xref: /netbsd-src/external/bsd/ntp/dist/ntpd/refclock_pst.c (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
1 /*	$NetBSD: refclock_pst.c,v 1.6 2024/08/18 20:47:18 christos Exp $	*/
2 
3 /*
4  * refclock_pst - clock driver for PSTI/Traconex WWV/WWVH receivers
5  */
6 
7 #ifdef HAVE_CONFIG_H
8 #include <config.h>
9 #endif
10 
11 #if defined(REFCLOCK) && defined(CLOCK_PST)
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 /*
22  * This driver supports the PSTI 1010 and Traconex 1020 WWV/WWVH
23  * Receivers. No specific claim of accuracy is made for these receiver,
24  * but actual experience suggests that 10 ms would be a conservative
25  * assumption.
26  *
27  * The DIPswitches should be set for 9600 bps line speed, 24-hour day-
28  * of-year format and UTC time zone. Automatic correction for DST should
29  * be disabled. It is very important that the year be set correctly in
30  * the DIPswitches; otherwise, the day of year will be incorrect after
31  * 28 April of a normal or leap year. The propagation delay DIPswitches
32  * should be set according to the distance from the transmitter for both
33  * WWV and WWVH, as described in the instructions. While the delay can
34  * be set only to within 11 ms, the fudge time1 parameter can be used
35  * for vernier corrections.
36  *
37  * Using the poll sequence QTQDQM, the response timecode is in three
38  * sections totalling 50 ASCII printing characters, as concatenated by
39  * the driver, in the following format:
40  *
41  * ahh:mm:ss.fffs<cr> yy/dd/mm/ddd<cr> frdzycchhSSFTttttuuxx<cr>
42  *
43  *	on-time = first <cr>
44  *	hh:mm:ss.fff = hours, minutes, seconds, milliseconds
45  *	a = AM/PM indicator (' ' for 24-hour mode)
46  *	yy = year (from internal switches)
47  *	dd/mm/ddd = day of month, month, day of year
48  *	s = daylight-saving indicator (' ' for 24-hour mode)
49  *	f = frequency enable (O = all frequencies enabled)
50  *	r = baud rate (3 = 1200, 6 = 9600)
51  *	d = features indicator (@ = month/day display enabled)
52  *	z = time zone (0 = UTC)
53  *	y = year (5 = 91)
54  *	cc = WWV propagation delay (52 = 22 ms)
55  *	hh = WWVH propagation delay (81 = 33 ms)
56  *	SS = status (80 or 82 = operating correctly)
57  *	F = current receive frequency (4 = 15 MHz)
58  *	T = transmitter (C = WWV, H = WWVH)
59  *	tttt = time since last update (0000 = minutes)
60  *	uu = flush character (03 = ^c)
61  *	xx = 94 (unknown)
62  *
63  * The alarm condition is indicated by other than '8' at A, which occurs
64  * during initial synchronization and when received signal is lost for
65  * an extended period; unlock condition is indicated by other than
66  * "0000" in the tttt subfield at Q.
67  *
68  * Fudge Factors
69  *
70  * There are no special fudge factors other than the generic.
71  */
72 
73 /*
74  * Interface definitions
75  */
76 #define	DEVICE		"/dev/wwv%d" /* device name and unit */
77 #define	SPEED232	B9600	/* uart speed (9600 baud) */
78 #define	PRECISION	(-10)	/* precision assumed (about 1 ms) */
79 #define	WWVREFID	"WWV\0"	/* WWV reference ID */
80 #define	WWVHREFID	"WWVH"	/* WWVH reference ID */
81 #define	DESCRIPTION	"PSTI/Traconex WWV/WWVH Receiver" /* WRU */
82 #define PST_PHI		(10e-6)	/* max clock oscillator offset */
83 #define LENPST		46	/* min timecode length */
84 
85 /*
86  * Unit control structure
87  */
88 struct pstunit {
89 	int	tcswitch;	/* timecode switch */
90 	char	*lastptr;	/* pointer to timecode data */
91 };
92 
93 /*
94  * Function prototypes
95  */
96 static	int	pst_start	(int, struct peer *);
97 static	void	pst_shutdown	(int, struct peer *);
98 static	void	pst_receive	(struct recvbuf *);
99 static	void	pst_poll	(int, struct peer *);
100 
101 /*
102  * Transfer vector
103  */
104 struct	refclock refclock_pst = {
105 	pst_start,		/* start up driver */
106 	pst_shutdown,		/* shut down driver */
107 	pst_poll,		/* transmit poll message */
108 	noentry,		/* not used (old pst_control) */
109 	noentry,		/* initialize driver */
110 	noentry,		/* not used (old pst_buginfo) */
111 	NOFLAGS			/* not used */
112 };
113 
114 
115 /*
116  * pst_start - open the devices and initialize data for processing
117  */
118 static int
119 pst_start(
120 	int unit,
121 	struct peer *peer
122 	)
123 {
124 	register struct pstunit *up;
125 	struct refclockproc *pp;
126 	int fd;
127 	char device[20];
128 
129 	/*
130 	 * Open serial port. Use CLK line discipline, if available.
131 	 */
132 	snprintf(device, sizeof(device), DEVICE, unit);
133 	fd = refclock_open(&peer->srcadr, device, SPEED232, LDISC_CLK);
134 	if (fd <= 0)
135 		return (0);
136 
137 	/*
138 	 * Allocate and initialize unit structure
139 	 */
140 	up = emalloc_zero(sizeof(*up));
141 	pp = peer->procptr;
142 	pp->io.clock_recv = pst_receive;
143 	pp->io.srcclock = peer;
144 	pp->io.datalen = 0;
145 	pp->io.fd = fd;
146 	if (!io_addclock(&pp->io)) {
147 		close(fd);
148 		pp->io.fd = -1;
149 		free(up);
150 		return (0);
151 	}
152 	pp->unitptr = up;
153 
154 	/*
155 	 * Initialize miscellaneous variables
156 	 */
157 	peer->precision = PRECISION;
158 	pp->clockdesc = DESCRIPTION;
159 	memcpy((char *)&pp->refid, WWVREFID, 4);
160 	return (1);
161 }
162 
163 
164 /*
165  * pst_shutdown - shut down the clock
166  */
167 static void
168 pst_shutdown(
169 	int unit,
170 	struct peer *peer
171 	)
172 {
173 	register struct pstunit *up;
174 	struct refclockproc *pp;
175 
176 	pp = peer->procptr;
177 	up = pp->unitptr;
178 	if (-1 != pp->io.fd)
179 		io_closeclock(&pp->io);
180 	if (NULL != up)
181 		free(up);
182 }
183 
184 
185 /*
186  * pst_receive - receive data from the serial interface
187  */
188 static void
189 pst_receive(
190 	struct recvbuf *rbufp
191 	)
192 {
193 	register struct pstunit *up;
194 	struct refclockproc *pp;
195 	struct peer *peer;
196 	l_fp trtmp;
197 	u_long ltemp;
198 	char ampmchar;		/* AM/PM indicator */
199 	char daychar;		/* standard/daylight indicator */
200 	char junque[10];	/* "yy/dd/mm/" discard */
201 	char info[14];		/* "frdzycchhSSFT" clock info */
202 
203 	/*
204 	 * Initialize pointers and read the timecode and timestamp
205 	 */
206 	peer = rbufp->recv_peer;
207 	pp = peer->procptr;
208 	up = pp->unitptr;
209 	up->lastptr += refclock_gtlin(rbufp, up->lastptr, pp->a_lastcode
210 	    + BMAX - 2 - up->lastptr, &trtmp);
211 	*up->lastptr++ = ' ';
212 	*up->lastptr = '\0';
213 
214 	/*
215 	 * Note we get a buffer and timestamp for each <cr>, but only
216 	 * the first timestamp is retained.
217 	 */
218 	if (up->tcswitch == 0)
219 		pp->lastrec = trtmp;
220 	up->tcswitch++;
221 	pp->lencode = up->lastptr - pp->a_lastcode;
222 	if (up->tcswitch < 3)
223 		return;
224 
225 	/*
226 	 * We get down to business, check the timecode format and decode
227 	 * its contents. If the timecode has invalid length or is not in
228 	 * proper format, we declare bad format and exit.
229 	 */
230 	if (pp->lencode < LENPST) {
231 		refclock_report(peer, CEVNT_BADREPLY);
232 		return;
233 	}
234 
235 	/*
236 	 * Timecode format:
237 	 * "ahh:mm:ss.fffs yy/dd/mm/ddd frdzycchhSSFTttttuuxx"
238 	 */
239 	if (sscanf(pp->a_lastcode,
240 	    "%c%2d:%2d:%2d.%3ld%c %9s%3d%13s%4ld",
241 	    &ampmchar, &pp->hour, &pp->minute, &pp->second, &pp->nsec,
242 	    &daychar, junque, &pp->day, info, &ltemp) != 10) {
243 		refclock_report(peer, CEVNT_BADREPLY);
244 		return;
245 	}
246 	pp->nsec *= 1000000;
247 
248 	/*
249 	 * Decode synchronization, quality and last update. If
250 	 * unsynchronized, set the leap bits accordingly and exit. Once
251 	 * synchronized, the dispersion depends only on when the clock
252 	 * was last heard, which depends on the time since last update,
253 	 * as reported by the clock.
254 	 */
255 	if (info[9] != '8')
256 		pp->leap = LEAP_NOTINSYNC;
257 	if (info[12] == 'H')
258 		memcpy((char *)&pp->refid, WWVHREFID, 4);
259 	else
260 		memcpy((char *)&pp->refid, WWVREFID, 4);
261 	if (peer->stratum <= 1)
262 		peer->refid = pp->refid;
263 	if (ltemp == 0)
264 		pp->lastref = pp->lastrec;
265 	pp->disp = PST_PHI * ltemp * 60;
266 
267 	/*
268 	 * Process the new sample in the median filter and determine the
269 	 * timecode timestamp.
270 	 */
271 	if (!refclock_process(pp))
272 		refclock_report(peer, CEVNT_BADTIME);
273 	else if (peer->disp > MAXDISTANCE)
274 		refclock_receive(peer);
275 }
276 
277 
278 /*
279  * pst_poll - called by the transmit procedure
280  */
281 static void
282 pst_poll(
283 	int unit,
284 	struct peer *peer
285 	)
286 {
287 	register struct pstunit *up;
288 	struct refclockproc *pp;
289 
290 	/*
291 	 * Time to poll the clock. The PSTI/Traconex clock responds to a
292 	 * "QTQDQMT" by returning a timecode in the format specified
293 	 * above. Note there is no checking on state, since this may not
294 	 * be the only customer reading the clock. Only one customer
295 	 * need poll the clock; all others just listen in. If the clock
296 	 * becomes unreachable, declare a timeout and keep going.
297 	 */
298 	pp = peer->procptr;
299 	up = pp->unitptr;
300 	up->tcswitch = 0;
301 	up->lastptr = pp->a_lastcode;
302 	if (write(pp->io.fd, "QTQDQMT", 6) != 6)
303 		refclock_report(peer, CEVNT_FAULT);
304 	if (pp->coderecv == pp->codeproc) {
305 		refclock_report(peer, CEVNT_TIMEOUT);
306 		return;
307 	}
308 	refclock_receive(peer);
309 	record_clock_stats(&peer->srcadr, pp->a_lastcode);
310 #ifdef DEBUG
311 	if (debug)
312 		printf("pst: timecode %d %s\n", pp->lencode,
313 		    pp->a_lastcode);
314 #endif
315 	pp->polls++;
316 }
317 
318 #else
319 NONEMPTY_TRANSLATION_UNIT
320 #endif /* REFCLOCK */
321