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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2006
* Markus Klotzbuecher, mk@denx.de
*/
/*
* Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
* Extremly Accurate DS3231 Real Time Clock (RTC).
*
* copied from ds1337.c
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_CMD_DATE)
/*
* RTC register addresses
*/
#define RTC_SEC_REG_ADDR 0x0
#define RTC_MIN_REG_ADDR 0x1
#define RTC_HR_REG_ADDR 0x2
#define RTC_DAY_REG_ADDR 0x3
#define RTC_DATE_REG_ADDR 0x4
#define RTC_MON_REG_ADDR 0x5
#define RTC_YR_REG_ADDR 0x6
#define RTC_CTL_REG_ADDR 0x0e
#define RTC_STAT_REG_ADDR 0x0f
/*
* RTC control register bits
*/
#define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */
#define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */
#define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */
#define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */
#define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */
#define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */
/*
* RTC status register bits
*/
#define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */
#define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */
#define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */
#define RTC_STAT_BIT_BB32KHZ 0x40 /* Battery backed 32KHz Output */
#define RTC_STAT_BIT_EN32KHZ 0x8 /* Enable 32KHz Output */
static uchar rtc_read (uchar reg);
static void rtc_write (uchar reg, uchar val);
/*
* Get the current time from the RTC
*/
int rtc_get (struct rtc_time *tmp)
{
int rel = 0;
uchar sec, min, hour, mday, wday, mon_cent, year, control, status;
control = rtc_read (RTC_CTL_REG_ADDR);
status = rtc_read (RTC_STAT_REG_ADDR);
sec = rtc_read (RTC_SEC_REG_ADDR);
min = rtc_read (RTC_MIN_REG_ADDR);
hour = rtc_read (RTC_HR_REG_ADDR);
wday = rtc_read (RTC_DAY_REG_ADDR);
mday = rtc_read (RTC_DATE_REG_ADDR);
mon_cent = rtc_read (RTC_MON_REG_ADDR);
year = rtc_read (RTC_YR_REG_ADDR);
debug("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
"hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
year, mon_cent, mday, wday, hour, min, sec, control, status);
if (status & RTC_STAT_BIT_OSF) {
printf ("### Warning: RTC oscillator has stopped\n");
/* clear the OSF flag */
rtc_write (RTC_STAT_REG_ADDR,
rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
rel = -1;
}
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_cent & 0x1F);
tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
tmp->tm_wday = bcd2bin ((wday - 1) & 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 rel;
}
/*
* Set the RTC
*/
int rtc_set (struct rtc_time *tmp)
{
uchar century;
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 (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
century = (tmp->tm_year >= 2000) ? 0x80 : 0;
rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);
rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
return 0;
}
/*
* Reset the RTC. We also enable the oscillator output on the
* SQW/INTB* pin and program it for 32,768 Hz output. Note that
* according to the datasheet, turning on the square wave output
* increases the current drain on the backup battery from about
* 600 nA to 2uA.
*/
void rtc_reset (void)
{
rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
}
/*
* Enable 32KHz output
*/
void rtc_enable_32khz_output(void)
{
rtc_write(RTC_STAT_REG_ADDR,
RTC_STAT_BIT_BB32KHZ | RTC_STAT_BIT_EN32KHZ);
}
/*
* Helper functions
*/
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);
}
#endif
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