/* $NetBSD:$ */

/*
 * Copyright (c) 2000 Jonathan Stone (hereinafter referred to as the author)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Jonathan Stone for
 *      the NetBSD project.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/timepps.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sysexits.h>

void	ppstest __P((const char *PPSfilename));
void	usage __P((void));

int
main(int argc, char **argv)
{
	const char *devname;
	struct stat st;

	if (argc != 2) {
		usage();
	}

	devname = argv[1];

	if (stat(devname, &st) < 0) {
		perror("ppstest: stat'ing device special file");
		exit(EX_NOINPUT);
	}
	if ((st.st_mode & S_IFMT) != S_IFCHR) {
		fprintf(stderr, "ppstest: %s is not a device special file\n",
			devname);
		usage();
	}
	
	ppstest(argv[1]);
	exit(0);
}

void
usage()
{
	fprintf(stderr, "usage: testpps <PPS-source device-special-file>\n");
	exit(EX_USAGE);
}

void
ppstest(PPSfilename)
	const char *PPSfilename;
{
	int fd;
	pps_handle_t handle;      /* handle for PPS sources */
	pps_params_t params;      /* selection of events, options */
	pps_info_t infobuf;       /* status of events */
	struct timespec timeout;  /* waiting time */
	int mode;                 /* supported mode bits */
	int status;		  /* status bits */
	int capturemode;
	u_long assert_seq, clear_seq;
	int first;
	
	/* Open a file descriptor and enable PPS on rising edges */
	fd = open(PPSfilename, O_RDWR, 0);
	if (fd < 0) {
		fprintf(stderr, "cannot open %s\n", PPSfilename);
		exit(1);
	}

	status = time_pps_create(fd, &handle);
	if (status < 0) {
		perror("ppstest: time_pps_create()");
		exit(2);
	}
	
	status = time_pps_getcap(handle, &mode);
	if (status < 0) {
		perror("ppstest setup: time_pps_getcap() failed");
		exit(2);
	}

	/* Complain if the implementation cannot capture ASSERT events. */
	if ((mode & PPS_CAPTUREASSERT) == 0) {
		fprintf(stderr,
			"ppstest: %s cannot  CAPTUREASSERT; mode=%#04x\n",
			PPSfilename, mode);
		exit(1);
	}

	/*
	 * Fetch parameters from kernel, set the desired capture mode,
	 * then write  those parameters backto the kernel.
	 * Always capture assert. Capture clear too, if the
	 * implementation supports it.
	 * (simple parallel-port setups only support one edge.)
	 */
	capturemode = mode & (PPS_CAPTUREASSERT|PPS_CAPTURECLEAR);

	status = time_pps_getparams(handle, &params);
	if (status < 0) {
		perror("ppstest setup: time_pps_getparams() failed");
		exit(2);
	}

	params.mode |= capturemode;
	params.mode |= PPS_TSFMT_TSPEC;   /* use ``struct timespec'' format */
	status = time_pps_setparams(handle, &params);
	if (status < 0) {
		perror("ppstest setup: time_pps_setparams() failed");
		exit(2);
	}

	/* create a zero-valued timeout */
	timeout.tv_sec = 0;
	timeout.tv_nsec = 0;

	status = time_pps_fetch(handle, PPS_TSFMT_TSPEC, &infobuf, &timeout);
	if (status < 0) {
		perror("ppstest: initial: time_pps_fetch() failed");
	}

	first = 1;
	
	/* loop, printing the most recent timestamp every second or so */
	for (first = 1; ;first = 0) {
		/*
		 * Poll at 1 sec - epsilon intervals, to allow for
		 * scheduling vagaries and clock drift.
		 * (NB: Nyquist's theorem does not apply to discrete events.)
		 */
		usleep(900000);

		status = time_pps_fetch(handle, PPS_TSFMT_TSPEC,
					&infobuf, &timeout);
		if (status < 0) {
			perror("ppstest loop: time_pps_fetch() failed");
		}

		/*
		 * If first time round the loop, print sequencenumbers.
		 * thereafter, print the timestamp(s) whose sequence-number
		 * changed since last printed.   If we see both assert
		 * and clear events in one iteration, print the timestamps
		 * in sequence-number order. (The loop may be out of phase.
		 * Or, since this is a diagnostic utility,  the kernel may
		 * have dropped a tick.)
		 */

		/* first clear timestamp,  or new and earlier than assert? */
		if ((mode & PPS_CAPTURECLEAR) && 
		    (first || clear_seq != infobuf.clear_sequence) &&
		    infobuf.clear_sequence < infobuf.assert_sequence) {
			printf("Clear timestamp: %d.%09d, sequence: %ld",
			       (int)infobuf.clear_timestamp.tv_sec,
			       (int)infobuf.clear_timestamp.tv_nsec,
			       (u_long) infobuf.clear_sequence);
			if (!first && clear_seq+1 != infobuf.clear_sequence)
				printf(" (dropped %d)",
				       infobuf.assert_sequence - clear_seq);
			putchar('\n');
			clear_seq = infobuf.clear_sequence;
		}
		/* first or new  assert timestamp? */
		if ((mode & PPS_CAPTURECLEAR) && 
		    (first || assert_seq != infobuf.assert_sequence)) {
			printf("Assert timestamp: %d.%09d, sequence: %ld",
			       (int)infobuf.assert_timestamp.tv_sec,
			       (int)infobuf.assert_timestamp.tv_nsec,
			       (u_long) infobuf.assert_sequence);
			if (!first && assert_seq+1 != infobuf.assert_sequence)
				printf(" (dropped %d)",
				       infobuf.assert_sequence - assert_seq);
			putchar('\n');
			assert_seq = infobuf.assert_sequence;
		}
		/* first or new clear timestamp, and later than assert? */
		if ((mode & PPS_CAPTURECLEAR) && 
		    (first || clear_seq != infobuf.clear_sequence) &&
		    infobuf.clear_sequence >= infobuf.assert_sequence) {
			printf("Clear timestamp: %d.%09d, sequence: %ld",
			       (int)infobuf.clear_timestamp.tv_sec,
			       (int)infobuf.clear_timestamp.tv_nsec,
			       (u_long) infobuf.clear_sequence);
			if (!first && clear_seq + 1 != infobuf.clear_sequence)
				printf(" (dropped %d)",
				       infobuf.clear_sequence - clear_seq);
			putchar('\n');
			clear_seq = infobuf.clear_sequence;
		}
		first = 0;
	}
}