdef DEBUG 382 if (debug) 383 printf("hpgps: only %d fields recognized in timezone\n", m); 384 #endif 385 refclock_report(peer, CEVNT_BADREPLY); 386 return; 387 } 388 if ((up->tzhour < -12) || (up->tzhour > 13) || 389 (up->tzminute < -59) || (up->tzminute > 59)){ 390 #ifdef DEBUG 391 if (debug) 392 printf("hpgps: timezone %d, %d out of range\n", 393 up->tzhour, up->tzminute); 394 #endif 395 refclock_report(peer, CEVNT_BADREPLY); 396 return; 397 } 398 return; 399 400 case 'T': 401 break; 402 403 default: 404 #ifdef DEBUG 405 if (debug) 406 printf("hpgps: unrecognized reply format %c%c\n", 407 tcodechar1, tcodechar2); 408 #endif 409 refclock_report(peer, CEVNT_BADREPLY); 410 return; 411 } /* end of tcodechar1 switch */ 412 413 414 switch (tcodechar2) { 415 416 case '2': 417 m = sscanf(tcp,"%*c%*c%4d%2d%2d%2d%2d%2d%c%c%c%c%c%2hx", 418 &pp->year, &month, &day, &pp->hour, &pp->minute, &pp->second, 419 &timequal, &freqqual, &leapchar, &servchar, &syncchar, 420 &expectedsm); 421 n = NTCODET2; 422 423 if (m != MTCODET2){ 424 #ifdef DEBUG 425 if (debug) 426 printf("hpgps: only %d fields recognized in timecode\n", m); 427 #endif 428 refclock_report(peer, CEVNT_BADREPLY); 429 return; 430 } 431 break; 432 433 default: 434 #ifdef DEBUG 435 if (debug) 436 printf("hpgps: unrecognized timecode format %c%c\n", 437 tcodechar1, tcodechar2); 438 #endif 439 refclock_report(peer, CEVNT_BADREPLY); 440 return; 441 } /* end of tcodechar2 format switch */ 442 443 /* 444 * Compute and verify the checksum. 445 * Characters are summed starting at tcodechar1, ending at just 446 * before the expected checksum. Bail out if incorrect. 447 */ 448 tcodechksm = 0; 449 while (n-- > 0) tcodechksm += *tcp++; 450 tcodechksm &= 0x00ff; 451 452 if (tcodechksm != expectedsm) { 453 #ifdef DEBUG 454 if (debug) 455 printf("hpgps: checksum %2hX doesn't match %2hX expected\n", 456 tcodechksm, expectedsm); 457 #endif 458 refclock_report(peer, CEVNT_BADREPLY); 459 return; 460 } 461 462 /* 463 * Compute the day of year from the yyyymmdd format. 464 */ 465 if (month < 1 || month > 12 || day < 1) { 466 refclock_report(peer, CEVNT_BADTIME); 467 return; 468 } 469 470 if ( ! isleap_4(pp->year) ) { /* Y2KFixes */ 471 /* not a leap year */ 472 if (day > day1tab[month - 1]) { 473 refclock_report(peer, CEVNT_BADTIME); 474 return; 475 } 476 for (i = 0; i < month - 1; i++) day += day1tab[i]; 477 lastday = 365; 478 } else { 479 /* a leap year */ 480 if (day > day2tab[month - 1]) { 481 refclock_report(peer, CEVNT_BADTIME); 482 return; 483 } 484 for (i = 0; i < month - 1; i++) day += day2tab[i]; 485 lastday = 366; 486 } 487 488 /* 489 * Deal with the timezone offset here. The receiver timecode is in 490 * local time = UTC + :PTIME:TZONE, so SUBTRACT the timezone values. 491 * For example, Pacific Standard Time is -8 hours , 0 minutes. 492 * Deal with the underflows and overflows. 493 */ 494 pp->minute -= up->tzminute; 495 pp->hour -= up->tzhour; 496 497 if (pp->minute < 0) { 498 pp->minute += 60; 499 pp->hour--; 500 } 501 if (pp->minute > 59) { 502 pp->minute -= 60; 503 pp->hour++; 504 } 505 if (pp->hour < 0) { 506 pp->hour += 24; 507 day--; 508 if (day < 1) { 509 pp->year--; 510 if ( isleap_4(pp->year) ) /* Y2KFixes */ 511 day = 366; 512 else 513 day = 365; 514 } 515 } 516 517 if (pp->hour > 23) { 518 pp->hour -= 24; 519 day++; 520 if (day > lastday) { 521 pp->year++; 522 day = 1; 523 } 524 } 525 526 pp->day = day; 527 528 /* 529 * Decode the MFLRV indicators. 530 * NEED TO FIGURE OUT how to deal with the request for service, 531 * time quality, and frequency quality indicators some day. 532 */ 533 if (syncchar != '0') { 534 pp->leap = LEAP_NOTINSYNC; 535 } 536 else { 537 pp->leap = LEAP_NOWARNING; 538 switch (leapchar) { 539 540 case '0': 541 break; 542 543 /* See http://bugs.ntp.org/1090 544 * Ignore leap announcements unless June or December. 545 * Better would be to use :GPSTime? to find the month, 546 * but that seems too likely to introduce other bugs. 547 */ 548 case '+': 549 if ((month==6) || (month==12)) 550 pp->leap = LEAP_ADDSECOND; 551 break; 552 553 case '-': 554 if ((month==6) || (month==12)) 555 pp->leap = LEAP_DELSECOND; 556 break; 557 558 default: 559 #ifdef DEBUG 560 if (debug) 561 printf("hpgps: unrecognized leap indicator: %c\n", 562 leapchar); 563 #endif 564 refclock_report(peer, CEVNT_BADTIME); 565 return; 566 } /* end of leapchar switch */ 567 } 568 569 /* 570 * Process the new sample in the median filter and determine the 571 * reference clock offset and dispersion. We use lastrec as both 572 * the reference time and receive time in order to avoid being 573 * cute, like setting the reference time later than the receive 574 * time, which may cause a paranoid protocol module to chuck out 575 * the data. 576 */ 577 if (!refclock_process(pp)) { 578 refclock_report(peer, CEVNT_BADTIME); 579 return; 580 } 581 pp->lastref = pp->lastrec; 582 refclock_receive(peer); 583 584 /* 585 * If CLK_FLAG4 is set, ask for the status screen response. 586 */ 587 if (pp->sloppyclockflag & CLK_FLAG4){ 588 up->linecnt = 22; 589 if (write(pp->io.fd, ":SYSTEM:PRINT?\r", 15) != 15) 590 refclock_report(peer, CEVNT_FAULT); 591 } 592 } 593 594 595 /* 596 * hpgps_poll - called by the transmit procedure 597 */ 598 static void 599 hpgps_poll( 600 int unit, 601 struct peer *peer 602 ) 603 { 604 register struct hpgpsunit *up; 605 struct refclockproc *pp; 606 607 /* 608 * Time to poll the clock. The HP 58503A responds to a 609 * ":PTIME:TCODE?" by returning a timecode in the format specified 610 * above. If nothing is heard from the clock for two polls, 611 * declare a timeout and keep going. 612 */ 613 pp = peer->procptr; 614 up = pp->unitptr; 615 if (up->pollcnt == 0) 616 refclock_report(peer, CEVNT_TIMEOUT); 617 else 618 up->pollcnt--; 619 if (write(pp->io.fd, ":PTIME:TCODE?\r", 14) != 14) { 620 refclock_report(peer, CEVNT_FAULT); 621 } 622 else 623 pp->polls++; 624 } 625 626 #else 627 int refclock_hpgps_bs; 628 #endif /* REFCLOCK */ 629