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  * SPDX-License-Identifier:     GPL-2.0+
  11  */
  12
  13 /*
  14  * Date & Time support for the DS164x RTC
  15  */
  16
  17 /* #define      RTC_DEBUG */
  18
  19 #include <common.h>
  20 #include <command.h>
  21 #include <rtc.h>
  22
  23
  24 #if defined(CONFIG_CMD_DATE)
  25
  26 static uchar    rtc_read(unsigned int addr );
  27 static void     rtc_write(unsigned int addr, uchar val);
  28
  29 #define RTC_EPOCH                 2000  /* century */
  30
  31 /*
  32  * DS164x registers layout
  33  */
  34 #define RTC_BASE                ( CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE )
  35
  36 #define RTC_YEAR                ( RTC_BASE + 0x07 )
  37 #define RTC_MONTH               ( RTC_BASE + 0x06 )
  38 #define RTC_DAY_OF_MONTH        ( RTC_BASE + 0x05 )
  39 #define RTC_DAY_OF_WEEK         ( RTC_BASE + 0x04 )
  40 #define RTC_HOURS               ( RTC_BASE + 0x03 )
  41 #define RTC_MINUTES             ( RTC_BASE + 0x02 )
  42 #define RTC_SECONDS             ( RTC_BASE + 0x01 )
  43 #define RTC_CONTROL             ( RTC_BASE + 0x00 )
  44
  45 #define RTC_CONTROLA            RTC_CONTROL     /* W=bit6, R=bit5 */
  46 #define   RTC_CA_WRITE            0x80
  47 #define   RTC_CA_READ             0x40
  48 #define RTC_CONTROLB            RTC_SECONDS     /* OSC=bit7       */
  49 #define   RTC_CB_OSC_DISABLE      0x80
  50 #define RTC_CONTROLC            RTC_DAY_OF_WEEK /* FT=bit6        */
  51 #define   RTC_CC_FREQ_TEST        0x40
  52
  53 /* ------------------------------------------------------------------------- */
  54
  55 int rtc_get( struct rtc_time *tmp )
  56 {
  57         uchar sec, min, hour;
  58         uchar mday, wday, mon, year;
  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
  74         /* unlock clock registers after read */
  75         rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  76
  77 #ifdef RTC_DEBUG
  78         printf( "Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  79                 "hr: %02x min: %02x sec: %02x\n",
  80                 year, mon, mday, wday,
  81                 hour, min, sec );
  82 #endif
  83         tmp->tm_sec  = bcd2bin( sec  & 0x7F );
  84         tmp->tm_min  = bcd2bin( min  & 0x7F );
  85         tmp->tm_hour = bcd2bin( hour & 0x3F );
  86         tmp->tm_mday = bcd2bin( mday & 0x3F );
  87         tmp->tm_mon  = bcd2bin( mon  & 0x1F );
  88         tmp->tm_wday = bcd2bin( wday & 0x07 );
  89
  90         /* glue year in century (2000) */
  91         tmp->tm_year = bcd2bin( year ) + RTC_EPOCH;
  92
  93         tmp->tm_yday = 0;
  94         tmp->tm_isdst= 0;
  95 #ifdef RTC_DEBUG
  96         printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  97                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  98                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
  99 #endif
 100
 101         return 0;
 102 }
 103
 104 int rtc_set( struct rtc_time *tmp )
 105 {
 106         uchar reg_a;
 107
 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 in century */
 126         rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
 127
 128         /* unlock clock registers after read */
 129         rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
 130
 131         return 0;
 132 }
 133
 134 void rtc_reset (void)
 135 {
 136         uchar reg_a, reg_b;
 137
 138         reg_a = rtc_read( RTC_CONTROLA );
 139         reg_b = rtc_read( RTC_CONTROLB );
 140
 141         if ( reg_b & RTC_CB_OSC_DISABLE )
 142         {
 143                 printf( "real-time-clock was stopped. Now starting...\n" );
 144                 reg_a |= RTC_CA_WRITE;
 145                 reg_b &= ~RTC_CB_OSC_DISABLE;
 146
 147                 rtc_write( RTC_CONTROLA, reg_a );
 148                 rtc_write( RTC_CONTROLB, reg_b );
 149         }
 150
 151         /* make sure read/write clock register bits are cleared */
 152         reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
 153         rtc_write( RTC_CONTROLA, reg_a );
 154 }
 155
 156 /* ------------------------------------------------------------------------- */
 157
 158 static uchar rtc_read( unsigned int addr )
 159 {
 160         uchar val = *(volatile unsigned char*)(addr);
 161
 162 #ifdef RTC_DEBUG
 163         printf( "rtc_read: %x:%x\n", addr, val );
 164 #endif
 165         return( val );
 166 }
 167
 168 static void rtc_write( unsigned int addr, uchar val )
 169 {
 170 #ifdef RTC_DEBUG
 171         printf( "rtc_write: %x:%x\n", addr, val );
 172 #endif
 173         *(volatile unsigned char*)(addr) = val;
 174 }
 175
 176 #endif