1 /* $NetBSD: refclock_pcf.c,v 1.10 2024/08/18 20:47:18 christos Exp $ */
2
3 /*
4 * refclock_pcf - clock driver for the Conrad parallel port radio clock
5 */
6
7 #ifdef HAVE_CONFIG_H
8 # include <config.h>
9 #endif
10
11 #if defined(REFCLOCK) && defined(CLOCK_PCF)
12
13 #include "ntpd.h"
14 #include "ntp_io.h"
15 #include "ntp_refclock.h"
16 #include "ntp_calendar.h"
17 #include "ntp_stdlib.h"
18
19 /*
20 * This driver supports the parallel port radio clock sold by Conrad
21 * Electronic under order numbers 967602 and 642002.
22 *
23 * It requires that the local timezone be CET/CEST and that the pcfclock
24 * device driver be installed. A device driver for Linux is available at
25 * http://home.pages.de/~voegele/pcf.html. Information about a FreeBSD
26 * driver is available at http://schumann.cx/pcfclock/.
27 */
28
29 /*
30 * Interface definitions
31 */
32 #define DEVICE "/dev/pcfclocks/%d"
33 #define OLDDEVICE "/dev/pcfclock%d"
34 #define PRECISION (-1) /* precision assumed (about 0.5 s) */
35 #define REFID "PCF"
36 #define DESCRIPTION "Conrad parallel port radio clock"
37
38 #define LENPCF 18 /* timecode length */
39
40 /*
41 * Function prototypes
42 */
43 static int pcf_start (int, struct peer *);
44 static void pcf_shutdown (int, struct peer *);
45 static void pcf_poll (int, struct peer *);
46
47 /*
48 * Transfer vector
49 */
50 struct refclock refclock_pcf = {
51 pcf_start, /* start up driver */
52 pcf_shutdown, /* shut down driver */
53 pcf_poll, /* transmit poll message */
54 noentry, /* not used */
55 noentry, /* initialize driver (not used) */
56 noentry, /* not used */
57 NOFLAGS /* not used */
58 };
59
60
61 /*
62 * pcf_start - open the device and initialize data for processing
63 */
64 static int
pcf_start(int unit,struct peer * peer)65 pcf_start(
66 int unit,
67 struct peer *peer
68 )
69 {
70 struct refclockproc *pp;
71 int fd;
72 char device[128];
73
74 /*
75 * Open device file for reading.
76 */
77 snprintf(device, sizeof(device), DEVICE, unit);
78 fd = open(device, O_RDONLY);
79 if (fd == -1) {
80 snprintf(device, sizeof(device), OLDDEVICE, unit);
81 fd = open(device, O_RDONLY);
82 }
83 #ifdef DEBUG
84 if (debug)
85 printf ("starting PCF with device %s\n",device);
86 #endif
87 if (fd == -1) {
88 return (0);
89 }
90
91 pp = peer->procptr;
92 pp->io.clock_recv = noentry;
93 pp->io.srcclock = peer;
94 pp->io.datalen = 0;
95 pp->io.fd = fd;
96
97 /*
98 * Initialize miscellaneous variables
99 */
100 peer->precision = PRECISION;
101 pp->clockdesc = DESCRIPTION;
102 /* one transmission takes 172.5 milliseconds since the radio clock
103 transmits 69 bits with a period of 2.5 milliseconds per bit */
104 pp->fudgetime1 = 0.1725;
105 memcpy((char *)&pp->refid, REFID, 4);
106
107 return (1);
108 }
109
110
111 /*
112 * pcf_shutdown - shut down the clock
113 */
114 static void
pcf_shutdown(int unit,struct peer * peer)115 pcf_shutdown(
116 int unit,
117 struct peer *peer
118 )
119 {
120 struct refclockproc *pp;
121
122 pp = peer->procptr;
123 if (NULL != pp)
124 close(pp->io.fd);
125 }
126
127
128 /*
129 * pcf_poll - called by the transmit procedure
130 */
131 static void
pcf_poll(int unit,struct peer * peer)132 pcf_poll(
133 int unit,
134 struct peer *peer
135 )
136 {
137 struct refclockproc *pp;
138 char buf[LENPCF];
139 struct tm tm, *tp;
140 time_t t;
141
142 pp = peer->procptr;
143
144 buf[0] = 0;
145 if (read(pp->io.fd, buf, sizeof(buf)) < (ssize_t)sizeof(buf) || buf[0] != 9) {
146 refclock_report(peer, CEVNT_FAULT);
147 return;
148 }
149
150 ZERO(tm);
151
152 tm.tm_mday = buf[11] * 10 + buf[10];
153 tm.tm_mon = buf[13] * 10 + buf[12] - 1;
154 tm.tm_year = buf[15] * 10 + buf[14];
155 tm.tm_hour = buf[7] * 10 + buf[6];
156 tm.tm_min = buf[5] * 10 + buf[4];
157 tm.tm_sec = buf[3] * 10 + buf[2];
158 tm.tm_isdst = (buf[8] & 1) ? 1 : (buf[8] & 2) ? 0 : -1;
159
160 /*
161 * Y2K convert the 2-digit year
162 */
163 if (tm.tm_year < 99)
164 tm.tm_year += 100;
165
166 t = mktime(&tm);
167 if (t == (time_t) -1) {
168 refclock_report(peer, CEVNT_BADTIME);
169 return;
170 }
171
172 #if defined(__GLIBC__) && defined(_BSD_SOURCE)
173 if ((tm.tm_isdst > 0 && tm.tm_gmtoff != 7200)
174 || (tm.tm_isdst == 0 && tm.tm_gmtoff != 3600)
175 || tm.tm_isdst < 0) {
176 #ifdef DEBUG
177 if (debug)
178 printf ("local time zone not set to CET/CEST\n");
179 #endif
180 refclock_report(peer, CEVNT_BADTIME);
181 return;
182 }
183 #endif
184
185 pp->lencode = strftime(pp->a_lastcode, BMAX, "%Y %m %d %H %M %S", &tm);
186
187 #if defined(_REENTRANT) || defined(_THREAD_SAFE)
188 tp = gmtime_r(&t, &tm);
189 #else
190 tp = gmtime(&t);
191 #endif
192 if (!tp) {
193 refclock_report(peer, CEVNT_FAULT);
194 return;
195 }
196
197 get_systime(&pp->lastrec);
198 pp->polls++;
199 pp->year = tp->tm_year + 1900;
200 pp->day = tp->tm_yday + 1;
201 pp->hour = tp->tm_hour;
202 pp->minute = tp->tm_min;
203 pp->second = tp->tm_sec;
204 pp->nsec = buf[16] * 31250000;
205 if (buf[17] & 1)
206 pp->nsec += 500000000;
207
208 #ifdef DEBUG
209 if (debug)
210 printf ("pcf%d: time is %04d/%02d/%02d %02d:%02d:%02d UTC\n",
211 unit, pp->year, tp->tm_mon + 1, tp->tm_mday, pp->hour,
212 pp->minute, pp->second);
213 #endif
214
215 if (!refclock_process(pp)) {
216 refclock_report(peer, CEVNT_BADTIME);
217 return;
218 }
219 record_clock_stats(&peer->srcadr, pp->a_lastcode);
220 if ((buf[1] & 1) && !(pp->sloppyclockflag & CLK_FLAG2))
221 pp->leap = LEAP_NOTINSYNC;
222 else
223 pp->leap = LEAP_NOWARNING;
224 pp->lastref = pp->lastrec;
225 refclock_receive(peer);
226 }
227 #else
228 NONEMPTY_TRANSLATION_UNIT
229 #endif /* REFCLOCK */
230