u-boot/drivers/rtc/rx8025.c

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/*
* (C) Copyright 2007
* Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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
*/
/*
* Epson RX8025 RTC driver.
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_CMD_DATE)
/*---------------------------------------------------------------------*/
#undef DEBUG_RTC
#ifdef DEBUG_RTC
#define DEBUGR(fmt,args...) printf(fmt ,##args)
#else
#define DEBUGR(fmt,args...)
#endif
/*---------------------------------------------------------------------*/
#ifndef CFG_I2C_RTC_ADDR
# define CFG_I2C_RTC_ADDR 0x32
#endif
/*
* RTC register addresses
*/
#define RTC_SEC_REG_ADDR 0x00
#define RTC_MIN_REG_ADDR 0x01
#define RTC_HR_REG_ADDR 0x02
#define RTC_DAY_REG_ADDR 0x03
#define RTC_DATE_REG_ADDR 0x04
#define RTC_MON_REG_ADDR 0x05
#define RTC_YR_REG_ADDR 0x06
#define RTC_CTL1_REG_ADDR 0x0e
#define RTC_CTL2_REG_ADDR 0x0f
/*
* Control register 1 bits
*/
#define RTC_CTL1_BIT_2412 0x20
/*
* Control register 2 bits
*/
#define RTC_CTL2_BIT_PON 0x10
#define RTC_CTL2_BIT_VDET 0x40
#define RTC_CTL2_BIT_XST 0x20
#define RTC_CTL2_BIT_VDSL 0x80
/*
* Note: the RX8025 I2C RTC requires register
* reads and write to consist of a single bus
* cycle. It is not allowed to write the register
* address in a first cycle that is terminated by
* a STOP condition. The chips needs a 'restart'
* sequence (start sequence without a prior stop).
* This driver has been written for a 4xx board.
* U-Boot's 4xx i2c driver is currently not capable
* to generate such cycles to some work arounds
* are used.
*/
/* static uchar rtc_read (uchar reg); */
#define rtc_read(reg) buf[((reg) + 1) & 0xf]
static void rtc_write (uchar reg, uchar val);
static uchar bin2bcd (unsigned int n);
static unsigned bcd2bin (uchar c);
/*
* 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, ctl2;
uchar buf[16];
if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16))
printf("Error reading from RTC\n");
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\n",
year, mon, mday, wday, hour, min, sec);
/* dump status */
ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
if (ctl2 & RTC_CTL2_BIT_PON) {
printf("RTC: power-on detected\n");
rel = -1;
}
if (ctl2 & RTC_CTL2_BIT_VDET) {
printf("RTC: voltage drop detected\n");
rel = -1;
}
if (!(ctl2 & RTC_CTL2_BIT_XST)) {
printf("RTC: oscillator stop detected\n");
rel = -1;
}
tmp->tm_sec = bcd2bin (sec & 0x7F);
tmp->tm_min = bcd2bin (min & 0x7F);
if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412)
tmp->tm_hour = bcd2bin (hour & 0x3F);
else
tmp->tm_hour = bcd2bin (hour & 0x1F) % 12 +
((hour & 0x20) ? 12 : 0);
tmp->tm_mday = bcd2bin (mday & 0x3F);
tmp->tm_mon = bcd2bin (mon & 0x1F);
tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 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
*/
void 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);
if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
printf("WARNING: year should be between 1970 and 2069!\n");
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));
rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
}
/*
* Reset the RTC. We setting the date back to 1970-01-01.
*/
void rtc_reset (void)
{
struct rtc_time tmp;
uchar buf[16];
uchar ctl2;
if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16))
printf("Error reading from RTC\n");
ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
rtc_write (RTC_CTL2_REG_ADDR, ctl2);
tmp.tm_year = 1970;
tmp.tm_mon = 1;
tmp.tm_mday= 1;
tmp.tm_hour = 0;
tmp.tm_min = 0;
tmp.tm_sec = 0;
rtc_set(&tmp);
printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
return;
}
/*
* Helper functions
*/
static void rtc_write (uchar reg, uchar val)
{
uchar buf[2];
buf[0] = reg << 4;
buf[1] = val;
if (i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
printf("Error writing to RTC\n");
}
static unsigned bcd2bin (uchar n)
{
return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
}
static unsigned char bin2bcd (unsigned int n)
{
return (((n / 10) << 4) | (n % 10));
}
#endif /* CONFIG_RTC_RX8025 && CONFIG_CMD_DATE */