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