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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 | // SPDX-License-Identifier: GPL-2.0 /* * rtc and date/time utility functions * * Copyright (C) 2005-06 Tower Technologies * Author: Alessandro Zummo <a.zummo@towertech.it> * * based on arch/arm/common/rtctime.c and other bits */ #include <linux/export.h> #include <linux/rtc.h> static const unsigned char rtc_days_in_month[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; static const unsigned short rtc_ydays[2][13] = { /* Normal years */ { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, /* Leap years */ { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } }; #define LEAPS_THRU_END_OF(y) ((y) / 4 - (y) / 100 + (y) / 400) /* * The number of days in the month. */ int rtc_month_days(unsigned int month, unsigned int year) { return rtc_days_in_month[month] + (is_leap_year(year) && month == 1); } EXPORT_SYMBOL(rtc_month_days); /* * The number of days since January 1. (0 to 365) */ int rtc_year_days(unsigned int day, unsigned int month, unsigned int year) { return rtc_ydays[is_leap_year(year)][month] + day - 1; } EXPORT_SYMBOL(rtc_year_days); /* * rtc_time64_to_tm - Converts time64_t to rtc_time. * Convert seconds since 01-01-1970 00:00:00 to Gregorian date. */ void rtc_time64_to_tm(time64_t time, struct rtc_time *tm) { unsigned int month, year, secs; int days; /* time must be positive */ days = div_s64_rem(time, 86400, &secs); /* day of the week, 1970-01-01 was a Thursday */ tm->tm_wday = (days + 4) % 7; year = 1970 + days / 365; days -= (year - 1970) * 365 + LEAPS_THRU_END_OF(year - 1) - LEAPS_THRU_END_OF(1970 - 1); while (days < 0) { year -= 1; days += 365 + is_leap_year(year); } tm->tm_year = year - 1900; tm->tm_yday = days + 1; for (month = 0; month < 11; month++) { int newdays; newdays = days - rtc_month_days(month, year); if (newdays < 0) break; days = newdays; } tm->tm_mon = month; tm->tm_mday = days + 1; tm->tm_hour = secs / 3600; secs -= tm->tm_hour * 3600; tm->tm_min = secs / 60; tm->tm_sec = secs - tm->tm_min * 60; tm->tm_isdst = 0; } EXPORT_SYMBOL(rtc_time64_to_tm); /* * Does the rtc_time represent a valid date/time? */ int rtc_valid_tm(struct rtc_time *tm) { if (tm->tm_year < 70 || tm->tm_year > (INT_MAX - 1900) || ((unsigned int)tm->tm_mon) >= 12 || tm->tm_mday < 1 || tm->tm_mday > rtc_month_days(tm->tm_mon, ((unsigned int)tm->tm_year + 1900)) || ((unsigned int)tm->tm_hour) >= 24 || ((unsigned int)tm->tm_min) >= 60 || ((unsigned int)tm->tm_sec) >= 60) return -EINVAL; return 0; } EXPORT_SYMBOL(rtc_valid_tm); /* * rtc_tm_to_time64 - Converts rtc_time to time64_t. * Convert Gregorian date to seconds since 01-01-1970 00:00:00. */ time64_t rtc_tm_to_time64(struct rtc_time *tm) { return mktime64(((unsigned int)tm->tm_year + 1900), tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); } EXPORT_SYMBOL(rtc_tm_to_time64); /* * Convert rtc_time to ktime */ ktime_t rtc_tm_to_ktime(struct rtc_time tm) { return ktime_set(rtc_tm_to_time64(&tm), 0); } EXPORT_SYMBOL_GPL(rtc_tm_to_ktime); /* * Convert ktime to rtc_time */ struct rtc_time rtc_ktime_to_tm(ktime_t kt) { struct timespec64 ts; struct rtc_time ret; ts = ktime_to_timespec64(kt); /* Round up any ns */ if (ts.tv_nsec) ts.tv_sec++; rtc_time64_to_tm(ts.tv_sec, &ret); return ret; } EXPORT_SYMBOL_GPL(rtc_ktime_to_tm); |