LXR uboot/drivers/rtc/ds174x.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2001
   4 * ARIO Data Networks, Inc. dchiu@ariodata.com
   5 *
   6 * Based on MontaVista DS1743 code and U-Boot mc146818 code
   7 */
   8
   9/*
  10 * Date & Time support for the DS174x RTC
  11 */
  12
  13/*#define       DEBUG*/
  14
  15#include <common.h>
  16#include <command.h>
  17#include <rtc.h>
  18
  19static uchar rtc_read( unsigned int addr );
  20static void  rtc_write( unsigned int addr, uchar val);
  21
  22#define RTC_BASE                ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )
  23
  24#define RTC_YEAR                ( RTC_BASE + 7 )
  25#define RTC_MONTH               ( RTC_BASE + 6 )
  26#define RTC_DAY_OF_MONTH        ( RTC_BASE + 5 )
  27#define RTC_DAY_OF_WEEK         ( RTC_BASE + 4 )
  28#define RTC_HOURS               ( RTC_BASE + 3 )
  29#define RTC_MINUTES             ( RTC_BASE + 2 )
  30#define RTC_SECONDS             ( RTC_BASE + 1 )
  31#define RTC_CENTURY             ( RTC_BASE + 0 )
  32
  33#define RTC_CONTROLA            RTC_CENTURY
  34#define RTC_CONTROLB            RTC_SECONDS
  35#define RTC_CONTROLC            RTC_DAY_OF_WEEK
  36
  37#define RTC_CA_WRITE            0x80
  38#define RTC_CA_READ             0x40
  39
  40#define RTC_CB_OSC_DISABLE      0x80
  41
  42#define RTC_CC_BATTERY_FLAG     0x80
  43#define RTC_CC_FREQ_TEST        0x40
  44
  45/* ------------------------------------------------------------------------- */
  46
  47int rtc_get( struct rtc_time *tmp )
  48{
  49        uchar sec, min, hour;
  50        uchar mday, wday, mon, year;
  51
  52        int century;
  53
  54        uchar reg_a;
  55
  56        reg_a = rtc_read( RTC_CONTROLA );
  57        /* lock clock registers for read */
  58        rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
  59
  60        sec     = rtc_read( RTC_SECONDS );
  61        min     = rtc_read( RTC_MINUTES );
  62        hour    = rtc_read( RTC_HOURS );
  63        mday    = rtc_read( RTC_DAY_OF_MONTH );
  64        wday    = rtc_read( RTC_DAY_OF_WEEK );
  65        mon     = rtc_read( RTC_MONTH );
  66        year    = rtc_read( RTC_YEAR );
  67        century = rtc_read( RTC_CENTURY );
  68
  69        /* unlock clock registers after read */
  70        rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  71
  72#ifdef RTC_DEBUG
  73        printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  74                "hr: %02x min: %02x sec: %02x\n",
  75                year, mon_cent, mday, wday,
  76                hour, min, sec );
  77#endif
  78        tmp->tm_sec  = bcd2bin( sec  & 0x7F );
  79        tmp->tm_min  = bcd2bin( min  & 0x7F );
  80        tmp->tm_hour = bcd2bin( hour & 0x3F );
  81        tmp->tm_mday = bcd2bin( mday & 0x3F );
  82        tmp->tm_mon  = bcd2bin( mon & 0x1F );
  83        tmp->tm_wday = bcd2bin( wday & 0x07 );
  84
  85        /* glue year from century and year in century */
  86        tmp->tm_year = bcd2bin( year ) +
  87                ( bcd2bin( century & 0x3F ) * 100 );
  88
  89        tmp->tm_yday = 0;
  90        tmp->tm_isdst= 0;
  91#ifdef RTC_DEBUG
  92        printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  93                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  94                tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
  95#endif
  96        return 0;
  97}
  98
  99int rtc_set( struct rtc_time *tmp )
 100{
 101        uchar reg_a;
 102#ifdef RTC_DEBUG
 103        printf( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 104                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 105                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 106#endif
 107        /* lock clock registers for write */
 108        reg_a = rtc_read( RTC_CONTROLA );
 109        rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
 110
 111        rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
 112
 113        rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
 114        rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
 115        rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
 116        rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
 117        rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
 118
 119        /* break year up into century and year in century */
 120        rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
 121        rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
 122
 123        /* unlock clock registers after read */
 124        rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
 125
 126        return 0;
 127}
 128
 129void rtc_reset (void)
 130{
 131        uchar reg_a, reg_b, reg_c;
 132
 133        reg_a = rtc_read( RTC_CONTROLA );
 134        reg_b = rtc_read( RTC_CONTROLB );
 135
 136        if ( reg_b & RTC_CB_OSC_DISABLE )
 137        {
 138                printf( "real-time-clock was stopped. Now starting...\n" );
 139                reg_a |= RTC_CA_WRITE;
 140                reg_b &= ~RTC_CB_OSC_DISABLE;
 141
 142                rtc_write( RTC_CONTROLA, reg_a );
 143                rtc_write( RTC_CONTROLB, reg_b );
 144        }
 145
 146        /* make sure read/write clock register bits are cleared */
 147        reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
 148        rtc_write( RTC_CONTROLA, reg_a );
 149
 150        reg_c = rtc_read( RTC_CONTROLC );
 151        if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
 152                printf( "RTC battery low. Clock setting may not be reliable.\n" );
 153}
 154
 155/* ------------------------------------------------------------------------- */
 156
 157static uchar rtc_read( unsigned int addr )
 158{
 159        uchar val = in8( addr );
 160#ifdef RTC_DEBUG
 161        printf( "rtc_read: %x:%x\n", addr, val );
 162#endif
 163        return( val );
 164}
 165
 166static void rtc_write( unsigned int addr, uchar val )
 167{
 168#ifdef RTC_DEBUG
 169        printf( "rtc_write: %x:%x\n", addr, val );
 170#endif
 171        out8( addr, val );
 172}
 173