patch-2.4.19 linux-2.4.19/arch/mips64/sgi-ip22/ip22-timer.c

• Lines: 263
• Date: Wed Dec 31 16:00:00 1969
• Orig file: linux-2.4.18/arch/mips64/sgi-ip22/ip22-timer.c
• Orig date: Sun Sep 9 10:43:02 2001

diff -urN linux-2.4.18/arch/mips64/sgi-ip22/ip22-timer.c linux-2.4.19/arch/mips64/sgi-ip22/ip22-timer.c
@@ -1,262 +0,0 @@
-/*
- * indy_timer.c: Setting up the clock on the INDY 8254 controller.
- *
- * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
- * Copytight (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
- */
-#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/kernel_stat.h>
-
-#include <asm/bootinfo.h>
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/ptrace.h>
-#include <asm/system.h>
-#include <asm/sgi/sgi.h>
-#include <asm/sgi/sgihpc.h>
-#include <asm/sgi/sgint23.h>
-#include <asm/sgialib.h>
-
-
-/* Because of a bug in the i8254 timer we need to use the onchip r4k
- * counter as our system wide timer interrupt running at 100HZ.
- */
-static unsigned long r4k_offset; /* Amount to increment compare reg each time */
-static unsigned long r4k_cur;    /* What counter should be at next timer irq */
-
-extern rwlock_t xtime_lock;
-
-static inline void ack_r4ktimer(unsigned long newval)
-{
-	write_32bit_cp0_register(CP0_COMPARE, newval);
-}
-
-static int set_rtc_mmss(unsigned long nowtime)
-{
-	struct indy_clock *clock = (struct indy_clock *)INDY_CLOCK_REGS;
-	int retval = 0;
-	int real_seconds, real_minutes, clock_minutes;
-
-#define FROB_FROM_CLOCK(x) (((x) & 0xf) | ((((x) & 0xf0) >> 4) * 10));
-#define FROB_TO_CLOCK(x)  ((((((x) & 0xff) / 10)<<4) | (((x) & 0xff) % 10)) & 0xff)
-
-	clock->cmd &= ~(0x80);
-	clock_minutes = clock->min;
-	clock->cmd |= (0x80);
-
-	clock_minutes = FROB_FROM_CLOCK(clock_minutes);
-	real_seconds = nowtime % 60;
-	real_minutes = nowtime / 60;
-
-	if(((abs(real_minutes - clock_minutes) + 15)/30) & 1)
-		real_minutes += 30; /* correct for half hour time zone */
-
-	real_minutes %= 60;
-	if(abs(real_minutes - clock_minutes) < 30) {
-		/* Force clock oscillator to be on. */
-		clock->month &= ~(0x80);
-
-		/* Write real_seconds and real_minutes into the Dallas. */
-		clock->cmd &= ~(0x80);
-		clock->sec = real_seconds;
-		clock->min = real_minutes;
-		clock->cmd |= (0x80);
-	} else
-		return -1;
-
-#undef FROB_FROM_CLOCK
-#undef FROB_TO_CLOCK
-
-	return retval;
-}
-
-static long last_rtc_update;
-unsigned long missed_heart_beats;
-
-void indy_timer_interrupt(struct pt_regs *regs)
-{
-	unsigned long count;
-	int irq = 7;
-
-	write_lock(&xtime_lock);
-	/* Ack timer and compute new compare. */
-	count = read_32bit_cp0_register(CP0_COUNT);
-	/* This has races.  */
-	if ((count - r4k_cur) >= r4k_offset) {
-		/* If this happens to often we'll need to compensate.  */
-		missed_heart_beats++;
-		r4k_cur = count + r4k_offset;
-	}
-        else
-            r4k_cur += r4k_offset;
-	ack_r4ktimer(r4k_cur);
-	kstat.irqs[0][irq]++;
-	do_timer(regs);
-
-	/* We update the Dallas time of day approx. every 11 minutes,
-	 * because of how the numbers work out we need to make
-	 * absolutely sure we do this update within 500ms before the
-	 * next second starts, thus the following code.
-	 */
-	if ((time_status & STA_UNSYNC) == 0 &&
-	    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
-			/* do it again in 60s  */
-			last_rtc_update = xtime.tv_sec - 600;
-	}
-	write_unlock(&xtime_lock);
-}
-
-static unsigned long dosample(volatile unsigned char *tcwp,
-                              volatile unsigned char *tc2p)
-{
-	unsigned long ct0, ct1;
-	unsigned char msb, lsb;
-
-	/* Start the counter. */
-	*tcwp = (SGINT_TCWORD_CNT2 | SGINT_TCWORD_CALL | SGINT_TCWORD_MRGEN);
-	*tc2p = (SGINT_TCSAMP_COUNTER & 0xff);
-	*tc2p = (SGINT_TCSAMP_COUNTER >> 8);
-
-	/* Get initial counter invariant */
-	ct0 = read_32bit_cp0_register(CP0_COUNT);
-
-	/* Latch and spin until top byte of counter2 is zero */
-	do {
-		*tcwp = (SGINT_TCWORD_CNT2 | SGINT_TCWORD_CLAT);
-		lsb = *tc2p;
-		msb = *tc2p;
-		ct1 = read_32bit_cp0_register(CP0_COUNT);
-	} while(msb);
-
-	/* Stop the counter. */
-	*tcwp = (SGINT_TCWORD_CNT2 | SGINT_TCWORD_CALL | SGINT_TCWORD_MSWST);
-
-	/* Return the difference, this is how far the r4k counter increments
-	 * for every one HZ.
-	 */
-	return ct1 - ct0;
-}
-
-static unsigned long __init get_indy_time(void)
-{
-	struct indy_clock *clock = (struct indy_clock *)INDY_CLOCK_REGS;
-	unsigned int year, mon, day, hour, min, sec;
-
-	/* Freeze it. */
-	clock->cmd &= ~(0x80);
-
-	/* Read regs. */
-	sec = clock->sec;
-	min = clock->min;
-	hour = (clock->hr & 0x3f);
-	day = (clock->date & 0x3f);
-	mon = (clock->month & 0x1f);
-	year = clock->year;
-
-	/* Unfreeze clock. */
-	clock->cmd |= 0x80;
-
-	/* Frob the bits. */
-#define FROB1(x)  (((x) & 0xf) + ((((x) & 0xf0) >> 4) * 10));
-#define FROB2(x)  (((x) & 0xf) + (((((x) & 0xf0) >> 4) & 0x3) * 10));
-
-	/* XXX Should really check that secs register is the same
-	 * XXX as when we first read it and if not go back and
-	 * XXX read the regs above again.
-	 */
-	sec = FROB1(sec); min = FROB1(min); day = FROB1(day);
-	mon = FROB1(mon); year = FROB1(year);
-	hour = FROB2(hour);
-
-#undef FROB1
-#undef FROB2
-
-	/* Wheee... */
-	if(year < 45)
-		year += 30;
-	if ((year += 1940) < 1970)
-		year += 100;
-
-	return mktime(year, mon, day, hour, min, sec);
-}
-
-#define ALLINTS (IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5)
-
-void __init indy_timer_init(void)
-{
-	struct sgi_ioc_timers *p;
-	volatile unsigned char *tcwp, *tc2p;
-
-	/* Figure out the r4k offset, the algorithm is very simple and works
-	 * in _all_ cases as long as the 8254 counter register itself works ok
-	 * (as an interrupt driving timer it does not because of bug, this is
-	 * why we are using the onchip r4k counter/compare register to serve
-	 * this purpose, but for r4k_offset calculation it will work ok for us).
-	 * There are other very complicated ways of performing this calculation
-	 * but this one works just fine so I am not going to futz around. ;-)
-	 */
-	p = ioc_timers;
-	tcwp = &p->tcword;
-	tc2p = &p->tcnt2;
-
-	printk("calculating r4koff... ");
-	dosample(tcwp, tc2p);			/* First sample. */
-	dosample(tcwp, tc2p);			/* Eat one.	*/
-	r4k_offset = dosample(tcwp, tc2p);	/* Second sample. */
-
-	printk("%08lx(%d)\n", r4k_offset, (int) r4k_offset);
-
-	r4k_cur = (read_32bit_cp0_register(CP0_COUNT) + r4k_offset);
-	write_32bit_cp0_register(CP0_COMPARE, r4k_cur);
-	set_cp0_status(ST0_IM, ALLINTS);
-	sti();
-
-	write_lock_irq(&xtime_lock);
-	xtime.tv_sec = get_indy_time();		/* Read time from RTC. */
-	xtime.tv_usec = 0;
-	write_unlock_irq(&xtime_lock);
-}
-
-void indy_8254timer_irq(void)
-{
-	int cpu = smp_processor_id();
-	int irq = 4;
-
-	irq_enter(cpu, irq);
-	kstat.irqs[0][irq]++;
-	panic("indy_8254timer_irq: Whoops, should not have gotten this IRQ\n");
-	irq_exit(cpu, irq);
-}
-
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-
-	read_lock_irqsave(&xtime_lock, flags);
-	*tv = xtime;
-	read_unlock_irqrestore(&xtime_lock, flags);
-}
-
-void do_settimeofday(struct timeval *tv)
-{
-	write_lock_irq(&xtime_lock);
-	xtime = *tv;
-	time_adjust = 0;		/* stop active adjtime() */
-	time_status |= STA_UNSYNC;
-	time_maxerror = NTP_PHASE_LIMIT;
-	time_esterror = NTP_PHASE_LIMIT;
-	write_unlock_irq(&xtime_lock);
-}