time_ut.c 2.7 KB

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