uboot/drivers/rtc/m41t11.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2002
   4 * Andrew May, Viasat Inc, amay@viasat.com
   5 */
   6
   7/*
   8 * M41T11 Serial Access Timekeeper(R) SRAM
   9 * can you believe a trademark on that?
  10 */
  11
  12/* #define DEBUG 1 */
  13
  14#include <common.h>
  15#include <command.h>
  16#include <log.h>
  17#include <rtc.h>
  18#include <i2c.h>
  19
  20/*
  21        I Don't have an example config file but this
  22        is what should be done.
  23
  24#define CONFIG_RTC_M41T11 1
  25#define CONFIG_SYS_I2C_RTC_ADDR 0x68
  26#if 0
  27#define CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  28#else
  29#define CONFIG_SYS_M41T11_BASE_YEAR 2000
  30#endif
  31*/
  32
  33/* ------------------------------------------------------------------------- */
  34/*
  35  these are simple defines for the chip local to here so they aren't too
  36  verbose
  37  DAY/DATE aren't nice but that is how they are on the data sheet
  38*/
  39#define RTC_SEC_ADDR       0x0
  40#define RTC_MIN_ADDR       0x1
  41#define RTC_HOUR_ADDR      0x2
  42#define RTC_DAY_ADDR       0x3
  43#define RTC_DATE_ADDR      0x4
  44#define RTC_MONTH_ADDR     0x5
  45#define RTC_YEARS_ADDR     0x6
  46
  47#define RTC_REG_CNT        7
  48
  49#define RTC_CONTROL_ADDR   0x7
  50
  51
  52#ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  53
  54#define REG_CNT            (RTC_REG_CNT+1)
  55
  56/*
  57  you only get 00-99 for the year we will asume you
  58  want from the year 2000 if you don't set the config
  59*/
  60#ifndef CONFIG_SYS_M41T11_BASE_YEAR
  61#define CONFIG_SYS_M41T11_BASE_YEAR 2000
  62#endif
  63
  64#else
  65/* we will store extra year info in byte 9*/
  66#define M41T11_YEAR_DATA   0x8
  67#define M41T11_YEAR_SIZE   1
  68#define REG_CNT            (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
  69#endif
  70
  71#define M41T11_STORAGE_SZ  (64-REG_CNT)
  72
  73int rtc_get (struct rtc_time *tmp)
  74{
  75        int rel = 0;
  76        uchar data[RTC_REG_CNT];
  77
  78        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
  79
  80        if( data[RTC_SEC_ADDR] & 0x80 ){
  81                printf( "m41t11 RTC Clock stopped!!!\n" );
  82                rel = -1;
  83        }
  84        tmp->tm_sec  = bcd2bin (data[RTC_SEC_ADDR]  & 0x7F);
  85        tmp->tm_min  = bcd2bin (data[RTC_MIN_ADDR]  & 0x7F);
  86        tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
  87        tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
  88        tmp->tm_mon  = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
  89#ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  90        tmp->tm_year = CONFIG_SYS_M41T11_BASE_YEAR
  91                + bcd2bin(data[RTC_YEARS_ADDR])
  92                + ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
  93#else
  94        {
  95                unsigned char cent;
  96                i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
  97                if( !(data[RTC_HOUR_ADDR] & 0x80) ){
  98                        printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
  99                        rel = -1;
 100                }
 101                if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
 102                        /*century flip store off new year*/
 103                        cent += 1;
 104                        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 105                }
 106                tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
 107        }
 108#endif
 109        tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR]  & 0x07);
 110        tmp->tm_yday = 0;
 111        tmp->tm_isdst= 0;
 112
 113        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 114              tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 115              tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 116
 117        return rel;
 118}
 119
 120int rtc_set (struct rtc_time *tmp)
 121{
 122        uchar data[RTC_REG_CNT];
 123
 124        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 125              tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 126              tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 127
 128        data[RTC_SEC_ADDR]    = bin2bcd(tmp->tm_sec) &  0x7F;/*just in case*/
 129        data[RTC_MIN_ADDR]    = bin2bcd(tmp->tm_min);
 130        data[RTC_HOUR_ADDR]   = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
 131        data[RTC_DATE_ADDR]   = bin2bcd(tmp->tm_mday) & 0x3F;
 132        data[RTC_MONTH_ADDR]  = bin2bcd(tmp->tm_mon);
 133        data[RTC_DAY_ADDR]    = bin2bcd(tmp->tm_wday) & 0x07;
 134
 135        data[RTC_HOUR_ADDR]   |= 0x80;/*we will always use CEB*/
 136
 137        data[RTC_YEARS_ADDR]  = bin2bcd(tmp->tm_year%100);/*same thing either way*/
 138#ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
 139        if( ((tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 200) ||
 140            (tmp->tm_year < CONFIG_SYS_M41T11_BASE_YEAR) ){
 141                printf( "m41t11 RTC setting year out of range!!need recompile\n" );
 142        }
 143        data[RTC_HOUR_ADDR] |= (tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
 144#else
 145        {
 146                unsigned char cent;
 147                cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
 148                data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
 149                i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 150        }
 151#endif
 152        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
 153
 154        return 0;
 155}
 156
 157void rtc_reset (void)
 158{
 159        unsigned char val;
 160        /* clear all control & status registers */
 161        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
 162        val = val & 0x7F;/*make sure we are running*/
 163        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
 164
 165        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
 166        val = val & 0x3F;/*turn off freq test keep calibration*/
 167        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
 168}
 169