u-boot/drivers/rtc/isl1208.c

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/*
* (C) Copyright 2008
* Tor Krill, Excito Elektronik i Skåne , tor@excito.com
*
* Modelled after the ds1337 driver
*
* 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 (no alarms) for Intersil
* ISL1208 Real Time Clock (RTC).
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
/*---------------------------------------------------------------------*/
#ifdef DEBUG_RTC
#define DEBUGR(fmt,args...) printf(fmt ,##args)
#else
#define DEBUGR(fmt,args...)
#endif
/*---------------------------------------------------------------------*/
/*
* RTC register addresses
*/
#define RTC_SEC_REG_ADDR 0x0
#define RTC_MIN_REG_ADDR 0x1
#define RTC_HR_REG_ADDR 0x2
#define RTC_DATE_REG_ADDR 0x3
#define RTC_MON_REG_ADDR 0x4
#define RTC_YR_REG_ADDR 0x5
#define RTC_DAY_REG_ADDR 0x6
#define RTC_STAT_REG_ADDR 0x7
/*
* RTC control register bits
*/
/*
* RTC status register bits
*/
#define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */
#define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */
#define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */
#define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */
#define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */
#define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */
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, year, status;
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 = rtc_read (RTC_MON_REG_ADDR);
year = rtc_read (RTC_YR_REG_ADDR);
DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
"hr: %02x min: %02x sec: %02x status: %02x\n",
year, mon, mday, wday, hour, min, sec, status);
if (status & RTC_STAT_BIT_RTCF) {
printf ("### Warning: RTC oscillator has stopped\n");
rtc_write(RTC_STAT_REG_ADDR,
rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF));
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 & 0x1F);
tmp->tm_year = bcd2bin (year)+2000;
tmp->tm_wday = bcd2bin (wday & 0x07);
tmp->tm_yday = 0;
tmp->tm_isdst= 0;
DEBUGR ("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)
{
DEBUGR ("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);
/* enable write */
rtc_write(RTC_STAT_REG_ADDR,
rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC);
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));
rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */
rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
/* disable write */
rtc_write(RTC_STAT_REG_ADDR,
rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC);
return 0;
}
void rtc_reset (void)
{
}
/*
* 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);
}