xref: /linux/arch/x86/kernel/hpet.c (revision 40d3057ac036f2501c1930728a6179be4fca577b)
1 #include <linux/clocksource.h>
2 #include <linux/clockchips.h>
3 #include <linux/delay.h>
4 #include <linux/errno.h>
5 #include <linux/hpet.h>
6 #include <linux/init.h>
7 #include <linux/sysdev.h>
8 #include <linux/pm.h>
9 
10 #include <asm/fixmap.h>
11 #include <asm/hpet.h>
12 #include <asm/i8253.h>
13 #include <asm/io.h>
14 
15 #define HPET_MASK	CLOCKSOURCE_MASK(32)
16 #define HPET_SHIFT	22
17 
18 /* FSEC = 10^-15
19    NSEC = 10^-9 */
20 #define FSEC_PER_NSEC	1000000L
21 
22 /*
23  * HPET address is set in acpi/boot.c, when an ACPI entry exists
24  */
25 unsigned long hpet_address;
26 static void __iomem *hpet_virt_address;
27 
28 unsigned long hpet_readl(unsigned long a)
29 {
30 	return readl(hpet_virt_address + a);
31 }
32 
33 static inline void hpet_writel(unsigned long d, unsigned long a)
34 {
35 	writel(d, hpet_virt_address + a);
36 }
37 
38 #ifdef CONFIG_X86_64
39 #include <asm/pgtable.h>
40 #endif
41 
42 static inline void hpet_set_mapping(void)
43 {
44 	hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
45 #ifdef CONFIG_X86_64
46 	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
47 #endif
48 }
49 
50 static inline void hpet_clear_mapping(void)
51 {
52 	iounmap(hpet_virt_address);
53 	hpet_virt_address = NULL;
54 }
55 
56 /*
57  * HPET command line enable / disable
58  */
59 static int boot_hpet_disable;
60 int hpet_force_user;
61 
62 static int __init hpet_setup(char* str)
63 {
64 	if (str) {
65 		if (!strncmp("disable", str, 7))
66 			boot_hpet_disable = 1;
67 		if (!strncmp("force", str, 5))
68 			hpet_force_user = 1;
69 	}
70 	return 1;
71 }
72 __setup("hpet=", hpet_setup);
73 
74 static int __init disable_hpet(char *str)
75 {
76 	boot_hpet_disable = 1;
77 	return 1;
78 }
79 __setup("nohpet", disable_hpet);
80 
81 static inline int is_hpet_capable(void)
82 {
83 	return (!boot_hpet_disable && hpet_address);
84 }
85 
86 /*
87  * HPET timer interrupt enable / disable
88  */
89 static int hpet_legacy_int_enabled;
90 
91 /**
92  * is_hpet_enabled - check whether the hpet timer interrupt is enabled
93  */
94 int is_hpet_enabled(void)
95 {
96 	return is_hpet_capable() && hpet_legacy_int_enabled;
97 }
98 EXPORT_SYMBOL_GPL(is_hpet_enabled);
99 
100 /*
101  * When the hpet driver (/dev/hpet) is enabled, we need to reserve
102  * timer 0 and timer 1 in case of RTC emulation.
103  */
104 #ifdef CONFIG_HPET
105 static void hpet_reserve_platform_timers(unsigned long id)
106 {
107 	struct hpet __iomem *hpet = hpet_virt_address;
108 	struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
109 	unsigned int nrtimers, i;
110 	struct hpet_data hd;
111 
112 	nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
113 
114 	memset(&hd, 0, sizeof (hd));
115 	hd.hd_phys_address = hpet_address;
116 	hd.hd_address = hpet;
117 	hd.hd_nirqs = nrtimers;
118 	hd.hd_flags = HPET_DATA_PLATFORM;
119 	hpet_reserve_timer(&hd, 0);
120 
121 #ifdef CONFIG_HPET_EMULATE_RTC
122 	hpet_reserve_timer(&hd, 1);
123 #endif
124 
125 	hd.hd_irq[0] = HPET_LEGACY_8254;
126 	hd.hd_irq[1] = HPET_LEGACY_RTC;
127 
128 	for (i = 2; i < nrtimers; timer++, i++) {
129 		hd.hd_irq[i] = (readl(&timer->hpet_config) & Tn_INT_ROUTE_CNF_MASK) >>
130 			Tn_INT_ROUTE_CNF_SHIFT;
131 	}
132 
133 	hpet_alloc(&hd);
134 
135 }
136 #else
137 static void hpet_reserve_platform_timers(unsigned long id) { }
138 #endif
139 
140 /*
141  * Common hpet info
142  */
143 static unsigned long hpet_period;
144 
145 static void hpet_legacy_set_mode(enum clock_event_mode mode,
146 			  struct clock_event_device *evt);
147 static int hpet_legacy_next_event(unsigned long delta,
148 			   struct clock_event_device *evt);
149 
150 /*
151  * The hpet clock event device
152  */
153 static struct clock_event_device hpet_clockevent = {
154 	.name		= "hpet",
155 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
156 	.set_mode	= hpet_legacy_set_mode,
157 	.set_next_event = hpet_legacy_next_event,
158 	.shift		= 32,
159 	.irq		= 0,
160 	.rating		= 50,
161 };
162 
163 static void hpet_start_counter(void)
164 {
165 	unsigned long cfg = hpet_readl(HPET_CFG);
166 
167 	cfg &= ~HPET_CFG_ENABLE;
168 	hpet_writel(cfg, HPET_CFG);
169 	hpet_writel(0, HPET_COUNTER);
170 	hpet_writel(0, HPET_COUNTER + 4);
171 	cfg |= HPET_CFG_ENABLE;
172 	hpet_writel(cfg, HPET_CFG);
173 }
174 
175 static void hpet_resume_device(void)
176 {
177 	force_hpet_resume();
178 }
179 
180 static void hpet_restart_counter(void)
181 {
182 	hpet_resume_device();
183 	hpet_start_counter();
184 }
185 
186 static void hpet_enable_legacy_int(void)
187 {
188 	unsigned long cfg = hpet_readl(HPET_CFG);
189 
190 	cfg |= HPET_CFG_LEGACY;
191 	hpet_writel(cfg, HPET_CFG);
192 	hpet_legacy_int_enabled = 1;
193 }
194 
195 static void hpet_legacy_clockevent_register(void)
196 {
197 	/* Start HPET legacy interrupts */
198 	hpet_enable_legacy_int();
199 
200 	/*
201 	 * The mult factor is defined as (include/linux/clockchips.h)
202 	 *  mult/2^shift = cyc/ns (in contrast to ns/cyc in clocksource.h)
203 	 * hpet_period is in units of femtoseconds (per cycle), so
204 	 *  mult/2^shift = cyc/ns = 10^6/hpet_period
205 	 *  mult = (10^6 * 2^shift)/hpet_period
206 	 *  mult = (FSEC_PER_NSEC << hpet_clockevent.shift)/hpet_period
207 	 */
208 	hpet_clockevent.mult = div_sc((unsigned long) FSEC_PER_NSEC,
209 				      hpet_period, hpet_clockevent.shift);
210 	/* Calculate the min / max delta */
211 	hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
212 							   &hpet_clockevent);
213 	/* 5 usec minimum reprogramming delta. */
214 	hpet_clockevent.min_delta_ns = 5000;
215 
216 	/*
217 	 * Start hpet with the boot cpu mask and make it
218 	 * global after the IO_APIC has been initialized.
219 	 */
220 	hpet_clockevent.cpumask = cpumask_of_cpu(smp_processor_id());
221 	clockevents_register_device(&hpet_clockevent);
222 	global_clock_event = &hpet_clockevent;
223 	printk(KERN_DEBUG "hpet clockevent registered\n");
224 }
225 
226 static void hpet_legacy_set_mode(enum clock_event_mode mode,
227 			  struct clock_event_device *evt)
228 {
229 	unsigned long cfg, cmp, now;
230 	uint64_t delta;
231 
232 	switch(mode) {
233 	case CLOCK_EVT_MODE_PERIODIC:
234 		delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * hpet_clockevent.mult;
235 		delta >>= hpet_clockevent.shift;
236 		now = hpet_readl(HPET_COUNTER);
237 		cmp = now + (unsigned long) delta;
238 		cfg = hpet_readl(HPET_T0_CFG);
239 		cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
240 		       HPET_TN_SETVAL | HPET_TN_32BIT;
241 		hpet_writel(cfg, HPET_T0_CFG);
242 		/*
243 		 * The first write after writing TN_SETVAL to the
244 		 * config register sets the counter value, the second
245 		 * write sets the period.
246 		 */
247 		hpet_writel(cmp, HPET_T0_CMP);
248 		udelay(1);
249 		hpet_writel((unsigned long) delta, HPET_T0_CMP);
250 		break;
251 
252 	case CLOCK_EVT_MODE_ONESHOT:
253 		cfg = hpet_readl(HPET_T0_CFG);
254 		cfg &= ~HPET_TN_PERIODIC;
255 		cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
256 		hpet_writel(cfg, HPET_T0_CFG);
257 		break;
258 
259 	case CLOCK_EVT_MODE_UNUSED:
260 	case CLOCK_EVT_MODE_SHUTDOWN:
261 		cfg = hpet_readl(HPET_T0_CFG);
262 		cfg &= ~HPET_TN_ENABLE;
263 		hpet_writel(cfg, HPET_T0_CFG);
264 		break;
265 
266 	case CLOCK_EVT_MODE_RESUME:
267 		hpet_enable_legacy_int();
268 		break;
269 	}
270 }
271 
272 static int hpet_legacy_next_event(unsigned long delta,
273 				  struct clock_event_device *evt)
274 {
275 	u32 cnt;
276 
277 	cnt = hpet_readl(HPET_COUNTER);
278 	cnt += (u32) delta;
279 	hpet_writel(cnt, HPET_T0_CMP);
280 
281 	/*
282 	 * We need to read back the CMP register to make sure that
283 	 * what we wrote hit the chip before we compare it to the
284 	 * counter.
285 	 */
286 	WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt);
287 
288 	return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
289 }
290 
291 /*
292  * Clock source related code
293  */
294 static cycle_t read_hpet(void)
295 {
296 	return (cycle_t)hpet_readl(HPET_COUNTER);
297 }
298 
299 #ifdef CONFIG_X86_64
300 static cycle_t __vsyscall_fn vread_hpet(void)
301 {
302 	return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
303 }
304 #endif
305 
306 static struct clocksource clocksource_hpet = {
307 	.name		= "hpet",
308 	.rating		= 250,
309 	.read		= read_hpet,
310 	.mask		= HPET_MASK,
311 	.shift		= HPET_SHIFT,
312 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
313 	.resume		= hpet_restart_counter,
314 #ifdef CONFIG_X86_64
315 	.vread		= vread_hpet,
316 #endif
317 };
318 
319 static int hpet_clocksource_register(void)
320 {
321 	u64 start, now;
322 	cycle_t t1;
323 
324 	/* Start the counter */
325 	hpet_start_counter();
326 
327 	/* Verify whether hpet counter works */
328 	t1 = read_hpet();
329 	rdtscll(start);
330 
331 	/*
332 	 * We don't know the TSC frequency yet, but waiting for
333 	 * 200000 TSC cycles is safe:
334 	 * 4 GHz == 50us
335 	 * 1 GHz == 200us
336 	 */
337 	do {
338 		rep_nop();
339 		rdtscll(now);
340 	} while ((now - start) < 200000UL);
341 
342 	if (t1 == read_hpet()) {
343 		printk(KERN_WARNING
344 		       "HPET counter not counting. HPET disabled\n");
345 		return -ENODEV;
346 	}
347 
348 	/*
349 	 * The definition of mult is (include/linux/clocksource.h)
350 	 * mult/2^shift = ns/cyc and hpet_period is in units of fsec/cyc
351 	 * so we first need to convert hpet_period to ns/cyc units:
352 	 *  mult/2^shift = ns/cyc = hpet_period/10^6
353 	 *  mult = (hpet_period * 2^shift)/10^6
354 	 *  mult = (hpet_period << shift)/FSEC_PER_NSEC
355 	 */
356 	clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
357 
358 	clocksource_register(&clocksource_hpet);
359 
360 	return 0;
361 }
362 
363 /**
364  * hpet_enable - Try to setup the HPET timer. Returns 1 on success.
365  */
366 int __init hpet_enable(void)
367 {
368 	unsigned long id;
369 	int i;
370 
371 	if (!is_hpet_capable())
372 		return 0;
373 
374 	hpet_set_mapping();
375 
376 	/*
377 	 * Read the period and check for a sane value:
378 	 */
379 	hpet_period = hpet_readl(HPET_PERIOD);
380 
381 	/*
382 	 * AMD SB700 based systems with spread spectrum enabled use a
383 	 * SMM based HPET emulation to provide proper frequency
384 	 * setting. The SMM code is initialized with the first HPET
385 	 * register access and takes some time to complete. During
386 	 * this time the config register reads 0xffffffff. We check
387 	 * for max. 1000 loops whether the config register reads a non
388 	 * 0xffffffff value to make sure that HPET is up and running
389 	 * before we go further. A counting loop is safe, as the HPET
390 	 * access takes thousands of CPU cycles. On non SB700 based
391 	 * machines this check is only done once and has no side
392 	 * effects.
393 	 */
394 	for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
395 		if (i == 1000) {
396 			printk(KERN_WARNING
397 			       "HPET config register value = 0xFFFFFFFF. "
398 			       "Disabling HPET\n");
399 			goto out_nohpet;
400 		}
401 	}
402 
403 	if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
404 		goto out_nohpet;
405 
406 	/*
407 	 * Read the HPET ID register to retrieve the IRQ routing
408 	 * information and the number of channels
409 	 */
410 	id = hpet_readl(HPET_ID);
411 
412 #ifdef CONFIG_HPET_EMULATE_RTC
413 	/*
414 	 * The legacy routing mode needs at least two channels, tick timer
415 	 * and the rtc emulation channel.
416 	 */
417 	if (!(id & HPET_ID_NUMBER))
418 		goto out_nohpet;
419 #endif
420 
421 	if (hpet_clocksource_register())
422 		goto out_nohpet;
423 
424 	if (id & HPET_ID_LEGSUP) {
425 		hpet_legacy_clockevent_register();
426 		return 1;
427 	}
428 	return 0;
429 
430 out_nohpet:
431 	hpet_clear_mapping();
432 	boot_hpet_disable = 1;
433 	return 0;
434 }
435 
436 /*
437  * Needs to be late, as the reserve_timer code calls kalloc !
438  *
439  * Not a problem on i386 as hpet_enable is called from late_time_init,
440  * but on x86_64 it is necessary !
441  */
442 static __init int hpet_late_init(void)
443 {
444 	if (boot_hpet_disable)
445 		return -ENODEV;
446 
447 	if (!hpet_address) {
448 		if (!force_hpet_address)
449 			return -ENODEV;
450 
451 		hpet_address = force_hpet_address;
452 		hpet_enable();
453 		if (!hpet_virt_address)
454 			return -ENODEV;
455 	}
456 
457 	hpet_reserve_platform_timers(hpet_readl(HPET_ID));
458 
459 	return 0;
460 }
461 fs_initcall(hpet_late_init);
462 
463 void hpet_disable(void)
464 {
465 	if (is_hpet_capable()) {
466 		unsigned long cfg = hpet_readl(HPET_CFG);
467 
468 		if (hpet_legacy_int_enabled) {
469 			cfg &= ~HPET_CFG_LEGACY;
470 			hpet_legacy_int_enabled = 0;
471 		}
472 		cfg &= ~HPET_CFG_ENABLE;
473 		hpet_writel(cfg, HPET_CFG);
474 	}
475 }
476 
477 #ifdef CONFIG_HPET_EMULATE_RTC
478 
479 /* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
480  * is enabled, we support RTC interrupt functionality in software.
481  * RTC has 3 kinds of interrupts:
482  * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
483  *    is updated
484  * 2) Alarm Interrupt - generate an interrupt at a specific time of day
485  * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
486  *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
487  * (1) and (2) above are implemented using polling at a frequency of
488  * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
489  * overhead. (DEFAULT_RTC_INT_FREQ)
490  * For (3), we use interrupts at 64Hz or user specified periodic
491  * frequency, whichever is higher.
492  */
493 #include <linux/mc146818rtc.h>
494 #include <linux/rtc.h>
495 #include <asm/rtc.h>
496 
497 #define DEFAULT_RTC_INT_FREQ	64
498 #define DEFAULT_RTC_SHIFT	6
499 #define RTC_NUM_INTS		1
500 
501 static unsigned long hpet_rtc_flags;
502 static int hpet_prev_update_sec;
503 static struct rtc_time hpet_alarm_time;
504 static unsigned long hpet_pie_count;
505 static unsigned long hpet_t1_cmp;
506 static unsigned long hpet_default_delta;
507 static unsigned long hpet_pie_delta;
508 static unsigned long hpet_pie_limit;
509 
510 static rtc_irq_handler irq_handler;
511 
512 /*
513  * Registers a IRQ handler.
514  */
515 int hpet_register_irq_handler(rtc_irq_handler handler)
516 {
517 	if (!is_hpet_enabled())
518 		return -ENODEV;
519 	if (irq_handler)
520 		return -EBUSY;
521 
522 	irq_handler = handler;
523 
524 	return 0;
525 }
526 EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
527 
528 /*
529  * Deregisters the IRQ handler registered with hpet_register_irq_handler()
530  * and does cleanup.
531  */
532 void hpet_unregister_irq_handler(rtc_irq_handler handler)
533 {
534 	if (!is_hpet_enabled())
535 		return;
536 
537 	irq_handler = NULL;
538 	hpet_rtc_flags = 0;
539 }
540 EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
541 
542 /*
543  * Timer 1 for RTC emulation. We use one shot mode, as periodic mode
544  * is not supported by all HPET implementations for timer 1.
545  *
546  * hpet_rtc_timer_init() is called when the rtc is initialized.
547  */
548 int hpet_rtc_timer_init(void)
549 {
550 	unsigned long cfg, cnt, delta, flags;
551 
552 	if (!is_hpet_enabled())
553 		return 0;
554 
555 	if (!hpet_default_delta) {
556 		uint64_t clc;
557 
558 		clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
559 		clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
560 		hpet_default_delta = (unsigned long) clc;
561 	}
562 
563 	if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
564 		delta = hpet_default_delta;
565 	else
566 		delta = hpet_pie_delta;
567 
568 	local_irq_save(flags);
569 
570 	cnt = delta + hpet_readl(HPET_COUNTER);
571 	hpet_writel(cnt, HPET_T1_CMP);
572 	hpet_t1_cmp = cnt;
573 
574 	cfg = hpet_readl(HPET_T1_CFG);
575 	cfg &= ~HPET_TN_PERIODIC;
576 	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
577 	hpet_writel(cfg, HPET_T1_CFG);
578 
579 	local_irq_restore(flags);
580 
581 	return 1;
582 }
583 EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
584 
585 /*
586  * The functions below are called from rtc driver.
587  * Return 0 if HPET is not being used.
588  * Otherwise do the necessary changes and return 1.
589  */
590 int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
591 {
592 	if (!is_hpet_enabled())
593 		return 0;
594 
595 	hpet_rtc_flags &= ~bit_mask;
596 	return 1;
597 }
598 EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
599 
600 int hpet_set_rtc_irq_bit(unsigned long bit_mask)
601 {
602 	unsigned long oldbits = hpet_rtc_flags;
603 
604 	if (!is_hpet_enabled())
605 		return 0;
606 
607 	hpet_rtc_flags |= bit_mask;
608 
609 	if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE))
610 		hpet_prev_update_sec = -1;
611 
612 	if (!oldbits)
613 		hpet_rtc_timer_init();
614 
615 	return 1;
616 }
617 EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
618 
619 int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
620 			unsigned char sec)
621 {
622 	if (!is_hpet_enabled())
623 		return 0;
624 
625 	hpet_alarm_time.tm_hour = hrs;
626 	hpet_alarm_time.tm_min = min;
627 	hpet_alarm_time.tm_sec = sec;
628 
629 	return 1;
630 }
631 EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
632 
633 int hpet_set_periodic_freq(unsigned long freq)
634 {
635 	uint64_t clc;
636 
637 	if (!is_hpet_enabled())
638 		return 0;
639 
640 	if (freq <= DEFAULT_RTC_INT_FREQ)
641 		hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
642 	else {
643 		clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
644 		do_div(clc, freq);
645 		clc >>= hpet_clockevent.shift;
646 		hpet_pie_delta = (unsigned long) clc;
647 	}
648 	return 1;
649 }
650 EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
651 
652 int hpet_rtc_dropped_irq(void)
653 {
654 	return is_hpet_enabled();
655 }
656 EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
657 
658 static void hpet_rtc_timer_reinit(void)
659 {
660 	unsigned long cfg, delta;
661 	int lost_ints = -1;
662 
663 	if (unlikely(!hpet_rtc_flags)) {
664 		cfg = hpet_readl(HPET_T1_CFG);
665 		cfg &= ~HPET_TN_ENABLE;
666 		hpet_writel(cfg, HPET_T1_CFG);
667 		return;
668 	}
669 
670 	if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
671 		delta = hpet_default_delta;
672 	else
673 		delta = hpet_pie_delta;
674 
675 	/*
676 	 * Increment the comparator value until we are ahead of the
677 	 * current count.
678 	 */
679 	do {
680 		hpet_t1_cmp += delta;
681 		hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
682 		lost_ints++;
683 	} while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
684 
685 	if (lost_ints) {
686 		if (hpet_rtc_flags & RTC_PIE)
687 			hpet_pie_count += lost_ints;
688 		if (printk_ratelimit())
689 			printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
690 				lost_ints);
691 	}
692 }
693 
694 irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
695 {
696 	struct rtc_time curr_time;
697 	unsigned long rtc_int_flag = 0;
698 
699 	hpet_rtc_timer_reinit();
700 	memset(&curr_time, 0, sizeof(struct rtc_time));
701 
702 	if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
703 		get_rtc_time(&curr_time);
704 
705 	if (hpet_rtc_flags & RTC_UIE &&
706 	    curr_time.tm_sec != hpet_prev_update_sec) {
707 		if (hpet_prev_update_sec >= 0)
708 			rtc_int_flag = RTC_UF;
709 		hpet_prev_update_sec = curr_time.tm_sec;
710 	}
711 
712 	if (hpet_rtc_flags & RTC_PIE &&
713 	    ++hpet_pie_count >= hpet_pie_limit) {
714 		rtc_int_flag |= RTC_PF;
715 		hpet_pie_count = 0;
716 	}
717 
718 	if (hpet_rtc_flags & RTC_AIE &&
719 	    (curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
720 	    (curr_time.tm_min == hpet_alarm_time.tm_min) &&
721 	    (curr_time.tm_hour == hpet_alarm_time.tm_hour))
722 			rtc_int_flag |= RTC_AF;
723 
724 	if (rtc_int_flag) {
725 		rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
726 		if (irq_handler)
727 			irq_handler(rtc_int_flag, dev_id);
728 	}
729 	return IRQ_HANDLED;
730 }
731 EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
732 #endif
733