time.c

MIZI Research, Inc.发布的嵌入式Linux内核源码

	node = prom_searchsiblings(node,"eeprom");
	if (!node) {
		prom_printf("CLOCK: No clock found!\n");
		prom_halt();
	}

	/* Get the model name and setup everything up. */
	model[0] = '\0';
	prom_getstring(node, "model", model, sizeof(model));
	if (strcmp(model, "mk48t02") == 0) {
		sp_clock_typ = MSTK48T02;
		if (prom_getproperty(node, "reg", (char *) clk_reg, sizeof(clk_reg)) == -1) {
			prom_printf("clock_probe: FAILED!\n");
			prom_halt();
		}
		if (sparc_cpu_model == sun4d)
			prom_apply_generic_ranges (bootbus, cpuunit, clk_reg, 1);
		else
			prom_apply_obio_ranges(clk_reg, 1);
		/* Map the clock register io area read-only */
		r.flags = clk_reg[0].which_io;
		r.start = clk_reg[0].phys_addr;
		mstk48t02_regs = sbus_ioremap(&r, 0,
		    sizeof(struct mostek48t02), "mk48t02");
		mstk48t08_regs = 0;  /* To catch weirdness */
	} else if (strcmp(model, "mk48t08") == 0) {
		sp_clock_typ = MSTK48T08;
		if(prom_getproperty(node, "reg", (char *) clk_reg,
				    sizeof(clk_reg)) == -1) {
			prom_printf("clock_probe: FAILED!\n");
			prom_halt();
		}
		if (sparc_cpu_model == sun4d)
			prom_apply_generic_ranges (bootbus, cpuunit, clk_reg, 1);
		else
			prom_apply_obio_ranges(clk_reg, 1);
		/* Map the clock register io area read-only */
		/* XXX r/o attribute is somewhere in r.flags */
		r.flags = clk_reg[0].which_io;
		r.start = clk_reg[0].phys_addr;
		mstk48t08_regs = (struct mostek48t08 *) sbus_ioremap(&r, 0,
		    sizeof(struct mostek48t08), "mk48t08");

		mstk48t02_regs = (unsigned long)&mstk48t08_regs->regs;
	} else {
		prom_printf("CLOCK: Unknown model name '%s'\n",model);
		prom_halt();
	}

	/* Report a low battery voltage condition. */
	if (has_low_battery())
		printk(KERN_CRIT "NVRAM: Low battery voltage!\n");

	/* Kick start the clock if it is completely stopped. */
	if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
		kick_start_clock();
}

void __init sbus_time_init(void)
{
	unsigned int year, mon, day, hour, min, sec;
	struct mostek48t02 *mregs;

#ifdef CONFIG_SUN4
	int temp;
	struct intersil *iregs;
#endif

	BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
	btfixup();

	if (ARCH_SUN4)
		sun4_clock_probe();
	else
		clock_probe();

	init_timers(timer_interrupt);
	
#ifdef CONFIG_SUN4
	if(idprom->id_machtype == (SM_SUN4 | SM_4_330)) {
#endif
	mregs = (struct mostek48t02 *)mstk48t02_regs;
	if(!mregs) {
		prom_printf("Something wrong, clock regs not mapped yet.\n");
		prom_halt();
	}		
	spin_lock_irq(&mostek_lock);
	mregs->creg |= MSTK_CREG_READ;
	sec = MSTK_REG_SEC(mregs);
	min = MSTK_REG_MIN(mregs);
	hour = MSTK_REG_HOUR(mregs);
	day = MSTK_REG_DOM(mregs);
	mon = MSTK_REG_MONTH(mregs);
	year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
	xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
	xtime.tv_usec = 0;
	mregs->creg &= ~MSTK_CREG_READ;
	spin_unlock_irq(&mostek_lock);
#ifdef CONFIG_SUN4
	} else if(idprom->id_machtype == (SM_SUN4 | SM_4_260) ) {
		/* initialise the intersil on sun4 */

		iregs=intersil_clock;
		if(!iregs) {
			prom_printf("Something wrong, clock regs not mapped yet.\n");
			prom_halt();
		}

		intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
		disable_pil_irq(10);
		intersil_stop(iregs);
		intersil_read_intr(intersil_clock, temp);

		temp = iregs->clk.int_csec;

		sec = iregs->clk.int_sec;
		min = iregs->clk.int_min;
		hour = iregs->clk.int_hour;
		day = iregs->clk.int_day;
		mon = iregs->clk.int_month;
		year = MSTK_CVT_YEAR(iregs->clk.int_year);

		enable_pil_irq(10);
		intersil_start(iregs);

		xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
		xtime.tv_usec = 0;
		printk("%u/%u/%u %u:%u:%u\n",day,mon,year,hour,min,sec);
	}
#endif

	/* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
	__sti();
}

void __init time_init(void)
{
#ifdef CONFIG_PCI
	extern void pci_time_init(void);
	if (pcic_present()) {
		pci_time_init();
		return;
	}
#endif
	sbus_time_init();
}

extern __inline__ unsigned long do_gettimeoffset(void)
{
	struct tasklet_struct *t;
	unsigned long offset = 0;
	unsigned int count;

	count = (*master_l10_counter >> 10) & 0x1fffff;

	t = &bh_task_vec[TIMER_BH];
	if (test_bit(TASKLET_STATE_SCHED, &t->state))
		offset = 1000000;

	return offset + count;
}

/* This need not obtain the xtime_lock as it is coded in
 * an implicitly SMP safe way already.
 */
void do_gettimeofday(struct timeval *tv)
{
	/* Load doubles must be used on xtime so that what we get
	 * is guarenteed to be atomic, this is why we can run this
	 * with interrupts on full blast.  Don't touch this... -DaveM
	 */
	__asm__ __volatile__(
	"sethi	%hi(master_l10_counter), %o1\n\t"
	"ld	[%o1 + %lo(master_l10_counter)], %g3\n\t"
	"sethi	%hi(xtime), %g2\n"
	"1:\n\t"
	"ldd	[%g2 + %lo(xtime)], %o4\n\t"
	"ld	[%g3], %o1\n\t"
	"ldd	[%g2 + %lo(xtime)], %o2\n\t"
	"xor	%o4, %o2, %o2\n\t"
	"xor	%o5, %o3, %o3\n\t"
	"orcc	%o2, %o3, %g0\n\t"
	"bne	1b\n\t"
	" cmp	%o1, 0\n\t"
	"bge	1f\n\t"
	" srl	%o1, 0xa, %o1\n\t"
	"sethi	%hi(tick), %o3\n\t"
	"ld	[%o3 + %lo(tick)], %o3\n\t"
	"sethi	%hi(0x1fffff), %o2\n\t"
	"or	%o2, %lo(0x1fffff), %o2\n\t"
	"add	%o5, %o3, %o5\n\t"
	"and	%o1, %o2, %o1\n"
	"1:\n\t"
	"add	%o5, %o1, %o5\n\t"
	"sethi	%hi(1000000), %o2\n\t"
	"or	%o2, %lo(1000000), %o2\n\t"
	"cmp	%o5, %o2\n\t"
	"bl,a	1f\n\t"
	" st	%o4, [%o0 + 0x0]\n\t"
	"add	%o4, 0x1, %o4\n\t"
	"sub	%o5, %o2, %o5\n\t"
	"st	%o4, [%o0 + 0x0]\n"
	"1:\n\t"
	"st	%o5, [%o0 + 0x4]\n");
}

void do_settimeofday(struct timeval *tv)
{
	write_lock_irq(&xtime_lock);
	bus_do_settimeofday(tv);
	write_unlock_irq(&xtime_lock);
}

static void sbus_do_settimeofday(struct timeval *tv)
{
	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_maxerror = NTP_PHASE_LIMIT;
	time_esterror = NTP_PHASE_LIMIT;
}

/*
 * BUG: This routine does not handle hour overflow properly; it just
 *      sets the minutes. Usually you won't notice until after reboot!
 */
static int set_rtc_mmss(unsigned long nowtime)
{
	int real_seconds, real_minutes, mostek_minutes;
	struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
	unsigned long flags;
#ifdef CONFIG_SUN4
	struct intersil *iregs = intersil_clock;
	int temp;
#endif

	/* Not having a register set can lead to trouble. */
	if (!regs) {
#ifdef CONFIG_SUN4
		if(!iregs)
		return -1;
	 	else {
			temp = iregs->clk.int_csec;

			mostek_minutes = iregs->clk.int_min;

			real_seconds = nowtime % 60;
			real_minutes = nowtime / 60;
			if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
				real_minutes += 30;	/* correct for half hour time zone */
			real_minutes %= 60;

			if (abs(real_minutes - mostek_minutes) < 30) {
				intersil_stop(iregs);
				iregs->clk.int_sec=real_seconds;
				iregs->clk.int_min=real_minutes;
				intersil_start(iregs);
			} else {
				printk(KERN_WARNING
			       "set_rtc_mmss: can't update from %d to %d\n",
				       mostek_minutes, real_minutes);
				return -1;
			}
			
			return 0;
		}
#endif
	}

	spin_lock_irqsave(&mostek_lock, flags);
	/* Read the current RTC minutes. */
	regs->creg |= MSTK_CREG_READ;
	mostek_minutes = MSTK_REG_MIN(regs);
	regs->creg &= ~MSTK_CREG_READ;

	/*
	 * since we're only adjusting minutes and seconds,
	 * don't interfere with hour overflow. This avoids
	 * messing with unknown time zones but requires your
	 * RTC not to be off by more than 15 minutes
	 */
	real_seconds = nowtime % 60;
	real_minutes = nowtime / 60;
	if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
		real_minutes += 30;	/* correct for half hour time zone */
	real_minutes %= 60;

	if (abs(real_minutes - mostek_minutes) < 30) {
		regs->creg |= MSTK_CREG_WRITE;
		MSTK_SET_REG_SEC(regs,real_seconds);
		MSTK_SET_REG_MIN(regs,real_minutes);
		regs->creg &= ~MSTK_CREG_WRITE;
		spin_unlock_irqrestore(&mostek_lock, flags);
		return 0;
	} else {
		spin_unlock_irqrestore(&mostek_lock, flags);
		return -1;
	}
}