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testptp.c
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1 /*
2  * PTP 1588 clock support - User space test program
3  *
4  * Copyright (C) 2010 OMICRON electronics GmbH
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <math.h>
23 #include <signal.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/ioctl.h>
28 #include <sys/mman.h>
29 #include <sys/stat.h>
30 #include <sys/time.h>
31 #include <sys/timex.h>
32 #include <sys/types.h>
33 #include <time.h>
34 #include <unistd.h>
35 
36 #include <linux/ptp_clock.h>
37 
38 #define DEVICE "/dev/ptp0"
39 
40 #ifndef ADJ_SETOFFSET
41 #define ADJ_SETOFFSET 0x0100
42 #endif
43 
44 #ifndef CLOCK_INVALID
45 #define CLOCK_INVALID -1
46 #endif
47 
48 /* When glibc offers the syscall, this will go away. */
49 #include <sys/syscall.h>
50 static int clock_adjtime(clockid_t id, struct timex *tx)
51 {
52  return syscall(__NR_clock_adjtime, id, tx);
53 }
54 
55 static clockid_t get_clockid(int fd)
56 {
57 #define CLOCKFD 3
58 #define FD_TO_CLOCKID(fd) ((~(clockid_t) (fd) << 3) | CLOCKFD)
59 
60  return FD_TO_CLOCKID(fd);
61 }
62 
63 static void handle_alarm(int s)
64 {
65  printf("received signal %d\n", s);
66 }
67 
68 static int install_handler(int signum, void (*handler)(int))
69 {
70  struct sigaction action;
71  sigset_t mask;
72 
73  /* Unblock the signal. */
74  sigemptyset(&mask);
75  sigaddset(&mask, signum);
76  sigprocmask(SIG_UNBLOCK, &mask, NULL);
77 
78  /* Install the signal handler. */
79  action.sa_handler = handler;
80  action.sa_flags = 0;
81  sigemptyset(&action.sa_mask);
82  sigaction(signum, &action, NULL);
83 
84  return 0;
85 }
86 
87 static long ppb_to_scaled_ppm(int ppb)
88 {
89  /*
90  * The 'freq' field in the 'struct timex' is in parts per
91  * million, but with a 16 bit binary fractional field.
92  * Instead of calculating either one of
93  *
94  * scaled_ppm = (ppb / 1000) << 16 [1]
95  * scaled_ppm = (ppb << 16) / 1000 [2]
96  *
97  * we simply use double precision math, in order to avoid the
98  * truncation in [1] and the possible overflow in [2].
99  */
100  return (long) (ppb * 65.536);
101 }
102 
103 static void usage(char *progname)
104 {
105  fprintf(stderr,
106  "usage: %s [options]\n"
107  " -a val request a one-shot alarm after 'val' seconds\n"
108  " -A val request a periodic alarm every 'val' seconds\n"
109  " -c query the ptp clock's capabilities\n"
110  " -d name device to open\n"
111  " -e val read 'val' external time stamp events\n"
112  " -f val adjust the ptp clock frequency by 'val' ppb\n"
113  " -g get the ptp clock time\n"
114  " -h prints this message\n"
115  " -p val enable output with a period of 'val' nanoseconds\n"
116  " -P val enable or disable (val=1|0) the system clock PPS\n"
117  " -s set the ptp clock time from the system time\n"
118  " -S set the system time from the ptp clock time\n"
119  " -t val shift the ptp clock time by 'val' seconds\n",
120  progname);
121 }
122 
123 int main(int argc, char *argv[])
124 {
125  struct ptp_clock_caps caps;
126  struct ptp_extts_event event;
127  struct ptp_extts_request extts_request;
128  struct ptp_perout_request perout_request;
129  struct timespec ts;
130  struct timex tx;
131 
132  static timer_t timerid;
133  struct itimerspec timeout;
134  struct sigevent sigevent;
135 
136  char *progname;
137  int c, cnt, fd;
138 
139  char *device = DEVICE;
140  clockid_t clkid;
141  int adjfreq = 0x7fffffff;
142  int adjtime = 0;
143  int capabilities = 0;
144  int extts = 0;
145  int gettime = 0;
146  int oneshot = 0;
147  int periodic = 0;
148  int perout = -1;
149  int pps = -1;
150  int settime = 0;
151 
152  progname = strrchr(argv[0], '/');
153  progname = progname ? 1+progname : argv[0];
154  while (EOF != (c = getopt(argc, argv, "a:A:cd:e:f:ghp:P:sSt:v"))) {
155  switch (c) {
156  case 'a':
157  oneshot = atoi(optarg);
158  break;
159  case 'A':
160  periodic = atoi(optarg);
161  break;
162  case 'c':
163  capabilities = 1;
164  break;
165  case 'd':
166  device = optarg;
167  break;
168  case 'e':
169  extts = atoi(optarg);
170  break;
171  case 'f':
172  adjfreq = atoi(optarg);
173  break;
174  case 'g':
175  gettime = 1;
176  break;
177  case 'p':
178  perout = atoi(optarg);
179  break;
180  case 'P':
181  pps = atoi(optarg);
182  break;
183  case 's':
184  settime = 1;
185  break;
186  case 'S':
187  settime = 2;
188  break;
189  case 't':
190  adjtime = atoi(optarg);
191  break;
192  case 'h':
193  usage(progname);
194  return 0;
195  case '?':
196  default:
197  usage(progname);
198  return -1;
199  }
200  }
201 
202  fd = open(device, O_RDWR);
203  if (fd < 0) {
204  fprintf(stderr, "opening %s: %s\n", device, strerror(errno));
205  return -1;
206  }
207 
208  clkid = get_clockid(fd);
209  if (CLOCK_INVALID == clkid) {
210  fprintf(stderr, "failed to read clock id\n");
211  return -1;
212  }
213 
214  if (capabilities) {
215  if (ioctl(fd, PTP_CLOCK_GETCAPS, &caps)) {
216  perror("PTP_CLOCK_GETCAPS");
217  } else {
218  printf("capabilities:\n"
219  " %d maximum frequency adjustment (ppb)\n"
220  " %d programmable alarms\n"
221  " %d external time stamp channels\n"
222  " %d programmable periodic signals\n"
223  " %d pulse per second\n",
224  caps.max_adj,
225  caps.n_alarm,
226  caps.n_ext_ts,
227  caps.n_per_out,
228  caps.pps);
229  }
230  }
231 
232  if (0x7fffffff != adjfreq) {
233  memset(&tx, 0, sizeof(tx));
234  tx.modes = ADJ_FREQUENCY;
235  tx.freq = ppb_to_scaled_ppm(adjfreq);
236  if (clock_adjtime(clkid, &tx)) {
237  perror("clock_adjtime");
238  } else {
239  puts("frequency adjustment okay");
240  }
241  }
242 
243  if (adjtime) {
244  memset(&tx, 0, sizeof(tx));
245  tx.modes = ADJ_SETOFFSET;
246  tx.time.tv_sec = adjtime;
247  tx.time.tv_usec = 0;
248  if (clock_adjtime(clkid, &tx) < 0) {
249  perror("clock_adjtime");
250  } else {
251  puts("time shift okay");
252  }
253  }
254 
255  if (gettime) {
256  if (clock_gettime(clkid, &ts)) {
257  perror("clock_gettime");
258  } else {
259  printf("clock time: %ld.%09ld or %s",
260  ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec));
261  }
262  }
263 
264  if (settime == 1) {
265  clock_gettime(CLOCK_REALTIME, &ts);
266  if (clock_settime(clkid, &ts)) {
267  perror("clock_settime");
268  } else {
269  puts("set time okay");
270  }
271  }
272 
273  if (settime == 2) {
274  clock_gettime(clkid, &ts);
275  if (clock_settime(CLOCK_REALTIME, &ts)) {
276  perror("clock_settime");
277  } else {
278  puts("set time okay");
279  }
280  }
281 
282  if (extts) {
283  memset(&extts_request, 0, sizeof(extts_request));
284  extts_request.index = 0;
285  extts_request.flags = PTP_ENABLE_FEATURE;
286  if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_request)) {
287  perror("PTP_EXTTS_REQUEST");
288  extts = 0;
289  } else {
290  puts("external time stamp request okay");
291  }
292  for (; extts; extts--) {
293  cnt = read(fd, &event, sizeof(event));
294  if (cnt != sizeof(event)) {
295  perror("read");
296  break;
297  }
298  printf("event index %u at %lld.%09u\n", event.index,
299  event.t.sec, event.t.nsec);
300  fflush(stdout);
301  }
302  /* Disable the feature again. */
303  extts_request.flags = 0;
304  if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_request)) {
305  perror("PTP_EXTTS_REQUEST");
306  }
307  }
308 
309  if (oneshot) {
310  install_handler(SIGALRM, handle_alarm);
311  /* Create a timer. */
312  sigevent.sigev_notify = SIGEV_SIGNAL;
313  sigevent.sigev_signo = SIGALRM;
314  if (timer_create(clkid, &sigevent, &timerid)) {
315  perror("timer_create");
316  return -1;
317  }
318  /* Start the timer. */
319  memset(&timeout, 0, sizeof(timeout));
320  timeout.it_value.tv_sec = oneshot;
321  if (timer_settime(timerid, 0, &timeout, NULL)) {
322  perror("timer_settime");
323  return -1;
324  }
325  pause();
326  timer_delete(timerid);
327  }
328 
329  if (periodic) {
330  install_handler(SIGALRM, handle_alarm);
331  /* Create a timer. */
332  sigevent.sigev_notify = SIGEV_SIGNAL;
333  sigevent.sigev_signo = SIGALRM;
334  if (timer_create(clkid, &sigevent, &timerid)) {
335  perror("timer_create");
336  return -1;
337  }
338  /* Start the timer. */
339  memset(&timeout, 0, sizeof(timeout));
340  timeout.it_interval.tv_sec = periodic;
341  timeout.it_value.tv_sec = periodic;
342  if (timer_settime(timerid, 0, &timeout, NULL)) {
343  perror("timer_settime");
344  return -1;
345  }
346  while (1) {
347  pause();
348  }
349  timer_delete(timerid);
350  }
351 
352  if (perout >= 0) {
353  if (clock_gettime(clkid, &ts)) {
354  perror("clock_gettime");
355  return -1;
356  }
357  memset(&perout_request, 0, sizeof(perout_request));
358  perout_request.index = 0;
359  perout_request.start.sec = ts.tv_sec + 2;
360  perout_request.start.nsec = 0;
361  perout_request.period.sec = 0;
362  perout_request.period.nsec = perout;
363  if (ioctl(fd, PTP_PEROUT_REQUEST, &perout_request)) {
364  perror("PTP_PEROUT_REQUEST");
365  } else {
366  puts("periodic output request okay");
367  }
368  }
369 
370  if (pps != -1) {
371  int enable = pps ? 1 : 0;
372  if (ioctl(fd, PTP_ENABLE_PPS, enable)) {
373  perror("PTP_ENABLE_PPS");
374  } else {
375  puts("pps for system time request okay");
376  }
377  }
378 
379  close(fd);
380  return 0;
381 }
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