drivers/rtc/s3c24x0_rtc.c

/*
 * (C) Copyright 2003
 * David Müller ELSOFT AG Switzerland. d.mueller@elsoft.ch
 *
 * 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 the built-in Samsung S3C24X0 RTC
 */

#include <common.h>
#include <command.h>

#if (defined(CONFIG_CMD_DATE))

#if defined(CONFIG_S3C2400)
#include <s3c2400.h>
#elif defined(CONFIG_S3C2410)
#include <s3c2410.h>
#endif

#include <rtc.h>

/*#define	DEBUG*/

typedef enum {
	RTC_ENABLE,
	RTC_DISABLE
} RTC_ACCESS;


static inline void SetRTC_Access(RTC_ACCESS a)
{
	S3C24X0_RTC * const rtc = S3C24X0_GetBase_RTC();
	switch (a) {
		case RTC_ENABLE:
			rtc->RTCCON |= 0x01; break;

		case RTC_DISABLE:
			rtc->RTCCON &= ~0x01; break;
	}
}

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));
}

/* ------------------------------------------------------------------------- */

int rtc_get (struct rtc_time *tmp)
{
	S3C24X0_RTC * const rtc = S3C24X0_GetBase_RTC();
	uchar sec, min, hour, mday, wday, mon, year;
	uchar a_sec,a_min, a_hour, a_date, a_mon, a_year, a_armed;

	/* enable access to RTC registers */
	SetRTC_Access(RTC_ENABLE);

	/* read RTC registers */
	do {
		sec	= rtc->BCDSEC;
		min	= rtc->BCDMIN;
		hour	= rtc->BCDHOUR;
		mday	= rtc->BCDDATE;
		wday	= rtc->BCDDAY;
		mon	= rtc->BCDMON;
		year	= rtc->BCDYEAR;
	} while (sec != rtc->BCDSEC);

	/* read ALARM registers */
	a_sec	= rtc->ALMSEC;
	a_min	= rtc->ALMMIN;
	a_hour	= rtc->ALMHOUR;
	a_date	= rtc->ALMDATE;
	a_mon	= rtc->ALMMON;
	a_year	= rtc->ALMYEAR;
	a_armed	= rtc->RTCALM;

	/* disable access to RTC registers */
	SetRTC_Access(RTC_DISABLE);

#ifdef RTC_DEBUG
	printf ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
		"hr: %02x min: %02x sec: %02x\n",
		year, mon, mday, wday,
		hour, min, sec);
	printf ( "Alarms: %02x: year: %02x month: %02x date: %02x hour: %02x min: %02x sec: %02x\n",
		a_armed,
		a_year, a_mon, a_date,
		a_hour, a_min, a_sec);
#endif

	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);
	tmp->tm_wday = bcd2bin(wday & 0x07);
	if(tmp->tm_year<70)
		tmp->tm_year+=2000;
	else
		tmp->tm_year+=1900;
	tmp->tm_yday = 0;
	tmp->tm_isdst= 0;
#ifdef RTC_DEBUG
	printf ( "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);
#endif

	return 0;
}

int rtc_set (struct rtc_time *tmp)
{
	S3C24X0_RTC * const rtc = S3C24X0_GetBase_RTC();
	uchar sec, min, hour, mday, wday, mon, year;

#ifdef RTC_DEBUG
	printf ( "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);
#endif
	year	= bin2bcd(tmp->tm_year % 100);
	mon	= bin2bcd(tmp->tm_mon);
	wday	= bin2bcd(tmp->tm_wday);
	mday	= bin2bcd(tmp->tm_mday);
	hour	= bin2bcd(tmp->tm_hour);
	min	= bin2bcd(tmp->tm_min);
	sec	= bin2bcd(tmp->tm_sec);

	/* enable access to RTC registers */
	SetRTC_Access(RTC_ENABLE);

	/* write RTC registers */
	rtc->BCDSEC	= sec;
	rtc->BCDMIN	= min;
	rtc->BCDHOUR	= hour;
	rtc->BCDDATE	= mday;
	rtc->BCDDAY	= wday;
	rtc->BCDMON	= mon;
	rtc->BCDYEAR	= year;

	/* disable access to RTC registers */
	SetRTC_Access(RTC_DISABLE);

	return 0;
}

void rtc_reset (void)
{
	S3C24X0_RTC * const rtc = S3C24X0_GetBase_RTC();

	rtc->RTCCON = (rtc->RTCCON & ~0x06) | 0x08;
	rtc->RTCCON &= ~(0x08|0x01);
}

#endif