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/*

 * inclue/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__

#ifdef __KERNEL__

#include <linux/mc146818rtc.h>

#include <linux/rtc.h>

#include <linux/bcd.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;

        spin_lock_irq(&rtc_lock);

        uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);

        spin_unlock_irq(&rtc_lock);

        return uip;

}

static inline unsigned int get_rtc_time(struct rtc_time *time)

{

        unsigned long uip_watchdog = jiffies;

        unsigned char ctrl;

#ifdef CONFIG_DECSTATION

        unsigned int real_year;

#endif

        /*

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

         * can take just over 2ms. We wait 10 to 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() != 0)

                while (jiffies - uip_watchdog < 2*HZ/100) {

                        barrier();

                        cpu_relax();

                }

        /*

         * 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_irq(&rtc_lock);

        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_DECSTATION

        real_year = CMOS_READ(RTC_DEC_YEAR);

#endif

        ctrl = CMOS_READ(RTC_CONTROL);

        spin_unlock_irq(&rtc_lock);

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

        {

                BCD_TO_BIN(time->tm_sec);

                BCD_TO_BIN(time->tm_min);

                BCD_TO_BIN(time->tm_hour);

                BCD_TO_BIN(time->tm_mday);

                BCD_TO_BIN(time->tm_mon);

                BCD_TO_BIN(time->tm_year);

        }

#ifdef CONFIG_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. */

static inline int set_rtc_time(struct rtc_time *time)

{

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

        unsigned char save_control, save_freq_select;

        unsigned int yrs;

#ifdef CONFIG_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_irq(&rtc_lock);

#ifdef CONFIG_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_irq(&rtc_lock);

                return -EINVAL;

        }

        if (yrs >= 100)

                yrs -= 100;

        if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)

            || RTC_ALWAYS_BCD) {

                BIN_TO_BCD(sec);

                BIN_TO_BCD(min);

                BIN_TO_BCD(hrs);

                BIN_TO_BCD(day);

                BIN_TO_BCD(mon);

                BIN_TO_BCD(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_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_irq(&rtc_lock);

        return 0;

}

static inline unsigned int get_rtc_ss(void)

{

        struct rtc_time h;

        get_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 /* __KERNEL__ */

#endif /* __ASM_RTC_H__ */