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  * SPDX-License-Identifier:     GPL-2.0+
  11  */
  12
  13 /*
  14  * Date & Time support for the DS1556 RTC
  15  */
  16
  17 /*#define       RTC_DEBUG */
  18
  19 #include <common.h>
  20 #include <command.h>
  21 #include <rtc.h>
  22
  23 #if defined(CONFIG_CMD_DATE)
  24
  25 static uchar rtc_read( unsigned int addr );
  26 static void  rtc_write( unsigned int addr, uchar val);
  27
  28 #define RTC_BASE                ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )
  29
  30 #define RTC_YEAR                ( RTC_BASE + 0xf )
  31 #define RTC_MONTH               ( RTC_BASE + 0xe )
  32 #define RTC_DAY_OF_MONTH        ( RTC_BASE + 0xd )
  33 #define RTC_DAY_OF_WEEK         ( RTC_BASE + 0xc )
  34 #define RTC_HOURS               ( RTC_BASE + 0xb )
  35 #define RTC_MINUTES             ( RTC_BASE + 0xa )
  36 #define RTC_SECONDS             ( RTC_BASE + 0x9 )
  37 #define RTC_CENTURY             ( RTC_BASE + 0x8 )
  38
  39 #define RTC_CONTROLA            RTC_CENTURY
  40 #define RTC_CONTROLB            RTC_SECONDS
  41 #define RTC_CONTROLC            RTC_BASE
  42
  43 #define RTC_CA_WRITE            0x80
  44 #define RTC_CA_READ             0x40
  45
  46 #define RTC_CB_OSC_DISABLE      0x80
  47
  48 #define RTC_CC_BATTERY_FLAG     0x10
  49 #define RTC_CC_FREQ_TEST        0x40
  50
  51 /* ------------------------------------------------------------------------- */
  52
  53 int rtc_get( struct rtc_time *tmp )
  54 {
  55         uchar sec, min, hour;
  56         uchar mday, wday, mon, year;
  57
  58         int century;
  59
  60         uchar reg_a;
  61
  62         reg_a = rtc_read( RTC_CONTROLA );
  63         /* lock clock registers for read */
  64         rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
  65
  66         sec     = rtc_read( RTC_SECONDS );
  67         min     = rtc_read( RTC_MINUTES );
  68         hour    = rtc_read( RTC_HOURS );
  69         mday    = rtc_read( RTC_DAY_OF_MONTH );
  70         wday    = rtc_read( RTC_DAY_OF_WEEK );
  71         mon     = rtc_read( RTC_MONTH );
  72         year    = rtc_read( RTC_YEAR );
  73         century = rtc_read( RTC_CENTURY );
  74
  75         /* unlock clock registers after read */
  76         rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  77
  78 #ifdef RTC_DEBUG
  79         printf( "Get RTC year: %02x mon/cent: %02x mon: %02x mday: %02x wday: %02x "
  80                 "hr: %02x min: %02x sec: %02x\n",
  81                 year, century, mon, mday, wday,
  82                 hour, min, sec );
  83 #endif
  84         tmp->tm_sec  = bcd2bin( sec  & 0x7F );
  85         tmp->tm_min  = bcd2bin( min  & 0x7F );
  86         tmp->tm_hour = bcd2bin( hour & 0x3F );
  87         tmp->tm_mday = bcd2bin( mday & 0x3F );
  88         tmp->tm_mon  = bcd2bin( mon & 0x1F );
  89         tmp->tm_wday = bcd2bin( wday & 0x07 );
  90
  91         /* glue year from century and year in century */
  92         tmp->tm_year = bcd2bin( year ) +
  93                 ( bcd2bin( century & 0x3F ) * 100 );
  94
  95         tmp->tm_yday = 0;
  96         tmp->tm_isdst= 0;
  97 #ifdef RTC_DEBUG
  98         printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  99                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 100                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
 101 #endif
 102         return 0;
 103 }
 104
 105 int rtc_set( struct rtc_time *tmp )
 106 {
 107         uchar reg_a;
 108 #ifdef RTC_DEBUG
 109         printf( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 110                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 111                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 112 #endif
 113         /* lock clock registers for write */
 114         reg_a = rtc_read( RTC_CONTROLA );
 115         rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
 116
 117         rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
 118
 119         rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
 120         rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
 121         rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
 122         rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
 123         rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
 124
 125         /* break year up into century and year in century */
 126         rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
 127         rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
 128
 129         /* unlock clock registers after read */
 130         rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
 131
 132         return 0;
 133 }
 134
 135 void rtc_reset (void)
 136 {
 137         uchar reg_a, reg_b, reg_c;
 138
 139         reg_a = rtc_read( RTC_CONTROLA );
 140         reg_b = rtc_read( RTC_CONTROLB );
 141
 142         if ( reg_b & RTC_CB_OSC_DISABLE )
 143         {
 144                 printf( "real-time-clock was stopped. Now starting...\n" );
 145                 reg_a |= RTC_CA_WRITE;
 146                 reg_b &= ~RTC_CB_OSC_DISABLE;
 147
 148                 rtc_write( RTC_CONTROLA, reg_a );
 149                 rtc_write( RTC_CONTROLB, reg_b );
 150         }
 151
 152         /* make sure read/write clock register bits are cleared */
 153         reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
 154         rtc_write( RTC_CONTROLA, reg_a );
 155
 156         reg_c = rtc_read( RTC_CONTROLC );
 157         if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
 158                 printf( "RTC battery low. Clock setting may not be reliable.\n" );
 159 }
 160
 161 /* ------------------------------------------------------------------------- */
 162
 163 static uchar rtc_read( unsigned int addr )
 164 {
 165         uchar val = *(volatile unsigned char*)(addr);
 166 #ifdef RTC_DEBUG
 167         printf( "rtc_read: %x:%x\n", addr, val );
 168 #endif
 169         return( val );
 170 }
 171
 172 static void rtc_write( unsigned int addr, uchar val )
 173 {
 174 #ifdef RTC_DEBUG
 175         printf( "rtc_write: %x:%x\n", addr, val );
 176 #endif
 177         *(volatile unsigned char*)(addr) = val;
 178 }
 179
 180 #endif