/* * Copyright (C) Miroslav Lichvar 2015 * * This program is free software; you can redistribute it and/or modify * it under the terms of version 2 of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* Check the frequency range of the system ntp_adjtime() implementation */ #include #include #include #include #include static int try_ntpadjtime(struct timex *t) { int r; r = ntp_adjtime(t); if (r < 0) printf("ntp_adjtime() failed : %s ", strerror(errno)); return r; } static void reset_ntpadjtime(void) { struct timex t; t.modes = MOD_OFFSET | MOD_FREQUENCY; t.offset = 0; t.freq = 0; try_ntpadjtime(&t); } static void test_freqrange(void) { struct timex t; int i; printf("freq range:\n"); for (i = -1000; i <= 1000; i += 50) { t.modes = MOD_FREQUENCY; t.freq = i * (1 << 16); printf("%4d ppm => ", i); if (try_ntpadjtime(&t) < 0) continue; printf("%4ld ppm : ", t.freq / (1 << 16)); printf("%s\n", t.freq == i * (1 << 16) ? "ok" : "fail"); } } int main() { test_freqrange(); reset_ntpadjtime(); return 0; }