1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2015 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
5 */
6
7 #include <errno.h>
8 #include <time.h>
9 #include <linux/delay.h>
10 #include <test/lib.h>
11 #include <test/ut.h>
12
test_get_timer(struct unit_test_state * uts)13 static int test_get_timer(struct unit_test_state *uts)
14 {
15 ulong base, start, next, diff;
16 int iter;
17
18 base = get_timer(0);
19 start = get_timer(0);
20 for (iter = 0; iter < 10; iter++) {
21 do {
22 next = get_timer(0);
23 } while (start == next);
24
25 if (start + 1 != next) {
26 printf("%s: iter=%d, start=%lu, next=%lu, expected a difference of 1\n",
27 __func__, iter, start, next);
28 return -EINVAL;
29 }
30 start++;
31 }
32
33 /*
34 * Check that get_timer(base) matches our elapsed time, allowing that
35 * an extra millisecond may have passed.
36 */
37 diff = get_timer(base);
38 if (diff != iter && diff != iter + 1) {
39 printf("%s: expected get_timer(base) to match elapsed time: diff=%lu, expected=%d\n",
40 __func__, diff, iter);
41 return -EINVAL;
42 }
43
44 return 0;
45 }
46 LIB_TEST(test_get_timer, 0);
47
test_timer_get_us(struct unit_test_state * uts)48 static int test_timer_get_us(struct unit_test_state *uts)
49 {
50 ulong prev, next, min = 1000000;
51 long delta;
52 int iter;
53
54 /* Find the minimum delta we can measure, in microseconds */
55 prev = timer_get_us();
56 for (iter = 0; iter < 100; ) {
57 next = timer_get_us();
58 if (next != prev) {
59 delta = next - prev;
60 if (delta < 0) {
61 printf("%s: timer_get_us() went backwards from %lu to %lu\n",
62 __func__, prev, next);
63 return -EINVAL;
64 } else if (delta != 0) {
65 if (delta < min)
66 min = delta;
67 prev = next;
68 iter++;
69 }
70 }
71 }
72
73 if (min != 1) {
74 printf("%s: Minimum microsecond delta should be 1 but is %lu\n",
75 __func__, min);
76 return -EINVAL;
77 }
78
79 return 0;
80 }
81 LIB_TEST(test_timer_get_us, 0);
82
test_time_comparison(struct unit_test_state * uts)83 static int test_time_comparison(struct unit_test_state *uts)
84 {
85 ulong start_us, end_us, delta_us;
86 long error;
87 ulong start;
88
89 start = get_timer(0);
90 start_us = timer_get_us();
91 while (get_timer(start) < 1000)
92 ;
93 end_us = timer_get_us();
94 delta_us = end_us - start_us;
95 error = delta_us - 1000000;
96 printf("%s: Microsecond time for 1 second: %lu, error = %ld\n",
97 __func__, delta_us, error);
98 if (abs(error) > 1000)
99 return -EINVAL;
100
101 return 0;
102 }
103 LIB_TEST(test_time_comparison, 0);
104
test_udelay(struct unit_test_state * uts)105 static int test_udelay(struct unit_test_state *uts)
106 {
107 long error;
108 ulong start, delta;
109 int iter;
110
111 start = get_timer(0);
112 for (iter = 0; iter < 1000; iter++)
113 udelay(1000);
114 delta = get_timer(start);
115 error = delta - 1000;
116 printf("%s: Delay time for 1000 udelay(1000): %lu ms, error = %ld\n",
117 __func__, delta, error);
118 if (abs(error) > 100)
119 return -EINVAL;
120
121 return 0;
122 }
123 LIB_TEST(test_udelay, 0);
124