test: Move time_ut test into lib

This test doesn't belong at the top level. Move it into the lib/
directory, to match its implementation. Rename it to drop the
unnecessary _ut suffix.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Tom Rini <trini@konsulko.com> # rpi_3, rpi_4, rpi_arm64, am64x_evm_a53, am64-sk
diff --git a/test/lib/Makefile b/test/lib/Makefile
index c36c8b0..217c3ba 100644
--- a/test/lib/Makefile
+++ b/test/lib/Makefile
@@ -27,6 +27,7 @@
 obj-$(CONFIG_GETOPT) += getopt.o
 obj-$(CONFIG_CRC8) += test_crc8.o
 obj-$(CONFIG_UT_LIB_CRYPT) += test_crypt.o
+obj-$(CONFIG_UT_TIME) += time.o
 obj-$(CONFIG_$(XPL_)UT_UNICODE) += unicode.o
 obj-$(CONFIG_LIB_UUID) += uuid.o
 else
diff --git a/test/lib/time.c b/test/lib/time.c
new file mode 100644
index 0000000..149c4b5
--- /dev/null
+++ b/test/lib/time.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <command.h>
+#include <errno.h>
+#include <time.h>
+#include <linux/delay.h>
+
+static int test_get_timer(void)
+{
+	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);
+
+		if (start + 1 != next) {
+			printf("%s: iter=%d, start=%lu, next=%lu, expected a difference of 1\n",
+			       __func__, iter, start, next);
+			return -EINVAL;
+		}
+		start++;
+	}
+
+	/*
+	 * Check that get_timer(base) matches our elapsed time, allowing that
+	 * an extra millisecond may have passed.
+	 */
+	diff = get_timer(base);
+	if (diff != iter && diff != iter + 1) {
+		printf("%s: expected get_timer(base) to match elapsed time: diff=%lu, expected=%d\n",
+		       __func__, diff, iter);
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int test_timer_get_us(void)
+{
+	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;
+			if (delta < 0) {
+				printf("%s: timer_get_us() went backwards from %lu to %lu\n",
+				       __func__, prev, next);
+				return -EINVAL;
+			} else if (delta != 0) {
+				if (delta < min)
+					min = delta;
+				prev = next;
+				iter++;
+			}
+		}
+	}
+
+	if (min != 1) {
+		printf("%s: Minimum microsecond delta should be 1 but is %lu\n",
+		       __func__, min);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int test_time_comparison(void)
+{
+	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);
+	if (abs(error) > 1000)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int test_udelay(void)
+{
+	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);
+	if (abs(error) > 100)
+		return -EINVAL;
+
+	return 0;
+}
+
+int do_ut_time(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+	int ret = 0;
+
+	ret |= test_get_timer();
+	ret |= test_timer_get_us();
+	ret |= test_time_comparison();
+	ret |= test_udelay();
+
+	printf("Test %s\n", ret ? "failed" : "passed");
+
+	return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}