drivers/rtc/ds164x.c

   1 /*
   2  * (C) Copyright 2002
   3  * ARIO Data Networks, Inc. dchiu@ariodata.com
   4  *
   5  * modified for DS164x:
   6  * The LEOX team <team@leox.org>, http://www.leox.org
   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 DS164x 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_DS164x) && 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_EPOCH                 2000  /* century */
  48
  49 /*
  50  * DS164x registers layout
  51  */
  52 #define RTC_BASE                ( CFG_NVRAM_BASE_ADDR + CFG_NVRAM_SIZE )
  53
  54 #define RTC_YEAR                ( RTC_BASE + 0x07 )
  55 #define RTC_MONTH               ( RTC_BASE + 0x06 )
  56 #define RTC_DAY_OF_MONTH        ( RTC_BASE + 0x05 )
  57 #define RTC_DAY_OF_WEEK         ( RTC_BASE + 0x04 )
  58 #define RTC_HOURS               ( RTC_BASE + 0x03 )
  59 #define RTC_MINUTES             ( RTC_BASE + 0x02 )
  60 #define RTC_SECONDS             ( RTC_BASE + 0x01 )
  61 #define RTC_CONTROL             ( RTC_BASE + 0x00 )
  62
  63 #define RTC_CONTROLA            RTC_CONTROL     /* W=bit6, R=bit5 */
  64 #define   RTC_CA_WRITE            0x80
  65 #define   RTC_CA_READ             0x40
  66 #define RTC_CONTROLB            RTC_SECONDS     /* OSC=bit7       */
  67 #define   RTC_CB_OSC_DISABLE      0x80
  68 #define RTC_CONTROLC            RTC_DAY_OF_WEEK /* FT=bit6        */
  69 #define   RTC_CC_FREQ_TEST        0x40
  70
  71 /* ------------------------------------------------------------------------- */
  72
  73 void rtc_get( struct rtc_time *tmp )
  74 {
  75         uchar sec, min, hour;
  76         uchar mday, wday, mon, year;
  77
  78         uchar reg_a;
  79
  80         reg_a = rtc_read( RTC_CONTROLA );
  81         /* lock clock registers for read */
  82         rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
  83
  84         sec     = rtc_read( RTC_SECONDS );
  85         min     = rtc_read( RTC_MINUTES );
  86         hour    = rtc_read( RTC_HOURS );
  87         mday    = rtc_read( RTC_DAY_OF_MONTH );
  88         wday    = rtc_read( RTC_DAY_OF_WEEK );
  89         mon     = rtc_read( RTC_MONTH );
  90         year    = rtc_read( RTC_YEAR );
  91
  92         /* unlock clock registers after read */
  93         rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  94
  95 #ifdef RTC_DEBUG
  96         printf( "Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  97                 "hr: %02x min: %02x sec: %02x\n",
  98                 year, mon, mday, wday,
  99                 hour, min, sec );
 100 #endif
 101         tmp->tm_sec  = bcd2bin( sec  & 0x7F );
 102         tmp->tm_min  = bcd2bin( min  & 0x7F );
 103         tmp->tm_hour = bcd2bin( hour & 0x3F );
 104         tmp->tm_mday = bcd2bin( mday & 0x3F );
 105         tmp->tm_mon  = bcd2bin( mon  & 0x1F );
 106         tmp->tm_wday = bcd2bin( wday & 0x07 );
 107
 108         /* glue year in century (2000) */
 109         tmp->tm_year = bcd2bin( year ) + RTC_EPOCH;
 110
 111         tmp->tm_yday = 0;
 112         tmp->tm_isdst= 0;
 113 #ifdef RTC_DEBUG
 114         printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 115                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 116                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
 117 #endif
 118 }
 119
 120 void rtc_set( struct rtc_time *tmp )
 121 {
 122         uchar reg_a;
 123
 124 #ifdef RTC_DEBUG
 125         printf( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 126                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 127                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 128 #endif
 129         /* lock clock registers for write */
 130         reg_a = rtc_read( RTC_CONTROLA );
 131         rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
 132
 133         rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
 134
 135         rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
 136         rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
 137         rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
 138         rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
 139         rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
 140
 141         /* break year in century */
 142         rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
 143
 144         /* unlock clock registers after read */
 145         rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
 146 }
 147
 148 void rtc_reset (void)
 149 {
 150         uchar reg_a, reg_b;
 151
 152         reg_a = rtc_read( RTC_CONTROLA );
 153         reg_b = rtc_read( RTC_CONTROLB );
 154
 155         if ( reg_b & RTC_CB_OSC_DISABLE )
 156         {
 157                 printf( "real-time-clock was stopped. Now starting...\n" );
 158                 reg_a |= RTC_CA_WRITE;
 159                 reg_b &= ~RTC_CB_OSC_DISABLE;
 160
 161                 rtc_write( RTC_CONTROLA, reg_a );
 162                 rtc_write( RTC_CONTROLB, reg_b );
 163         }
 164
 165         /* make sure read/write clock register bits are cleared */
 166         reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
 167         rtc_write( RTC_CONTROLA, reg_a );
 168 }
 169
 170 /* ------------------------------------------------------------------------- */
 171
 172 static uchar rtc_read( unsigned int addr )
 173 {
 174         uchar val = *(volatile unsigned char*)(addr);
 175
 176 #ifdef RTC_DEBUG
 177         printf( "rtc_read: %x:%x\n", addr, val );
 178 #endif
 179         return( val );
 180 }
 181
 182 static void rtc_write( unsigned int addr, uchar val )
 183 {
 184 #ifdef RTC_DEBUG
 185         printf( "rtc_write: %x:%x\n", addr, val );
 186 #endif
 187         *(volatile unsigned char*)(addr) = val;
 188 }
 189
 190 static unsigned bcd2bin (uchar n)
 191 {
 192         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 193 }
 194
 195 static unsigned char bin2bcd (unsigned int n)
 196 {
 197         return (((n / 10) << 4) | (n % 10));
 198 }
 199
 200 #endif