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 - 1, *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(secs, &result);
54
55		days = div_s64(secs, 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, &month, &mday, &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