m41t62.c
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/*
* (C) Copyright 2008
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
* based on a the Linux rtc-m41t80.c driver which is:
* Alexander Bigga <ab@mycable.de>, 2006 (c) mycable GmbH
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Date & Time support for STMicroelectronics M41T62
*/
/* #define DEBUG */
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_CMD_DATE)
#define M41T62_REG_SSEC 0
#define M41T62_REG_SEC 1
#define M41T62_REG_MIN 2
#define M41T62_REG_HOUR 3
#define M41T62_REG_WDAY 4
#define M41T62_REG_DAY 5
#define M41T62_REG_MON 6
#define M41T62_REG_YEAR 7
#define M41T62_REG_ALARM_MON 0xa
#define M41T62_REG_ALARM_DAY 0xb
#define M41T62_REG_ALARM_HOUR 0xc
#define M41T62_REG_ALARM_MIN 0xd
#define M41T62_REG_ALARM_SEC 0xe
#define M41T62_REG_FLAGS 0xf
#define M41T62_DATETIME_REG_SIZE (M41T62_REG_YEAR + 1)
#define M41T62_ALARM_REG_SIZE \
(M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON)
#define M41T62_SEC_ST (1 << 7) /* ST: Stop Bit */
#define M41T62_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
#define M41T62_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
#define M41T62_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
#define M41T62_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
#define M41T62_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
#define M41T62_FEATURE_HT (1 << 0)
#define M41T62_FEATURE_BL (1 << 1)
#define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
int rtc_get(struct rtc_time *tm)
{
u8 buf[M41T62_DATETIME_REG_SIZE];
i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
"mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
__FUNCTION__,
buf[0], buf[1], buf[2], buf[3],
buf[4], buf[5], buf[6], buf[7]);
tm->tm_sec = bcd2bin(buf[M41T62_REG_SEC] & 0x7f);
tm->tm_min = bcd2bin(buf[M41T62_REG_MIN] & 0x7f);
tm->tm_hour = bcd2bin(buf[M41T62_REG_HOUR] & 0x3f);
tm->tm_mday = bcd2bin(buf[M41T62_REG_DAY] & 0x3f);
tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07;
tm->tm_mon = bcd2bin(buf[M41T62_REG_MON] & 0x1f);
/* assume 20YY not 19YY, and ignore the Century Bit */
/* U-Boot needs to add 1900 here */
tm->tm_year = bcd2bin(buf[M41T62_REG_YEAR]) + 100 + 1900;
debug("%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__FUNCTION__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
return 0;
}
int rtc_set(struct rtc_time *tm)
{
u8 buf[M41T62_DATETIME_REG_SIZE];
debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
/* Merge time-data and register flags into buf[0..7] */
buf[M41T62_REG_SSEC] = 0;
buf[M41T62_REG_SEC] =
bin2bcd(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f);
buf[M41T62_REG_MIN] =
bin2bcd(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f);
buf[M41T62_REG_HOUR] =
bin2bcd(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ;
buf[M41T62_REG_WDAY] =
(tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07);
buf[M41T62_REG_DAY] =
bin2bcd(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f);
buf[M41T62_REG_MON] =
bin2bcd(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f);
/* assume 20YY not 19YY */
buf[M41T62_REG_YEAR] = bin2bcd(tm->tm_year % 100);
if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) {
printf("I2C write failed in %s()\n", __func__);
return -1;
}
return 0;
}
void rtc_reset(void)
{
u8 val;
/*
* M41T82: Make sure HT (Halt Update) bit is cleared.
* This bit is 0 in M41T62 so its save to clear it always.
*/
i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
val &= ~M41T80_ALHOUR_HT;
i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
}
#endif