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/Kconfig b/test/Kconfig
index 1fb1716a4ad59196742f0fbb18b81ee8723c6ba4..3270c84213b033fc666b52d990228f0ce9dc85e1 100644 (file)
--- a/test/Kconfig
+++ b/test/Kconfig
@@ -1 +1,9 @@
+config CMD_UT_TIME
+       bool "Unit tests for time functions"
+       help
+         Enables the 'ut_time' command which tests that the time functions
+         work correctly. The test is fairly simple and will not catch all
+         problems. But if you are having problems with udelay() and the like,
+         this is a good place to start.
+
 source "test/dm/Kconfig"

diff --git a/test/Makefile b/test/Makefile
index 9c95805c44e06e2f8230635adc0773033ef6b70f..08330e020c5d3450ebc5d549bf98c62459cdcdd9 100644 (file)
--- a/test/Makefile
+++ b/test/Makefile
@@ -6,3 +6,4 @@
 
 obj-$(CONFIG_SANDBOX) += command_ut.o
 obj-$(CONFIG_SANDBOX) += compression.o
+obj-$(CONFIG_CMD_UT_TIME) += time_ut.o

diff --git a/test/time_ut.c b/test/time_ut.c
new file mode 100644 (file)
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",
+       ""
+);