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/*

 *  linux/arch/arm/kernel/time.c

 *

 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds

 *  Modifications for ARM (C) 1994, 1995, 1996,1997 Russell King

 *

 * This file contains the ARM-specific time handling details:

 * reading the RTC at bootup, etc...

 *

 * 1994-07-02  Alan Modra

 *             fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime

 * 1997-09-10  Updated NTP code according to technical memorandum Jan '96

 *             "A Kernel Model for Precision Timekeeping" by Dave Mills

 */

#include <linux/errno.h>

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/param.h>

#include <linux/string.h>

#include <linux/mm.h>

#include <linux/interrupt.h>

#include <asm/segment.h>

#include <asm/io.h>

#include <asm/irq.h>

#include <linux/timex.h>

#include <asm/hardware.h>

#ifndef BCD_TO_BIN

#define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)

#endif

#ifndef BIN_TO_BCD

#define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)

#endif

#define DEBUG 1

/* Converts Gregorian date to seconds since 1970-01-01 00:00:00.

 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59

 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.

 *

 * [For the Julian calendar (which was used in Russia before 1917,

 * Britain & colonies before 1752, anywhere else before 1582,

 * and is still in use by some communities) leave out the

 * -year/100+year/400 terms, and add 10.]

 *

 * This algorithm was first published by Gauss (I think).

 *

 * WARNING: this function will overflow on 2106-02-07 06:28:16 on

 * machines were long is 32-bit! (However, as time_t is signed, we

 * will already get problems at other places on 2038-01-19 03:14:08)

 */

static inline unsigned long mktime(unsigned int year, unsigned int mon,

        unsigned int day, unsigned int hour,

        unsigned int min, unsigned int sec)

{

        if (0 >= (int) (mon -= 2)) {     /* 1..12 -> 11,12,1..10 */

                mon += 12;      /* Puts Feb last since it has leap day */

                year -= 1;

        }

        return (((

                    (unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) +

                      year*365 - 719499

                    )*24 + hour /* now have hours */

                   )*60 + min /* now have minutes */

                  )*60 + sec; /* finally seconds */

}

#include <asm/arch/time.h>

static unsigned long do_gettimeoffset(void)

{

        return gettimeoffset ();

}

void do_gettimeofday(struct timeval *tv)

{

        unsigned long flags;

        save_flags_cli (flags);

        *tv = xtime;

        tv->tv_usec += do_gettimeoffset();

        if (tv->tv_usec >= 1000000) {

                tv->tv_usec -= 1000000;

                tv->tv_sec++;

        }

        restore_flags(flags);

}

void do_settimeofday(struct timeval *tv)

{

        cli ();

        /* This is revolting. We need to set the xtime.tv_usec

         * correctly. However, the value in this location is

         * is value at the last tick.

         * Discover what correction gettimeofday

         * would have done, and then undo it!

         */

        tv->tv_usec -= do_gettimeoffset();

        if (tv->tv_usec < 0) {

                tv->tv_usec += 1000000;

                tv->tv_sec--;

        }

        xtime = *tv;

        time_adjust = 0;         /* stop active adjtime() */

        time_status |= STA_UNSYNC;

        time_state = TIME_ERROR;        /* p. 24, (a) */

        time_maxerror = NTP_PHASE_LIMIT;

        time_esterror = NTP_PHASE_LIMIT;

        sti ();

}

/*

 * timer_interrupt() needs to keep up the real-time clock,

 * as well as call the "do_timer()" routine every clocktick.

 */

static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)

{

        if (reset_timer ())

                do_timer(regs);

        update_rtc ();

}

static struct irqaction irqtimer1 = { timer_interrupt, 0, 0, "timer", NULL, NULL};

extern int setup_arm_irq(int, struct irqaction *);

#ifdef DEBUG

unsigned long arch_setup_timer (void)

{

        register volatile struct trio_timers* tt = (struct trio_timers*) (PERIPH_BASE+TC_OFFSET);

        register volatile struct trio_timer_channel* tc = &tt->chans[1].ch;

        unsigned long v;

        /* program NO signal on XC1 */

        v = tt->bcr;

        v = (v & ~(3 << 2)) | (1 << 2);

        tt->bcr = v;

        tc->ccr = 0x20;  /* disable the channel */

        /* select ACLK/128 as inupt frequensy for TC1 and enable CPCTRG */

        tc->cmr = 3 | (1 << 14);

        tc->idr = ~0ul;  /* disable all interrupt */

        tc->rc = ((ARM_CLK/128)/HZ - 1);   /* load the count limit into the CR register */

        tc->ier = TC_CPCS;  /* enable CPCS interrupt */

        /* enable the channel */

        tc->ccr = TC_SWTRG|TC_CLKEN;

        return mktime(1999, 11, 1, 0, 0, 0);

}

#define setup_timer arch_setup_timer

#endif

void time_init(void)

{

        xtime.tv_sec = setup_timer();

        xtime.tv_usec = 0;

        setup_arm_irq(IRQ_TC1, &irqtimer1);

}