1 /*	$NetBSD: refclock_heath.c,v 1.2 2009/12/14 00:46:21 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  */
179 static int day1tab[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
180 static 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  */
186 static int speed[] = {B1200, B2400, B4800, B9600};
187 
188 /*
189  * Function prototypes
190  */
191 static	int	heath_start	(int, struct peer *);
192 static	void	heath_shutdown	(int, struct peer *);
193 static	void	heath_receive	(struct recvbuf *);
194 static	void	heath_poll	(int, struct peer *);
195 
196 /*
197  * Transfer vector
198  */
199 struct	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  */
213 static int
214 heath_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 	sprintf(device, DEVICE, unit);
227 	if (!(fd = refclock_open(device, speed[peer->ttl & 0x3],
228 	    LDISC_REMOTE)))
229 		return (0);
230 	pp = peer->procptr;
231 	pp->io.clock_recv = heath_receive;
232 	pp->io.srcclock = (caddr_t)peer;
233 	pp->io.datalen = 0;
234 	pp->io.fd = fd;
235 	if (!io_addclock(&pp->io)) {
236 		(void) close(fd);
237 		return (0);
238 	}
239 
240 	/*
241 	 * Initialize miscellaneous variables
242 	 */
243 	peer->precision = PRECISION;
244 	peer->burst = NSTAGE;
245 	pp->clockdesc = DESCRIPTION;
246 	memcpy((char *)&pp->refid, REFID, 4);
247 	return (1);
248 }
249 
250 
251 /*
252  * heath_shutdown - shut down the clock
253  */
254 static void
255 heath_shutdown(
256 	int unit,
257 	struct peer *peer
258 	)
259 {
260 	struct refclockproc *pp;
261 
262 	pp = peer->procptr;
263 	io_closeclock(&pp->io);
264 }
265 
266 
267 /*
268  * heath_receive - receive data from the serial interface
269  */
270 static void
271 heath_receive(
272 	struct recvbuf *rbufp
273 	)
274 {
275 	struct refclockproc *pp;
276 	struct peer *peer;
277 	l_fp trtmp;
278 	int month, day;
279 	int i;
280 	char dsec, a[5];
281 
282 	/*
283 	 * Initialize pointers and read the timecode and timestamp
284 	 */
285 	peer = (struct peer *)rbufp->recv_srcclock;
286 	pp = peer->procptr;
287 	pp->lencode = refclock_gtlin(rbufp, pp->a_lastcode, BMAX,
288 	    &trtmp);
289 
290 	/*
291 	 * We get down to business, check the timecode format and decode
292 	 * its contents. If the timecode has invalid length or is not in
293 	 * proper format, we declare bad format and exit.
294 	 */
295 	switch (pp->lencode) {
296 
297 	/*
298 	 * GC-1000 timecode format: "hh:mm:ss.f AM  mm/dd/yy"
299 	 * GC-1001 II timecode format: "hh:mm:ss.f   "
300 	 */
301 	case LENHEATH1:
302 		if (sscanf(pp->a_lastcode,
303 		    "%2d:%2d:%2d.%c%5c%2d/%2d/%2d", &pp->hour,
304 		    &pp->minute, &pp->second, &dsec, a, &month, &day,
305 		    &pp->year) != 8) {
306 			refclock_report(peer, CEVNT_BADREPLY);
307 			return;
308 		}
309 		break;
310 
311 #if 0	/* BUG 689 */
312 	/*
313 	 * GC-1001 II timecode format: "hh:mm:ss.f   "
314 	 */
315 	case LENHEATH2:
316 		if (sscanf(pp->a_lastcode, "%2d:%2d:%2d.%c", &pp->hour,
317 		    &pp->minute, &pp->second, &dsec) != 4) {
318 			refclock_report(peer, CEVNT_BADREPLY);
319 			return;
320 		} else {
321 			struct tm *tm_time_p;
322 			time_t     now;
323 
324 			time(&now);	/* we should grab 'now' earlier */
325 			tm_time_p = gmtime(&now);
326 			/*
327 			 * There is a window of time around midnight
328 			 * where this will Do The Wrong Thing.
329 			 */
330 			if (tm_time_p) {
331 				month = tm_time_p->tm_mon + 1;
332 				day = tm_time_p->tm_mday;
333 			} else {
334 				refclock_report(peer, CEVNT_FAULT);
335 				return;
336 			}
337 		}
338 		break;
339 #endif
340 
341 	default:
342 		refclock_report(peer, CEVNT_BADREPLY);
343 		return;
344 	}
345 
346 	/*
347 	 * We determine the day of the year from the DIPswitches. This
348 	 * should be fixed, since somebody might forget to set them.
349 	 * Someday this hazard will be fixed by a fiendish scheme that
350 	 * looks at the timecode and year the radio shows, then computes
351 	 * the residue of the seconds mod the seconds in a leap cycle.
352 	 * If in the third year of that cycle and the third and later
353 	 * months of that year, add one to the day. Then, correct the
354 	 * timecode accordingly. Icky pooh. This bit of nonsense could
355 	 * be avoided if the engineers had been required to write a
356 	 * device driver before finalizing the timecode format.
357 	 */
358 	if (month < 1 || month > 12 || day < 1) {
359 		refclock_report(peer, CEVNT_BADTIME);
360 		return;
361 	}
362 	if (pp->year % 4) {
363 		if (day > day1tab[month - 1]) {
364 			refclock_report(peer, CEVNT_BADTIME);
365 			return;
366 		}
367 		for (i = 0; i < month - 1; i++)
368 		    day += day1tab[i];
369 	} else {
370 		if (day > day2tab[month - 1]) {
371 			refclock_report(peer, CEVNT_BADTIME);
372 			return;
373 		}
374 		for (i = 0; i < month - 1; i++)
375 		    day += day2tab[i];
376 	}
377 	pp->day = day;
378 
379 	/*
380 	 * Determine synchronization and last update
381 	 */
382 	if (!isdigit((unsigned char)dsec))
383 		pp->leap = LEAP_NOTINSYNC;
384 	else {
385 		pp->nsec = (dsec - '0') * 100000000;
386 		pp->leap = LEAP_NOWARNING;
387 	}
388 	if (!refclock_process(pp))
389 		refclock_report(peer, CEVNT_BADTIME);
390 }
391 
392 
393 /*
394  * heath_poll - called by the transmit procedure
395  */
396 static void
397 heath_poll(
398 	int unit,
399 	struct peer *peer
400 	)
401 {
402 	struct refclockproc *pp;
403 	int bits = TIOCM_RTS;
404 
405 	/*
406 	 * At each poll we check for timeout and toggle the RTS modem
407 	 * control line, then take a timestamp. Presumably, this is the
408 	 * event the radio captures to generate the timecode.
409 	 * Apparently, the radio takes about a second to make up its
410 	 * mind to send a timecode, so the receive timestamp is
411 	 * worthless.
412 	 */
413 	pp = peer->procptr;
414 
415 	/*
416 	 * We toggle the RTS modem control lead (GC-1000) and sent a T
417 	 * (GC-1001 II) to kick a timecode loose from the radio. This
418 	 * code works only for POSIX and SYSV interfaces. With bsd you
419 	 * are on your own. We take a timestamp between the up and down
420 	 * edges to lengthen the pulse, which should be about 50 usec on
421 	 * a Sun IPC. With hotshot CPUs, the pulse might get too short.
422 	 * Later.
423 	 *
424 	 * Bug 689: Even though we no longer support the GC-1001 II,
425 	 * I'm leaving the 'T' write in for timing purposes.
426 	 */
427 	if (ioctl(pp->io.fd, TIOCMBIC, (char *)&bits) < 0)
428 		refclock_report(peer, CEVNT_FAULT);
429 	get_systime(&pp->lastrec);
430 	if (write(pp->io.fd, "T", 1) != 1)
431 		refclock_report(peer, CEVNT_FAULT);
432 	ioctl(pp->io.fd, TIOCMBIS, (char *)&bits);
433 	if (peer->burst > 0)
434 		return;
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 	peer->burst = MAXSTAGE;
448 	pp->polls++;
449 }
450 
451 #else
452 int refclock_heath_bs;
453 #endif /* REFCLOCK */
454