1// SPDX-License-Identifier: LGPL-2.1+
2
3#include <kunit/test.h>
4#include <linux/rtc.h>
5
6/*
7 * Advance a date by one day.
8 */
9static void advance_date(int *year, int *month, int *mday, int *yday)
10{
11 if (*mday != rtc_month_days(month: *month - 1, year: *year)) {
12 ++*mday;
13 ++*yday;
14 return;
15 }
16
17 *mday = 1;
18 if (*month != 12) {
19 ++*month;
20 ++*yday;
21 return;
22 }
23
24 *month = 1;
25 *yday = 1;
26 ++*year;
27}
28
29/*
30 * Checks every day in a 160000 years interval starting on 1970-01-01
31 * against the expected result.
32 */
33static void rtc_time64_to_tm_test_date_range(struct kunit *test)
34{
35 /*
36 * 160000 years = (160000 / 400) * 400 years
37 * = (160000 / 400) * 146097 days
38 * = (160000 / 400) * 146097 * 86400 seconds
39 */
40 time64_t total_secs = ((time64_t) 160000) / 400 * 146097 * 86400;
41
42 int year = 1970;
43 int month = 1;
44 int mday = 1;
45 int yday = 1;
46
47 struct rtc_time result;
48 time64_t secs;
49 s64 days;
50
51 for (secs = 0; secs <= total_secs; secs += 86400) {
52
53 rtc_time64_to_tm(time: secs, tm: &result);
54
55 days = div_s64(dividend: secs, divisor: 86400);
56
57 #define FAIL_MSG "%d/%02d/%02d (%2d) : %lld", \
58 year, month, mday, yday, days
59
60 KUNIT_ASSERT_EQ_MSG(test, year - 1900, result.tm_year, FAIL_MSG);
61 KUNIT_ASSERT_EQ_MSG(test, month - 1, result.tm_mon, FAIL_MSG);
62 KUNIT_ASSERT_EQ_MSG(test, mday, result.tm_mday, FAIL_MSG);
63 KUNIT_ASSERT_EQ_MSG(test, yday, result.tm_yday, FAIL_MSG);
64
65 advance_date(year: &year, month: &month, mday: &mday, yday: &yday);
66 }
67}
68
69static struct kunit_case rtc_lib_test_cases[] = {
70 KUNIT_CASE(rtc_time64_to_tm_test_date_range),
71 {}
72};
73
74static struct kunit_suite rtc_lib_test_suite = {
75 .name = "rtc_lib_test_cases",
76 .test_cases = rtc_lib_test_cases,
77};
78
79kunit_test_suite(rtc_lib_test_suite);
80
81MODULE_LICENSE("GPL");
82

source code of linux/drivers/rtc/lib_test.c