LXR uboot/test/time

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