/* 

 * include/asm-generic/rtc.h

 *

 * Author: Tom Rini <trini@mvista.com>

 *

 * Based on:

 * drivers/char/rtc.c

 *

 * Please read the COPYING file for all license details.

 */

#ifndef __ASM_RTC_H__

#define __ASM_RTC_H__

#include <linux/mc146818rtc.h>

#include <linux/rtc.h>

#include <linux/bcd.h>

#include <linux/delay.h>

#define RTC_PIE 0x40		/* periodic interrupt enable */

#define RTC_AIE 0x20		/* alarm interrupt enable */

#define RTC_UIE 0x10		/* update-finished interrupt enable */

/* some dummy definitions */

#define RTC_BATT_BAD 0x100	/* battery bad */

#define RTC_SQWE 0x08		/* enable square-wave output */

#define RTC_DM_BINARY 0x04	/* all time/date values are BCD if clear */

#define RTC_24H 0x02		/* 24 hour mode - else hours bit 7 means pm */

#define RTC_DST_EN 0x01	        /* auto switch DST - works f. USA only */

/*

 * Returns true if a clock update is in progress

 */

static inline unsigned char rtc_is_updating(void)

{

	unsigned char uip;

	unsigned long flags;

	spin_lock_irqsave(&rtc_lock, flags);

	uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);

	spin_unlock_irqrestore(&rtc_lock, flags);

	return uip;

}

{

	unsigned char ctrl;

	unsigned long flags;

#ifdef CONFIG_MACH_DECSTATION

	unsigned int real_year;

#endif

	/*

	 * read RTC once any update in progress is done. The update

	 * can take just over 2ms. We wait 20ms. There is no need to

	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.

	 * If you need to know *exactly* when a second has started, enable

	 * periodic update complete interrupts, (via ioctl) and then 

	 * immediately read /dev/rtc which will block until you get the IRQ.

	 * Once the read clears, read the RTC time (again via ioctl). Easy.

	 */

	if (rtc_is_updating())

		mdelay(20);

	/*

	 * Only the values that we read from the RTC are set. We leave

	 * tm_wday, tm_yday and tm_isdst untouched. Even though the

	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated

	 * by the RTC when initially set to a non-zero value.

	 */

	spin_lock_irqsave(&rtc_lock, flags);

	time->tm_sec = CMOS_READ(RTC_SECONDS);

	time->tm_min = CMOS_READ(RTC_MINUTES);

	time->tm_hour = CMOS_READ(RTC_HOURS);

	time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);

	time->tm_mon = CMOS_READ(RTC_MONTH);

	time->tm_year = CMOS_READ(RTC_YEAR);

#ifdef CONFIG_MACH_DECSTATION

	real_year = CMOS_READ(RTC_DEC_YEAR);

#endif

	ctrl = CMOS_READ(RTC_CONTROL);

	spin_unlock_irqrestore(&rtc_lock, flags);

	if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)

	{

		time->tm_sec = bcd2bin(time->tm_sec);

		time->tm_min = bcd2bin(time->tm_min);

		time->tm_hour = bcd2bin(time->tm_hour);

		time->tm_mday = bcd2bin(time->tm_mday);

		time->tm_mon = bcd2bin(time->tm_mon);

		time->tm_year = bcd2bin(time->tm_year);

	}

#ifdef CONFIG_MACH_DECSTATION

	time->tm_year += real_year - 72;

#endif

	/*

	 * Account for differences between how the RTC uses the values

	 * and how they are defined in a struct rtc_time;

	 */

	if (time->tm_year <= 69)

		time->tm_year += 100;

	time->tm_mon--;

	return RTC_24H;

}

/* Set the current date and time in the real time clock. */

{

	unsigned long flags;

	unsigned char mon, day, hrs, min, sec;

	unsigned char save_control, save_freq_select;

	unsigned int yrs;

#ifdef CONFIG_MACH_DECSTATION

	unsigned int real_yrs, leap_yr;

#endif

	yrs = time->tm_year;

	mon = time->tm_mon + 1;   /* tm_mon starts at zero */

	day = time->tm_mday;

	hrs = time->tm_hour;

	min = time->tm_min;

	sec = time->tm_sec;

	if (yrs > 255)	/* They are unsigned */

		return -EINVAL;

	spin_lock_irqsave(&rtc_lock, flags);

#ifdef CONFIG_MACH_DECSTATION

	real_yrs = yrs;

	leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||

			!((yrs + 1900) % 400));

	yrs = 72;

	/*

	 * We want to keep the year set to 73 until March

	 * for non-leap years, so that Feb, 29th is handled

	 * correctly.

	 */

	if (!leap_yr && mon < 3) {

		real_yrs--;

		yrs = 73;

	}

#endif

	/* These limits and adjustments are independent of

	 * whether the chip is in binary mode or not.

	 */

	if (yrs > 169) {

		spin_unlock_irqrestore(&rtc_lock, flags);

		return -EINVAL;

	}

	if (yrs >= 100)

		yrs -= 100;

	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)

	    || RTC_ALWAYS_BCD) {

		sec = bin2bcd(sec);

		min = bin2bcd(min);

		hrs = bin2bcd(hrs);

		day = bin2bcd(day);

		mon = bin2bcd(mon);

		yrs = bin2bcd(yrs);

	}

	save_control = CMOS_READ(RTC_CONTROL);

	CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);

	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);

	CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);

#ifdef CONFIG_MACH_DECSTATION

	CMOS_WRITE(real_yrs, RTC_DEC_YEAR);

#endif

	CMOS_WRITE(yrs, RTC_YEAR);

	CMOS_WRITE(mon, RTC_MONTH);

	CMOS_WRITE(day, RTC_DAY_OF_MONTH);

	CMOS_WRITE(hrs, RTC_HOURS);

	CMOS_WRITE(min, RTC_MINUTES);

	CMOS_WRITE(sec, RTC_SECONDS);

	CMOS_WRITE(save_control, RTC_CONTROL);

	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);

	spin_unlock_irqrestore(&rtc_lock, flags);

	return 0;

}

static inline unsigned int get_rtc_ss(void)

{

	struct rtc_time h;

	return h.tm_sec;

}

static inline int get_rtc_pll(struct rtc_pll_info *pll)

{

	return -EINVAL;

}

static inline int set_rtc_pll(struct rtc_pll_info *pll)

{

	return -EINVAL;

}

#endif /* __ASM_RTC_H__ */