tools/testing/selftests/timers/set-tai.c

   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
  29 static inline int ksft_exit_pass(void)
  30 {
  31         exit(0);
  32 }
  33 static inline int ksft_exit_fail(void)
  34 {
  35         exit(1);
  36 }
  37 #endif
  38
  39 int 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
  51 int 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
  61 int 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 }