1 files changed, 106 insertions, 0 deletions
diff --git a/test/lib/time.c b/test/lib/time.c
new file mode 100644
index 00000000000..b99e738c500
--- /dev/null
+++ b/test/lib/time.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <errno.h>
+#include <time.h>
+#include <linux/delay.h>
+#include <test/lib.h>
+#include <test/ut.h>
+
+static int test_get_timer(struct unit_test_state *uts)
+{
+	ulong base, start, next, diff;
+	int iter;
+
+	base = get_timer(0);
+	start = get_timer(0);
+	for (iter = 0; iter < 10; iter++) {
+		do {
+			next = get_timer(0);
+		} while (start == next);
+
+		ut_asserteq(start + 1, next);
+		start++;
+	}
+
+	/*
+	 * Check that get_timer(base) matches our elapsed time, allowing that
+	 * an extra millisecond may have passed.
+	 */
+	diff = get_timer(base);
+	ut_assert(diff == iter || diff == iter + 1);
+
+	return 0;
+}
+LIB_TEST(test_get_timer, 0);
+
+static int test_timer_get_us(struct unit_test_state *uts)
+{
+	ulong prev, next, min = 1000000;
+	long delta;
+	int iter;
+
+	/* Find the minimum delta we can measure, in microseconds */
+	prev = timer_get_us();
+	for (iter = 0; iter < 100; ) {
+		next = timer_get_us();
+		if (next != prev) {
+			delta = next - prev;
+			ut_assert(delta >= 0);
+			if (delta) {
+				if (delta < min)
+					min = delta;
+				prev = next;
+				iter++;
+			}
+		}
+	}
+
+	ut_asserteq(1, min);
+
+	return 0;
+}
+LIB_TEST(test_timer_get_us, 0);
+
+static int test_time_comparison(struct unit_test_state *uts)
+{
+	ulong start_us, end_us, delta_us;
+	long error;
+	ulong start;
+
+	start = get_timer(0);
+	start_us = timer_get_us();
+	while (get_timer(start) < 1000)
+		;
+	end_us = timer_get_us();
+	delta_us = end_us - start_us;
+	error = delta_us - 1000000;
+	printf("%s: Microsecond time for 1 second: %lu, error = %ld\n",
+	       __func__, delta_us, error);
+	ut_assert(abs(error) <= 1000);
+
+	return 0;
+}
+LIB_TEST(test_time_comparison, 0);
+
+static int test_udelay(struct unit_test_state *uts)
+{
+	long error;
+	ulong start, delta;
+	int iter;
+
+	start = get_timer(0);
+	for (iter = 0; iter < 1000; iter++)
+		udelay(1000);
+	delta = get_timer(start);
+	error = delta - 1000;
+	printf("%s: Delay time for 1000 udelay(1000): %lu ms, error = %ld\n",
+	       __func__, delta, error);
+	ut_assert(abs(error) <= 100);
+
+	return 0;
+}
+LIB_TEST(test_udelay, 0);