u-boot/rtc/m41t11.c

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/*
* (C) Copyright 2002
* Andrew May, Viasat Inc, amay@viasat.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* M41T11 Serial Access Timekeeper(R) SRAM
* can you believe a trademark on that?
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
/*
I Don't have an example config file but this
is what should be done.
#define CONFIG_RTC_M41T11 1
#define CFG_I2C_RTC_ADDR 0x68
#if 0
#define CFG_M41T11_EXT_CENTURY_DATA
#else
#define CFG_M41T11_BASE_YEAR 2000
#endif
*/
#if defined(CONFIG_RTC_M41T11) && defined(CFG_I2C_RTC_ADDR) && (CONFIG_COMMANDS & CFG_CMD_DATE)
#define DEBUG 1
static unsigned bcd2bin (uchar n)
{
return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
}
static unsigned char bin2bcd (unsigned int n)
{
return (((n / 10) << 4) | (n % 10));
}
/* ------------------------------------------------------------------------- */
/*
these are simple defines for the chip local to here so they aren't too
verbose
DAY/DATE aren't nice but that is how they are on the data sheet
*/
#define RTC_SEC_ADDR 0x0
#define RTC_MIN_ADDR 0x1
#define RTC_HOUR_ADDR 0x2
#define RTC_DAY_ADDR 0x3
#define RTC_DATE_ADDR 0x4
#define RTC_MONTH_ADDR 0x5
#define RTC_YEARS_ADDR 0x6
#define RTC_REG_CNT 7
#define RTC_CONTROL_ADDR 0x7
#ifndef CFG_M41T11_EXT_CENTURY_DATA
#define REG_CNT (RTC_REG_CNT+1)
/*
you only get 00-99 for the year we will asume you
want from the year 2000 if you don't set the config
*/
#ifndef CFG_M41T11_BASE_YEAR
#define CFG_M41T11_BASE_YEAR 2000
#endif
#else
/* we will store extra year info in byte 9*/
#define M41T11_YEAR_DATA 0x8
#define M41T11_YEAR_SIZE 1
#define REG_CNT (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
#endif
#define M41T11_STORAGE_SZ (64-REG_CNT)
void rtc_get (struct rtc_time *tmp)
{
uchar data[RTC_REG_CNT];
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i2c_read(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
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if( data[RTC_SEC_ADDR] & 0x80 ){
printf( "m41t11 RTC Clock stopped!!!\n" );
}
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tmp->tm_sec = bcd2bin (data[RTC_SEC_ADDR] & 0x7F);
tmp->tm_min = bcd2bin (data[RTC_MIN_ADDR] & 0x7F);
tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
tmp->tm_mon = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
#ifndef CFG_M41T11_EXT_CENTURY_DATA
tmp->tm_year = CFG_M41T11_BASE_YEAR
+ bcd2bin(data[RTC_YEARS_ADDR])
+ ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
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#else
{
unsigned char cent;
i2c_read(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
if( !(data[RTC_HOUR_ADDR] & 0x80) ){
printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
}
if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
/*century flip store off new year*/
cent += 1;
i2c_write(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
}
tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
}
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#endif
tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR] & 0x07);
tmp->tm_yday = 0;
tmp->tm_isdst= 0;
debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
}
void rtc_set (struct rtc_time *tmp)
{
uchar data[RTC_REG_CNT];
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debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
data[RTC_SEC_ADDR] = bin2bcd(tmp->tm_sec) & 0x7F;/*just in case*/
data[RTC_MIN_ADDR] = bin2bcd(tmp->tm_min);
data[RTC_HOUR_ADDR] = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
data[RTC_DATE_ADDR] = bin2bcd(tmp->tm_mday) & 0x3F;
data[RTC_MONTH_ADDR] = bin2bcd(tmp->tm_mon);
data[RTC_DAY_ADDR] = bin2bcd(tmp->tm_wday) & 0x07;
data[RTC_HOUR_ADDR] |= 0x80;/*we will always use CEB*/
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data[RTC_YEARS_ADDR] = bin2bcd(tmp->tm_year%100);/*same thing either way*/
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#ifndef CFG_M41T11_EXT_CENTURY_DATA
if( ((tmp->tm_year - CFG_M41T11_BASE_YEAR) > 200) ||
(tmp->tm_year < CFG_M41T11_BASE_YEAR) ){
printf( "m41t11 RTC setting year out of range!!need recompile\n" );
}
data[RTC_HOUR_ADDR] |= (tmp->tm_year - CFG_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
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#else
{
unsigned char cent;
cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
i2c_write(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
}
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#endif
i2c_write(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
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}
void rtc_reset (void)
{
unsigned char val;
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/* clear all control & status registers */
i2c_read(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
val = val & 0x7F;/*make sure we are running*/
i2c_write(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
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i2c_read(CFG_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
val = val & 0x3F;/*turn off freq test keep calibration*/
i2c_write(CFG_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
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}
int rtc_store(int addr, unsigned char* data, int size)
{
/*don't let things wrap onto the time on a write*/
if( (addr+size) >= M41T11_STORAGE_SZ )
return 1;
return i2c_write( CFG_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size );
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}
int rtc_recall(int addr, unsigned char* data, int size)
{
return i2c_read( CFG_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size );
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}
#endif /* CONFIG_RTC_M41T11 && CFG_I2C_RTC_ADDR && CFG_CMD_DATE */