1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * Copyright (c) 2015 Google, Inc
3*4882a593Smuzhiyun * Written by Simon Glass <sjg@chromium.org>
4*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <command.h>
9*4882a593Smuzhiyun #include <errno.h>
10*4882a593Smuzhiyun
test_get_timer(void)11*4882a593Smuzhiyun static int test_get_timer(void)
12*4882a593Smuzhiyun {
13*4882a593Smuzhiyun ulong base, start, next, diff;
14*4882a593Smuzhiyun int iter;
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun base = get_timer(0);
17*4882a593Smuzhiyun start = get_timer(0);
18*4882a593Smuzhiyun for (iter = 0; iter < 10; iter++) {
19*4882a593Smuzhiyun do {
20*4882a593Smuzhiyun next = get_timer(0);
21*4882a593Smuzhiyun } while (start == next);
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun if (start + 1 != next) {
24*4882a593Smuzhiyun printf("%s: iter=%d, start=%lu, next=%lu, expected a difference of 1\n",
25*4882a593Smuzhiyun __func__, iter, start, next);
26*4882a593Smuzhiyun return -EINVAL;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun start++;
29*4882a593Smuzhiyun }
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun /*
32*4882a593Smuzhiyun * Check that get_timer(base) matches our elapsed time, allowing that
33*4882a593Smuzhiyun * an extra millisecond may have passed.
34*4882a593Smuzhiyun */
35*4882a593Smuzhiyun diff = get_timer(base);
36*4882a593Smuzhiyun if (diff != iter && diff != iter + 1) {
37*4882a593Smuzhiyun printf("%s: expected get_timer(base) to match elapsed time: diff=%lu, expected=%d\n",
38*4882a593Smuzhiyun __func__, diff, iter);
39*4882a593Smuzhiyun return -EINVAL;
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun return 0;
43*4882a593Smuzhiyun }
44*4882a593Smuzhiyun
test_timer_get_us(void)45*4882a593Smuzhiyun static int test_timer_get_us(void)
46*4882a593Smuzhiyun {
47*4882a593Smuzhiyun ulong prev, next, min = 1000000;
48*4882a593Smuzhiyun long delta;
49*4882a593Smuzhiyun int iter;
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun /* Find the minimum delta we can measure, in microseconds */
52*4882a593Smuzhiyun prev = timer_get_us();
53*4882a593Smuzhiyun for (iter = 0; iter < 100; ) {
54*4882a593Smuzhiyun next = timer_get_us();
55*4882a593Smuzhiyun if (next != prev) {
56*4882a593Smuzhiyun delta = next - prev;
57*4882a593Smuzhiyun if (delta < 0) {
58*4882a593Smuzhiyun printf("%s: timer_get_us() went backwards from %lu to %lu\n",
59*4882a593Smuzhiyun __func__, prev, next);
60*4882a593Smuzhiyun return -EINVAL;
61*4882a593Smuzhiyun } else if (delta != 0) {
62*4882a593Smuzhiyun if (delta < min)
63*4882a593Smuzhiyun min = delta;
64*4882a593Smuzhiyun prev = next;
65*4882a593Smuzhiyun iter++;
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun if (min != 1) {
71*4882a593Smuzhiyun printf("%s: Minimum microsecond delta should be 1 but is %lu\n",
72*4882a593Smuzhiyun __func__, min);
73*4882a593Smuzhiyun return -EINVAL;
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun return 0;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun
test_time_comparison(void)79*4882a593Smuzhiyun static int test_time_comparison(void)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun ulong start_us, end_us, delta_us;
82*4882a593Smuzhiyun long error;
83*4882a593Smuzhiyun ulong start;
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun start = get_timer(0);
86*4882a593Smuzhiyun start_us = timer_get_us();
87*4882a593Smuzhiyun while (get_timer(start) < 1000)
88*4882a593Smuzhiyun ;
89*4882a593Smuzhiyun end_us = timer_get_us();
90*4882a593Smuzhiyun delta_us = end_us - start_us;
91*4882a593Smuzhiyun error = delta_us - 1000000;
92*4882a593Smuzhiyun printf("%s: Microsecond time for 1 second: %lu, error = %ld\n",
93*4882a593Smuzhiyun __func__, delta_us, error);
94*4882a593Smuzhiyun if (abs(error) > 1000)
95*4882a593Smuzhiyun return -EINVAL;
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun return 0;
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun
test_udelay(void)100*4882a593Smuzhiyun static int test_udelay(void)
101*4882a593Smuzhiyun {
102*4882a593Smuzhiyun long error;
103*4882a593Smuzhiyun ulong start, delta;
104*4882a593Smuzhiyun int iter;
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun start = get_timer(0);
107*4882a593Smuzhiyun for (iter = 0; iter < 1000; iter++)
108*4882a593Smuzhiyun udelay(1000);
109*4882a593Smuzhiyun delta = get_timer(start);
110*4882a593Smuzhiyun error = delta - 1000;
111*4882a593Smuzhiyun printf("%s: Delay time for 1000 udelay(1000): %lu ms, error = %ld\n",
112*4882a593Smuzhiyun __func__, delta, error);
113*4882a593Smuzhiyun if (abs(error) > 100)
114*4882a593Smuzhiyun return -EINVAL;
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun return 0;
117*4882a593Smuzhiyun }
118*4882a593Smuzhiyun
do_ut_time(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])119*4882a593Smuzhiyun int do_ut_time(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
120*4882a593Smuzhiyun {
121*4882a593Smuzhiyun int ret = 0;
122*4882a593Smuzhiyun
123*4882a593Smuzhiyun ret |= test_get_timer();
124*4882a593Smuzhiyun ret |= test_timer_get_us();
125*4882a593Smuzhiyun ret |= test_time_comparison();
126*4882a593Smuzhiyun ret |= test_udelay();
127*4882a593Smuzhiyun
128*4882a593Smuzhiyun printf("Test %s\n", ret ? "failed" : "passed");
129*4882a593Smuzhiyun
130*4882a593Smuzhiyun return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
131*4882a593Smuzhiyun }
132