rtc/pcf8563.c

   1 /*
   2  * (C) Copyright 2001
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 /*
  25  * Date & Time support for Philips PCF8563 RTC
  26  */
  27
  28 /* #define      DEBUG   */
  29
  30 #include <common.h>
  31 #include <command.h>
  32 #include <rtc.h>
  33 #include <i2c.h>
  34
  35 #if defined(CONFIG_RTC_PCF8563) && (CONFIG_COMMANDS & CFG_CMD_DATE)
  36
  37 static uchar rtc_read  (uchar reg);
  38 static void  rtc_write (uchar reg, uchar val);
  39 static uchar bin2bcd   (unsigned int n);
  40 static unsigned bcd2bin(uchar c);
  41
  42 /* ------------------------------------------------------------------------- */
  43
  44 void rtc_get (struct rtc_time *tmp)
  45 {
  46         uchar sec, min, hour, mday, wday, mon_cent, year;
  47
  48         sec     = rtc_read (0x02);
  49         min     = rtc_read (0x03);
  50         hour    = rtc_read (0x04);
  51         mday    = rtc_read (0x05);
  52         wday    = rtc_read (0x06);
  53         mon_cent= rtc_read (0x07);
  54         year    = rtc_read (0x08);
  55
  56         debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  57                 "hr: %02x min: %02x sec: %02x\n",
  58                 year, mon_cent, mday, wday,
  59                 hour, min, sec );
  60         debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
  61                 rtc_read (0x0C),
  62                 rtc_read (0x0B),
  63                 rtc_read (0x0A),
  64                 rtc_read (0x09) );
  65
  66         if (sec & 0x80) {
  67                 puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
  68         }
  69
  70         tmp->tm_sec  = bcd2bin (sec  & 0x7F);
  71         tmp->tm_min  = bcd2bin (min  & 0x7F);
  72         tmp->tm_hour = bcd2bin (hour & 0x3F);
  73         tmp->tm_mday = bcd2bin (mday & 0x3F);
  74         tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
  75         tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
  76         tmp->tm_wday = bcd2bin (wday & 0x07);
  77         tmp->tm_yday = 0;
  78         tmp->tm_isdst= 0;
  79
  80         debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  81                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  82                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  83 }
  84
  85 void rtc_set (struct rtc_time *tmp)
  86 {
  87         uchar century;
  88
  89         debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  90                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  91                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  92
  93         rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
  94
  95         century = (tmp->tm_year >= 2000) ? 0x80 : 0;
  96         rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
  97
  98         rtc_write (0x06, bin2bcd(tmp->tm_wday));
  99         rtc_write (0x05, bin2bcd(tmp->tm_mday));
 100         rtc_write (0x04, bin2bcd(tmp->tm_hour));
 101         rtc_write (0x03, bin2bcd(tmp->tm_min ));
 102         rtc_write (0x02, bin2bcd(tmp->tm_sec ));
 103 }
 104
 105 void rtc_reset (void)
 106 {
 107         /* clear all control & status registers */
 108         rtc_write (0x00, 0x00);
 109         rtc_write (0x01, 0x00);
 110         rtc_write (0x0D, 0x00);
 111
 112         /* clear Voltage Low bit */
 113         rtc_write (0x02, rtc_read (0x02) & 0x7F);
 114
 115         /* reset all alarms */
 116         rtc_write (0x09, 0x00);
 117         rtc_write (0x0A, 0x00);
 118         rtc_write (0x0B, 0x00);
 119         rtc_write (0x0C, 0x00);
 120 }
 121
 122 /* ------------------------------------------------------------------------- */
 123
 124 static uchar rtc_read (uchar reg)
 125 {
 126         return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
 127 }
 128
 129 static void rtc_write (uchar reg, uchar val)
 130 {
 131         i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
 132 }
 133
 134 static unsigned bcd2bin (uchar n)
 135 {
 136         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 137 }
 138
 139 static unsigned char bin2bcd (unsigned int n)
 140 {
 141         return (((n / 10) << 4) | (n % 10));
 142 }
 143
 144 #endif  /* CONFIG_RTC_PCF8563 && CFG_CMD_DATE */