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/*
* linux/arch/mips/philips/nino/time.c
*
* Copyright (C) 1999 Harald Koerfgen (Harald.Koerfgen@home.ivm.de)
* Copyright (C) 2000 Pavel Machek (pavel@suse.cz)
* Copyright (C) 2001 Steven 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 details for PR31700.
*/
#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/philips/pr31700.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_STATUS
static unsigned long do_gettimeoffset(void)
{
/*
* This is a kludge
*/
return 0;
}
static
void 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 void
timer_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;
}
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