LXR uboot/test/time

   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 <common.h>
   8#include <command.h>
   9#include <errno.h>
  10#include <time.h>
  11#include <linux/delay.h>
  12
  13static int test_get_timer(void)
  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
  47static int test_timer_get_us(void)
  48{
  49        ulong prev, next, min = 1000000;
  50        long delta;
  51        int iter;
  52
  53        /* Find the minimum delta we can measure, in microseconds */
  54        prev = timer_get_us();
  55        for (iter = 0; iter < 100; ) {
  56                next = timer_get_us();
  57                if (next != prev) {
  58                        delta = next - prev;
  59                        if (delta < 0) {
  60                                printf("%s: timer_get_us() went backwards from %lu to %lu\n",
  61                                       __func__, prev, next);
  62                                return -EINVAL;
  63                        } else if (delta != 0) {
  64                                if (delta < min)
  65                                        min = delta;
  66                                prev = next;
  67                                iter++;
  68                        }
  69                }
  70        }
  71
  72        if (min != 1) {
  73                printf("%s: Minimum microsecond delta should be 1 but is %lu\n",
  74                       __func__, min);
  75                return -EINVAL;
  76        }
  77
  78        return 0;
  79}
  80
  81static int test_time_comparison(void)
  82{
  83        ulong start_us, end_us, delta_us;
  84        long error;
  85        ulong start;
  86
  87        start = get_timer(0);
  88        start_us = timer_get_us();
  89        while (get_timer(start) < 1000)
  90                ;
  91        end_us = timer_get_us();
  92        delta_us = end_us - start_us;
  93        error = delta_us - 1000000;
  94        printf("%s: Microsecond time for 1 second: %lu, error = %ld\n",
  95               __func__, delta_us, error);
  96        if (abs(error) > 1000)
  97                return -EINVAL;
  98
  99        return 0;
 100}
 101
 102static int test_udelay(void)
 103{
 104        long error;
 105        ulong start, delta;
 106        int iter;
 107
 108        start = get_timer(0);
 109        for (iter = 0; iter < 1000; iter++)
 110                udelay(1000);
 111        delta = get_timer(start);
 112        error = delta - 1000;
 113        printf("%s: Delay time for 1000 udelay(1000): %lu ms, error = %ld\n",
 114               __func__, delta, error);
 115        if (abs(error) > 100)
 116                return -EINVAL;
 117
 118        return 0;
 119}
 120
 121int do_ut_time(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 122{
 123        int ret = 0;
 124
 125        ret |= test_get_timer();
 126        ret |= test_timer_get_us();
 127        ret |= test_time_comparison();
 128        ret |= test_udelay();
 129
 130        printf("Test %s\n", ret ? "failed" : "passed");
 131
 132        return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
 133}
 134