LXR uboot/drivers/rtc/ds174x.c

   1/*
   2 * (C) Copyright 2001
   3 * ARIO Data Networks, Inc. dchiu@ariodata.com
   4 *
   5 * Based on MontaVista DS1743 code and U-Boot mc146818 code
   6 *
   7 * SPDX-License-Identifier:     GPL-2.0+
   8 */
   9
  10/*
  11 * Date & Time support for the DS174x RTC
  12 */
  13
  14/*#define       DEBUG*/
  15
  16#include <common.h>
  17#include <command.h>
  18#include <rtc.h>
  19
  20#if defined(CONFIG_CMD_DATE)
  21
  22static uchar rtc_read( unsigned int addr );
  23static void  rtc_write( unsigned int addr, uchar val);
  24
  25#define RTC_BASE                ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )
  26
  27#define RTC_YEAR                ( RTC_BASE + 7 )
  28#define RTC_MONTH               ( RTC_BASE + 6 )
  29#define RTC_DAY_OF_MONTH        ( RTC_BASE + 5 )
  30#define RTC_DAY_OF_WEEK         ( RTC_BASE + 4 )
  31#define RTC_HOURS               ( RTC_BASE + 3 )
  32#define RTC_MINUTES             ( RTC_BASE + 2 )
  33#define RTC_SECONDS             ( RTC_BASE + 1 )
  34#define RTC_CENTURY             ( RTC_BASE + 0 )
  35
  36#define RTC_CONTROLA            RTC_CENTURY
  37#define RTC_CONTROLB            RTC_SECONDS
  38#define RTC_CONTROLC            RTC_DAY_OF_WEEK
  39
  40#define RTC_CA_WRITE            0x80
  41#define RTC_CA_READ             0x40
  42
  43#define RTC_CB_OSC_DISABLE      0x80
  44
  45#define RTC_CC_BATTERY_FLAG     0x80
  46#define RTC_CC_FREQ_TEST        0x40
  47
  48/* ------------------------------------------------------------------------- */
  49
  50int rtc_get( struct rtc_time *tmp )
  51{
  52        uchar sec, min, hour;
  53        uchar mday, wday, mon, year;
  54
  55        int century;
  56
  57        uchar reg_a;
  58
  59        reg_a = rtc_read( RTC_CONTROLA );
  60        /* lock clock registers for read */
  61        rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
  62
  63        sec     = rtc_read( RTC_SECONDS );
  64        min     = rtc_read( RTC_MINUTES );
  65        hour    = rtc_read( RTC_HOURS );
  66        mday    = rtc_read( RTC_DAY_OF_MONTH );
  67        wday    = rtc_read( RTC_DAY_OF_WEEK );
  68        mon     = rtc_read( RTC_MONTH );
  69        year    = rtc_read( RTC_YEAR );
  70        century = rtc_read( RTC_CENTURY );
  71
  72        /* unlock clock registers after read */
  73        rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
  74
  75#ifdef RTC_DEBUG
  76        printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  77                "hr: %02x min: %02x sec: %02x\n",
  78                year, mon_cent, mday, wday,
  79                hour, min, sec );
  80#endif
  81        tmp->tm_sec  = bcd2bin( sec  & 0x7F );
  82        tmp->tm_min  = bcd2bin( min  & 0x7F );
  83        tmp->tm_hour = bcd2bin( hour & 0x3F );
  84        tmp->tm_mday = bcd2bin( mday & 0x3F );
  85        tmp->tm_mon  = bcd2bin( mon & 0x1F );
  86        tmp->tm_wday = bcd2bin( wday & 0x07 );
  87
  88        /* glue year from century and year in century */
  89        tmp->tm_year = bcd2bin( year ) +
  90                ( bcd2bin( century & 0x3F ) * 100 );
  91
  92        tmp->tm_yday = 0;
  93        tmp->tm_isdst= 0;
  94#ifdef RTC_DEBUG
  95        printf( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  96                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  97                tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
  98#endif
  99        return 0;
 100}
 101
 102int rtc_set( struct rtc_time *tmp )
 103{
 104        uchar reg_a;
 105#ifdef RTC_DEBUG
 106        printf( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 107                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 108                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 109#endif
 110        /* lock clock registers for write */
 111        reg_a = rtc_read( RTC_CONTROLA );
 112        rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
 113
 114        rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
 115
 116        rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
 117        rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
 118        rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
 119        rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
 120        rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
 121
 122        /* break year up into century and year in century */
 123        rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
 124        rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
 125
 126        /* unlock clock registers after read */
 127        rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
 128
 129        return 0;
 130}
 131
 132void rtc_reset (void)
 133{
 134        uchar reg_a, reg_b, reg_c;
 135
 136        reg_a = rtc_read( RTC_CONTROLA );
 137        reg_b = rtc_read( RTC_CONTROLB );
 138
 139        if ( reg_b & RTC_CB_OSC_DISABLE )
 140        {
 141                printf( "real-time-clock was stopped. Now starting...\n" );
 142                reg_a |= RTC_CA_WRITE;
 143                reg_b &= ~RTC_CB_OSC_DISABLE;
 144
 145                rtc_write( RTC_CONTROLA, reg_a );
 146                rtc_write( RTC_CONTROLB, reg_b );
 147        }
 148
 149        /* make sure read/write clock register bits are cleared */
 150        reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
 151        rtc_write( RTC_CONTROLA, reg_a );
 152
 153        reg_c = rtc_read( RTC_CONTROLC );
 154        if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
 155                printf( "RTC battery low. Clock setting may not be reliable.\n" );
 156}
 157
 158/* ------------------------------------------------------------------------- */
 159
 160static uchar rtc_read( unsigned int addr )
 161{
 162        uchar val = in8( addr );
 163#ifdef RTC_DEBUG
 164        printf( "rtc_read: %x:%x\n", addr, val );
 165#endif
 166        return( val );
 167}
 168
 169static void rtc_write( unsigned int addr, uchar val )
 170{
 171#ifdef RTC_DEBUG
 172        printf( "rtc_write: %x:%x\n", addr, val );
 173#endif
 174        out8( addr, val );
 175}
 176
 177#endif
 178