max6900.c
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/*
* (C) Copyright 2004
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Date & Time support for MAXIM MAX6900 RTC
*/
/* #define DEBUG */
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_CMD_DATE)
#ifndef CONFIG_SYS_I2C_RTC_ADDR
#define CONFIG_SYS_I2C_RTC_ADDR 0x50
#endif
/* ------------------------------------------------------------------------- */
static uchar rtc_read (uchar reg)
{
return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
}
static void rtc_write (uchar reg, uchar val)
{
i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
udelay(2500);
}
/* ------------------------------------------------------------------------- */
int rtc_get (struct rtc_time *tmp)
{
uchar sec, min, hour, mday, wday, mon, cent, year;
int retry = 1;
do {
sec = rtc_read (0x80);
min = rtc_read (0x82);
hour = rtc_read (0x84);
mday = rtc_read (0x86);
mon = rtc_read (0x88);
wday = rtc_read (0x8a);
year = rtc_read (0x8c);
cent = rtc_read (0x92);
/*
* Check for seconds rollover
*/
if ((sec != 59) || (rtc_read(0x80) == sec)){
retry = 0;
}
} while (retry);
debug ( "Get RTC year: %02x mon: %02x cent: %02x mday: %02x wday: %02x "
"hr: %02x min: %02x sec: %02x\n",
year, mon, cent, mday, wday,
hour, min, sec );
tmp->tm_sec = bcd2bin (sec & 0x7F);
tmp->tm_min = bcd2bin (min & 0x7F);
tmp->tm_hour = bcd2bin (hour & 0x3F);
tmp->tm_mday = bcd2bin (mday & 0x3F);
tmp->tm_mon = bcd2bin (mon & 0x1F);
tmp->tm_year = bcd2bin (year) + bcd2bin(cent) * 100;
tmp->tm_wday = bcd2bin (wday & 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);
return 0;
}
int rtc_set (struct rtc_time *tmp)
{
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);
rtc_write (0x9E, 0x00);
rtc_write (0x80, 0); /* Clear seconds to ensure no rollover */
rtc_write (0x92, bin2bcd(tmp->tm_year / 100));
rtc_write (0x8c, bin2bcd(tmp->tm_year % 100));
rtc_write (0x8a, bin2bcd(tmp->tm_wday));
rtc_write (0x88, bin2bcd(tmp->tm_mon));
rtc_write (0x86, bin2bcd(tmp->tm_mday));
rtc_write (0x84, bin2bcd(tmp->tm_hour));
rtc_write (0x82, bin2bcd(tmp->tm_min ));
rtc_write (0x80, bin2bcd(tmp->tm_sec ));
return 0;
}
void rtc_reset (void)
{
}
#endif