arch/sh/boards/snapgear/rtc.c - kernel/msm - Gitiles

 /****************************************************************************/
 /*
  * linux/arch/sh/boards/snapgear/rtc.c -- Secureedge5410 RTC code
  *
  *  Copyright (C) 2002  David McCullough <davidm@snapgear.com>
  *  Copyright (C) 2003  Paul Mundt <lethal@linux-sh.org>
  *
  * The SecureEdge5410 can have one of 2 real time clocks, the SH
  * built in version or the preferred external DS1302.  Here we work out
  * each to see what we have and then run with it.
  */
 /****************************************************************************/

 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/time.h>
 #include <linux/rtc.h>
 #include <linux/mc146818rtc.h>
 #include <asm/io.h>

 /****************************************************************************/

 static int use_ds1302 = 0;

 /****************************************************************************/
 /*
  *	we need to implement a DS1302 driver here that can operate in
  *	conjunction with the builtin rtc driver which is already quite friendly
  */
 /*****************************************************************************/

 #define	RTC_CMD_READ	0x81		/* Read command */
 #define	RTC_CMD_WRITE	0x80		/* Write command */

 #define	RTC_ADDR_YEAR	0x06		/* Address of year register */
 #define	RTC_ADDR_DAY	0x05		/* Address of day of week register */
 #define	RTC_ADDR_MON	0x04		/* Address of month register */
 #define	RTC_ADDR_DATE	0x03		/* Address of day of month register */
 #define	RTC_ADDR_HOUR	0x02		/* Address of hour register */
 #define	RTC_ADDR_MIN	0x01		/* Address of minute register */
 #define	RTC_ADDR_SEC	0x00		/* Address of second register */

 #define	RTC_RESET	0x1000
 #define	RTC_IODATA	0x0800
 #define	RTC_SCLK	0x0400

 #define set_dirp(x)
 #define get_dirp(x) 0
 #define set_dp(x)	SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
 #define get_dp(x)	SECUREEDGE_READ_IOPORT()

 static void ds1302_sendbits(unsigned int val)
 {
 	int	i;

 	for (i = 8; (i); i--, val >>= 1) {
 		set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ? RTC_IODATA : 0));
 		set_dp(get_dp() | RTC_SCLK);	// clock high
 		set_dp(get_dp() & ~RTC_SCLK);	// clock low
 	}
 }

 static unsigned int ds1302_recvbits(void)
 {
 	unsigned int	val;
 	int		i;

 	for (i = 0, val = 0; (i < 8); i++) {
 		val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
 		set_dp(get_dp() | RTC_SCLK);	// clock high
 		set_dp(get_dp() & ~RTC_SCLK);	// clock low
 	}
 	return(val);
 }

 static unsigned int ds1302_readbyte(unsigned int addr)
 {
 	unsigned int	val;
 	unsigned long	flags;

 #if 0
 	printk("SnapGear RTC: ds1302_readbyte(addr=%x)\n", addr);
 #endif

 	local_irq_save(flags);
 	set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
 	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));

 	set_dp(get_dp() | RTC_RESET);
 	ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
 	set_dirp(get_dirp() & ~RTC_IODATA);
 	val = ds1302_recvbits();
 	set_dp(get_dp() & ~RTC_RESET);
 	local_irq_restore(flags);

 	return(val);
 }

 static void ds1302_writebyte(unsigned int addr, unsigned int val)
 {
 	unsigned long	flags;

 #if 0
 	printk("SnapGear RTC: ds1302_writebyte(addr=%x)\n", addr);
 #endif

 	local_irq_save(flags);
 	set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
 	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
 	set_dp(get_dp() | RTC_RESET);
 	ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
 	ds1302_sendbits(val);
 	set_dp(get_dp() & ~RTC_RESET);
 	local_irq_restore(flags);
 }

 static void ds1302_reset(void)
 {
 	unsigned long	flags;
 	/* Hardware dependant reset/init */
 	local_irq_save(flags);
 	set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
 	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
 	local_irq_restore(flags);
 }

 /*****************************************************************************/

 static inline int bcd2int(int val)
 {
 	return((((val & 0xf0) >> 4) * 10) + (val & 0xf));
 }

 static inline int int2bcd(int val)
 {
 	return(((val / 10) << 4) + (val % 10));
 }

 /*****************************************************************************/
 /*
  *	Write and Read some RAM in the DS1302,  if it works assume it's there
  *	Otherwise use the SH4 internal RTC
  */

 void snapgear_rtc_gettimeofday(struct timespec *);
 int snapgear_rtc_settimeofday(const time_t);

 void __init secureedge5410_rtc_init(void)
 {
 	unsigned char *test = "snapgear";
 	int i;

 	ds1302_reset();

 	use_ds1302 = 1;

 	for (i = 0; test[i]; i++)
 		ds1302_writebyte(32 + i, test[i]);

 	for (i = 0; test[i]; i++)
 		if (ds1302_readbyte(32 + i) != test[i]) {
 			use_ds1302 = 0;
 			break;
 		}

 	if (use_ds1302) {
 		rtc_get_time = snapgear_rtc_gettimeofday;
 		rtc_set_time = snapgear_rtc_settimeofday;
 	} else {
 		rtc_get_time = sh_rtc_gettimeofday;
 		rtc_set_time = sh_rtc_settimeofday;
 	}

 	printk("SnapGear RTC: using %s rtc.\n", use_ds1302 ? "ds1302" : "internal");
 }

 /****************************************************************************/
 /*
  *	our generic interface that chooses the correct code to use
  */

 void snapgear_rtc_gettimeofday(struct timespec *ts)
 {
 	unsigned int sec, min, hr, day, mon, yr;

 	if (!use_ds1302) {
 		sh_rtc_gettimeofday(ts);
 		return;
 	}

  	sec = bcd2int(ds1302_readbyte(RTC_ADDR_SEC));
  	min = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));
  	hr  = bcd2int(ds1302_readbyte(RTC_ADDR_HOUR));
  	day = bcd2int(ds1302_readbyte(RTC_ADDR_DATE));
  	mon = bcd2int(ds1302_readbyte(RTC_ADDR_MON));
  	yr  = bcd2int(ds1302_readbyte(RTC_ADDR_YEAR));

 bad_time:
 	if (yr > 99 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
 	    hr > 23 || min > 59 || sec > 59) {
 		printk(KERN_ERR
 		       "SnapGear RTC: invalid value, resetting to 1 Jan 2000\n");
 		ds1302_writebyte(RTC_ADDR_MIN,  min = 0);
 		ds1302_writebyte(RTC_ADDR_HOUR, hr  = 0);
 		ds1302_writebyte(RTC_ADDR_DAY,        7);
 		ds1302_writebyte(RTC_ADDR_DATE, day = 1);
 		ds1302_writebyte(RTC_ADDR_MON,  mon = 1);
 		ds1302_writebyte(RTC_ADDR_YEAR, yr  = 0);
 		ds1302_writebyte(RTC_ADDR_SEC,  sec = 0);
 	}

 	ts->tv_sec = mktime(2000 + yr, mon, day, hr, min, sec);
 	if (ts->tv_sec < 0) {
 #if 0
 		printk("BAD TIME %d %d %d %d %d %d\n", yr, mon, day, hr, min, sec);
 #endif
 		yr = 100;
 		goto bad_time;
 	}
 	ts->tv_nsec = 0;
 }

 int snapgear_rtc_settimeofday(const time_t secs)
 {
 	int retval = 0;
 	int real_seconds, real_minutes, cmos_minutes;
 	unsigned long nowtime;

 	if (!use_ds1302)
 		return sh_rtc_settimeofday(secs);

 /*
  *	This is called direct from the kernel timer handling code.
  *	It is supposed to synchronize the kernel clock to the RTC.
  */

 	nowtime = secs;

 #if 1
 	printk("SnapGear RTC: snapgear_rtc_settimeofday(nowtime=%ld)\n", nowtime);
 #endif

 	/* STOP RTC */
 	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);

 	cmos_minutes = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));

 	/*
 	 * since we're only adjusting minutes and seconds,
 	 * don't interfere with hour overflow. This avoids
 	 * messing with unknown time zones but requires your
 	 * RTC not to be off by more than 15 minutes
 	 */
 	real_seconds = nowtime % 60;
 	real_minutes = nowtime / 60;
 	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
 		real_minutes += 30;	/* correct for half hour time zone */
 	real_minutes %= 60;

 	if (abs(real_minutes - cmos_minutes) < 30) {
 		ds1302_writebyte(RTC_ADDR_MIN, int2bcd(real_minutes));
 		ds1302_writebyte(RTC_ADDR_SEC, int2bcd(real_seconds));
 	} else {
 		printk(KERN_WARNING
 		       "SnapGear RTC: can't update from %d to %d\n",
 		       cmos_minutes, real_minutes);
 		retval = -1;
 	}

 	/* START RTC */
 	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
 	return(0);
 }

 unsigned char secureedge5410_cmos_read(int addr)
 {
 	unsigned char val = 0;

 	if (!use_ds1302)
 		return(__CMOS_READ(addr, w));

 	switch(addr) {
 	case RTC_SECONDS:       val = ds1302_readbyte(RTC_ADDR_SEC);  break;
 	case RTC_SECONDS_ALARM:                                       break;
 	case RTC_MINUTES:       val = ds1302_readbyte(RTC_ADDR_MIN);  break;
 	case RTC_MINUTES_ALARM:                                       break;
 	case RTC_HOURS:         val = ds1302_readbyte(RTC_ADDR_HOUR); break;
 	case RTC_HOURS_ALARM:                                         break;
 	case RTC_DAY_OF_WEEK:   val = ds1302_readbyte(RTC_ADDR_DAY);  break;
 	case RTC_DAY_OF_MONTH:  val = ds1302_readbyte(RTC_ADDR_DATE); break;
 	case RTC_MONTH:         val = ds1302_readbyte(RTC_ADDR_MON);  break;
 	case RTC_YEAR:          val = ds1302_readbyte(RTC_ADDR_YEAR); break;
 	case RTC_REG_A:         /* RTC_FREQ_SELECT */                 break;
 	case RTC_REG_B:	        /* RTC_CONTROL */                     break;
 	case RTC_REG_C:	        /* RTC_INTR_FLAGS */                  break;
 	case RTC_REG_D:         val = RTC_VRT /* RTC_VALID */;        break;
 	default:                                                      break;
 	}

 	return(val);
 }

 void secureedge5410_cmos_write(unsigned char val, int addr)
 {
 	if (!use_ds1302) {
 		__CMOS_WRITE(val, addr, w);
 		return;
 	}

 	switch(addr) {
 	case RTC_SECONDS:       ds1302_writebyte(RTC_ADDR_SEC, val);  break;
 	case RTC_SECONDS_ALARM:                                       break;
 	case RTC_MINUTES:       ds1302_writebyte(RTC_ADDR_MIN, val);  break;
 	case RTC_MINUTES_ALARM:                                       break;
 	case RTC_HOURS:         ds1302_writebyte(RTC_ADDR_HOUR, val); break;
 	case RTC_HOURS_ALARM:                                         break;
 	case RTC_DAY_OF_WEEK:   ds1302_writebyte(RTC_ADDR_DAY, val);  break;
 	case RTC_DAY_OF_MONTH:  ds1302_writebyte(RTC_ADDR_DATE, val); break;
 	case RTC_MONTH:         ds1302_writebyte(RTC_ADDR_MON, val);  break;
 	case RTC_YEAR:          ds1302_writebyte(RTC_ADDR_YEAR, val); break;
 	case RTC_REG_A:         /* RTC_FREQ_SELECT */                 break;
 	case RTC_REG_B:        	/* RTC_CONTROL */                     break;
 	case RTC_REG_C:	        /* RTC_INTR_FLAGS */                  break;
 	case RTC_REG_D:	        /* RTC_VALID */                       break;
 	default:                                                      break;
 	}
 }

 /****************************************************************************/
	/****************************************************************************/
	/*
	* linux/arch/sh/boards/snapgear/rtc.c -- Secureedge5410 RTC code
	*
	* Copyright (C) 2002 David McCullough <davidm@snapgear.com>
	* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
	*
	* The SecureEdge5410 can have one of 2 real time clocks, the SH
	* built in version or the preferred external DS1302. Here we work out
	* each to see what we have and then run with it.
	*/
	/****************************************************************************/

	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/time.h>
	#include <linux/rtc.h>
	#include <linux/mc146818rtc.h>
	#include <asm/io.h>

	/****************************************************************************/

	static int use_ds1302 = 0;

	/****************************************************************************/
	/*
	* we need to implement a DS1302 driver here that can operate in
	* conjunction with the builtin rtc driver which is already quite friendly
	*/
	/*****************************************************************************/

	#define RTC_CMD_READ 0x81 /* Read command */
	#define RTC_CMD_WRITE 0x80 /* Write command */

	#define RTC_ADDR_YEAR 0x06 /* Address of year register */
	#define RTC_ADDR_DAY 0x05 /* Address of day of week register */
	#define RTC_ADDR_MON 0x04 /* Address of month register */
	#define RTC_ADDR_DATE 0x03 /* Address of day of month register */
	#define RTC_ADDR_HOUR 0x02 /* Address of hour register */
	#define RTC_ADDR_MIN 0x01 /* Address of minute register */
	#define RTC_ADDR_SEC 0x00 /* Address of second register */

	#define RTC_RESET 0x1000
	#define RTC_IODATA 0x0800
	#define RTC_SCLK 0x0400

	#define set_dirp(x)
	#define get_dirp(x) 0
	#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
	#define get_dp(x) SECUREEDGE_READ_IOPORT()

	static void ds1302_sendbits(unsigned int val)
	{
	int i;

	for (i = 8; (i); i--, val >>= 1) {
	set_dp((get_dp() & ~RTC_IODATA) \| ((val & 0x1) ? RTC_IODATA : 0));
	set_dp(get_dp() \| RTC_SCLK); // clock high
	set_dp(get_dp() & ~RTC_SCLK); // clock low
	}
	}

	static unsigned int ds1302_recvbits(void)
	{
	unsigned int val;
	int i;

	for (i = 0, val = 0; (i < 8); i++) {
	val \|= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
	set_dp(get_dp() \| RTC_SCLK); // clock high
	set_dp(get_dp() & ~RTC_SCLK); // clock low
	}
	return(val);
	}

	static unsigned int ds1302_readbyte(unsigned int addr)
	{
	unsigned int val;
	unsigned long flags;

	#if 0
	printk("SnapGear RTC: ds1302_readbyte(addr=%x)\n", addr);
	#endif

	local_irq_save(flags);
	set_dirp(get_dirp() \| RTC_RESET \| RTC_IODATA \| RTC_SCLK);
	set_dp(get_dp() & ~(RTC_RESET \| RTC_IODATA \| RTC_SCLK));

	set_dp(get_dp() \| RTC_RESET);
	ds1302_sendbits(((addr & 0x3f) << 1) \| RTC_CMD_READ);
	set_dirp(get_dirp() & ~RTC_IODATA);
	val = ds1302_recvbits();
	set_dp(get_dp() & ~RTC_RESET);
	local_irq_restore(flags);

	return(val);
	}

	static void ds1302_writebyte(unsigned int addr, unsigned int val)
	{
	unsigned long flags;

	#if 0
	printk("SnapGear RTC: ds1302_writebyte(addr=%x)\n", addr);
	#endif

	local_irq_save(flags);
	set_dirp(get_dirp() \| RTC_RESET \| RTC_IODATA \| RTC_SCLK);
	set_dp(get_dp() & ~(RTC_RESET \| RTC_IODATA \| RTC_SCLK));
	set_dp(get_dp() \| RTC_RESET);
	ds1302_sendbits(((addr & 0x3f) << 1) \| RTC_CMD_WRITE);
	ds1302_sendbits(val);
	set_dp(get_dp() & ~RTC_RESET);
	local_irq_restore(flags);
	}

	static void ds1302_reset(void)
	{
	unsigned long flags;
	/* Hardware dependant reset/init */
	local_irq_save(flags);
	set_dirp(get_dirp() \| RTC_RESET \| RTC_IODATA \| RTC_SCLK);
	set_dp(get_dp() & ~(RTC_RESET \| RTC_IODATA \| RTC_SCLK));
	local_irq_restore(flags);
	}

	/*****************************************************************************/

	static inline int bcd2int(int val)
	{
	return((((val & 0xf0) >> 4) * 10) + (val & 0xf));
	}

	static inline int int2bcd(int val)
	{
	return(((val / 10) << 4) + (val % 10));
	}

	/*****************************************************************************/
	/*
	* Write and Read some RAM in the DS1302, if it works assume it's there
	* Otherwise use the SH4 internal RTC
	*/

	void snapgear_rtc_gettimeofday(struct timespec *);
	int snapgear_rtc_settimeofday(const time_t);

	void __init secureedge5410_rtc_init(void)
	{
	unsigned char *test = "snapgear";
	int i;

	ds1302_reset();

	use_ds1302 = 1;

	for (i = 0; test[i]; i++)
	ds1302_writebyte(32 + i, test[i]);

	for (i = 0; test[i]; i++)
	if (ds1302_readbyte(32 + i) != test[i]) {
	use_ds1302 = 0;
	break;
	}

	if (use_ds1302) {
	rtc_get_time = snapgear_rtc_gettimeofday;
	rtc_set_time = snapgear_rtc_settimeofday;
	} else {
	rtc_get_time = sh_rtc_gettimeofday;
	rtc_set_time = sh_rtc_settimeofday;
	}

	printk("SnapGear RTC: using %s rtc.\n", use_ds1302 ? "ds1302" : "internal");
	}

	/****************************************************************************/
	/*
	* our generic interface that chooses the correct code to use
	*/

	void snapgear_rtc_gettimeofday(struct timespec *ts)
	{
	unsigned int sec, min, hr, day, mon, yr;

	if (!use_ds1302) {
	sh_rtc_gettimeofday(ts);
	return;
	}

	sec = bcd2int(ds1302_readbyte(RTC_ADDR_SEC));
	min = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));
	hr = bcd2int(ds1302_readbyte(RTC_ADDR_HOUR));
	day = bcd2int(ds1302_readbyte(RTC_ADDR_DATE));
	mon = bcd2int(ds1302_readbyte(RTC_ADDR_MON));
	yr = bcd2int(ds1302_readbyte(RTC_ADDR_YEAR));

	bad_time:
	if (yr > 99 \|\| mon < 1 \|\| mon > 12 \|\| day > 31 \|\| day < 1 \|\|
	hr > 23 \|\| min > 59 \|\| sec > 59) {
	printk(KERN_ERR
	"SnapGear RTC: invalid value, resetting to 1 Jan 2000\n");
	ds1302_writebyte(RTC_ADDR_MIN, min = 0);
	ds1302_writebyte(RTC_ADDR_HOUR, hr = 0);
	ds1302_writebyte(RTC_ADDR_DAY, 7);
	ds1302_writebyte(RTC_ADDR_DATE, day = 1);
	ds1302_writebyte(RTC_ADDR_MON, mon = 1);
	ds1302_writebyte(RTC_ADDR_YEAR, yr = 0);
	ds1302_writebyte(RTC_ADDR_SEC, sec = 0);
	}

	ts->tv_sec = mktime(2000 + yr, mon, day, hr, min, sec);
	if (ts->tv_sec < 0) {
	#if 0
	printk("BAD TIME %d %d %d %d %d %d\n", yr, mon, day, hr, min, sec);
	#endif
	yr = 100;
	goto bad_time;
	}
	ts->tv_nsec = 0;
	}

	int snapgear_rtc_settimeofday(const time_t secs)
	{
	int retval = 0;
	int real_seconds, real_minutes, cmos_minutes;
	unsigned long nowtime;

	if (!use_ds1302)
	return sh_rtc_settimeofday(secs);

	/*
	* This is called direct from the kernel timer handling code.
	* It is supposed to synchronize the kernel clock to the RTC.
	*/

	nowtime = secs;

	#if 1
	printk("SnapGear RTC: snapgear_rtc_settimeofday(nowtime=%ld)\n", nowtime);
	#endif

	/* STOP RTC */
	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) \| 0x80);

	cmos_minutes = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));

	/*
	* since we're only adjusting minutes and seconds,
	* don't interfere with hour overflow. This avoids
	* messing with unknown time zones but requires your
	* RTC not to be off by more than 15 minutes
	*/
	real_seconds = nowtime % 60;
	real_minutes = nowtime / 60;
	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
	real_minutes += 30; /* correct for half hour time zone */
	real_minutes %= 60;

	if (abs(real_minutes - cmos_minutes) < 30) {
	ds1302_writebyte(RTC_ADDR_MIN, int2bcd(real_minutes));
	ds1302_writebyte(RTC_ADDR_SEC, int2bcd(real_seconds));
	} else {
	printk(KERN_WARNING
	"SnapGear RTC: can't update from %d to %d\n",
	cmos_minutes, real_minutes);
	retval = -1;
	}

	/* START RTC */
	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
	return(0);
	}

	unsigned char secureedge5410_cmos_read(int addr)
	{
	unsigned char val = 0;

	if (!use_ds1302)
	return(__CMOS_READ(addr, w));

	switch(addr) {
	case RTC_SECONDS: val = ds1302_readbyte(RTC_ADDR_SEC); break;
	case RTC_SECONDS_ALARM: break;
	case RTC_MINUTES: val = ds1302_readbyte(RTC_ADDR_MIN); break;
	case RTC_MINUTES_ALARM: break;
	case RTC_HOURS: val = ds1302_readbyte(RTC_ADDR_HOUR); break;
	case RTC_HOURS_ALARM: break;
	case RTC_DAY_OF_WEEK: val = ds1302_readbyte(RTC_ADDR_DAY); break;
	case RTC_DAY_OF_MONTH: val = ds1302_readbyte(RTC_ADDR_DATE); break;
	case RTC_MONTH: val = ds1302_readbyte(RTC_ADDR_MON); break;
	case RTC_YEAR: val = ds1302_readbyte(RTC_ADDR_YEAR); break;
	case RTC_REG_A: /* RTC_FREQ_SELECT */ break;
	case RTC_REG_B: /* RTC_CONTROL */ break;
	case RTC_REG_C: /* RTC_INTR_FLAGS */ break;
	case RTC_REG_D: val = RTC_VRT /* RTC_VALID */; break;
	default: break;
	}

	return(val);
	}

	void secureedge5410_cmos_write(unsigned char val, int addr)
	{
	if (!use_ds1302) {
	__CMOS_WRITE(val, addr, w);
	return;
	}

	switch(addr) {
	case RTC_SECONDS: ds1302_writebyte(RTC_ADDR_SEC, val); break;
	case RTC_SECONDS_ALARM: break;
	case RTC_MINUTES: ds1302_writebyte(RTC_ADDR_MIN, val); break;
	case RTC_MINUTES_ALARM: break;
	case RTC_HOURS: ds1302_writebyte(RTC_ADDR_HOUR, val); break;
	case RTC_HOURS_ALARM: break;
	case RTC_DAY_OF_WEEK: ds1302_writebyte(RTC_ADDR_DAY, val); break;
	case RTC_DAY_OF_MONTH: ds1302_writebyte(RTC_ADDR_DATE, val); break;
	case RTC_MONTH: ds1302_writebyte(RTC_ADDR_MON, val); break;
	case RTC_YEAR: ds1302_writebyte(RTC_ADDR_YEAR, val); break;
	case RTC_REG_A: /* RTC_FREQ_SELECT */ break;
	case RTC_REG_B: /* RTC_CONTROL */ break;
	case RTC_REG_C: /* RTC_INTR_FLAGS */ break;
	case RTC_REG_D: /* RTC_VALID */ break;
	default: break;
	}
	}

	/****************************************************************************/