time.c

linux-2.6.15.6

	report_lost_ticks = 1;
	return 1;
}

static struct irqaction irq0 = {
	timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "timer", NULL, NULL
};

extern void __init config_acpi_tables(void);

void __init time_init(void)
{
	char *timename;

#ifdef HPET_HACK_ENABLE_DANGEROUS
        if (!vxtime.hpet_address) {
		printk(KERN_WARNING "time.c: WARNING: Enabling HPET base "
		       "manually!\n");
                outl(0x800038a0, 0xcf8);
                outl(0xff000001, 0xcfc);
                outl(0x800038a0, 0xcf8);
                vxtime.hpet_address = inl(0xcfc) & 0xfffffffe;
		printk(KERN_WARNING "time.c: WARNING: Enabled HPET "
		       "at %#lx.\n", vxtime.hpet_address);
        }
#endif
	if (nohpet)
		vxtime.hpet_address = 0;

	xtime.tv_sec = get_cmos_time();
	xtime.tv_nsec = 0;

	set_normalized_timespec(&wall_to_monotonic,
	                        -xtime.tv_sec, -xtime.tv_nsec);

	if (!hpet_init())
                vxtime_hz = (1000000000000000L + hpet_period / 2) /
			hpet_period;
	else
		vxtime.hpet_address = 0;

	if (hpet_use_timer) {
		cpu_khz = hpet_calibrate_tsc();
		timename = "HPET";
#ifdef CONFIG_X86_PM_TIMER
	} else if (pmtmr_ioport && !vxtime.hpet_address) {
		vxtime_hz = PM_TIMER_FREQUENCY;
		timename = "PM";
		pit_init();
		cpu_khz = pit_calibrate_tsc();
#endif
	} else {
		pit_init();
		cpu_khz = pit_calibrate_tsc();
		timename = "PIT";
	}

	printk(KERN_INFO "time.c: Using %ld.%06ld MHz %s timer.\n",
	       vxtime_hz / 1000000, vxtime_hz % 1000000, timename);
	printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
		cpu_khz / 1000, cpu_khz % 1000);
	vxtime.mode = VXTIME_TSC;
	vxtime.quot = (1000000L << 32) / vxtime_hz;
	vxtime.tsc_quot = (1000L << 32) / cpu_khz;
	rdtscll_sync(&vxtime.last_tsc);
	setup_irq(0, &irq0);

	set_cyc2ns_scale(cpu_khz);

#ifndef CONFIG_SMP
	time_init_gtod();
#endif
}

/*
 * Make an educated guess if the TSC is trustworthy and synchronized
 * over all CPUs.
 */
static __init int unsynchronized_tsc(void)
{
#ifdef CONFIG_SMP
	if (oem_force_hpet_timer())
		return 1;
 	/* Intel systems are normally all synchronized. Exceptions
 	   are handled in the OEM check above. */
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
 		return 0;
#endif
 	/* Assume multi socket systems are not synchronized */
 	return num_online_cpus() > 1;
}

/*
 * Decide after all CPUs are booted what mode gettimeofday should use.
 */
void __init time_init_gtod(void)
{
	char *timetype;

	if (unsynchronized_tsc())
		notsc = 1;
	if (vxtime.hpet_address && notsc) {
		timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
		vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
		vxtime.mode = VXTIME_HPET;
		do_gettimeoffset = do_gettimeoffset_hpet;
#ifdef CONFIG_X86_PM_TIMER
	/* Using PM for gettimeofday is quite slow, but we have no other
	   choice because the TSC is too unreliable on some systems. */
	} else if (pmtmr_ioport && !vxtime.hpet_address && notsc) {
		timetype = "PM";
		do_gettimeoffset = do_gettimeoffset_pm;
		vxtime.mode = VXTIME_PMTMR;
		sysctl_vsyscall = 0;
		printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n");
#endif
	} else {
		timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
		vxtime.mode = VXTIME_TSC;
	}

	printk(KERN_INFO "time.c: Using %s based timekeeping.\n", timetype);
}

__setup("report_lost_ticks", time_setup);

static long clock_cmos_diff;
static unsigned long sleep_start;

static int timer_suspend(struct sys_device *dev, pm_message_t state)
{
	/*
	 * Estimate time zone so that set_time can update the clock
	 */
	long cmos_time =  get_cmos_time();

	clock_cmos_diff = -cmos_time;
	clock_cmos_diff += get_seconds();
	sleep_start = cmos_time;
	return 0;
}

static int timer_resume(struct sys_device *dev)
{
	unsigned long flags;
	unsigned long sec;
	unsigned long ctime = get_cmos_time();
	unsigned long sleep_length = (ctime - sleep_start) * HZ;

	if (vxtime.hpet_address)
		hpet_reenable();
	else
		i8254_timer_resume();

	sec = ctime + clock_cmos_diff;
	write_seqlock_irqsave(&xtime_lock,flags);
	xtime.tv_sec = sec;
	xtime.tv_nsec = 0;
	write_sequnlock_irqrestore(&xtime_lock,flags);
	jiffies += sleep_length;
	wall_jiffies += sleep_length;
	touch_softlockup_watchdog();
	return 0;
}

static struct sysdev_class timer_sysclass = {
	.resume = timer_resume,
	.suspend = timer_suspend,
	set_kset_name("timer"),
};


/* XXX this driverfs stuff should probably go elsewhere later -john */
static struct sys_device device_timer = {
	.id	= 0,
	.cls	= &timer_sysclass,
};

static int time_init_device(void)
{
	int error = sysdev_class_register(&timer_sysclass);
	if (!error)
		error = sysdev_register(&device_timer);
	return error;
}

device_initcall(time_init_device);

#ifdef CONFIG_HPET_EMULATE_RTC
/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
 * is enabled, we support RTC interrupt functionality in software.
 * RTC has 3 kinds of interrupts:
 * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
 *    is updated
 * 2) Alarm Interrupt - generate an interrupt at a specific time of day
 * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
 *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
 * (1) and (2) above are implemented using polling at a frequency of
 * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
 * overhead. (DEFAULT_RTC_INT_FREQ)
 * For (3), we use interrupts at 64Hz or user specified periodic
 * frequency, whichever is higher.
 */
#include <linux/rtc.h>

extern irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs);

#define DEFAULT_RTC_INT_FREQ 	64
#define RTC_NUM_INTS 		1

static unsigned long UIE_on;
static unsigned long prev_update_sec;

static unsigned long AIE_on;
static struct rtc_time alarm_time;

static unsigned long PIE_on;
static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ;
static unsigned long PIE_count;

static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
static unsigned int hpet_t1_cmp; /* cached comparator register */

int is_hpet_enabled(void)
{
	return vxtime.hpet_address != 0;
}

/*
 * Timer 1 for RTC, we do not use periodic interrupt feature,
 * even if HPET supports periodic interrupts on Timer 1.
 * The reason being, to set up a periodic interrupt in HPET, we need to
 * stop the main counter. And if we do that everytime someone diables/enables
 * RTC, we will have adverse effect on main kernel timer running on Timer 0.
 * So, for the time being, simulate the periodic interrupt in software.
 *
 * hpet_rtc_timer_init() is called for the first time and during subsequent
 * interuppts reinit happens through hpet_rtc_timer_reinit().
 */
int hpet_rtc_timer_init(void)
{
	unsigned int cfg, cnt;
	unsigned long flags;

	if (!is_hpet_enabled())
		return 0;
	/*
	 * Set the counter 1 and enable the interrupts.
	 */
	if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
		hpet_rtc_int_freq = PIE_freq;
	else
		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;

	local_irq_save(flags);
	cnt = hpet_readl(HPET_COUNTER);
	cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
	hpet_writel(cnt, HPET_T1_CMP);
	hpet_t1_cmp = cnt;
	local_irq_restore(flags);

	cfg = hpet_readl(HPET_T1_CFG);
	cfg &= ~HPET_TN_PERIODIC;
	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
	hpet_writel(cfg, HPET_T1_CFG);

	return 1;
}

static void hpet_rtc_timer_reinit(void)
{
	unsigned int cfg, cnt;

	if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
		cfg = hpet_readl(HPET_T1_CFG);
		cfg &= ~HPET_TN_ENABLE;
		hpet_writel(cfg, HPET_T1_CFG);
		return;
	}

	if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
		hpet_rtc_int_freq = PIE_freq;
	else
		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;

	/* It is more accurate to use the comparator value than current count.*/
	cnt = hpet_t1_cmp;
	cnt += hpet_tick*HZ/hpet_rtc_int_freq;
	hpet_writel(cnt, HPET_T1_CMP);
	hpet_t1_cmp = cnt;
}

/*
 * The functions below are called from rtc driver.
 * Return 0 if HPET is not being used.
 * Otherwise do the necessary changes and return 1.
 */
int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
{
	if (!is_hpet_enabled())
		return 0;

	if (bit_mask & RTC_UIE)
		UIE_on = 0;
	if (bit_mask & RTC_PIE)
		PIE_on = 0;
	if (bit_mask & RTC_AIE)
		AIE_on = 0;

	return 1;
}

int hpet_set_rtc_irq_bit(unsigned long bit_mask)
{
	int timer_init_reqd = 0;

	if (!is_hpet_enabled())
		return 0;

	if (!(PIE_on | AIE_on | UIE_on))
		timer_init_reqd = 1;

	if (bit_mask & RTC_UIE) {
		UIE_on = 1;
	}
	if (bit_mask & RTC_PIE) {
		PIE_on = 1;
		PIE_count = 0;
	}
	if (bit_mask & RTC_AIE) {
		AIE_on = 1;
	}

	if (timer_init_reqd)
		hpet_rtc_timer_init();

	return 1;
}

int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
{
	if (!is_hpet_enabled())
		return 0;

	alarm_time.tm_hour = hrs;
	alarm_time.tm_min = min;
	alarm_time.tm_sec = sec;

	return 1;
}

int hpet_set_periodic_freq(unsigned long freq)
{
	if (!is_hpet_enabled())
		return 0;

	PIE_freq = freq;
	PIE_count = 0;

	return 1;
}

int hpet_rtc_dropped_irq(void)
{
	if (!is_hpet_enabled())
		return 0;

	return 1;
}

irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct rtc_time curr_time;
	unsigned long rtc_int_flag = 0;
	int call_rtc_interrupt = 0;

	hpet_rtc_timer_reinit();

	if (UIE_on | AIE_on) {
		rtc_get_rtc_time(&curr_time);
	}
	if (UIE_on) {
		if (curr_time.tm_sec != prev_update_sec) {
			/* Set update int info, call real rtc int routine */
			call_rtc_interrupt = 1;
			rtc_int_flag = RTC_UF;
			prev_update_sec = curr_time.tm_sec;
		}
	}
	if (PIE_on) {
		PIE_count++;
		if (PIE_count >= hpet_rtc_int_freq/PIE_freq) {
			/* Set periodic int info, call real rtc int routine */
			call_rtc_interrupt = 1;
			rtc_int_flag |= RTC_PF;
			PIE_count = 0;
		}
	}
	if (AIE_on) {
		if ((curr_time.tm_sec == alarm_time.tm_sec) &&
		    (curr_time.tm_min == alarm_time.tm_min) &&
		    (curr_time.tm_hour == alarm_time.tm_hour)) {
			/* Set alarm int info, call real rtc int routine */
			call_rtc_interrupt = 1;
			rtc_int_flag |= RTC_AF;
		}
	}
	if (call_rtc_interrupt) {
		rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
		rtc_interrupt(rtc_int_flag, dev_id, regs);
	}
	return IRQ_HANDLED;
}
#endif



static int __init nohpet_setup(char *s) 
{ 
	nohpet = 1;
	return 0;
} 

__setup("nohpet", nohpet_setup);


static int __init notsc_setup(char *s)
{
	notsc = 1;
	return 0;
}

__setup("notsc", notsc_setup);