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 } 80