u-boot/drivers/rtc/pcf8563.c
Benoît Thébaudeau df930e9b3c rtc: pcf8563: Make century compatible with Linux
This driver uses the century bit of this RTC in the opposite way Linux does.
From Linux's rtc-pcf8563.c:
	/*
	 * The meaning of MO_C bit varies by the chip type.
	 * From PCF8563 datasheet: this bit is toggled when the years
	 * register overflows from 99 to 00
	 *   0 indicates the century is 20xx
	 *   1 indicates the century is 19xx
	 * From RTC8564 datasheet: this bit indicates change of
	 * century. When the year digit data overflows from 99 to 00,
	 * this bit is set. By presetting it to 0 while still in the
	 * 20th century, it will be set in year 2000, ...
	 * There seems no reliable way to know how the system use this
	 * bit.  So let's do it heuristically, assuming we are live in
	 * 1970...2069.
	 */

As U-Boot's PCF8563 driver does not say it is supposed to support the RTC8564,
make this driver compatible with Linux's by giving the opposite meaning to the
century bit.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Wolfgang Denk <wd@denx.de>
2012-09-02 17:31:00 +02:00

138 lines
3.6 KiB
C

/*
* (C) Copyright 2001
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* 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
*/
/*
* Date & Time support for Philips PCF8563 RTC
*/
/* #define DEBUG */
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_CMD_DATE)
static uchar rtc_read (uchar reg);
static void rtc_write (uchar reg, uchar val);
/* ------------------------------------------------------------------------- */
int rtc_get (struct rtc_time *tmp)
{
int rel = 0;
uchar sec, min, hour, mday, wday, mon_cent, year;
sec = rtc_read (0x02);
min = rtc_read (0x03);
hour = rtc_read (0x04);
mday = rtc_read (0x05);
wday = rtc_read (0x06);
mon_cent= rtc_read (0x07);
year = rtc_read (0x08);
debug ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
"hr: %02x min: %02x sec: %02x\n",
year, mon_cent, mday, wday,
hour, min, sec );
debug ( "Alarms: wday: %02x day: %02x hour: %02x min: %02x\n",
rtc_read (0x0C),
rtc_read (0x0B),
rtc_read (0x0A),
rtc_read (0x09) );
if (sec & 0x80) {
puts ("### Warning: RTC Low Voltage - date/time not reliable\n");
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_cent & 0x1F);
tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 1900 : 2000);
tmp->tm_wday = bcd2bin (wday & 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 rel;
}
int rtc_set (struct rtc_time *tmp)
{
uchar century;
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 (0x08, bin2bcd(tmp->tm_year % 100));
century = (tmp->tm_year >= 2000) ? 0 : 0x80;
rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
rtc_write (0x06, bin2bcd(tmp->tm_wday));
rtc_write (0x05, bin2bcd(tmp->tm_mday));
rtc_write (0x04, bin2bcd(tmp->tm_hour));
rtc_write (0x03, bin2bcd(tmp->tm_min ));
rtc_write (0x02, bin2bcd(tmp->tm_sec ));
return 0;
}
void rtc_reset (void)
{
/* clear all control & status registers */
rtc_write (0x00, 0x00);
rtc_write (0x01, 0x00);
rtc_write (0x0D, 0x00);
/* clear Voltage Low bit */
rtc_write (0x02, rtc_read (0x02) & 0x7F);
/* reset all alarms */
rtc_write (0x09, 0x00);
rtc_write (0x0A, 0x00);
rtc_write (0x0B, 0x00);
rtc_write (0x0C, 0x00);
}
/* ------------------------------------------------------------------------- */
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);
}
#endif