1/* $NetBSD: refclock_heath.c,v 1.9 2020/05/25 20:47:25 christos Exp $ */ 2 3/* 4 * refclock_heath - clock driver for Heath GC-1000 5 * (but no longer the GC-1001 Model II, which apparently never worked) 6 */ 7 8#ifdef HAVE_CONFIG_H 9# include <config.h> 10#endif 11 12#if defined(REFCLOCK) && defined(CLOCK_HEATH) 13 14#include "ntpd.h" 15#include "ntp_io.h" 16#include "ntp_refclock.h" 17#include "ntp_stdlib.h" 18 19#include <stdio.h> 20#include <ctype.h> 21 22#ifdef HAVE_SYS_IOCTL_H 23# include <sys/ioctl.h> 24#endif /* not HAVE_SYS_IOCTL_H */ 25 26/* 27 * This driver supports the Heath GC-1000 Most Accurate Clock, with 28 * RS232C Output Accessory. This is a WWV/WWVH receiver somewhat less 29 * robust than other supported receivers. Its claimed accuracy is 100 ms 30 * when actually synchronized to the broadcast signal, but this doesn't 31 * happen even most of the time, due to propagation conditions, ambient 32 * noise sources, etc. When not synchronized, the accuracy is at the 33 * whim of the internal clock oscillator, which can wander into the 34 * sunset without warning. Since the indicated precision is 100 ms, 35 * expect a host synchronized only to this thing to wander to and fro, 36 * occasionally being rudely stepped when the offset exceeds the default 37 * clock_max of 128 ms. 38 * 39 * There were two GC-1000 versions supported by this driver. The original 40 * GC-1000 with RS-232 output first appeared in 1983, but dissapeared 41 * from the market a few years later. The GC-1001 II with RS-232 output 42 * first appeared circa 1990, but apparently is no longer manufactured. 43 * The two models differ considerably, both in interface and commands. 44 * The GC-1000 has a pseudo-bipolar timecode output triggered by a RTS 45 * transition. The timecode includes both the day of year and time of 46 * day. The GC-1001 II has a true bipolar output and a complement of 47 * single character commands. The timecode includes only the time of 48 * day. 49 * 50 * The GC-1001 II was apparently never tested and, based on a Coverity 51 * scan, apparently never worked [Bug 689]. Related code has been disabled. 52 * 53 * GC-1000 54 * 55 * The internal DIPswitches should be set to operate in MANUAL mode. The 56 * external DIPswitches should be set to GMT and 24-hour format. 57 * 58 * In MANUAL mode the clock responds to a rising edge of the request to 59 * send (RTS) modem control line by sending the timecode. Therefore, it 60 * is necessary that the operating system implement the TIOCMBIC and 61 * TIOCMBIS ioctl system calls and TIOCM_RTS control bit. Present 62 * restrictions require the use of a POSIX-compatible programming 63 * interface, although other interfaces may work as well. 64 * 65 * A simple hardware modification to the clock can be made which 66 * prevents the clock hearing the request to send (RTS) if the HI SPEC 67 * lamp is out. Route the HISPEC signal to the tone decoder board pin 68 * 19, from the display, pin 19. Isolate pin 19 of the decoder board 69 * first, but maintain connection with pin 10. Also isolate pin 38 of 70 * the CPU on the tone board, and use half an added 7400 to gate the 71 * original signal to pin 38 with that from pin 19. 72 * 73 * The clock message consists of 23 ASCII printing characters in the 74 * following format: 75 * 76 * hh:mm:ss.f AM dd/mm/yr<cr> 77 * 78 * hh:mm:ss.f = hours, minutes, seconds 79 * f = deciseconds ('?' when out of spec) 80 * AM/PM/bb = blank in 24-hour mode 81 * dd/mm/yr = day, month, year 82 * 83 * The alarm condition is indicated by '?', rather than a digit, at f. 84 * Note that 0?:??:??.? is displayed before synchronization is first 85 * established and hh:mm:ss.? once synchronization is established and 86 * then lost again for about a day. 87 * 88 * GC-1001 II 89 * 90 * Commands consist of a single letter and are case sensitive. When 91 * enterred in lower case, a description of the action performed is 92 * displayed. When enterred in upper case the action is performed. 93 * Following is a summary of descriptions as displayed by the clock: 94 * 95 * The clock responds with a command The 'A' command returns an ASCII 96 * local time string: HH:MM:SS.T xx<CR>, where 97 * 98 * HH = hours 99 * MM = minutes 100 * SS = seconds 101 * T = tenths-of-seconds 102 * xx = 'AM', 'PM', or ' ' 103 * <CR> = carriage return 104 * 105 * The 'D' command returns 24 pairs of bytes containing the variable 106 * divisor value at the end of each of the previous 24 hours. This 107 * allows the timebase trimming process to be observed. UTC hour 00 is 108 * always returned first. The first byte of each pair is the high byte 109 * of (variable divisor * 16); the second byte is the low byte of 110 * (variable divisor * 16). For example, the byte pair 3C 10 would be 111 * returned for a divisor of 03C1 hex (961 decimal). 112 * 113 * The 'I' command returns: | TH | TL | ER | DH | DL | U1 | I1 | I2 | , 114 * where 115 * 116 * TH = minutes since timebase last trimmed (high byte) 117 * TL = minutes since timebase last trimmed (low byte) 118 * ER = last accumulated error in 1.25 ms increments 119 * DH = high byte of (current variable divisor * 16) 120 * DL = low byte of (current variable divisor * 16) 121 * U1 = UT1 offset (/.1 s): | + | 4 | 2 | 1 | 0 | 0 | 0 | 0 | 122 * I1 = information byte 1: | W | C | D | I | U | T | Z | 1 | , 123 * where 124 * 125 * W = set by WWV(H) 126 * C = CAPTURE LED on 127 * D = TRIM DN LED on 128 * I = HI SPEC LED on 129 * U = TRIM UP LED on 130 * T = DST switch on 131 * Z = UTC switch on 132 * 1 = UT1 switch on 133 * 134 * I2 = information byte 2: | 8 | 8 | 4 | 2 | 1 | D | d | S | , 135 * where 136 * 137 * 8, 8, 4, 2, 1 = TIME ZONE switch settings 138 * D = DST bit (#55) in last-received frame 139 * d = DST bit (#2) in last-received frame 140 * S = clock is in simulation mode 141 * 142 * The 'P' command returns 24 bytes containing the number of frames 143 * received without error during UTC hours 00 through 23, providing an 144 * indication of hourly propagation. These bytes are updated each hour 145 * to reflect the previous 24 hour period. UTC hour 00 is always 146 * returned first. 147 * 148 * The 'T' command returns the UTC time: | HH | MM | SS | T0 | , where 149 * HH = tens-of-hours and hours (packed BCD) 150 * MM = tens-of-minutes and minutes (packed BCD) 151 * SS = tens-of-seconds and seconds (packed BCD) 152 * T = tenths-of-seconds (BCD) 153 * 154 * Fudge Factors 155 * 156 * A fudge time1 value of .04 s appears to center the clock offset 157 * residuals. The fudge time2 parameter is the local time offset east of 158 * Greenwich, which depends on DST. Sorry about that, but the clock 159 * gives no hint on what the DIPswitches say. 160 */ 161 162/* 163 * Interface definitions 164 */ 165#define DEVICE "/dev/heath%d" /* device name and unit */ 166#define PRECISION (-4) /* precision assumed (about 100 ms) */ 167#define REFID "WWV\0" /* reference ID */ 168#define DESCRIPTION "Heath GC-1000 Most Accurate Clock" /* WRU */ 169 170#define LENHEATH1 23 /* min timecode length */ 171#if 0 /* BUG 689 */ 172#define LENHEATH2 13 /* min timecode length */ 173#endif 174 175/* 176 * Tables to compute the ddd of year form icky dd/mm timecode. Viva la 177 * leap. 178 */ 179static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 180static int day2tab[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 181 182/* 183 * Baud rate table. The GC-1000 supports 1200, 2400 and 4800; the 184 * GC-1001 II supports only 9600. 185 */ 186static int speed[] = {B1200, B2400, B4800, B9600}; 187 188/* 189 * Function prototypes 190 */ 191static int heath_start (int, struct peer *); 192static void heath_shutdown (int, struct peer *); 193static void heath_receive (struct recvbuf *); 194static void heath_poll (int, struct peer *); 195 196/* 197 * Transfer vector 198 */ 199struct refclock refclock_heath = { 200 heath_start, /* start up driver */ 201 heath_shutdown, /* shut down driver */ 202 heath_poll, /* transmit poll message */ 203 noentry, /* not used (old heath_control) */ 204 noentry, /* initialize driver */ 205 noentry, /* not used (old heath_buginfo) */ 206 NOFLAGS /* not used */ 207}; 208 209 210/* 211 * heath_start - open the devices and initialize data for processing 212 */ 213static int 214heath_start( 215 int unit, 216 struct peer *peer 217 ) 218{ 219 struct refclockproc *pp; 220 int fd; 221 char device[20]; 222 223 /* 224 * Open serial port 225 */ 226 snprintf(device, sizeof(device), DEVICE, unit); 227 fd = refclock_open(device, speed[peer->ttl & 0x3], 228 LDISC_REMOTE); 229 if (fd <= 0) 230 return (0); 231 pp = peer->procptr; 232 pp->io.clock_recv = heath_receive; 233 pp->io.srcclock = peer; 234 pp->io.datalen = 0; 235 pp->io.fd = fd; 236 if (!io_addclock(&pp->io)) { 237 close(fd); 238 pp->io.fd = -1; 239 return (0); 240 } 241 242 /* 243 * Initialize miscellaneous variables 244 */ 245 peer->precision = PRECISION; 246 pp->clockdesc = DESCRIPTION; 247 memcpy(&pp->refid, REFID, 4); 248 return (1); 249} 250 251 252/* 253 * heath_shutdown - shut down the clock 254 */ 255static void 256heath_shutdown( 257 int unit, 258 struct peer *peer 259 ) 260{ 261 struct refclockproc *pp; 262 263 pp = peer->procptr; 264 if (-1 != pp->io.fd) 265 io_closeclock(&pp->io); 266} 267 268 269/* 270 * heath_receive - receive data from the serial interface 271 */ 272static void 273heath_receive( 274 struct recvbuf *rbufp 275 ) 276{ 277 struct refclockproc *pp; 278 struct peer *peer; 279 l_fp trtmp; 280 int month, day; 281 int i; 282 char dsec, a[5]; 283 284 /* 285 * Initialize pointers and read the timecode and timestamp 286 */ 287 peer = rbufp->recv_peer; 288 pp = peer->procptr; 289 pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, 290 &trtmp); 291 292 /* 293 * We get down to business, check the timecode format and decode 294 * its contents. If the timecode has invalid length or is not in 295 * proper format, we declare bad format and exit. 296 */ 297 switch (pp->lencode) { 298 299 /* 300 * GC-1000 timecode format: "hh:mm:ss.f AM mm/dd/yy" 301 * GC-1001 II timecode format: "hh:mm:ss.f " 302 */ 303 case LENHEATH1: 304 if (sscanf(pp->a_lastcode, 305 "%2d:%2d:%2d.%c%5c%2d/%2d/%2d", &pp->hour, 306 &pp->minute, &pp->second, &dsec, a, &month, &day, 307 &pp->year) != 8) { 308 refclock_report(peer, CEVNT_BADREPLY); 309 return; 310 } 311 break; 312 313#if 0 /* BUG 689 */ 314 /* 315 * GC-1001 II timecode format: "hh:mm:ss.f " 316 */ 317 case LENHEATH2: 318 if (sscanf(pp->a_lastcode, "%2d:%2d:%2d.%c", &pp->hour, 319 &pp->minute, &pp->second, &dsec) != 4) { 320 refclock_report(peer, CEVNT_BADREPLY); 321 return; 322 } else { 323 struct tm *tm_time_p; 324 time_t now; 325 326 time(&now); /* we should grab 'now' earlier */ 327 tm_time_p = gmtime(&now); 328 /* 329 * There is a window of time around midnight 330 * where this will Do The Wrong Thing. 331 */ 332 if (tm_time_p) { 333 month = tm_time_p->tm_mon + 1; 334 day = tm_time_p->tm_mday; 335 } else { 336 refclock_report(peer, CEVNT_FAULT); 337 return; 338 } 339 } 340 break; 341#endif 342 343 default: 344 refclock_report(peer, CEVNT_BADREPLY); 345 return; 346 } 347 348 /* 349 * We determine the day of the year from the DIPswitches. This 350 * should be fixed, since somebody might forget to set them. 351 * Someday this hazard will be fixed by a fiendish scheme that 352 * looks at the timecode and year the radio shows, then computes 353 * the residue of the seconds mod the seconds in a leap cycle. 354 * If in the third year of that cycle and the third and later 355 * months of that year, add one to the day. Then, correct the 356 * timecode accordingly. Icky pooh. This bit of nonsense could 357 * be avoided if the engineers had been required to write a 358 * device driver before finalizing the timecode format. 359 */ 360 if (month < 1 || month > 12 || day < 1) { 361 refclock_report(peer, CEVNT_BADTIME); 362 return; 363 } 364 if (pp->year % 4) { 365 if (day > day1tab[month - 1]) { 366 refclock_report(peer, CEVNT_BADTIME); 367 return; 368 } 369 for (i = 0; i < month - 1; i++) 370 day += day1tab[i]; 371 } else { 372 if (day > day2tab[month - 1]) { 373 refclock_report(peer, CEVNT_BADTIME); 374 return; 375 } 376 for (i = 0; i < month - 1; i++) 377 day += day2tab[i]; 378 } 379 pp->day = day; 380 381 /* 382 * Determine synchronization and last update 383 */ 384 if (!isdigit((unsigned char)dsec)) 385 pp->leap = LEAP_NOTINSYNC; 386 else { 387 pp->nsec = (dsec - '0') * 100000000; 388 pp->leap = LEAP_NOWARNING; 389 } 390 if (!refclock_process(pp)) 391 refclock_report(peer, CEVNT_BADTIME); 392} 393 394 395/* 396 * heath_poll - called by the transmit procedure 397 */ 398static void 399heath_poll( 400 int unit, 401 struct peer *peer 402 ) 403{ 404 struct refclockproc *pp; 405 int bits = TIOCM_RTS; 406 407 /* 408 * At each poll we check for timeout and toggle the RTS modem 409 * control line, then take a timestamp. Presumably, this is the 410 * event the radio captures to generate the timecode. 411 * Apparently, the radio takes about a second to make up its 412 * mind to send a timecode, so the receive timestamp is 413 * worthless. 414 */ 415 pp = peer->procptr; 416 417 /* 418 * We toggle the RTS modem control lead (GC-1000) and sent a T 419 * (GC-1001 II) to kick a timecode loose from the radio. This 420 * code works only for POSIX and SYSV interfaces. With bsd you 421 * are on your own. We take a timestamp between the up and down 422 * edges to lengthen the pulse, which should be about 50 usec on 423 * a Sun IPC. With hotshot CPUs, the pulse might get too short. 424 * Later. 425 * 426 * Bug 689: Even though we no longer support the GC-1001 II, 427 * I'm leaving the 'T' write in for timing purposes. 428 */ 429 if (ioctl(pp->io.fd, TIOCMBIC, (char *)&bits) < 0) 430 refclock_report(peer, CEVNT_FAULT); 431 get_systime(&pp->lastrec); 432 if (write(pp->io.fd, "T", 1) != 1) 433 refclock_report(peer, CEVNT_FAULT); 434 ioctl(pp->io.fd, TIOCMBIS, (char *)&bits); 435 if (pp->coderecv == pp->codeproc) { 436 refclock_report(peer, CEVNT_TIMEOUT); 437 return; 438 } 439 pp->lastref = pp->lastrec; 440 refclock_receive(peer); 441 record_clock_stats(&peer->srcadr, pp->a_lastcode); 442#ifdef DEBUG 443 if (debug) 444 printf("heath: timecode %d %s\n", pp->lencode, 445 pp->a_lastcode); 446#endif 447 pp->polls++; 448} 449 450#else 451int refclock_heath_bs; 452#endif /* REFCLOCK */ 453