/* *  linux/arch/mips/philips/nino/time.c * *  Copyright (C) 1999 Harald Koerfgen *  Copyright (C) 2000 Pavel Machek (pavel@suse.cz) *  Copyright (C) 2001 Steven J. Hill (sjhill@realitydiluted.com) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * *  Time handling functinos for Philips Nino. */#include <linux/errno.h>#include <linux/init.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 <linux/timex.h>#include <linux/delay.h>#include <asm/tx3912.h>extern volatile unsigned long wall_jiffies;extern rwlock_t xtime_lock;static struct timeval xbase;#define USECS_PER_JIFFY (1000000/HZ)/* * Poll the Interrupt Status Registers */#undef POLL_STATUSstatic unsigned long do_gettimeoffset(void){    /*     * This is a kludge     */    return 0;}staticvoid inline readRTC(unsigned long *high, unsigned long *low){	/* read twice, and keep reading till we find two	 * the same pairs. This is needed in case the RTC	 * was updating its registers and we read a old	 * High but a new Low. */	do {		*high = RTChigh & RTC_HIGHMASK;		*low = RTClow;	} while (*high != (RTChigh & RTC_HIGHMASK) || RTClow!=*low);}/* * This version of gettimeofday has near millisecond resolution. */void do_gettimeofday(struct timeval *tv){    unsigned long flags;    unsigned long high, low;    read_lock_irqsave(&xtime_lock, flags);    // 40 bit RTC, driven by 32khz source:    // +-----------+-----------------------------------------+    // | HHHH.HHHH | LLLL.LLLL.LLLL.LLLL.LMMM.MMMM.MMMM.MMMM |    // +-----------+-----------------------------------------+    readRTC(&high,&low);    tv->tv_sec  = (high << 17) | (low >> 15);    tv->tv_usec = (low % 32768) * 1953 / 64;    tv->tv_sec += xbase.tv_sec;    tv->tv_usec += xbase.tv_usec;    tv->tv_usec += do_gettimeoffset();    /*     * xtime is atomically updated in timer_bh. lost_ticks is     * nonzero if the timer bottom half hasnt executed yet.     */    if (jiffies - wall_jiffies)	tv->tv_usec += USECS_PER_JIFFY;    read_unlock_irqrestore(&xtime_lock, flags);    if (tv->tv_usec >= 1000000) {	tv->tv_usec -= 1000000;	tv->tv_sec++;    }}void do_settimeofday(struct timeval *tv){    write_lock_irq(&xtime_lock);    /* 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--;    }    /* reset RTC to 0 (real time is xbase + RTC) */    xbase = *tv;    RTCtimerControl |=  TIM_RTCCLEAR;    RTCtimerControl &= ~TIM_RTCCLEAR;    RTCalarmHigh = RTCalarmLow = ~0UL;    xtime = *tv;    time_state = TIME_BAD;    time_maxerror = MAXPHASE;    time_esterror = MAXPHASE;    write_unlock_irq(&xtime_lock);}static int set_rtc_mmss(unsigned long nowtime){    int retval = 0;    return retval;}/* last time the cmos clock got updated */static long last_rtc_update = 0;/* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */int do_write = 1;static voidtimer_interrupt(int irq, void *dev_id, struct pt_regs *regs){#ifdef POLL_STATUS    static unsigned long old_IntStatus1 = 0;    static unsigned long old_IntStatus3 = 0;    static unsigned long old_IntStatus4 = 0;    static unsigned long old_IntStatus5 = 0;    static int counter = 0;    int i;    new_spircv = SPIData & 0xff;    if ((old_spircv != new_spircv) && (new_spircv != 0xff)) {	    printk( "SPIData changed: %x\n", new_spircv );    }    old_spircv = new_spircv;    if (do_write)	    SPIData = 0;#endif    if (!user_mode(regs)) {	if (prof_buffer && current->pid) {	    extern int _stext;	    unsigned long pc = regs->cp0_epc;	    pc -= (unsigned long) &_stext;	    pc >>= prof_shift;	    /*	     * Dont ignore out-of-bounds pc values silently,	     * put them into the last histogram slot, so if	     * present, they will show up as a sharp peak.	     */	    if (pc > prof_len - 1)		pc = prof_len - 1;		atomic_inc((atomic_t *) & prof_buffer[pc]);	    }    }    /*     * aaaand... action!     */    do_timer(regs);    /*     * If we have an externally syncronized Linux clock, then update     * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be     * called as close as possible to 500 ms before the new second starts.     */    if (time_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 &&	xtime.tv_usec > 500000 - (tick >> 1) &&	xtime.tv_usec < 500000 + (tick >> 1))    {	if (set_rtc_mmss(xtime.tv_sec) == 0)	    last_rtc_update = xtime.tv_sec;	else	    last_rtc_update = xtime.tv_sec - 600;  /* do it again in 60 s */    }}static struct irqaction irq0 = {timer_interrupt, SA_INTERRUPT, 0, 			 "timer", NULL, NULL};void (*board_time_init) (struct irqaction * irq);int __init time_init(void){    struct timeval starttime;    starttime.tv_sec = mktime(2000, 1, 1, 0, 0, 0);    starttime.tv_usec = 0;    do_settimeofday(&starttime);    board_time_init(&irq0);    return 0;}