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-rw-r--r--rtc/m41t11.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/rtc/m41t11.c b/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];
+
+ 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, &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]);
+ }
+#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, &cent, 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 /* CONFIG_RTC_M41T11 && CFG_I2C_RTC_ADDR && CFG_CMD_DATE */
generated by cgit v1.1 at 2024-11-21 23:43:54 +0000