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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2006
* Markus Klotzbuecher, mk@denx.de
*
* (C) Copyright 2019 NXP
* Chuanhua Han <chuanhua.han@nxp.com>
*/
/*
* 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 <dm.h>
#include <log.h>
#include <rtc.h>
#include <i2c.h>
/*
* 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 */
#if !CONFIG_IS_ENABLED(DM_RTC)
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
*/
#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
void rtc_enable_32khz_output(void)
{
rtc_write(RTC_STAT_REG_ADDR,
RTC_STAT_BIT_BB32KHZ | RTC_STAT_BIT_EN32KHZ);
}
#endif
/*
* 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);
}
#else
static int ds3231_rtc_get(struct udevice *dev, struct rtc_time *tmp)
{
uchar sec, min, hour, mday, wday, mon_cent, year, status;
status = dm_i2c_reg_read(dev, RTC_STAT_REG_ADDR);
sec = dm_i2c_reg_read(dev, RTC_SEC_REG_ADDR);
min = dm_i2c_reg_read(dev, RTC_MIN_REG_ADDR);
hour = dm_i2c_reg_read(dev, RTC_HR_REG_ADDR);
wday = dm_i2c_reg_read(dev, RTC_DAY_REG_ADDR);
mday = dm_i2c_reg_read(dev, RTC_DATE_REG_ADDR);
mon_cent = dm_i2c_reg_read(dev, RTC_MON_REG_ADDR);
year = dm_i2c_reg_read(dev, RTC_YR_REG_ADDR);
if (status & RTC_STAT_BIT_OSF) {
printf("### Warning: RTC oscillator has stopped\n");
/* clear the OSF flag */
dm_i2c_reg_write(dev, RTC_STAT_REG_ADDR,
dm_i2c_reg_read(dev, RTC_STAT_REG_ADDR)
& ~RTC_STAT_BIT_OSF);
return -EINVAL;
}
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 0;
}
static int ds3231_rtc_set(struct udevice *dev, const 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);
dm_i2c_reg_write(dev, RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year % 100));
century = (tmp->tm_year >= 2000) ? 0x80 : 0;
dm_i2c_reg_write(dev, RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon) | century);
dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR, bin2bcd(tmp->tm_wday + 1));
dm_i2c_reg_write(dev, RTC_DATE_REG_ADDR, bin2bcd(tmp->tm_mday));
dm_i2c_reg_write(dev, RTC_HR_REG_ADDR, bin2bcd(tmp->tm_hour));
dm_i2c_reg_write(dev, RTC_MIN_REG_ADDR, bin2bcd(tmp->tm_min));
dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, bin2bcd(tmp->tm_sec));
return 0;
}
static int ds3231_rtc_reset(struct udevice *dev)
{
int ret;
ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
if (ret < 0)
return ret;
return 0;
}
static int ds3231_probe(struct udevice *dev)
{
i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
DM_I2C_CHIP_WR_ADDRESS);
return 0;
}
#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
int rtc_enable_32khz_output(int busnum, int chip_addr)
{
int ret;
struct udevice *dev;
ret = i2c_get_chip_for_busnum(busnum, chip_addr, 1, &dev);
if (!ret) {
ret = dm_i2c_reg_write(dev, RTC_STAT_REG_ADDR,
RTC_STAT_BIT_BB32KHZ |
RTC_STAT_BIT_EN32KHZ);
}
return ret;
}
#endif
static const struct rtc_ops ds3231_rtc_ops = {
.get = ds3231_rtc_get,
.set = ds3231_rtc_set,
.reset = ds3231_rtc_reset,
};
static const struct udevice_id ds3231_rtc_ids[] = {
{ .compatible = "dallas,ds3231" },
{ .compatible = "dallas,ds3232" },
{ }
};
U_BOOT_DRIVER(rtc_ds3231) = {
.name = "rtc-ds3231",
.id = UCLASS_RTC,
.probe = ds3231_probe,
.of_match = ds3231_rtc_ids,
.ops = &ds3231_rtc_ops,
};
#endif
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