drivers/rtc/m41t11.c

   1 /*
   2  * (C) Copyright 2002
   3  * Andrew May, Viasat Inc, amay@viasat.com
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * M41T11 Serial Access Timekeeper(R) SRAM
  10  * can you believe a trademark on that?
  11  */
  12
  13 /* #define DEBUG 1 */
  14
  15 #include <common.h>
  16 #include <command.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 #if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)
  34
  35 /* ------------------------------------------------------------------------- */
  36 /*
  37   these are simple defines for the chip local to here so they aren't too
  38   verbose
  39   DAY/DATE aren't nice but that is how they are on the data sheet
  40 */
  41 #define RTC_SEC_ADDR       0x0
  42 #define RTC_MIN_ADDR       0x1
  43 #define RTC_HOUR_ADDR      0x2
  44 #define RTC_DAY_ADDR       0x3
  45 #define RTC_DATE_ADDR      0x4
  46 #define RTC_MONTH_ADDR     0x5
  47 #define RTC_YEARS_ADDR     0x6
  48
  49 #define RTC_REG_CNT        7
  50
  51 #define RTC_CONTROL_ADDR   0x7
  52
  53
  54 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  55
  56 #define REG_CNT            (RTC_REG_CNT+1)
  57
  58 /*
  59   you only get 00-99 for the year we will asume you
  60   want from the year 2000 if you don't set the config
  61 */
  62 #ifndef CONFIG_SYS_M41T11_BASE_YEAR
  63 #define CONFIG_SYS_M41T11_BASE_YEAR 2000
  64 #endif
  65
  66 #else
  67 /* we will store extra year info in byte 9*/
  68 #define M41T11_YEAR_DATA   0x8
  69 #define M41T11_YEAR_SIZE   1
  70 #define REG_CNT            (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
  71 #endif
  72
  73 #define M41T11_STORAGE_SZ  (64-REG_CNT)
  74
  75 int rtc_get (struct rtc_time *tmp)
  76 {
  77         int rel = 0;
  78         uchar data[RTC_REG_CNT];
  79
  80         i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
  81
  82         if( data[RTC_SEC_ADDR] & 0x80 ){
  83                 printf( "m41t11 RTC Clock stopped!!!\n" );
  84                 rel = -1;
  85         }
  86         tmp->tm_sec  = bcd2bin (data[RTC_SEC_ADDR]  & 0x7F);
  87         tmp->tm_min  = bcd2bin (data[RTC_MIN_ADDR]  & 0x7F);
  88         tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
  89         tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
  90         tmp->tm_mon  = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
  91 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
  92         tmp->tm_year = CONFIG_SYS_M41T11_BASE_YEAR
  93                 + bcd2bin(data[RTC_YEARS_ADDR])
  94                 + ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
  95 #else
  96         {
  97                 unsigned char cent;
  98                 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
  99                 if( !(data[RTC_HOUR_ADDR] & 0x80) ){
 100                         printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
 101                         rel = -1;
 102                 }
 103                 if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
 104                         /*century flip store off new year*/
 105                         cent += 1;
 106                         i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 107                 }
 108                 tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
 109         }
 110 #endif
 111         tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR]  & 0x07);
 112         tmp->tm_yday = 0;
 113         tmp->tm_isdst= 0;
 114
 115         debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 116                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 117                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 118
 119         return rel;
 120 }
 121
 122 int rtc_set (struct rtc_time *tmp)
 123 {
 124         uchar data[RTC_REG_CNT];
 125
 126         debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 127                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 128                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 129
 130         data[RTC_SEC_ADDR]    = bin2bcd(tmp->tm_sec) &  0x7F;/*just in case*/
 131         data[RTC_MIN_ADDR]    = bin2bcd(tmp->tm_min);
 132         data[RTC_HOUR_ADDR]   = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
 133         data[RTC_DATE_ADDR]   = bin2bcd(tmp->tm_mday) & 0x3F;
 134         data[RTC_MONTH_ADDR]  = bin2bcd(tmp->tm_mon);
 135         data[RTC_DAY_ADDR]    = bin2bcd(tmp->tm_wday) & 0x07;
 136
 137         data[RTC_HOUR_ADDR]   |= 0x80;/*we will always use CEB*/
 138
 139         data[RTC_YEARS_ADDR]  = bin2bcd(tmp->tm_year%100);/*same thing either way*/
 140 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
 141         if( ((tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 200) ||
 142             (tmp->tm_year < CONFIG_SYS_M41T11_BASE_YEAR) ){
 143                 printf( "m41t11 RTC setting year out of range!!need recompile\n" );
 144         }
 145         data[RTC_HOUR_ADDR] |= (tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
 146 #else
 147         {
 148                 unsigned char cent;
 149                 cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
 150                 data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
 151                 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
 152         }
 153 #endif
 154         i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
 155
 156         return 0;
 157 }
 158
 159 void rtc_reset (void)
 160 {
 161         unsigned char val;
 162         /* clear all control & status registers */
 163         i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
 164         val = val & 0x7F;/*make sure we are running*/
 165         i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
 166
 167         i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
 168         val = val & 0x3F;/*turn off freq test keep calibration*/
 169         i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
 170 }
 171 #endif