drivers/rtc/mc146818.c

   1 /*
   2  * (C) Copyright 2001
   3  * Denis Peter MPL AG Switzerland. d.peter@mpl.ch
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Date & Time support for the MC146818 (PIXX4) RTC
  10  */
  11
  12 /*#define       DEBUG*/
  13
  14 #include <common.h>
  15 #include <command.h>
  16 #include <rtc.h>
  17
  18 #ifdef __I386__
  19 #include <asm/io.h>
  20 #define in8(p) inb(p)
  21 #define out8(p, v) outb(v, p)
  22 #endif
  23
  24 #if defined(CONFIG_CMD_DATE)
  25
  26 static uchar rtc_read  (uchar reg);
  27 static void  rtc_write (uchar reg, uchar val);
  28
  29 #define RTC_PORT_MC146818       CONFIG_SYS_ISA_IO_BASE_ADDRESS +  0x70
  30 #define RTC_SECONDS             0x00
  31 #define RTC_SECONDS_ALARM       0x01
  32 #define RTC_MINUTES             0x02
  33 #define RTC_MINUTES_ALARM       0x03
  34 #define RTC_HOURS               0x04
  35 #define RTC_HOURS_ALARM         0x05
  36 #define RTC_DAY_OF_WEEK         0x06
  37 #define RTC_DATE_OF_MONTH       0x07
  38 #define RTC_MONTH               0x08
  39 #define RTC_YEAR                0x09
  40 #define RTC_CONFIG_A            0x0A
  41 #define RTC_CONFIG_B            0x0B
  42 #define RTC_CONFIG_C            0x0C
  43 #define RTC_CONFIG_D            0x0D
  44
  45
  46 /* ------------------------------------------------------------------------- */
  47
  48 int rtc_get (struct rtc_time *tmp)
  49 {
  50         uchar sec, min, hour, mday, wday, mon, year;
  51   /* here check if rtc can be accessed */
  52         while((rtc_read(RTC_CONFIG_A)&0x80)==0x80);
  53         sec     = rtc_read (RTC_SECONDS);
  54         min     = rtc_read (RTC_MINUTES);
  55         hour    = rtc_read (RTC_HOURS);
  56         mday    = rtc_read (RTC_DATE_OF_MONTH);
  57         wday    = rtc_read (RTC_DAY_OF_WEEK);
  58         mon     = rtc_read (RTC_MONTH);
  59         year    = rtc_read (RTC_YEAR);
  60 #ifdef RTC_DEBUG
  61         printf ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  62                 "hr: %02x min: %02x sec: %02x\n",
  63                 year, mon, mday, wday,
  64                 hour, min, sec );
  65         printf ( "Alarms: month: %02x hour: %02x min: %02x sec: %02x\n",
  66                 rtc_read (RTC_CONFIG_D) & 0x3F,
  67                 rtc_read (RTC_HOURS_ALARM),
  68                 rtc_read (RTC_MINUTES_ALARM),
  69                 rtc_read (RTC_SECONDS_ALARM) );
  70 #endif
  71         tmp->tm_sec  = bcd2bin (sec  & 0x7F);
  72         tmp->tm_min  = bcd2bin (min  & 0x7F);
  73         tmp->tm_hour = bcd2bin (hour & 0x3F);
  74         tmp->tm_mday = bcd2bin (mday & 0x3F);
  75         tmp->tm_mon  = bcd2bin (mon & 0x1F);
  76         tmp->tm_year = bcd2bin (year);
  77         tmp->tm_wday = bcd2bin (wday & 0x07);
  78         if(tmp->tm_year<70)
  79                 tmp->tm_year+=2000;
  80         else
  81                 tmp->tm_year+=1900;
  82         tmp->tm_yday = 0;
  83         tmp->tm_isdst= 0;
  84 #ifdef RTC_DEBUG
  85         printf ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  86                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  87                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  88 #endif
  89
  90         return 0;
  91 }
  92
  93 int rtc_set (struct rtc_time *tmp)
  94 {
  95 #ifdef RTC_DEBUG
  96         printf ( "Set 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         rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
 101
 102         rtc_write (RTC_YEAR, bin2bcd(tmp->tm_year % 100));
 103         rtc_write (RTC_MONTH, bin2bcd(tmp->tm_mon));
 104         rtc_write (RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday));
 105         rtc_write (RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
 106         rtc_write (RTC_HOURS, bin2bcd(tmp->tm_hour));
 107         rtc_write (RTC_MINUTES, bin2bcd(tmp->tm_min ));
 108         rtc_write (RTC_SECONDS, bin2bcd(tmp->tm_sec ));
 109         rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
 110
 111         return 0;
 112 }
 113
 114 void rtc_reset (void)
 115 {
 116         rtc_write(RTC_CONFIG_B,0x82); /* disables the RTC to update the regs */
 117         rtc_write(RTC_CONFIG_A,0x20); /* Normal OP */
 118         rtc_write(RTC_CONFIG_B,0x00);
 119         rtc_write(RTC_CONFIG_B,0x00);
 120         rtc_write(RTC_CONFIG_B,0x02); /* enables the RTC to update the regs */
 121 }
 122
 123 /* ------------------------------------------------------------------------- */
 124
 125 #ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
 126 /*
 127  * use direct memory access
 128  */
 129 static uchar rtc_read (uchar reg)
 130 {
 131         return(in8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg));
 132 }
 133
 134 static void rtc_write (uchar reg, uchar val)
 135 {
 136         out8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg, val);
 137 }
 138 #else
 139 static uchar rtc_read (uchar reg)
 140 {
 141         out8(RTC_PORT_MC146818,reg);
 142         return(in8(RTC_PORT_MC146818+1));
 143 }
 144
 145 static void rtc_write (uchar reg, uchar val)
 146 {
 147         out8(RTC_PORT_MC146818,reg);
 148         out8(RTC_PORT_MC146818+1,val);
 149 }
 150 #endif
 151
 152 #endif