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 11 static 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 45 static 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 79 static 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 } 99 100 static 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 } 118 119 int 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