diff options
Diffstat (limited to 'drivers/rtc/m41t11.c')
| -rw-r--r-- | drivers/rtc/m41t11.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/rtc/m41t11.c b/drivers/rtc/m41t11.c new file mode 100644 index 0000000000..81da33a31e --- /dev/null +++ b/drivers/rtc/m41t11.c @@ -0,0 +1,202 @@ +/* + * (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? + */ + +/* #define DEBUG 1 */ + +#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) && defined(CONFIG_CMD_DATE) + +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]; + + i2c_read(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT); + + if( data[RTC_SEC_ADDR] & 0x80 ){ + printf( "m41t11 RTC Clock stopped!!!\n" ); + } + 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); +#else + { + unsigned char cent; + i2c_read(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, 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, ¢, M41T11_YEAR_SIZE); + } + tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]); + } +#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]; + + 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*/ + + data[RTC_YEARS_ADDR] = bin2bcd(tmp->tm_year%100);/*same thing either way*/ +#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; +#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, ¢, M41T11_YEAR_SIZE); + } +#endif + i2c_write(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT); +} + +void rtc_reset (void) +{ + unsigned char val; + /* 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); + + 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); +} + +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 ); +} + +int rtc_recall(int addr, unsigned char* data, int size) +{ + return i2c_read( CFG_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size ); +} + +#endif |