/*
   * PTP 1588 clock support - User space test program
   *
   * Copyright (C) 2010 OMICRON electronics GmbH
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  #include <errno.h>
  #include <fcntl.h>
  #include <math.h>
  #include <signal.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/ioctl.h>
  #include <sys/mman.h>
  #include <sys/stat.h>
  #include <sys/time.h>
  #include <sys/timex.h>
  #include <sys/types.h>
  #include <time.h>
  #include <unistd.h>
  
  #include <linux/ptp_clock.h>
  
  #define DEVICE "/dev/ptp0"
  
  #ifndef ADJ_SETOFFSET
  #define ADJ_SETOFFSET 0x0100
  #endif
  
  #ifndef CLOCK_INVALID
  #define CLOCK_INVALID -1
  #endif
  
  /* When glibc offers the syscall, this will go away. */
  #include <sys/syscall.h>
  static int clock_adjtime(clockid_t id, struct timex *tx)
  {
  	return syscall(__NR_clock_adjtime, id, tx);
  }
  
  static clockid_t get_clockid(int fd)
  {
  #define CLOCKFD 3
  #define FD_TO_CLOCKID(fd)	((~(clockid_t) (fd) << 3) | CLOCKFD)
  
  	return FD_TO_CLOCKID(fd);
  }
  
  static void handle_alarm(int s)
  {
  	printf("received signal %d
  ", s);
  }
  
  static int install_handler(int signum, void (*handler)(int))
  {
  	struct sigaction action;
  	sigset_t mask;
  
  	/* Unblock the signal. */
  	sigemptyset(&mask);
  	sigaddset(&mask, signum);
  	sigprocmask(SIG_UNBLOCK, &mask, NULL);
  
  	/* Install the signal handler. */
  	action.sa_handler = handler;
  	action.sa_flags = 0;
  	sigemptyset(&action.sa_mask);
  	sigaction(signum, &action, NULL);
  
  	return 0;
  }
  
  static long ppb_to_scaled_ppm(int ppb)
  {
  	/*
  	 * The 'freq' field in the 'struct timex' is in parts per
  	 * million, but with a 16 bit binary fractional field.
  	 * Instead of calculating either one of
  	 *
  	 *    scaled_ppm = (ppb / 1000) << 16  [1]
  	 *    scaled_ppm = (ppb << 16) / 1000  [2]
  	 *
  	 * we simply use double precision math, in order to avoid the
  	 * truncation in [1] and the possible overflow in [2].
  	 */
  	return (long) (ppb * 65.536);
  }
  
  static int64_t pctns(struct ptp_clock_time *t)
  {
  	return t->sec * 1000000000LL + t->nsec;
  }
  
  static void usage(char *progname)
  {
  	fprintf(stderr,
  		"usage: %s [options]
  "
  		" -a val     request a one-shot alarm after 'val' seconds
  "
  		" -A val     request a periodic alarm every 'val' seconds
  "
  		" -c         query the ptp clock's capabilities
  "
  		" -d name    device to open
  "
  		" -e val     read 'val' external time stamp events
  "
  		" -f val     adjust the ptp clock frequency by 'val' ppb
  "
  		" -g         get the ptp clock time
  "
  		" -h         prints this message
  "
  		" -i val     index for event/trigger
  "
  		" -k val     measure the time offset between system and phc clock
  "
  		"            for 'val' times (Maximum 25)
  "
  		" -p val     enable output with a period of 'val' nanoseconds
  "
  		" -P val     enable or disable (val=1|0) the system clock PPS
  "
  		" -s         set the ptp clock time from the system time
  "
  		" -S         set the system time from the ptp clock time
  "
  		" -t val     shift the ptp clock time by 'val' seconds
  ",
  		progname);
  }
  
  int main(int argc, char *argv[])
  {
  	struct ptp_clock_caps caps;
  	struct ptp_extts_event event;
  	struct ptp_extts_request extts_request;
  	struct ptp_perout_request perout_request;
  	struct timespec ts;
  	struct timex tx;
  
  	static timer_t timerid;
  	struct itimerspec timeout;
  	struct sigevent sigevent;
  
  	struct ptp_clock_time *pct;
  	struct ptp_sys_offset *sysoff;
  
  
  	char *progname;
  	int i, c, cnt, fd;
  
  	char *device = DEVICE;
  	clockid_t clkid;
  	int adjfreq = 0x7fffffff;
  	int adjtime = 0;
  	int capabilities = 0;
  	int extts = 0;
  	int gettime = 0;
  	int index = 0;
  	int oneshot = 0;
  	int pct_offset = 0;
  	int n_samples = 0;
  	int periodic = 0;
  	int perout = -1;
  	int pps = -1;
  	int settime = 0;
  
  	int64_t t1, t2, tp;
  	int64_t interval, offset;
  
  	progname = strrchr(argv[0], '/');
  	progname = progname ? 1+progname : argv[0];
  	while (EOF != (c = getopt(argc, argv, "a:A:cd:e:f:ghi:k:p:P:sSt:v"))) {
  		switch (c) {
  		case 'a':
  			oneshot = atoi(optarg);
  			break;
  		case 'A':
  			periodic = atoi(optarg);
  			break;
  		case 'c':
  			capabilities = 1;
  			break;
  		case 'd':
  			device = optarg;
  			break;
  		case 'e':
  			extts = atoi(optarg);
  			break;
  		case 'f':
  			adjfreq = atoi(optarg);
  			break;
  		case 'g':
  			gettime = 1;
  			break;
  		case 'i':
  			index = atoi(optarg);
  			break;
  		case 'k':
  			pct_offset = 1;
  			n_samples = atoi(optarg);
  			break;
  		case 'p':
  			perout = atoi(optarg);
  			break;
  		case 'P':
  			pps = atoi(optarg);
  			break;
  		case 's':
  			settime = 1;
  			break;
  		case 'S':
  			settime = 2;
  			break;
  		case 't':
  			adjtime = atoi(optarg);
  			break;
  		case 'h':
  			usage(progname);
  			return 0;
  		case '?':
  		default:
  			usage(progname);
  			return -1;
  		}
  	}
  
  	fd = open(device, O_RDWR);
  	if (fd < 0) {
  		fprintf(stderr, "opening %s: %s
  ", device, strerror(errno));
  		return -1;
  	}
  
  	clkid = get_clockid(fd);
  	if (CLOCK_INVALID == clkid) {
  		fprintf(stderr, "failed to read clock id
  ");
  		return -1;
  	}
  
  	if (capabilities) {
  		if (ioctl(fd, PTP_CLOCK_GETCAPS, &caps)) {
  			perror("PTP_CLOCK_GETCAPS");
  		} else {
  			printf("capabilities:
  "
  			       "  %d maximum frequency adjustment (ppb)
  "
  			       "  %d programmable alarms
  "
  			       "  %d external time stamp channels
  "
  			       "  %d programmable periodic signals
  "
  			       "  %d pulse per second
  ",
  			       caps.max_adj,
  			       caps.n_alarm,
  			       caps.n_ext_ts,
  			       caps.n_per_out,
  			       caps.pps);
  		}
  	}
  
  	if (0x7fffffff != adjfreq) {
  		memset(&tx, 0, sizeof(tx));
  		tx.modes = ADJ_FREQUENCY;
  		tx.freq = ppb_to_scaled_ppm(adjfreq);
  		if (clock_adjtime(clkid, &tx)) {
  			perror("clock_adjtime");
  		} else {
  			puts("frequency adjustment okay");
  		}
  	}
  
  	if (adjtime) {
  		memset(&tx, 0, sizeof(tx));
  		tx.modes = ADJ_SETOFFSET;
  		tx.time.tv_sec = adjtime;
  		tx.time.tv_usec = 0;
  		if (clock_adjtime(clkid, &tx) < 0) {
  			perror("clock_adjtime");
  		} else {
  			puts("time shift okay");
  		}
  	}
  
  	if (gettime) {
  		if (clock_gettime(clkid, &ts)) {
  			perror("clock_gettime");
  		} else {
  			printf("clock time: %ld.%09ld or %s",
  			       ts.tv_sec, ts.tv_nsec, ctime(&ts.tv_sec));
  		}
  	}
  
  	if (settime == 1) {
  		clock_gettime(CLOCK_REALTIME, &ts);
  		if (clock_settime(clkid, &ts)) {
  			perror("clock_settime");
  		} else {
  			puts("set time okay");
  		}
  	}
  
  	if (settime == 2) {
  		clock_gettime(clkid, &ts);
  		if (clock_settime(CLOCK_REALTIME, &ts)) {
  			perror("clock_settime");
  		} else {
  			puts("set time okay");
  		}
  	}
  
  	if (extts) {
  		memset(&extts_request, 0, sizeof(extts_request));
  		extts_request.index = index;
  		extts_request.flags = PTP_ENABLE_FEATURE;
  		if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_request)) {
  			perror("PTP_EXTTS_REQUEST");
  			extts = 0;
  		} else {
  			puts("external time stamp request okay");
  		}
  		for (; extts; extts--) {
  			cnt = read(fd, &event, sizeof(event));
  			if (cnt != sizeof(event)) {
  				perror("read");
  				break;
  			}
  			printf("event index %u at %lld.%09u
  ", event.index,
  			       event.t.sec, event.t.nsec);
  			fflush(stdout);
  		}
  		/* Disable the feature again. */
  		extts_request.flags = 0;
  		if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_request)) {
  			perror("PTP_EXTTS_REQUEST");
  		}
  	}
  
  	if (oneshot) {
  		install_handler(SIGALRM, handle_alarm);
  		/* Create a timer. */
  		sigevent.sigev_notify = SIGEV_SIGNAL;
  		sigevent.sigev_signo = SIGALRM;
  		if (timer_create(clkid, &sigevent, &timerid)) {
  			perror("timer_create");
  			return -1;
  		}
  		/* Start the timer. */
  		memset(&timeout, 0, sizeof(timeout));
  		timeout.it_value.tv_sec = oneshot;
  		if (timer_settime(timerid, 0, &timeout, NULL)) {
  			perror("timer_settime");
  			return -1;
  		}
  		pause();
  		timer_delete(timerid);
  	}
  
  	if (periodic) {
  		install_handler(SIGALRM, handle_alarm);
  		/* Create a timer. */
  		sigevent.sigev_notify = SIGEV_SIGNAL;
  		sigevent.sigev_signo = SIGALRM;
  		if (timer_create(clkid, &sigevent, &timerid)) {
  			perror("timer_create");
  			return -1;
  		}
  		/* Start the timer. */
  		memset(&timeout, 0, sizeof(timeout));
  		timeout.it_interval.tv_sec = periodic;
  		timeout.it_value.tv_sec = periodic;
  		if (timer_settime(timerid, 0, &timeout, NULL)) {
  			perror("timer_settime");
  			return -1;
  		}
  		while (1) {
  			pause();
  		}
  		timer_delete(timerid);
  	}
  
  	if (perout >= 0) {
  		if (clock_gettime(clkid, &ts)) {
  			perror("clock_gettime");
  			return -1;
  		}
  		memset(&perout_request, 0, sizeof(perout_request));
  		perout_request.index = index;
  		perout_request.start.sec = ts.tv_sec + 2;
  		perout_request.start.nsec = 0;
  		perout_request.period.sec = 0;
  		perout_request.period.nsec = perout;
  		if (ioctl(fd, PTP_PEROUT_REQUEST, &perout_request)) {
  			perror("PTP_PEROUT_REQUEST");
  		} else {
  			puts("periodic output request okay");
  		}
  	}
  
  	if (pps != -1) {
  		int enable = pps ? 1 : 0;
  		if (ioctl(fd, PTP_ENABLE_PPS, enable)) {
  			perror("PTP_ENABLE_PPS");
  		} else {
  			puts("pps for system time request okay");
  		}
  	}
  
  	if (pct_offset) {
  		if (n_samples <= 0 || n_samples > 25) {
  			puts("n_samples should be between 1 and 25");
  			usage(progname);
  			return -1;
  		}
  
  		sysoff = calloc(1, sizeof(*sysoff));
  		if (!sysoff) {
  			perror("calloc");
  			return -1;
  		}
  		sysoff->n_samples = n_samples;
  
  		if (ioctl(fd, PTP_SYS_OFFSET, sysoff))
  			perror("PTP_SYS_OFFSET");
  		else
  			puts("system and phc clock time offset request okay");
  
  		pct = &sysoff->ts[0];
  		for (i = 0; i < sysoff->n_samples; i++) {
  			t1 = pctns(pct+2*i);
  			tp = pctns(pct+2*i+1);
  			t2 = pctns(pct+2*i+2);
  			interval = t2 - t1;
  			offset = (t2 + t1) / 2 - tp;
  
  			printf("system time: %ld.%ld
  ",
  				(pct+2*i)->sec, (pct+2*i)->nsec);
  			printf("phc    time: %ld.%ld
  ",
  				(pct+2*i+1)->sec, (pct+2*i+1)->nsec);
  			printf("system time: %ld.%ld
  ",
  				(pct+2*i+2)->sec, (pct+2*i+2)->nsec);
  			printf("system/phc clock time offset is %ld ns
  "
  				"system     clock time delay  is %ld ns
  ",
  				offset, interval);
  		}
  
  		free(sysoff);
  	}
  
  	close(fd);
  	return 0;
  }