LXR uboot/drivers/rtc/m41t11.c

   1/*
   2 * (C) Copyright 2002
   3 * Andrew May, Viasat Inc, amay@viasat.com
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation; either version 2 of
   8 * the License, or (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  18 * MA 02111-1307 USA
  19 */
  20
  21/*
  22 * M41T11 Serial Access Timekeeper(R) SRAM
  23 * can you believe a trademark on that?
  24 */
  25
  26/* #define DEBUG 1 */
  27
  28#include <common.h>
  29#include <command.h>
  30#include <rtc.h>
  31#include <i2c.h>
  32
  33/*
  34        I Don't have an example config file but this
  35        is what should be done.
  36
  37#define CONFIG_RTC_M41T11 1
  38#define CONFIG_SYS_I2C_RTC_ADDR 0x68
  39#if 0
  40#define CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  41#else
  42#define CONFIG_SYS_M41T11_BASE_YEAR 2000
  43#endif
  44*/
  45
  46#if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)
  47
  48static unsigned bcd2bin (uchar n)
  49{
  50        return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
  51}
  52
  53static unsigned char bin2bcd (unsigned int n)
  54{
  55        return (((n / 10) << 4) | (n % 10));
  56}
  57
  58
  59/* ------------------------------------------------------------------------- */
  60/*
  61  these are simple defines for the chip local to here so they aren't too
  62  verbose
  63  DAY/DATE aren't nice but that is how they are on the data sheet
  64*/
  65#define RTC_SEC_ADDR       0x0
  66#define RTC_MIN_ADDR       0x1
  67#define RTC_HOUR_ADDR      0x2
  68#define RTC_DAY_ADDR       0x3
  69#define RTC_DATE_ADDR      0x4
  70#define RTC_MONTH_ADDR     0x5
  71#define RTC_YEARS_ADDR     0x6
  72
  73#define RTC_REG_CNT        7
  74
  75#define RTC_CONTROL_ADDR   0x7
  76
  77
  78#ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  79
  80#define REG_CNT            (RTC_REG_CNT+1)
  81
  82/*
  83  you only get 00-99 for the year we will asume you
  84  want from the year 2000 if you don't set the config
  85*/
  86#ifndef CONFIG_SYS_M41T11_BASE_YEAR
  87#define CONFIG_SYS_M41T11_BASE_YEAR 2000
  88#endif
  89
  90#else
  91/* we will store extra year info in byte 9*/
  92#define M41T11_YEAR_DATA   0x8
  93#define M41T11_YEAR_SIZE   1
  94#define REG_CNT            (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
  95#endif
  96
  97#define M41T11_STORAGE_SZ  (64-REG_CNT)
  98
  99int rtc_get (struct rtc_time *tmp)
 100{
 101        int rel = 0;
 102        uchar data[RTC_REG_CNT];
 103
 104        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
 105
 106        if( data[RTC_SEC_ADDR] & 0x80 ){
 107                printf( "m41t11 RTC Clock stopped!!!\n" );
 108                rel = -1;
 109        }
 110        tmp->tm_sec  = bcd2bin (data[RTC_SEC_ADDR]  & 0x7F);
 111        tmp->tm_min  = bcd2bin (data[RTC_MIN_ADDR]  & 0x7F);
 112        tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
 113        tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
 114        tmp->tm_mon  = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
 115#ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
 116        tmp->tm_year = CONFIG_SYS_M41T11_BASE_YEAR
 117                + bcd2bin(data[RTC_YEARS_ADDR])
 118                + ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
 119#else
 120        {
 121                unsigned char cent;
 122                i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 123                if( !(data[RTC_HOUR_ADDR] & 0x80) ){
 124                        printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
 125                        rel = -1;
 126                }
 127                if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
 128                        /*century flip store off new year*/
 129                        cent += 1;
 130                        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 131                }
 132                tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
 133        }
 134#endif
 135        tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR]  & 0x07);
 136        tmp->tm_yday = 0;
 137        tmp->tm_isdst= 0;
 138
 139        debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 140                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 141                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 142
 143        return rel;
 144}
 145
 146int rtc_set (struct rtc_time *tmp)
 147{
 148        uchar data[RTC_REG_CNT];
 149
 150        debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 151                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 152                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 153
 154        data[RTC_SEC_ADDR]    = bin2bcd(tmp->tm_sec) &  0x7F;/*just in case*/
 155        data[RTC_MIN_ADDR]    = bin2bcd(tmp->tm_min);
 156        data[RTC_HOUR_ADDR]   = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
 157        data[RTC_DATE_ADDR]   = bin2bcd(tmp->tm_mday) & 0x3F;
 158        data[RTC_MONTH_ADDR]  = bin2bcd(tmp->tm_mon);
 159        data[RTC_DAY_ADDR]    = bin2bcd(tmp->tm_wday) & 0x07;
 160
 161        data[RTC_HOUR_ADDR]   |= 0x80;/*we will always use CEB*/
 162
 163        data[RTC_YEARS_ADDR]  = bin2bcd(tmp->tm_year%100);/*same thing either way*/
 164#ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
 165        if( ((tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 200) ||
 166            (tmp->tm_year < CONFIG_SYS_M41T11_BASE_YEAR) ){
 167                printf( "m41t11 RTC setting year out of range!!need recompile\n" );
 168        }
 169        data[RTC_HOUR_ADDR] |= (tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
 170#else
 171        {
 172                unsigned char cent;
 173                cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
 174                data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
 175                i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 176        }
 177#endif
 178        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
 179
 180        return 0;
 181}
 182
 183void rtc_reset (void)
 184{
 185        unsigned char val;
 186        /* clear all control & status registers */
 187        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
 188        val = val & 0x7F;/*make sure we are running*/
 189        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
 190
 191        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
 192        val = val & 0x3F;/*turn off freq test keep calibration*/
 193        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
 194}
 195
 196int rtc_store(int addr, unsigned char* data, int size)
 197{
 198        /*don't let things wrap onto the time on a write*/
 199        if( (addr+size) >= M41T11_STORAGE_SZ )
 200                return 1;
 201        return i2c_write( CONFIG_SYS_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size );
 202}
 203
 204int rtc_recall(int addr, unsigned char* data, int size)
 205{
 206        return i2c_read( CONFIG_SYS_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size );
 207}
 208
 209#endif
 210