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 #include "../kselftest.h"
27 
set_tai(int offset)28 int set_tai(int offset)
29 {
30 	struct timex tx;
31 
32 	memset(&tx, 0, sizeof(tx));
33 
34 	tx.modes = ADJ_TAI;
35 	tx.constant = offset;
36 
37 	return adjtimex(&tx);
38 }
39 
get_tai(void)40 int get_tai(void)
41 {
42 	struct timex tx;
43 
44 	memset(&tx, 0, sizeof(tx));
45 
46 	adjtimex(&tx);
47 	return tx.tai;
48 }
49 
main(int argc,char ** argv)50 int main(int argc, char **argv)
51 {
52 	int i, ret;
53 
54 	ret = get_tai();
55 	printf("tai offset started at %i\n", ret);
56 
57 	printf("Checking tai offsets can be properly set: ");
58 	fflush(stdout);
59 	for (i = 1; i <= 60; i++) {
60 		ret = set_tai(i);
61 		ret = get_tai();
62 		if (ret != i) {
63 			printf("[FAILED] expected: %i got %i\n", i, ret);
64 			return ksft_exit_fail();
65 		}
66 	}
67 	printf("[OK]\n");
68 	return ksft_exit_pass();
69 }
70