rtc4543.c
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/*
* (C) Copyright 2008, 2009
* Andreas Pfefferle, DENX Software Engineering, ap@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm/io.h>
#include <common.h>
#include <command.h>
#include <config.h>
#include <rtc.h>
#include <tws.h>
#if defined(CONFIG_CMD_DATE)
/*
* Note: The acrobatics below is due to the hideously ingenius idea of
* the chip designers. As the chip does not allow register
* addressing, all values need to be read and written in one go. Sure
* enough, the 'wday' field (0-6) is transferred using the economic
* number of 4 bits right in the middle of the packet.....
*/
int rtc_get(struct rtc_time *tm)
{
int rel = 0;
uchar buffer[7];
memset(buffer, 0, 7);
/* Read 52 bits into our buffer */
tws_read(buffer, 52);
tm->tm_sec = bcd2bin( buffer[0] & 0x7F);
tm->tm_min = bcd2bin( buffer[1] & 0x7F);
tm->tm_hour = bcd2bin( buffer[2] & 0x3F);
tm->tm_wday = bcd2bin( buffer[3] & 0x07);
tm->tm_mday = bcd2bin((buffer[3] & 0xF0) >> 4 | (buffer[4] & 0x0F) << 4);
tm->tm_mon = bcd2bin((buffer[4] & 0x30) >> 4 | (buffer[5] & 0x0F) << 4);
tm->tm_year = bcd2bin((buffer[5] & 0xF0) >> 4 | (buffer[6] & 0x0F) << 4) + 2000;
tm->tm_yday = 0;
tm->tm_isdst = 0;
if (tm->tm_sec & 0x80) {
puts("### Warning: RTC Low Voltage - date/time not reliable\n");
rel = -1;
}
debug("Get 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);
return rel;
}
int rtc_set(struct rtc_time *tm)
{
uchar buffer[7];
uchar tmp;
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);
memset(buffer, 0, 7);
buffer[0] = bin2bcd(tm->tm_sec);
buffer[1] = bin2bcd(tm->tm_min);
buffer[2] = bin2bcd(tm->tm_hour);
buffer[3] = bin2bcd(tm->tm_wday);
tmp = bin2bcd(tm->tm_mday);
buffer[3] |= (tmp & 0x0F) << 4;
buffer[4] = (tmp & 0xF0) >> 4;
tmp = bin2bcd(tm->tm_mon);
buffer[4] |= (tmp & 0x0F) << 4;
buffer[5] = (tmp & 0xF0) >> 4;
tmp = bin2bcd(tm->tm_year % 100);
buffer[5] |= (tmp & 0x0F) << 4;
buffer[6] = (tmp & 0xF0) >> 4;
/* Write the resulting 52 bits to device */
tws_write(buffer, 52);
return 0;
}
void rtc_reset(void)
{
struct rtc_time tmp;
tmp.tm_sec = 0;
tmp.tm_min = 0;
tmp.tm_hour = 0;
tmp.tm_wday = 4;
tmp.tm_mday = 1;
tmp.tm_mon = 1;
tmp.tm_year = 2000;
rtc_set(&tmp);
}
#endif