1/* Set tai offset
2 *              by: John Stultz <john.stultz@linaro.org>
3 *              (C) Copyright Linaro 2013
4 *              Licensed under the GPLv2
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
17
18#include <stdio.h>
19#include <stdlib.h>
20#include <time.h>
21#include <sys/time.h>
22#include <sys/timex.h>
23#include <string.h>
24#include <signal.h>
25#include <unistd.h>
26#ifdef KTEST
27#include "../kselftest.h"
28#else
29static inline int ksft_exit_pass(void)
30{
31	exit(0);
32}
33static inline int ksft_exit_fail(void)
34{
35	exit(1);
36}
37#endif
38
39int set_tai(int offset)
40{
41	struct timex tx;
42
43	memset(&tx, 0, sizeof(tx));
44
45	tx.modes = ADJ_TAI;
46	tx.constant = offset;
47
48	return adjtimex(&tx);
49}
50
51int get_tai(void)
52{
53	struct timex tx;
54
55	memset(&tx, 0, sizeof(tx));
56
57	adjtimex(&tx);
58	return tx.tai;
59}
60
61int main(int argc, char **argv)
62{
63	int i, ret;
64
65	ret = get_tai();
66	printf("tai offset started at %i\n", ret);
67
68	printf("Checking tai offsets can be properly set: ");
69	for (i = 1; i <= 60; i++) {
70		ret = set_tai(i);
71		ret = get_tai();
72		if (ret != i) {
73			printf("[FAILED] expected: %i got %i\n", i, ret);
74			return ksft_exit_fail();
75		}
76	}
77	printf("[OK]\n");
78	return ksft_exit_pass();
79}
80