1 files changed, 75 insertions, 0 deletions
diff --git a/test/kernel/ntpadjtime.c b/test/kernel/ntpadjtime.c
new file mode 100644
index 0000000..4af96b4
--- /dev/null
+++ b/test/kernel/ntpadjtime.c
@@ -0,0 +1,75 @@
+/*
+ * 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 <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/timex.h>
+
+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;
+}