1 // SPDX-License-Identifier: GPL-2.0-only
3 * Intel & MS High Precision Event Timer Implementation.
5 * Copyright (C) 2003 Intel Corporation
7 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
8 * Bob Picco <robert.picco@hp.com>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/miscdevice.h>
15 #include <linux/major.h>
16 #include <linux/ioport.h>
17 #include <linux/fcntl.h>
18 #include <linux/init.h>
19 #include <linux/io-64-nonatomic-lo-hi.h>
20 #include <linux/poll.h>
22 #include <linux/proc_fs.h>
23 #include <linux/spinlock.h>
24 #include <linux/sysctl.h>
25 #include <linux/wait.h>
26 #include <linux/sched/signal.h>
27 #include <linux/bcd.h>
28 #include <linux/seq_file.h>
29 #include <linux/bitops.h>
30 #include <linux/compat.h>
31 #include <linux/clocksource.h>
32 #include <linux/uaccess.h>
33 #include <linux/slab.h>
35 #include <linux/acpi.h>
36 #include <linux/hpet.h>
37 #include <asm/current.h>
39 #include <asm/div64.h>
42 * The High Precision Event Timer driver.
43 * This driver is closely modelled after the rtc.c driver.
44 * See HPET spec revision 1.
46 #define HPET_USER_FREQ (64)
47 #define HPET_DRIFT (500)
49 #define HPET_RANGE_SIZE 1024 /* from HPET spec */
52 /* WARNING -- don't get confused. These macros are never used
53 * to write the (single) counter, and rarely to read it.
54 * They're badly named; to fix, someday.
56 #if BITS_PER_LONG == 64
57 #define write_counter(V, MC) writeq(V, MC)
58 #define read_counter(MC) readq(MC)
60 #define write_counter(V, MC) writel(V, MC)
61 #define read_counter(MC) readl(MC)
64 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
65 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
67 /* A lock for concurrent access by app and isr hpet activity. */
68 static DEFINE_SPINLOCK(hpet_lock);
70 #define HPET_DEV_NAME (7)
73 struct hpets *hd_hpets;
74 struct hpet __iomem *hd_hpet;
75 struct hpet_timer __iomem *hd_timer;
76 unsigned long hd_ireqfreq;
77 unsigned long hd_irqdata;
78 wait_queue_head_t hd_waitqueue;
79 struct fasync_struct *hd_async_queue;
80 unsigned int hd_flags;
82 unsigned int hd_hdwirq;
83 char hd_name[HPET_DEV_NAME];
87 struct hpets *hp_next;
88 struct hpet __iomem *hp_hpet;
89 unsigned long hp_hpet_phys;
90 struct clocksource *hp_clocksource;
91 unsigned long long hp_tick_freq;
92 unsigned long hp_delta;
93 unsigned int hp_ntimer;
94 unsigned int hp_which;
95 struct hpet_dev hp_dev[] __counted_by(hp_ntimer);
98 static struct hpets *hpets;
100 #define HPET_OPEN 0x0001
101 #define HPET_IE 0x0002 /* interrupt enabled */
102 #define HPET_PERIODIC 0x0004
103 #define HPET_SHARED_IRQ 0x0008
105 static irqreturn_t hpet_interrupt(int irq, void *data)
107 struct hpet_dev *devp;
111 isr = 1 << (devp - devp->hd_hpets->hp_dev);
113 if ((devp->hd_flags & HPET_SHARED_IRQ) &&
114 !(isr & readl(&devp->hd_hpet->hpet_isr)))
117 spin_lock(&hpet_lock);
121 * For non-periodic timers, increment the accumulator.
122 * This has the effect of treating non-periodic like periodic.
124 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
125 unsigned long t, mc, base, k;
126 struct hpet __iomem *hpet = devp->hd_hpet;
127 struct hpets *hpetp = devp->hd_hpets;
129 t = devp->hd_ireqfreq;
130 read_counter(&devp->hd_timer->hpet_compare);
131 mc = read_counter(&hpet->hpet_mc);
132 /* The time for the next interrupt would logically be t + m,
133 * however, if we are very unlucky and the interrupt is delayed
134 * for longer than t then we will completely miss the next
135 * interrupt if we set t + m and an application will hang.
136 * Therefore we need to make a more complex computation assuming
137 * that there exists a k for which the following is true:
138 * k * t + base < mc + delta
139 * (k + 1) * t + base > mc + delta
140 * where t is the interval in hpet ticks for the given freq,
141 * base is the theoretical start value 0 < base < t,
142 * mc is the main counter value at the time of the interrupt,
143 * delta is the time it takes to write the a value to the
145 * k may then be computed as (mc - base + delta) / t .
148 k = (mc - base + hpetp->hp_delta) / t;
149 write_counter(t * (k + 1) + base,
150 &devp->hd_timer->hpet_compare);
153 if (devp->hd_flags & HPET_SHARED_IRQ)
154 writel(isr, &devp->hd_hpet->hpet_isr);
155 spin_unlock(&hpet_lock);
157 wake_up_interruptible(&devp->hd_waitqueue);
159 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
164 static void hpet_timer_set_irq(struct hpet_dev *devp)
168 struct hpet_timer __iomem *timer;
170 spin_lock_irq(&hpet_lock);
171 if (devp->hd_hdwirq) {
172 spin_unlock_irq(&hpet_lock);
176 timer = devp->hd_timer;
178 /* we prefer level triggered mode */
179 v = readl(&timer->hpet_config);
180 if (!(v & Tn_INT_TYPE_CNF_MASK)) {
181 v |= Tn_INT_TYPE_CNF_MASK;
182 writel(v, &timer->hpet_config);
184 spin_unlock_irq(&hpet_lock);
186 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
187 Tn_INT_ROUTE_CAP_SHIFT;
190 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
191 * legacy device. In IO APIC mode, we skip all the legacy IRQS.
193 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
198 for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
199 if (irq >= nr_irqs) {
204 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
209 /* FIXME: Setup interrupt source table */
212 if (irq < HPET_MAX_IRQ) {
213 spin_lock_irq(&hpet_lock);
214 v = readl(&timer->hpet_config);
215 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
216 writel(v, &timer->hpet_config);
217 devp->hd_hdwirq = gsi;
218 spin_unlock_irq(&hpet_lock);
223 static int hpet_open(struct inode *inode, struct file *file)
225 struct hpet_dev *devp;
229 if (file->f_mode & FMODE_WRITE)
232 mutex_lock(&hpet_mutex);
233 spin_lock_irq(&hpet_lock);
235 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
236 for (i = 0; i < hpetp->hp_ntimer; i++)
237 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) {
240 devp = &hpetp->hp_dev[i];
245 spin_unlock_irq(&hpet_lock);
246 mutex_unlock(&hpet_mutex);
250 file->private_data = devp;
251 devp->hd_irqdata = 0;
252 devp->hd_flags |= HPET_OPEN;
253 spin_unlock_irq(&hpet_lock);
254 mutex_unlock(&hpet_mutex);
256 hpet_timer_set_irq(devp);
262 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
264 DECLARE_WAITQUEUE(wait, current);
267 struct hpet_dev *devp;
269 devp = file->private_data;
270 if (!devp->hd_ireqfreq)
273 if (count < sizeof(unsigned long))
276 add_wait_queue(&devp->hd_waitqueue, &wait);
279 set_current_state(TASK_INTERRUPTIBLE);
281 spin_lock_irq(&hpet_lock);
282 data = devp->hd_irqdata;
283 devp->hd_irqdata = 0;
284 spin_unlock_irq(&hpet_lock);
288 } else if (file->f_flags & O_NONBLOCK) {
291 } else if (signal_pending(current)) {
292 retval = -ERESTARTSYS;
298 retval = put_user(data, (unsigned long __user *)buf);
300 retval = sizeof(unsigned long);
302 __set_current_state(TASK_RUNNING);
303 remove_wait_queue(&devp->hd_waitqueue, &wait);
308 static __poll_t hpet_poll(struct file *file, poll_table * wait)
311 struct hpet_dev *devp;
313 devp = file->private_data;
315 if (!devp->hd_ireqfreq)
318 poll_wait(file, &devp->hd_waitqueue, wait);
320 spin_lock_irq(&hpet_lock);
321 v = devp->hd_irqdata;
322 spin_unlock_irq(&hpet_lock);
325 return EPOLLIN | EPOLLRDNORM;
330 #ifdef CONFIG_HPET_MMAP
331 #ifdef CONFIG_HPET_MMAP_DEFAULT
332 static int hpet_mmap_enabled = 1;
334 static int hpet_mmap_enabled = 0;
337 static __init int hpet_mmap_enable(char *str)
339 get_option(&str, &hpet_mmap_enabled);
340 pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled");
343 __setup("hpet_mmap=", hpet_mmap_enable);
345 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
347 struct hpet_dev *devp;
350 if (!hpet_mmap_enabled)
353 devp = file->private_data;
354 addr = devp->hd_hpets->hp_hpet_phys;
356 if (addr & (PAGE_SIZE - 1))
359 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
360 return vm_iomap_memory(vma, addr, PAGE_SIZE);
363 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
369 static int hpet_fasync(int fd, struct file *file, int on)
371 struct hpet_dev *devp;
373 devp = file->private_data;
375 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
381 static int hpet_release(struct inode *inode, struct file *file)
383 struct hpet_dev *devp;
384 struct hpet_timer __iomem *timer;
387 devp = file->private_data;
388 timer = devp->hd_timer;
390 spin_lock_irq(&hpet_lock);
392 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
393 &timer->hpet_config);
398 devp->hd_ireqfreq = 0;
400 if (devp->hd_flags & HPET_PERIODIC
401 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
404 v = readq(&timer->hpet_config);
405 v ^= Tn_TYPE_CNF_MASK;
406 writeq(v, &timer->hpet_config);
409 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
410 spin_unlock_irq(&hpet_lock);
415 file->private_data = NULL;
419 static int hpet_ioctl_ieon(struct hpet_dev *devp)
421 struct hpet_timer __iomem *timer;
422 struct hpet __iomem *hpet;
425 unsigned long g, v, t, m;
426 unsigned long flags, isr;
428 timer = devp->hd_timer;
429 hpet = devp->hd_hpet;
430 hpetp = devp->hd_hpets;
432 if (!devp->hd_ireqfreq)
435 spin_lock_irq(&hpet_lock);
437 if (devp->hd_flags & HPET_IE) {
438 spin_unlock_irq(&hpet_lock);
442 devp->hd_flags |= HPET_IE;
444 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
445 devp->hd_flags |= HPET_SHARED_IRQ;
446 spin_unlock_irq(&hpet_lock);
448 irq = devp->hd_hdwirq;
451 unsigned long irq_flags;
453 if (devp->hd_flags & HPET_SHARED_IRQ) {
455 * To prevent the interrupt handler from seeing an
456 * unwanted interrupt status bit, program the timer
457 * so that it will not fire in the near future ...
459 writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
460 &timer->hpet_config);
461 write_counter(read_counter(&hpet->hpet_mc),
462 &timer->hpet_compare);
463 /* ... and clear any left-over status. */
464 isr = 1 << (devp - devp->hd_hpets->hp_dev);
465 writel(isr, &hpet->hpet_isr);
468 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
469 irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0;
470 if (request_irq(irq, hpet_interrupt, irq_flags,
471 devp->hd_name, (void *)devp)) {
472 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
478 spin_lock_irq(&hpet_lock);
479 devp->hd_flags ^= HPET_IE;
480 spin_unlock_irq(&hpet_lock);
485 t = devp->hd_ireqfreq;
486 v = readq(&timer->hpet_config);
488 /* 64-bit comparators are not yet supported through the ioctls,
489 * so force this into 32-bit mode if it supports both modes
491 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
493 if (devp->hd_flags & HPET_PERIODIC) {
494 g |= Tn_TYPE_CNF_MASK;
495 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
496 writeq(v, &timer->hpet_config);
497 local_irq_save(flags);
500 * NOTE: First we modify the hidden accumulator
501 * register supported by periodic-capable comparators.
502 * We never want to modify the (single) counter; that
503 * would affect all the comparators. The value written
504 * is the counter value when the first interrupt is due.
506 m = read_counter(&hpet->hpet_mc);
507 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
509 * Then we modify the comparator, indicating the period
510 * for subsequent interrupt.
512 write_counter(t, &timer->hpet_compare);
514 local_irq_save(flags);
515 m = read_counter(&hpet->hpet_mc);
516 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
519 if (devp->hd_flags & HPET_SHARED_IRQ) {
520 isr = 1 << (devp - devp->hd_hpets->hp_dev);
521 writel(isr, &hpet->hpet_isr);
523 writeq(g, &timer->hpet_config);
524 local_irq_restore(flags);
529 /* converts Hz to number of timer ticks */
530 static inline unsigned long hpet_time_div(struct hpets *hpets,
533 unsigned long long m;
535 m = hpets->hp_tick_freq + (dis >> 1);
536 return div64_ul(m, dis);
540 hpet_ioctl_common(struct hpet_dev *devp, unsigned int cmd, unsigned long arg,
541 struct hpet_info *info)
543 struct hpet_timer __iomem *timer;
554 timer = devp->hd_timer;
555 hpetp = devp->hd_hpets;
558 return hpet_ioctl_ieon(devp);
567 if ((devp->hd_flags & HPET_IE) == 0)
569 v = readq(&timer->hpet_config);
570 v &= ~Tn_INT_ENB_CNF_MASK;
571 writeq(v, &timer->hpet_config);
573 free_irq(devp->hd_irq, devp);
576 devp->hd_flags ^= HPET_IE;
580 memset(info, 0, sizeof(*info));
581 if (devp->hd_ireqfreq)
583 hpet_time_div(hpetp, devp->hd_ireqfreq);
585 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
586 info->hi_hpet = hpetp->hp_which;
587 info->hi_timer = devp - hpetp->hp_dev;
591 v = readq(&timer->hpet_config);
592 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
596 devp->hd_flags |= HPET_PERIODIC;
599 v = readq(&timer->hpet_config);
600 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
604 if (devp->hd_flags & HPET_PERIODIC &&
605 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
606 v = readq(&timer->hpet_config);
607 v ^= Tn_TYPE_CNF_MASK;
608 writeq(v, &timer->hpet_config);
610 devp->hd_flags &= ~HPET_PERIODIC;
613 if ((arg > hpet_max_freq) &&
614 !capable(CAP_SYS_RESOURCE)) {
624 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
631 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
633 struct hpet_info info;
636 mutex_lock(&hpet_mutex);
637 err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
638 mutex_unlock(&hpet_mutex);
640 if ((cmd == HPET_INFO) && !err &&
641 (copy_to_user((void __user *)arg, &info, sizeof(info))))
648 struct compat_hpet_info {
649 compat_ulong_t hi_ireqfreq; /* Hz */
650 compat_ulong_t hi_flags; /* information */
651 unsigned short hi_hpet;
652 unsigned short hi_timer;
656 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
658 struct hpet_info info;
661 mutex_lock(&hpet_mutex);
662 err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
663 mutex_unlock(&hpet_mutex);
665 if ((cmd == HPET_INFO) && !err) {
666 struct compat_hpet_info __user *u = compat_ptr(arg);
667 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
668 put_user(info.hi_flags, &u->hi_flags) ||
669 put_user(info.hi_hpet, &u->hi_hpet) ||
670 put_user(info.hi_timer, &u->hi_timer))
678 static const struct file_operations hpet_fops = {
679 .owner = THIS_MODULE,
683 .unlocked_ioctl = hpet_ioctl,
685 .compat_ioctl = hpet_compat_ioctl,
688 .release = hpet_release,
689 .fasync = hpet_fasync,
693 static int hpet_is_known(struct hpet_data *hdp)
697 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
698 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
704 static struct ctl_table hpet_table[] = {
706 .procname = "max-user-freq",
707 .data = &hpet_max_freq,
708 .maxlen = sizeof(int),
710 .proc_handler = proc_dointvec,
714 static struct ctl_table_header *sysctl_header;
717 * Adjustment for when arming the timer with
718 * initial conditions. That is, main counter
719 * ticks expired before interrupts are enabled.
721 #define TICK_CALIBRATE (1000UL)
723 static unsigned long __hpet_calibrate(struct hpets *hpetp)
725 struct hpet_timer __iomem *timer = NULL;
726 unsigned long t, m, count, i, flags, start;
727 struct hpet_dev *devp;
729 struct hpet __iomem *hpet;
731 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
732 if ((devp->hd_flags & HPET_OPEN) == 0) {
733 timer = devp->hd_timer;
740 hpet = hpetp->hp_hpet;
741 t = read_counter(&timer->hpet_compare);
744 count = hpet_time_div(hpetp, TICK_CALIBRATE);
746 local_irq_save(flags);
748 start = read_counter(&hpet->hpet_mc);
751 m = read_counter(&hpet->hpet_mc);
752 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
753 } while (i++, (m - start) < count);
755 local_irq_restore(flags);
757 return (m - start) / i;
760 static unsigned long hpet_calibrate(struct hpets *hpetp)
762 unsigned long ret = ~0UL;
766 * Try to calibrate until return value becomes stable small value.
767 * If SMI interruption occurs in calibration loop, the return value
768 * will be big. This avoids its impact.
771 tmp = __hpet_calibrate(hpetp);
780 int hpet_alloc(struct hpet_data *hdp)
783 struct hpet_dev *devp;
786 struct hpet __iomem *hpet;
787 static struct hpets *last;
788 unsigned long period;
789 unsigned long long temp;
793 * hpet_alloc can be called by platform dependent code.
794 * If platform dependent code has allocated the hpet that
795 * ACPI has also reported, then we catch it here.
797 if (hpet_is_known(hdp)) {
798 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
803 hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs),
809 hpetp->hp_which = hpet_nhpet++;
810 hpetp->hp_hpet = hdp->hd_address;
811 hpetp->hp_hpet_phys = hdp->hd_phys_address;
813 hpetp->hp_ntimer = hdp->hd_nirqs;
815 for (i = 0; i < hdp->hd_nirqs; i++)
816 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
818 hpet = hpetp->hp_hpet;
820 cap = readq(&hpet->hpet_cap);
822 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
824 if (hpetp->hp_ntimer != ntimer) {
825 printk(KERN_WARNING "hpet: number irqs doesn't agree"
826 " with number of timers\n");
832 last->hp_next = hpetp;
838 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
839 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
840 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
841 temp += period >> 1; /* round */
842 do_div(temp, period);
843 hpetp->hp_tick_freq = temp; /* ticks per second */
845 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
846 hpetp->hp_which, hdp->hd_phys_address,
847 hpetp->hp_ntimer > 1 ? "s" : "");
848 for (i = 0; i < hpetp->hp_ntimer; i++)
849 printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
850 printk(KERN_CONT "\n");
852 temp = hpetp->hp_tick_freq;
853 remainder = do_div(temp, 1000000);
855 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
856 hpetp->hp_which, hpetp->hp_ntimer,
857 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
858 (unsigned) temp, remainder);
860 mcfg = readq(&hpet->hpet_config);
861 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
862 write_counter(0L, &hpet->hpet_mc);
863 mcfg |= HPET_ENABLE_CNF_MASK;
864 writeq(mcfg, &hpet->hpet_config);
867 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
868 struct hpet_timer __iomem *timer;
870 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
872 devp->hd_hpets = hpetp;
873 devp->hd_hpet = hpet;
874 devp->hd_timer = timer;
877 * If the timer was reserved by platform code,
878 * then make timer unavailable for opens.
880 if (hdp->hd_state & (1 << i)) {
881 devp->hd_flags = HPET_OPEN;
885 init_waitqueue_head(&devp->hd_waitqueue);
888 hpetp->hp_delta = hpet_calibrate(hpetp);
893 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
895 struct hpet_data *hdp;
897 struct acpi_resource_address64 addr;
901 status = acpi_resource_to_address64(res, &addr);
903 if (ACPI_SUCCESS(status)) {
904 hdp->hd_phys_address = addr.address.minimum;
905 hdp->hd_address = ioremap(addr.address.minimum, addr.address.address_length);
906 if (!hdp->hd_address)
909 if (hpet_is_known(hdp)) {
910 iounmap(hdp->hd_address);
911 return AE_ALREADY_EXISTS;
913 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
914 struct acpi_resource_fixed_memory32 *fixmem32;
916 fixmem32 = &res->data.fixed_memory32;
918 hdp->hd_phys_address = fixmem32->address;
919 hdp->hd_address = ioremap(fixmem32->address,
921 if (!hdp->hd_address)
924 if (hpet_is_known(hdp)) {
925 iounmap(hdp->hd_address);
926 return AE_ALREADY_EXISTS;
928 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
929 struct acpi_resource_extended_irq *irqp;
932 irqp = &res->data.extended_irq;
934 for (i = 0; i < irqp->interrupt_count; i++) {
935 if (hdp->hd_nirqs >= HPET_MAX_TIMERS)
938 irq = acpi_register_gsi(NULL, irqp->interrupts[i],
944 hdp->hd_irq[hdp->hd_nirqs] = irq;
952 static int hpet_acpi_add(struct acpi_device *device)
955 struct hpet_data data;
957 memset(&data, 0, sizeof(data));
960 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
961 hpet_resources, &data);
963 if (ACPI_FAILURE(result))
966 if (!data.hd_address || !data.hd_nirqs) {
968 iounmap(data.hd_address);
969 printk("%s: no address or irqs in _CRS\n", __func__);
973 return hpet_alloc(&data);
976 static const struct acpi_device_id hpet_device_ids[] = {
981 static struct acpi_driver hpet_acpi_driver = {
983 .ids = hpet_device_ids,
985 .add = hpet_acpi_add,
989 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
991 static int __init hpet_init(void)
995 result = misc_register(&hpet_misc);
999 sysctl_header = register_sysctl("dev/hpet", hpet_table);
1001 result = acpi_bus_register_driver(&hpet_acpi_driver);
1004 unregister_sysctl_table(sysctl_header);
1005 misc_deregister(&hpet_misc);
1011 device_initcall(hpet_init);
1014 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1015 MODULE_LICENSE("GPL");