diff options
| -rw-r--r-- | drivers/rtc/date.c | 71 |
1 files changed, 32 insertions, 39 deletions
diff --git a/drivers/rtc/date.c b/drivers/rtc/date.c index 8c643a0b46..bfa2e1378e 100644 --- a/drivers/rtc/date.c +++ b/drivers/rtc/date.c @@ -5,10 +5,6 @@ * SPDX-License-Identifier: GPL-2.0+ */ -/* - * Date & Time support for Philips PCF8563 RTC - */ - #include <common.h> #include <command.h> #include <errno.h> @@ -28,53 +24,52 @@ static int month_days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; +static int month_offset[] = { + 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 +}; + /* * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) */ int rtc_calc_weekday(struct rtc_time *tm) { - int leapsToDate; - int lastYear; + int leaps_to_date; + int last_year; int day; - int MonthOffset[] = { 0,31,59,90,120,151,181,212,243,273,304,334 }; if (tm->tm_year < 1753) - return -EINVAL; - lastYear=tm->tm_year-1; + return -1; + last_year = tm->tm_year - 1; - /* - * Number of leap corrections to apply up to end of last year - */ - leapsToDate = lastYear/4 - lastYear/100 + lastYear/400; + /* Number of leap corrections to apply up to end of last year */ + leaps_to_date = last_year / 4 - last_year / 100 + last_year / 400; /* * This year is a leap year if it is divisible by 4 except when it is * divisible by 100 unless it is divisible by 400 * - * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 will be + * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 is. */ - if((tm->tm_year%4==0) && - ((tm->tm_year%100!=0) || (tm->tm_year%400==0)) && - (tm->tm_mon>2)) { - /* - * We are past Feb. 29 in a leap year - */ - day=1; + if (tm->tm_year % 4 == 0 && + ((tm->tm_year % 100 != 0) || (tm->tm_year % 400 == 0)) && + tm->tm_mon > 2) { + /* We are past Feb. 29 in a leap year */ + day = 1; } else { - day=0; + day = 0; } - day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + tm->tm_mday; - - tm->tm_wday=day%7; + day += last_year * 365 + leaps_to_date + month_offset[tm->tm_mon - 1] + + tm->tm_mday; + tm->tm_wday = day % 7; return 0; } int rtc_to_tm(int tim, struct rtc_time *tm) { - register int i; - register long hms, day; + register int i; + register long hms, day; day = tim / SECDAY; hms = tim % SECDAY; @@ -85,22 +80,19 @@ int rtc_to_tm(int tim, struct rtc_time *tm) tm->tm_sec = (hms % 3600) % 60; /* Number of years in days */ - for (i = STARTOFTIME; day >= days_in_year(i); i++) { + for (i = STARTOFTIME; day >= days_in_year(i); i++) day -= days_in_year(i); - } tm->tm_year = i; /* Number of months in days left */ - if (leapyear(tm->tm_year)) { + if (leapyear(tm->tm_year)) days_in_month(FEBRUARY) = 29; - } - for (i = 1; day >= days_in_month(i); i++) { + for (i = 1; day >= days_in_month(i); i++) day -= days_in_month(i); - } days_in_month(FEBRUARY) = 28; tm->tm_mon = i; - /* Days are what is left over (+1) from all that. */ + /* Days are what is left over (+1) from all that */ tm->tm_mday = day + 1; /* Zero unused fields */ @@ -113,19 +105,20 @@ int rtc_to_tm(int tim, struct rtc_time *tm) return rtc_calc_weekday(tm); } -/* Converts Gregorian date to seconds since 1970-01-01 00:00:00. +/* + * Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. * * [For the Julian calendar (which was used in Russia before 1917, * Britain & colonies before 1752, anywhere else before 1582, * and is still in use by some communities) leave out the - * -year/100+year/400 terms, and add 10.] + * -year / 100 + year / 400 terms, and add 10.] * * This algorithm was first published by Gauss (I think). * * WARNING: this function will overflow on 2106-02-07 06:28:16 on - * machines were long is 32-bit! (However, as time_t is signed, we + * machines where long is 32-bit! (However, as time_t is signed, we * will already get problems at other places on 2038-01-19 03:14:08) */ unsigned long rtc_mktime(const struct rtc_time *tm) @@ -135,8 +128,8 @@ unsigned long rtc_mktime(const struct rtc_time *tm) int days, hours; mon -= 2; - if (0 >= (int)mon) { /* 1..12 -> 11,12,1..10 */ - mon += 12; /* Puts Feb last since it has leap day */ + if (0 >= (int)mon) { /* 1..12 -> 11, 12, 1..10 */ + mon += 12; /* Puts Feb last since it has leap day */ year -= 1; } |