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/*
* Copyright 2010 Freescale Semiconductor, Inc.
*
* Author: Priyanka Jain <Priyanka.Jain@freescale.com>
*
* SPDX-License-Identifier: GPL-2.0+
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*/
/*
* This file provides Date & Time support (no alarms) for PT7C4338 chip.
*
* This file is based on drivers/rtc/ds1337.c
*
* PT7C4338 chip is manufactured by Pericom Technology Inc.
* It is a serial real-time clock which provides
* 1)Low-power clock/calendar.
* 2)Programmable square-wave output.
* It has 56 bytes of nonvolatile RAM.
*/
#include <common.h>
#include <command.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_STAT_REG_ADDR 0x7
/* RTC second register address bit */
#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
/* RTC control and status register bits */
#define RTC_CTL_STAT_BIT_RS0 0x1 /* Rate select 0 */
#define RTC_CTL_STAT_BIT_RS1 0x2 /* Rate select 1 */
#define RTC_CTL_STAT_BIT_SQWE 0x10 /* Square Wave Enable */
#define RTC_CTL_STAT_BIT_OSF 0x20 /* Oscillator Stop Flag */
#define RTC_CTL_STAT_BIT_OUT 0x80 /* Output Level Control */
/* RTC reset value */
#define RTC_PT7C4338_RESET_VAL \
(RTC_CTL_STAT_BIT_RS0 | RTC_CTL_STAT_BIT_RS1 | RTC_CTL_STAT_BIT_OUT)
/****** Helper functions ****************************************/
static u8 rtc_read(u8 reg)
{
return i2c_reg_read(CONFIG_SYS_I2C_RTC_ADDR, reg);
}
static void rtc_write(u8 reg, u8 val)
{
i2c_reg_write(CONFIG_SYS_I2C_RTC_ADDR, reg, val);
}
/****************************************************************/
/* Get the current time from the RTC */
int rtc_get(struct rtc_time *tmp)
{
int ret = 0;
u8 sec, min, hour, mday, wday, mon, year, ctl_stat;
ctl_stat = rtc_read(RTC_CTL_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 = rtc_read(RTC_MON_REG_ADDR);
year = rtc_read(RTC_YR_REG_ADDR);
debug("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
"hr: %02x min: %02x sec: %02x control_status: %02x\n",
year, mon, mday, wday, hour, min, sec, ctl_stat);
if (ctl_stat & RTC_CTL_STAT_BIT_OSF) {
printf("### Warning: RTC oscillator has stopped\n");
/* clear the OSF flag */
rtc_write(RTC_CTL_STAT_REG_ADDR,
rtc_read(RTC_CTL_STAT_REG_ADDR)\
& ~RTC_CTL_STAT_BIT_OSF);
ret = -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 & 0x1F);
tmp->tm_year = bcd2bin(year) + 2000;
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 ret;
}
/* Set the RTC */
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(RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year % 100));
rtc_write(RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon));
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 */
void rtc_reset(void)
{
rtc_write(RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
rtc_write(RTC_CTL_STAT_REG_ADDR, RTC_PT7C4338_RESET_VAL);
}