[people/ms/u-boot.git] / drivers / rtc / ds3231.c

/*
 * (C) Copyright 2006
 * Markus Klotzbuecher, mk@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 (no alarms) for Dallas Semiconductor (now Maxim)
 * Extremly Accurate DS3231 Real Time Clock (RTC).
 *
 * copied from ds1337.c
 */

#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>

#if defined(CONFIG_RTC_DS3231) && defined(CONFIG_CMD_DATE)

/*---------------------------------------------------------------------*/
#undef DEBUG_RTC

#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_DAY_REG_ADDR	0x3
#define RTC_DATE_REG_ADDR	0x4
#define RTC_MON_REG_ADDR	0x5
#define RTC_YR_REG_ADDR		0x6
#define RTC_CTL_REG_ADDR	0x0e
#define RTC_STAT_REG_ADDR	0x0f


/*
 * RTC control register bits
 */
#define RTC_CTL_BIT_A1IE	0x1	/* Alarm 1 interrupt enable     */
#define RTC_CTL_BIT_A2IE	0x2	/* Alarm 2 interrupt enable     */
#define RTC_CTL_BIT_INTCN	0x4	/* Interrupt control            */
#define RTC_CTL_BIT_RS1		0x8	/* Rate select 1                */
#define RTC_CTL_BIT_RS2		0x10	/* Rate select 2                */
#define RTC_CTL_BIT_DOSC	0x80	/* Disable Oscillator           */

/*
 * RTC status register bits
 */
#define RTC_STAT_BIT_A1F	0x1	/* Alarm 1 flag                 */
#define RTC_STAT_BIT_A2F	0x2	/* Alarm 2 flag                 */
#define RTC_STAT_BIT_OSF	0x80	/* Oscillator stop flag         */


static uchar rtc_read (uchar reg);
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_cent, year, control, status;

	control = rtc_read (RTC_CTL_REG_ADDR);
	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_cent = rtc_read (RTC_MON_REG_ADDR);
	year = rtc_read (RTC_YR_REG_ADDR);

	DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
		"hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
		year, mon_cent, mday, wday, hour, min, sec, control, status);

	if (status & RTC_STAT_BIT_OSF) {
		printf ("### Warning: RTC oscillator has stopped\n");
		/* clear the OSF flag */
		rtc_write (RTC_STAT_REG_ADDR,
			   rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
		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) ? 2000 : 1900);
	tmp->tm_wday = bcd2bin ((wday - 1) & 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)
{
	uchar century;

	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);

	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));

	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);

	rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
	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));
}


/*
 * Reset the RTC.  We also enable the oscillator output on the
 * SQW/INTB* pin and program it for 32,768 Hz output. Note that
 * according to the datasheet, turning on the square wave output
 * increases the current drain on the backup battery from about
 * 600 nA to 2uA.
 */
void rtc_reset (void)
{
	rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
}


/*
 * Helper functions
 */

static
uchar rtc_read (uchar reg)
{
	return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
}


static void rtc_write (uchar reg, uchar val)
{
	i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
}

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
Commit	Line	Data
0be62728 MK	1	/*
	2	* (C) Copyright 2006
	3	* Markus Klotzbuecher, mk@denx.de
	4	*
	5	* See file CREDITS for list of people who contributed to this
	6	* project.
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License as
	10	* published by the Free Software Foundation; either version 2 of
	11	* the License, or (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	21	* MA 02111-1307 USA
	22	*/
	23
	24	/*
	25	* Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
	26	* Extremly Accurate DS3231 Real Time Clock (RTC).
	27	*
	28	* copied from ds1337.c
	29	*/
	30
	31	#include <common.h>
	32	#include <command.h>
	33	#include <rtc.h>
	34	#include <i2c.h>
	35
a593814f	36	#if defined(CONFIG_RTC_DS3231) && defined(CONFIG_CMD_DATE)
0be62728 MK	37
	38	/---------------------------------------------------------------------/
	39	#undef DEBUG_RTC
	40
	41	#ifdef DEBUG_RTC
	42	#define DEBUGR(fmt,args...) printf(fmt ,##args)
	43	#else
	44	#define DEBUGR(fmt,args...)
	45	#endif
	46	/---------------------------------------------------------------------/
	47
	48	/*
	49	* RTC register addresses
	50	*/
	51	#define RTC_SEC_REG_ADDR 0x0
	52	#define RTC_MIN_REG_ADDR 0x1
	53	#define RTC_HR_REG_ADDR 0x2
	54	#define RTC_DAY_REG_ADDR 0x3
	55	#define RTC_DATE_REG_ADDR 0x4
	56	#define RTC_MON_REG_ADDR 0x5
	57	#define RTC_YR_REG_ADDR 0x6
	58	#define RTC_CTL_REG_ADDR 0x0e
	59	#define RTC_STAT_REG_ADDR 0x0f
	60
	61
	62	/*
	63	* RTC control register bits
	64	*/
	65	#define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */
	66	#define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */
	67	#define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */
	68	#define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */
	69	#define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */
	70	#define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */
	71
	72	/*
	73	* RTC status register bits
	74	*/
	75	#define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */
	76	#define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */
	77	#define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */
	78
	79
	80	static uchar rtc_read (uchar reg);
	81	static void rtc_write (uchar reg, uchar val);
	82	static uchar bin2bcd (unsigned int n);
	83	static unsigned bcd2bin (uchar c);
	84
	85
	86	/*
	87	* Get the current time from the RTC
	88	*/
b73a19e1	89	int rtc_get (struct rtc_time *tmp)
0be62728	90	{
b73a19e1	91	int rel = 0;
0be62728 MK	92	uchar sec, min, hour, mday, wday, mon_cent, year, control, status;
	93
	94	control = rtc_read (RTC_CTL_REG_ADDR);
	95	status = rtc_read (RTC_STAT_REG_ADDR);
	96	sec = rtc_read (RTC_SEC_REG_ADDR);
	97	min = rtc_read (RTC_MIN_REG_ADDR);
	98	hour = rtc_read (RTC_HR_REG_ADDR);
	99	wday = rtc_read (RTC_DAY_REG_ADDR);
	100	mday = rtc_read (RTC_DATE_REG_ADDR);
	101	mon_cent = rtc_read (RTC_MON_REG_ADDR);
	102	year = rtc_read (RTC_YR_REG_ADDR);
	103
	104	DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
	105	"hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
	106	year, mon_cent, mday, wday, hour, min, sec, control, status);
	107
	108	if (status & RTC_STAT_BIT_OSF) {
	109	printf ("### Warning: RTC oscillator has stopped\n");
	110	/* clear the OSF flag */
	111	rtc_write (RTC_STAT_REG_ADDR,
	112	rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
b73a19e1	113	rel = -1;
0be62728 MK	114	}
	115
	116	tmp->tm_sec = bcd2bin (sec & 0x7F);
	117	tmp->tm_min = bcd2bin (min & 0x7F);
	118	tmp->tm_hour = bcd2bin (hour & 0x3F);
	119	tmp->tm_mday = bcd2bin (mday & 0x3F);
	120	tmp->tm_mon = bcd2bin (mon_cent & 0x1F);
	121	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
	122	tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
	123	tmp->tm_yday = 0;
	124	tmp->tm_isdst= 0;
	125
	126	DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	127	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	128	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
b73a19e1 YT	129
b73a19e1 YT	130	return rel;
0be62728 MK	131	}
	132
	133
	134	/*
	135	* Set the RTC
	136	*/
	137	void rtc_set (struct rtc_time *tmp)
	138	{
	139	uchar century;
	140
	141	DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	142	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	143	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
	144
	145	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
	146
	147	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
	148	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) \| century);
	149
	150	rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
	151	rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
	152	rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
	153	rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
	154	rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
	155	}
	156
	157
	158	/*
	159	* Reset the RTC. We also enable the oscillator output on the
	160	* SQW/INTB* pin and program it for 32,768 Hz output. Note that
	161	* according to the datasheet, turning on the square wave output
	162	* increases the current drain on the backup battery from about
	163	* 600 nA to 2uA.
	164	*/
	165	void rtc_reset (void)
	166	{
	167	rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 \| RTC_CTL_BIT_RS2);
	168	}
	169
	170
	171	/*
	172	* Helper functions
	173	*/
	174
	175	static
	176	uchar rtc_read (uchar reg)
	177	{
	178	return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
	179	}
	180
	181
	182	static void rtc_write (uchar reg, uchar val)
	183	{
	184	i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
	185	}
	186
	187	static unsigned bcd2bin (uchar n)
	188	{
	189	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
	190	}
	191
	192	static unsigned char bin2bcd (unsigned int n)
	193	{
	194	return (((n / 10) << 4) \| (n % 10));
195	}
196
a593814f	197	#endif