firmware/drivers/rtc/rtc_as3514.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2007 by Barry Wardell
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include <stdbool.h>
  22 #include "config.h"
  23 #include "rtc.h"
  24 #include "as3514.h"
  25 #include "ascodec.h"
  26
  27 /* AMS Sansas start counting from Jan 1st 1970 instead of 1980 (not as3525v2) */
  28 #if (CONFIG_CPU==AS3525)
  29 #define SECS_ADJUST 315532800   /* seconds between 1970-1-1 and 1980-1-1 */
  30 #elif (CONFIG_CPU==AS3525v2)
  31 #define SECS_ADJUST 315532800 - (2*365*24*3600) - 26*(24*3600) + 7*3600 + 25*60
  32 #else
  33 #define SECS_ADJUST 0
  34 #endif
  35
  36 #define MINUTE_SECONDS      60
  37 #define HOUR_SECONDS        3600
  38 #define DAY_SECONDS         86400
  39 #define WEEK_SECONDS        604800
  40 #define YEAR_SECONDS        31536000
  41 #define LEAP_YEAR_SECONDS   31622400
  42
  43 /* Days in each month */
  44 static unsigned int days_in_month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  45
  46 static inline bool is_leapyear(int year)
  47 {
  48     if( ((year%4)==0) && (((year%100)!=0) || ((year%400)==0)) )
  49         return true;
  50     else
  51         return false;
  52 }
  53
  54 void rtc_init(void)
  55 {
  56 }
  57
  58 int rtc_read_datetime(struct tm *tm)
  59 {
  60     char tmp[4];
  61     int i, year, mday, hour, min;
  62     unsigned int seconds;
  63
  64     /* RTC_AS3514's slave address is 0x46*/
  65     for (i = 0; i < 4; i++){
  66         tmp[i] = ascodec_read(AS3514_RTC_0 + i);
  67     }
  68     seconds = tmp[0] + (tmp[1]<<8) + (tmp[2]<<16) + (tmp[3]<<24);
  69     seconds -= SECS_ADJUST;
  70
  71     /* Convert seconds since Jan-1-1980 to format compatible with
  72      * get_time() from firmware/common/timefuncs.c */
  73
  74     /* weekday */
  75     tm->tm_wday = ((seconds % WEEK_SECONDS) / DAY_SECONDS + 2) % 7;
  76
  77     /* Year */
  78     year = 1980;
  79     while (seconds >= LEAP_YEAR_SECONDS)
  80     {
  81         if (is_leapyear(year)){
  82             seconds -= LEAP_YEAR_SECONDS;
  83         } else {
  84             seconds -= YEAR_SECONDS;
  85         }
  86
  87         year++;
  88     }
  89
  90     if (is_leapyear(year)) {
  91         days_in_month[1] = 29;
  92     } else {
  93         days_in_month[1] = 28;
  94         if(seconds>YEAR_SECONDS){
  95             year++;
  96             seconds -= YEAR_SECONDS;
  97         }
  98     }
  99     tm->tm_year = year%100 + 100;
 100
 101     /* Month */
 102     for (i = 0; i < 12; i++)
 103     {
 104         if (seconds < days_in_month[i]*DAY_SECONDS){
 105             tm->tm_mon = i;
 106             break;
 107         }
 108
 109         seconds -= days_in_month[i]*DAY_SECONDS;
 110     }
 111
 112     /* Month Day */
 113     mday = seconds/DAY_SECONDS;
 114     seconds -= mday*DAY_SECONDS;
 115     tm->tm_mday = mday + 1; /* 1 ... 31 */
 116
 117     /* Hour */
 118     hour = seconds/HOUR_SECONDS;
 119     seconds -= hour*HOUR_SECONDS;
 120     tm->tm_hour = hour;
 121
 122     /* Minute */
 123     min = seconds/MINUTE_SECONDS;
 124     seconds -= min*MINUTE_SECONDS;
 125     tm->tm_min = min;
 126
 127     /* Second */
 128     tm->tm_sec = seconds;
 129
 130     return 7;
 131 }
 132
 133 int rtc_write_datetime(const struct tm *tm)
 134 {
 135     int i, year;
 136     unsigned int year_days = 0;
 137     unsigned int month_days = 0;
 138     unsigned int seconds = 0;
 139
 140     year = 2000 + tm->tm_year - 100;
 141
 142     if(is_leapyear(year)) {
 143         days_in_month[1] = 29;
 144     } else {
 145         days_in_month[1] = 28;
 146     }
 147
 148     /* Number of days in months gone by this year*/
 149     for(i = 0; i < tm->tm_mon; i++){
 150         month_days += days_in_month[i];
 151     }
 152
 153     /* Number of days in years gone by since 1-Jan-1980 */
 154     year_days = 365*(tm->tm_year-100+20) + (tm->tm_year-100-1)/4 + 6;
 155
 156     /* Convert to seconds since 1-Jan-1980 */
 157     seconds = tm->tm_sec
 158             + tm->tm_min*MINUTE_SECONDS
 159             + tm->tm_hour*HOUR_SECONDS
 160             + (tm->tm_mday-1)*DAY_SECONDS
 161             + month_days*DAY_SECONDS
 162             + year_days*DAY_SECONDS;
 163     seconds += SECS_ADJUST;
 164
 165     /* Send data to RTC */
 166     for (i=0; i<4; i++){
 167         ascodec_write(AS3514_RTC_0 + i, ((seconds >> (8 * i)) & 0xff));
 168     }
 169     return 1;
 170 }
 171