u-boot/drivers/rtc/m41t62.c
Stefan Roese 038f3c54ba rtc/m41t62: Add support for M41T82 with HT (Halt Update)
Add support for the M41T82 RTC to the m41t62 driver. The only
difference that needs to be handled by this driver, is to
clear the HT (Halt Update) bit upon reset. This bit is not
used on the M41T62, so its save to clear this bit always.

The M41T82 support will be used by the X600 (SPEAr600)
board support.

Signed-off-by: Stefan Roese <sr@denx.de>
2012-07-07 14:07:43 +02:00

148 lines
4.5 KiB
C

/*
* (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
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* 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