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Based on kernel version 3.13. Page generated on 2014-01-20 22:04 EST.

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 int64_t pctns(struct ptp_clock_time *t)
104	{
105		return t->sec * 1000000000LL + t->nsec;
106	}
107	
108	static void usage(char *progname)
109	{
110		fprintf(stderr,
111			"usage: %s [options]\n"
112			" -a val     request a one-shot alarm after 'val' seconds\n"
113			" -A val     request a periodic alarm every 'val' seconds\n"
114			" -c         query the ptp clock's capabilities\n"
115			" -d name    device to open\n"
116			" -e val     read 'val' external time stamp events\n"
117			" -f val     adjust the ptp clock frequency by 'val' ppb\n"
118			" -g         get the ptp clock time\n"
119			" -h         prints this message\n"
120			" -k val     measure the time offset between system and phc clock\n"
121			"            for 'val' times (Maximum 25)\n"
122			" -p val     enable output with a period of 'val' nanoseconds\n"
123			" -P val     enable or disable (val=1|0) the system clock PPS\n"
124			" -s         set the ptp clock time from the system time\n"
125			" -S         set the system time from the ptp clock time\n"
126			" -t val     shift the ptp clock time by 'val' seconds\n",
127			progname);
128	}
129	
130	int main(int argc, char *argv[])
131	{
132		struct ptp_clock_caps caps;
133		struct ptp_extts_event event;
134		struct ptp_extts_request extts_request;
135		struct ptp_perout_request perout_request;
136		struct timespec ts;
137		struct timex tx;
138	
139		static timer_t timerid;
140		struct itimerspec timeout;
141		struct sigevent sigevent;
142	
143		struct ptp_clock_time *pct;
144		struct ptp_sys_offset *sysoff;
145	
146	
147		char *progname;
148		int i, c, cnt, fd;
149	
150		char *device = DEVICE;
151		clockid_t clkid;
152		int adjfreq = 0x7fffffff;
153		int adjtime = 0;
154		int capabilities = 0;
155		int extts = 0;
156		int gettime = 0;
157		int oneshot = 0;
158		int pct_offset = 0;
159		int n_samples = 0;
160		int periodic = 0;
161		int perout = -1;
162		int pps = -1;
163		int settime = 0;
164	
165		int64_t t1, t2, tp;
166		int64_t interval, offset;
167	
168		progname = strrchr(argv[0], '/');
169		progname = progname ? 1+progname : argv[0];
170		while (EOF != (c = getopt(argc, argv, "a:A:cd:e:f:ghk:p:P:sSt:v"))) {
171			switch (c) {
172			case 'a':
173				oneshot = atoi(optarg);
174				break;
175			case 'A':
176				periodic = atoi(optarg);
177				break;
178			case 'c':
179				capabilities = 1;
180				break;
181			case 'd':
182				device = optarg;
183				break;
184			case 'e':
185				extts = atoi(optarg);
186				break;
187			case 'f':
188				adjfreq = atoi(optarg);
189				break;
190			case 'g':
191				gettime = 1;
192				break;
193			case 'k':
194				pct_offset = 1;
195				n_samples = atoi(optarg);
196				break;
197			case 'p':
198				perout = atoi(optarg);
199				break;
200			case 'P':
201				pps = atoi(optarg);
202				break;
203			case 's':
204				settime = 1;
205				break;
206			case 'S':
207				settime = 2;
208				break;
209			case 't':
210				adjtime = atoi(optarg);
211				break;
212			case 'h':
213				usage(progname);
214				return 0;
215			case '?':
216			default:
217				usage(progname);
218				return -1;
219			}
220		}
221	
222		fd = open(device, O_RDWR);
223		if (fd < 0) {
224			fprintf(stderr, "opening %s: %s\n", device, strerror(errno));
225			return -1;
226		}
227	
228		clkid = get_clockid(fd);
229		if (CLOCK_INVALID == clkid) {
230			fprintf(stderr, "failed to read clock id\n");
231			return -1;
232		}
233	
234		if (capabilities) {
235			if (ioctl(fd, PTP_CLOCK_GETCAPS, &caps)) {
236				perror("PTP_CLOCK_GETCAPS");
237			} else {
238				printf("capabilities:\n"
239				       "  %d maximum frequency adjustment (ppb)\n"
240				       "  %d programmable alarms\n"
241				       "  %d external time stamp channels\n"
242				       "  %d programmable periodic signals\n"
243				       "  %d pulse per second\n",
244				       caps.max_adj,
245				       caps.n_alarm,
246				       caps.n_ext_ts,
247				       caps.n_per_out,
248				       caps.pps);
249			}
250		}
251	
252		if (0x7fffffff != adjfreq) {
253			memset(&tx, 0, sizeof(tx));
254			tx.modes = ADJ_FREQUENCY;
255			tx.freq = ppb_to_scaled_ppm(adjfreq);
256			if (clock_adjtime(clkid, &tx)) {
257				perror("clock_adjtime");
258			} else {
259				puts("frequency adjustment okay");
260			}
261		}
262	
263		if (adjtime) {
264			memset(&tx, 0, sizeof(tx));
265			tx.modes = ADJ_SETOFFSET;
266			tx.time.tv_sec = adjtime;
267			tx.time.tv_usec = 0;
268			if (clock_adjtime(clkid, &tx) < 0) {
269				perror("clock_adjtime");
270			} else {
271				puts("time shift okay");
272			}
273		}
274	
275		if (gettime) {
276			if (clock_gettime(clkid, &ts)) {
277				perror("clock_gettime");
278			} else {
279				printf("clock time: %ld.%09ld or %s",
280				       ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec));
281			}
282		}
283	
284		if (settime == 1) {
285			clock_gettime(CLOCK_REALTIME, &ts);
286			if (clock_settime(clkid, &ts)) {
287				perror("clock_settime");
288			} else {
289				puts("set time okay");
290			}
291		}
292	
293		if (settime == 2) {
294			clock_gettime(clkid, &ts);
295			if (clock_settime(CLOCK_REALTIME, &ts)) {
296				perror("clock_settime");
297			} else {
298				puts("set time okay");
299			}
300		}
301	
302		if (extts) {
303			memset(&extts_request, 0, sizeof(extts_request));
304			extts_request.index = 0;
305			extts_request.flags = PTP_ENABLE_FEATURE;
306			if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_request)) {
307				perror("PTP_EXTTS_REQUEST");
308				extts = 0;
309			} else {
310				puts("external time stamp request okay");
311			}
312			for (; extts; extts--) {
313				cnt = read(fd, &event, sizeof(event));
314				if (cnt != sizeof(event)) {
315					perror("read");
316					break;
317				}
318				printf("event index %u at %lld.%09u\n", event.index,
319				       event.t.sec, event.t.nsec);
320				fflush(stdout);
321			}
322			/* Disable the feature again. */
323			extts_request.flags = 0;
324			if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_request)) {
325				perror("PTP_EXTTS_REQUEST");
326			}
327		}
328	
329		if (oneshot) {
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_value.tv_sec = oneshot;
341			if (timer_settime(timerid, 0, &timeout, NULL)) {
342				perror("timer_settime");
343				return -1;
344			}
345			pause();
346			timer_delete(timerid);
347		}
348	
349		if (periodic) {
350			install_handler(SIGALRM, handle_alarm);
351			/* Create a timer. */
352			sigevent.sigev_notify = SIGEV_SIGNAL;
353			sigevent.sigev_signo = SIGALRM;
354			if (timer_create(clkid, &sigevent, &timerid)) {
355				perror("timer_create");
356				return -1;
357			}
358			/* Start the timer. */
359			memset(&timeout, 0, sizeof(timeout));
360			timeout.it_interval.tv_sec = periodic;
361			timeout.it_value.tv_sec = periodic;
362			if (timer_settime(timerid, 0, &timeout, NULL)) {
363				perror("timer_settime");
364				return -1;
365			}
366			while (1) {
367				pause();
368			}
369			timer_delete(timerid);
370		}
371	
372		if (perout >= 0) {
373			if (clock_gettime(clkid, &ts)) {
374				perror("clock_gettime");
375				return -1;
376			}
377			memset(&perout_request, 0, sizeof(perout_request));
378			perout_request.index = 0;
379			perout_request.start.sec = ts.tv_sec + 2;
380			perout_request.start.nsec = 0;
381			perout_request.period.sec = 0;
382			perout_request.period.nsec = perout;
383			if (ioctl(fd, PTP_PEROUT_REQUEST, &perout_request)) {
384				perror("PTP_PEROUT_REQUEST");
385			} else {
386				puts("periodic output request okay");
387			}
388		}
389	
390		if (pps != -1) {
391			int enable = pps ? 1 : 0;
392			if (ioctl(fd, PTP_ENABLE_PPS, enable)) {
393				perror("PTP_ENABLE_PPS");
394			} else {
395				puts("pps for system time request okay");
396			}
397		}
398	
399		if (pct_offset) {
400			if (n_samples <= 0 || n_samples > 25) {
401				puts("n_samples should be between 1 and 25");
402				usage(progname);
403				return -1;
404			}
405	
406			sysoff = calloc(1, sizeof(*sysoff));
407			if (!sysoff) {
408				perror("calloc");
409				return -1;
410			}
411			sysoff->n_samples = n_samples;
412	
413			if (ioctl(fd, PTP_SYS_OFFSET, sysoff))
414				perror("PTP_SYS_OFFSET");
415			else
416				puts("system and phc clock time offset request okay");
417	
418			pct = &sysoff->ts[0];
419			for (i = 0; i < sysoff->n_samples; i++) {
420				t1 = pctns(pct+2*i);
421				tp = pctns(pct+2*i+1);
422				t2 = pctns(pct+2*i+2);
423				interval = t2 - t1;
424				offset = (t2 + t1) / 2 - tp;
425	
426				printf("system time: %ld.%ld\n",
427					(pct+2*i)->sec, (pct+2*i)->nsec);
428				printf("phc    time: %ld.%ld\n",
429					(pct+2*i+1)->sec, (pct+2*i+1)->nsec);
430				printf("system time: %ld.%ld\n",
431					(pct+2*i+2)->sec, (pct+2*i+2)->nsec);
432				printf("system/phc clock time offset is %ld ns\n"
433					"system     clock time delay  is %ld ns\n",
434					offset, interval);
435			}
436	
437			free(sysoff);
438		}
439	
440		close(fd);
441		return 0;
442	}
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