drivers/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) && defined(CONFIG_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 int rtc_get (struct rtc_time *tmp)
  45 {
  46         int rel = 0;
  47         uchar sec, min, hour, mday, wday, mon_cent, year;
  48
  49         sec     = rtc_read (0x02);
  50         min     = rtc_read (0x03);
  51         hour    = rtc_read (0x04);
  52         mday    = rtc_read (0x05);
  53         wday    = rtc_read (0x06);
  54         mon_cent= rtc_read (0x07);
  55         year    = rtc_read (0x08);
  56
  57         debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  58                 "hr: %02x min: %02x sec: %02x\n",
  59                 year, mon_cent, mday, wday,
  60                 hour, min, sec );
  61         debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
  62                 rtc_read (0x0C),
  63                 rtc_read (0x0B),
  64                 rtc_read (0x0A),
  65                 rtc_read (0x09) );
  66
  67         if (sec & 0x80) {
  68                 puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
  69                 rel = -1;
  70         }
  71
  72         tmp->tm_sec  = bcd2bin (sec  & 0x7F);
  73         tmp->tm_min  = bcd2bin (min  & 0x7F);
  74         tmp->tm_hour = bcd2bin (hour & 0x3F);
  75         tmp->tm_mday = bcd2bin (mday & 0x3F);
  76         tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
  77         tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
  78         tmp->tm_wday = bcd2bin (wday & 0x07);
  79         tmp->tm_yday = 0;
  80         tmp->tm_isdst= 0;
  81
  82         debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  83                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  84                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  85
  86         return rel;
  87 }
  88
  89 void rtc_set (struct rtc_time *tmp)
  90 {
  91         uchar century;
  92
  93         debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  94                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  95                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  96
  97         rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
  98
  99         century = (tmp->tm_year >= 2000) ? 0x80 : 0;
 100         rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
 101
 102         rtc_write (0x06, bin2bcd(tmp->tm_wday));
 103         rtc_write (0x05, bin2bcd(tmp->tm_mday));
 104         rtc_write (0x04, bin2bcd(tmp->tm_hour));
 105         rtc_write (0x03, bin2bcd(tmp->tm_min ));
 106         rtc_write (0x02, bin2bcd(tmp->tm_sec ));
 107 }
 108
 109 void rtc_reset (void)
 110 {
 111         /* clear all control & status registers */
 112         rtc_write (0x00, 0x00);
 113         rtc_write (0x01, 0x00);
 114         rtc_write (0x0D, 0x00);
 115
 116         /* clear Voltage Low bit */
 117         rtc_write (0x02, rtc_read (0x02) & 0x7F);
 118
 119         /* reset all alarms */
 120         rtc_write (0x09, 0x00);
 121         rtc_write (0x0A, 0x00);
 122         rtc_write (0x0B, 0x00);
 123         rtc_write (0x0C, 0x00);
 124 }
 125
 126 /* ------------------------------------------------------------------------- */
 127
 128 static uchar rtc_read (uchar reg)
 129 {
 130         return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
 131 }
 132
 133 static void rtc_write (uchar reg, uchar val)
 134 {
 135         i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
 136 }
 137
 138 static unsigned bcd2bin (uchar n)
 139 {
 140         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 141 }
 142
 143 static unsigned char bin2bcd (unsigned int n)
 144 {
 145         return (((n / 10) << 4) | (n % 10));
 146 }
 147
 148 #endif