test: Add a simple time test
Sometimes the time functions are incorrect due to bad time support on a
board. Add a unit test which tries to detect this.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/time_ut.c b/test/time_ut.c
new file mode 100644
index 0000000..6b52245
--- /dev/null
+++ b/test/time_ut.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <errno.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;
+}
+
+static int do_ut_time(cmd_tbl_t *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;
+}
+
+U_BOOT_CMD(
+ ut_time, 1, 1, do_ut_time,
+ "Very basic test of time functions",
+ ""
+);