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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2012 by Bertrik Sikken
*
* Based on code from: rtc_as3514.c
* Copyright (C) 2007 by Barry Wardell
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdbool.h>
#include <stdint.h>
#include "time.h"
#define MINUTE_SECONDS 60
#define HOUR_SECONDS 3600
#define DAY_SECONDS 86400
#define WEEK_SECONDS 604800
#define YEAR_SECONDS 31536000
#define LEAP_YEAR_SECONDS 31622400
/* Days in each month */
static uint8_t days_in_month[] =
{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
static inline bool is_leapyear(int year)
{
return (((year%4)==0) && (((year%100)!=0) || ((year%400)==0)));
}
struct tm *gmtime(const time_t *timep)
{
static struct tm time;
return gmtime_r(timep, &time);
}
struct tm *gmtime_r(const time_t *timep, struct tm *tm)
{
time_t seconds = *timep;
int year, i, mday, hour, min;
/* weekday */
tm->tm_wday = ((seconds % WEEK_SECONDS) / DAY_SECONDS + 4) % 7;
/* Year */
year = 1970;
while (seconds >= LEAP_YEAR_SECONDS)
{
if (is_leapyear(year)){
seconds -= LEAP_YEAR_SECONDS;
} else {
seconds -= YEAR_SECONDS;
}
year++;
}
if (is_leapyear(year)) {
days_in_month[1] = 29;
} else {
days_in_month[1] = 28;
if(seconds>YEAR_SECONDS){
year++;
seconds -= YEAR_SECONDS;
}
}
tm->tm_year = year - 1900;
/* Month */
for (i = 0; i < 12; i++)
{
if (seconds < days_in_month[i]*DAY_SECONDS){
tm->tm_mon = i;
break;
}
seconds -= days_in_month[i]*DAY_SECONDS;
}
/* Month Day */
mday = seconds/DAY_SECONDS;
seconds -= mday*DAY_SECONDS;
tm->tm_mday = mday + 1; /* 1 ... 31 */
/* Hour */
hour = seconds/HOUR_SECONDS;
seconds -= hour*HOUR_SECONDS;
tm->tm_hour = hour;
/* Minute */
min = seconds/MINUTE_SECONDS;
seconds -= min*MINUTE_SECONDS;
tm->tm_min = min;
/* Second */
tm->tm_sec = seconds;
return tm;
}
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