drivers/rtc/ds1556.c

   1 /*
   2  * (C) Copyright 2002
   3  * ARIO Data Networks, Inc. dchiu@ariodata.com
   4  *
   5  * modified for DS1556:
   6  * Frank Panno <fpanno@delphintech.com>, Delphin Technology AG
   7  *
   8  * Based on MontaVista DS1743 code and U-Boot mc146818 code
   9  *
  10  * See file CREDITS for list of people who contributed to this
  11  * project.
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License as
  15  * published by the Free Software Foundation; either version 2 of
  16  * the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  26  * MA 02111-1307 USA
  27  */
  28
  29 /*
  30  * Date & Time support for the DS1556 RTC
  31  */
  32
  33 /*#define       RTC_DEBUG */
  34
  35 #include <common.h>
  36 #include <command.h>
  37 #include <rtc.h>
  38
  39
  40 #if defined(CONFIG_RTC_DS1556) && defined(CONFIG_CMD_DATE)
  41
  42 static uchar rtc_read( unsigned int addr );
  43 static void  rtc_write( unsigned int addr, uchar val);
  44 static uchar bin2bcd   (unsigned int n);
  45 static unsigned bcd2bin(uchar c);
  46
  47 #define RTC_BASE                ( CFG_NVRAM_SIZE + CFG_NVRAM_BASE_ADDR )
  48
  49 #define RTC_YEAR                ( RTC_BASE + 0xf )
  50 #define RTC_MONTH               ( RTC_BASE + 0xe )
  51 #define RTC_DAY_OF_MONTH        ( RTC_BASE + 0xd )
  52 #define RTC_DAY_OF_WEEK         ( RTC_BASE + 0xc )
  53 #define RTC_HOURS               ( RTC_BASE + 0xb )
  54 #define RTC_MINUTES             ( RTC_BASE + 0xa )
  55 #define RTC_SECONDS             ( RTC_BASE + 0x9 )
  56 #define RTC_CENTURY             ( RTC_BASE + 0x8 )
  57
  58 #define RTC_CONTROLA            RTC_CENTURY
  59 #define RTC_CONTROLB            RTC_SECONDS
  60 #define RTC_CONTROLC            RTC_BASE
  61
  62 #define RTC_CA_WRITE            0x80
  63 #define RTC_CA_READ             0x40
  64
  65 #define RTC_CB_OSC_DISABLE      0x80
  66
  67 #define RTC_CC_BATTERY_FLAG     0x10
  68 #define RTC_CC_FREQ_TEST        0x40
  69
  70 /* ------------------------------------------------------------------------- */
  71
  72 int rtc_get( struct rtc_time *tmp )
  73 {
  74         uchar sec, min, hour;
  75         uchar mday, wday, mon, year;
  76
  77         int century;
  78
  79         uchar reg_a;
  80
  81         reg_a = rtc_read( RTC_CONTROLA );
  82         /* lock clock registers for read */
  83         rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
  84
  85         sec     = rtc_read( RTC_SECONDS );
  86         min     = rtc_read( RTC_MINUTES );
  87         hour    = rtc_read( RTC_HOURS );
  88         mday    = rtc_read( RTC_DAY_OF_MONTH );
  89         wday    = rtc_read( RTC_DAY_OF_WEEK );
  90         mon     = rtc_read( RTC_MONTH );
  91         year    = rtc_read( RTC_YEAR );
  92         century = rtc_read( RTC_CENTURY );
  93
  94         /* unlock clock registers after read */
  95         rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  96
  97 #ifdef RTC_DEBUG
  98         printf( "Get RTC year: %02x mon/cent: %02x mon: %02x mday: %02x wday: %02x "
  99                 "hr: %02x min: %02x sec: %02x\n",
 100                 year, century, mon, mday, wday,
 101                 hour, min, sec );
 102 #endif
 103         tmp->tm_sec  = bcd2bin( sec  & 0x7F );
 104         tmp->tm_min  = bcd2bin( min  & 0x7F );
 105         tmp->tm_hour = bcd2bin( hour & 0x3F );
 106         tmp->tm_mday = bcd2bin( mday & 0x3F );
 107         tmp->tm_mon  = bcd2bin( mon & 0x1F );
 108         tmp->tm_wday = bcd2bin( wday & 0x07 );
 109
 110         /* glue year from century and year in century */
 111         tmp->tm_year = bcd2bin( year ) +
 112                 ( bcd2bin( century & 0x3F ) * 100 );
 113
 114         tmp->tm_yday = 0;
 115         tmp->tm_isdst= 0;
 116 #ifdef RTC_DEBUG
 117         printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 118                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 119                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
 120 #endif
 121         return 0;
 122 }
 123
 124 void rtc_set( struct rtc_time *tmp )
 125 {
 126         uchar reg_a;
 127 #ifdef RTC_DEBUG
 128         printf( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 129                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 130                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 131 #endif
 132         /* lock clock registers for write */
 133         reg_a = rtc_read( RTC_CONTROLA );
 134         rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
 135
 136         rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
 137
 138         rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
 139         rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
 140         rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
 141         rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
 142         rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
 143
 144         /* break year up into century and year in century */
 145         rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
 146         rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
 147
 148         /* unlock clock registers after read */
 149         rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
 150 }
 151
 152 void rtc_reset (void)
 153 {
 154         uchar reg_a, reg_b, reg_c;
 155
 156         reg_a = rtc_read( RTC_CONTROLA );
 157         reg_b = rtc_read( RTC_CONTROLB );
 158
 159         if ( reg_b & RTC_CB_OSC_DISABLE )
 160         {
 161                 printf( "real-time-clock was stopped. Now starting...\n" );
 162                 reg_a |= RTC_CA_WRITE;
 163                 reg_b &= ~RTC_CB_OSC_DISABLE;
 164
 165                 rtc_write( RTC_CONTROLA, reg_a );
 166                 rtc_write( RTC_CONTROLB, reg_b );
 167         }
 168
 169         /* make sure read/write clock register bits are cleared */
 170         reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
 171         rtc_write( RTC_CONTROLA, reg_a );
 172
 173         reg_c = rtc_read( RTC_CONTROLC );
 174         if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
 175                 printf( "RTC battery low. Clock setting may not be reliable.\n" );
 176 }
 177
 178 /* ------------------------------------------------------------------------- */
 179
 180 static uchar rtc_read( unsigned int addr )
 181 {
 182         uchar val = *(volatile unsigned char*)(addr);
 183 #ifdef RTC_DEBUG
 184         printf( "rtc_read: %x:%x\n", addr, val );
 185 #endif
 186         return( val );
 187 }
 188
 189 static void rtc_write( unsigned int addr, uchar val )
 190 {
 191 #ifdef RTC_DEBUG
 192         printf( "rtc_write: %x:%x\n", addr, val );
 193 #endif
 194         *(volatile unsigned char*)(addr) = val;
 195 }
 196
 197 static unsigned bcd2bin (uchar n)
 198 {
 199         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 200 }
 201
 202 static unsigned char bin2bcd (unsigned int n)
 203 {
 204         return (((n / 10) << 4) | (n % 10));
 205 }
 206
 207 #endif