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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id: rtc_as3514.c 12131 2007-01-27 20:48:48Z dan_a $
*
* Copyright (C) 2007 by Barry Wardell
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdbool.h>
#include "rtc.h"
#include "i2c-pp.h"
#include "as3514.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
#define BCD2DEC(X) (((((X)>>4) & 0x0f) * 10) + ((X) & 0xf))
#define DEC2BCD(X) ((((X)/10)<<4) | ((X)%10))
/* Days in each month */
static unsigned int days_in_month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
static inline bool is_leapyear(int year)
{
if( ((year%4)==0) && (((year%100)!=0) || ((year%400)==0)) )
return true;
else
return false;
}
void rtc_init(void)
{
}
int rtc_read_datetime(unsigned char* buf)
{
char tmp[4];
int year;
int i;
unsigned int seconds;
/* RTC_AS3514's slave address is 0x46*/
for (i=0;i<4;i++){
tmp[i] = i2c_readbyte(AS3514_I2C_ADDR, AS3514_RTC_0 + i);
}
seconds = tmp[0] + (tmp[1]<<8) + (tmp[2]<<16) + (tmp[3]<<24);
/* Convert seconds since Jan-1-1980 to format compatible with
* get_time() from firmware/common/timefuncs.c */
/* weekday */
buf[3] = ((seconds % WEEK_SECONDS) / DAY_SECONDS + 2) % 7;
/* Year */
year = 1980;
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;
}
}
buf[6] = year%100;
/* Month */
for(i=0; i<12; i++)
{
if(seconds < days_in_month[i]*DAY_SECONDS){
buf[5] = i+1;
break;
}
seconds -= days_in_month[i]*DAY_SECONDS;
}
/* Month Day */
buf[4] = seconds/DAY_SECONDS;
seconds -= buf[4]*DAY_SECONDS;
buf[4]++; /* 1 ... 31 */
/* Hour */
buf[2] = seconds/HOUR_SECONDS;
seconds -= buf[2]*HOUR_SECONDS;
/* Minute */
buf[1] = seconds/MINUTE_SECONDS;
seconds -= buf[1]*MINUTE_SECONDS;
/* Second */
buf[0] = seconds;
/* Convert to Binary Coded Decimal format */
for(i=0; i<7; i++)
buf[i] = DEC2BCD(buf[i]);
return 7;
}
int rtc_write_datetime(unsigned char* buf)
{
int i, year;
unsigned int year_days = 0;
unsigned int month_days = 0;
unsigned int seconds = 0;
/* Convert from Binary Coded Decimal format */
for(i=0; i<7; i++)
buf[i] = BCD2DEC(buf[i]);
year = 2000 + buf[6];
if(is_leapyear(year)) {
days_in_month[1] = 29;
} else {
days_in_month[1] = 28;
}
/* Number of days in months gone by this year*/
for(i=0; i<(buf[5]-1); i++){
month_days += days_in_month[i];
}
/* Number of days in years gone by since 1-Jan-1980 */
year_days = 365*(buf[6]+20) + (buf[6]-1)/4 + 6;
/* Convert to seconds since 1-Jan-1980 */
seconds = buf[0]
+ buf[1]*MINUTE_SECONDS
+ buf[2]*HOUR_SECONDS
+ (buf[4]-1)*DAY_SECONDS
+ month_days*DAY_SECONDS
+ year_days*DAY_SECONDS;
/* Send data to RTC */
for (i=0;i<4;i++){
pp_i2c_send(AS3514_I2C_ADDR, AS3514_RTC_0 + i, ((seconds >> (8 * i)) & 0xff));
}
return 1;
}
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