2 * Intel & MS High Precision Event Timer Implementation.
4 * Copyright (C) 2003 Intel Corporation
6 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
7 * Bob Picco <robert.picco@hp.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/smp_lock.h>
18 #include <linux/types.h>
19 #include <linux/miscdevice.h>
20 #include <linux/major.h>
21 #include <linux/ioport.h>
22 #include <linux/fcntl.h>
23 #include <linux/init.h>
24 #include <linux/poll.h>
26 #include <linux/proc_fs.h>
27 #include <linux/spinlock.h>
28 #include <linux/sysctl.h>
29 #include <linux/wait.h>
30 #include <linux/bcd.h>
31 #include <linux/seq_file.h>
32 #include <linux/bitops.h>
33 #include <linux/compat.h>
34 #include <linux/clocksource.h>
35 #include <linux/slab.h>
37 #include <asm/current.h>
38 #include <asm/uaccess.h>
39 #include <asm/system.h>
42 #include <asm/div64.h>
44 #include <linux/acpi.h>
45 #include <acpi/acpi_bus.h>
46 #include <linux/hpet.h>
49 * The High Precision Event Timer driver.
50 * This driver is closely modelled after the rtc.c driver.
51 * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
53 #define HPET_USER_FREQ (64)
54 #define HPET_DRIFT (500)
56 #define HPET_RANGE_SIZE 1024 /* from HPET spec */
59 /* WARNING -- don't get confused. These macros are never used
60 * to write the (single) counter, and rarely to read it.
61 * They're badly named; to fix, someday.
63 #if BITS_PER_LONG == 64
64 #define write_counter(V, MC) writeq(V, MC)
65 #define read_counter(MC) readq(MC)
67 #define write_counter(V, MC) writel(V, MC)
68 #define read_counter(MC) readl(MC)
71 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
72 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
74 /* This clocksource driver currently only works on ia64 */
76 static void __iomem *hpet_mctr;
78 static cycle_t read_hpet(struct clocksource *cs)
80 return (cycle_t)read_counter((void __iomem *)hpet_mctr);
83 static struct clocksource clocksource_hpet = {
87 .mask = CLOCKSOURCE_MASK(64),
88 .mult = 0, /* to be calculated */
90 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
92 static struct clocksource *hpet_clocksource;
95 /* A lock for concurrent access by app and isr hpet activity. */
96 static DEFINE_SPINLOCK(hpet_lock);
98 #define HPET_DEV_NAME (7)
101 struct hpets *hd_hpets;
102 struct hpet __iomem *hd_hpet;
103 struct hpet_timer __iomem *hd_timer;
104 unsigned long hd_ireqfreq;
105 unsigned long hd_irqdata;
106 wait_queue_head_t hd_waitqueue;
107 struct fasync_struct *hd_async_queue;
108 unsigned int hd_flags;
110 unsigned int hd_hdwirq;
111 char hd_name[HPET_DEV_NAME];
115 struct hpets *hp_next;
116 struct hpet __iomem *hp_hpet;
117 unsigned long hp_hpet_phys;
118 struct clocksource *hp_clocksource;
119 unsigned long long hp_tick_freq;
120 unsigned long hp_delta;
121 unsigned int hp_ntimer;
122 unsigned int hp_which;
123 struct hpet_dev hp_dev[1];
126 static struct hpets *hpets;
128 #define HPET_OPEN 0x0001
129 #define HPET_IE 0x0002 /* interrupt enabled */
130 #define HPET_PERIODIC 0x0004
131 #define HPET_SHARED_IRQ 0x0008
135 static inline unsigned long long readq(void __iomem *addr)
137 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
142 static inline void writeq(unsigned long long v, void __iomem *addr)
144 writel(v & 0xffffffff, addr);
145 writel(v >> 32, addr + 4);
149 static irqreturn_t hpet_interrupt(int irq, void *data)
151 struct hpet_dev *devp;
155 isr = 1 << (devp - devp->hd_hpets->hp_dev);
157 if ((devp->hd_flags & HPET_SHARED_IRQ) &&
158 !(isr & readl(&devp->hd_hpet->hpet_isr)))
161 spin_lock(&hpet_lock);
165 * For non-periodic timers, increment the accumulator.
166 * This has the effect of treating non-periodic like periodic.
168 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
171 t = devp->hd_ireqfreq;
172 m = read_counter(&devp->hd_timer->hpet_compare);
173 write_counter(t + m, &devp->hd_timer->hpet_compare);
176 if (devp->hd_flags & HPET_SHARED_IRQ)
177 writel(isr, &devp->hd_hpet->hpet_isr);
178 spin_unlock(&hpet_lock);
180 wake_up_interruptible(&devp->hd_waitqueue);
182 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
187 static void hpet_timer_set_irq(struct hpet_dev *devp)
191 struct hpet_timer __iomem *timer;
193 spin_lock_irq(&hpet_lock);
194 if (devp->hd_hdwirq) {
195 spin_unlock_irq(&hpet_lock);
199 timer = devp->hd_timer;
201 /* we prefer level triggered mode */
202 v = readl(&timer->hpet_config);
203 if (!(v & Tn_INT_TYPE_CNF_MASK)) {
204 v |= Tn_INT_TYPE_CNF_MASK;
205 writel(v, &timer->hpet_config);
207 spin_unlock_irq(&hpet_lock);
209 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
210 Tn_INT_ROUTE_CAP_SHIFT;
213 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
214 * legacy device. In IO APIC mode, we skip all the legacy IRQS.
216 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
221 for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
222 if (irq >= nr_irqs) {
227 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
232 /* FIXME: Setup interrupt source table */
235 if (irq < HPET_MAX_IRQ) {
236 spin_lock_irq(&hpet_lock);
237 v = readl(&timer->hpet_config);
238 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
239 writel(v, &timer->hpet_config);
240 devp->hd_hdwirq = gsi;
241 spin_unlock_irq(&hpet_lock);
246 static int hpet_open(struct inode *inode, struct file *file)
248 struct hpet_dev *devp;
252 if (file->f_mode & FMODE_WRITE)
255 mutex_lock(&hpet_mutex);
256 spin_lock_irq(&hpet_lock);
258 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
259 for (i = 0; i < hpetp->hp_ntimer; i++)
260 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
263 devp = &hpetp->hp_dev[i];
268 spin_unlock_irq(&hpet_lock);
269 mutex_unlock(&hpet_mutex);
273 file->private_data = devp;
274 devp->hd_irqdata = 0;
275 devp->hd_flags |= HPET_OPEN;
276 spin_unlock_irq(&hpet_lock);
277 mutex_unlock(&hpet_mutex);
279 hpet_timer_set_irq(devp);
285 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
287 DECLARE_WAITQUEUE(wait, current);
290 struct hpet_dev *devp;
292 devp = file->private_data;
293 if (!devp->hd_ireqfreq)
296 if (count < sizeof(unsigned long))
299 add_wait_queue(&devp->hd_waitqueue, &wait);
302 set_current_state(TASK_INTERRUPTIBLE);
304 spin_lock_irq(&hpet_lock);
305 data = devp->hd_irqdata;
306 devp->hd_irqdata = 0;
307 spin_unlock_irq(&hpet_lock);
311 else if (file->f_flags & O_NONBLOCK) {
314 } else if (signal_pending(current)) {
315 retval = -ERESTARTSYS;
321 retval = put_user(data, (unsigned long __user *)buf);
323 retval = sizeof(unsigned long);
325 __set_current_state(TASK_RUNNING);
326 remove_wait_queue(&devp->hd_waitqueue, &wait);
331 static unsigned int hpet_poll(struct file *file, poll_table * wait)
334 struct hpet_dev *devp;
336 devp = file->private_data;
338 if (!devp->hd_ireqfreq)
341 poll_wait(file, &devp->hd_waitqueue, wait);
343 spin_lock_irq(&hpet_lock);
344 v = devp->hd_irqdata;
345 spin_unlock_irq(&hpet_lock);
348 return POLLIN | POLLRDNORM;
353 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
355 #ifdef CONFIG_HPET_MMAP
356 struct hpet_dev *devp;
359 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
362 devp = file->private_data;
363 addr = devp->hd_hpets->hp_hpet_phys;
365 if (addr & (PAGE_SIZE - 1))
368 vma->vm_flags |= VM_IO;
369 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
371 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
372 PAGE_SIZE, vma->vm_page_prot)) {
373 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
384 static int hpet_fasync(int fd, struct file *file, int on)
386 struct hpet_dev *devp;
388 devp = file->private_data;
390 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
396 static int hpet_release(struct inode *inode, struct file *file)
398 struct hpet_dev *devp;
399 struct hpet_timer __iomem *timer;
402 devp = file->private_data;
403 timer = devp->hd_timer;
405 spin_lock_irq(&hpet_lock);
407 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
408 &timer->hpet_config);
413 devp->hd_ireqfreq = 0;
415 if (devp->hd_flags & HPET_PERIODIC
416 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
419 v = readq(&timer->hpet_config);
420 v ^= Tn_TYPE_CNF_MASK;
421 writeq(v, &timer->hpet_config);
424 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
425 spin_unlock_irq(&hpet_lock);
430 file->private_data = NULL;
434 static int hpet_ioctl_ieon(struct hpet_dev *devp)
436 struct hpet_timer __iomem *timer;
437 struct hpet __iomem *hpet;
440 unsigned long g, v, t, m;
441 unsigned long flags, isr;
443 timer = devp->hd_timer;
444 hpet = devp->hd_hpet;
445 hpetp = devp->hd_hpets;
447 if (!devp->hd_ireqfreq)
450 spin_lock_irq(&hpet_lock);
452 if (devp->hd_flags & HPET_IE) {
453 spin_unlock_irq(&hpet_lock);
457 devp->hd_flags |= HPET_IE;
459 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
460 devp->hd_flags |= HPET_SHARED_IRQ;
461 spin_unlock_irq(&hpet_lock);
463 irq = devp->hd_hdwirq;
466 unsigned long irq_flags;
468 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
469 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
470 ? IRQF_SHARED : IRQF_DISABLED;
471 if (request_irq(irq, hpet_interrupt, irq_flags,
472 devp->hd_name, (void *)devp)) {
473 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
479 spin_lock_irq(&hpet_lock);
480 devp->hd_flags ^= HPET_IE;
481 spin_unlock_irq(&hpet_lock);
486 t = devp->hd_ireqfreq;
487 v = readq(&timer->hpet_config);
489 /* 64-bit comparators are not yet supported through the ioctls,
490 * so force this into 32-bit mode if it supports both modes
492 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
494 if (devp->hd_flags & HPET_PERIODIC) {
495 g |= Tn_TYPE_CNF_MASK;
496 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
497 writeq(v, &timer->hpet_config);
498 local_irq_save(flags);
501 * NOTE: First we modify the hidden accumulator
502 * register supported by periodic-capable comparators.
503 * We never want to modify the (single) counter; that
504 * would affect all the comparators. The value written
505 * is the counter value when the first interrupt is due.
507 m = read_counter(&hpet->hpet_mc);
508 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
510 * Then we modify the comparator, indicating the period
511 * for subsequent interrupt.
513 write_counter(t, &timer->hpet_compare);
515 local_irq_save(flags);
516 m = read_counter(&hpet->hpet_mc);
517 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
520 if (devp->hd_flags & HPET_SHARED_IRQ) {
521 isr = 1 << (devp - devp->hd_hpets->hp_dev);
522 writel(isr, &hpet->hpet_isr);
524 writeq(g, &timer->hpet_config);
525 local_irq_restore(flags);
530 /* converts Hz to number of timer ticks */
531 static inline unsigned long hpet_time_div(struct hpets *hpets,
534 unsigned long long m;
536 m = hpets->hp_tick_freq + (dis >> 1);
538 return (unsigned long)m;
542 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
543 struct hpet_info *info)
545 struct hpet_timer __iomem *timer;
546 struct hpet __iomem *hpet;
557 timer = devp->hd_timer;
558 hpet = devp->hd_hpet;
559 hpetp = devp->hd_hpets;
562 return hpet_ioctl_ieon(devp);
571 if ((devp->hd_flags & HPET_IE) == 0)
573 v = readq(&timer->hpet_config);
574 v &= ~Tn_INT_ENB_CNF_MASK;
575 writeq(v, &timer->hpet_config);
577 free_irq(devp->hd_irq, devp);
580 devp->hd_flags ^= HPET_IE;
584 if (devp->hd_ireqfreq)
586 hpet_time_div(hpetp, devp->hd_ireqfreq);
588 info->hi_ireqfreq = 0;
590 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
591 info->hi_hpet = hpetp->hp_which;
592 info->hi_timer = devp - hpetp->hp_dev;
596 v = readq(&timer->hpet_config);
597 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
601 devp->hd_flags |= HPET_PERIODIC;
604 v = readq(&timer->hpet_config);
605 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
609 if (devp->hd_flags & HPET_PERIODIC &&
610 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
611 v = readq(&timer->hpet_config);
612 v ^= Tn_TYPE_CNF_MASK;
613 writeq(v, &timer->hpet_config);
615 devp->hd_flags &= ~HPET_PERIODIC;
618 if ((arg > hpet_max_freq) &&
619 !capable(CAP_SYS_RESOURCE)) {
629 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
636 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
638 struct hpet_info info;
641 mutex_lock(&hpet_mutex);
642 err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
643 mutex_unlock(&hpet_mutex);
645 if ((cmd == HPET_INFO) && !err &&
646 (copy_to_user((void __user *)arg, &info, sizeof(info))))
653 struct compat_hpet_info {
654 compat_ulong_t hi_ireqfreq; /* Hz */
655 compat_ulong_t hi_flags; /* information */
656 unsigned short hi_hpet;
657 unsigned short hi_timer;
661 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
663 struct hpet_info info;
666 mutex_lock(&hpet_mutex);
667 err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
668 mutex_unlock(&hpet_mutex);
670 if ((cmd == HPET_INFO) && !err) {
671 struct compat_hpet_info __user *u = compat_ptr(arg);
672 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
673 put_user(info.hi_flags, &u->hi_flags) ||
674 put_user(info.hi_hpet, &u->hi_hpet) ||
675 put_user(info.hi_timer, &u->hi_timer))
683 static const struct file_operations hpet_fops = {
684 .owner = THIS_MODULE,
688 .unlocked_ioctl = hpet_ioctl,
690 .compat_ioctl = hpet_compat_ioctl,
693 .release = hpet_release,
694 .fasync = hpet_fasync,
698 static int hpet_is_known(struct hpet_data *hdp)
702 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
703 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
709 static ctl_table hpet_table[] = {
711 .procname = "max-user-freq",
712 .data = &hpet_max_freq,
713 .maxlen = sizeof(int),
715 .proc_handler = proc_dointvec,
720 static ctl_table hpet_root[] = {
730 static ctl_table dev_root[] = {
740 static struct ctl_table_header *sysctl_header;
743 * Adjustment for when arming the timer with
744 * initial conditions. That is, main counter
745 * ticks expired before interrupts are enabled.
747 #define TICK_CALIBRATE (1000UL)
749 static unsigned long __hpet_calibrate(struct hpets *hpetp)
751 struct hpet_timer __iomem *timer = NULL;
752 unsigned long t, m, count, i, flags, start;
753 struct hpet_dev *devp;
755 struct hpet __iomem *hpet;
757 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
758 if ((devp->hd_flags & HPET_OPEN) == 0) {
759 timer = devp->hd_timer;
766 hpet = hpetp->hp_hpet;
767 t = read_counter(&timer->hpet_compare);
770 count = hpet_time_div(hpetp, TICK_CALIBRATE);
772 local_irq_save(flags);
774 start = read_counter(&hpet->hpet_mc);
777 m = read_counter(&hpet->hpet_mc);
778 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
779 } while (i++, (m - start) < count);
781 local_irq_restore(flags);
783 return (m - start) / i;
786 static unsigned long hpet_calibrate(struct hpets *hpetp)
788 unsigned long ret = -1;
792 * Try to calibrate until return value becomes stable small value.
793 * If SMI interruption occurs in calibration loop, the return value
794 * will be big. This avoids its impact.
797 tmp = __hpet_calibrate(hpetp);
806 int hpet_alloc(struct hpet_data *hdp)
809 struct hpet_dev *devp;
813 struct hpet __iomem *hpet;
814 static struct hpets *last = NULL;
815 unsigned long period;
816 unsigned long long temp;
820 * hpet_alloc can be called by platform dependent code.
821 * If platform dependent code has allocated the hpet that
822 * ACPI has also reported, then we catch it here.
824 if (hpet_is_known(hdp)) {
825 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
830 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
831 sizeof(struct hpet_dev));
833 hpetp = kzalloc(siz, GFP_KERNEL);
838 hpetp->hp_which = hpet_nhpet++;
839 hpetp->hp_hpet = hdp->hd_address;
840 hpetp->hp_hpet_phys = hdp->hd_phys_address;
842 hpetp->hp_ntimer = hdp->hd_nirqs;
844 for (i = 0; i < hdp->hd_nirqs; i++)
845 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
847 hpet = hpetp->hp_hpet;
849 cap = readq(&hpet->hpet_cap);
851 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
853 if (hpetp->hp_ntimer != ntimer) {
854 printk(KERN_WARNING "hpet: number irqs doesn't agree"
855 " with number of timers\n");
861 last->hp_next = hpetp;
867 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
868 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
869 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
870 temp += period >> 1; /* round */
871 do_div(temp, period);
872 hpetp->hp_tick_freq = temp; /* ticks per second */
874 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
875 hpetp->hp_which, hdp->hd_phys_address,
876 hpetp->hp_ntimer > 1 ? "s" : "");
877 for (i = 0; i < hpetp->hp_ntimer; i++)
878 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
881 temp = hpetp->hp_tick_freq;
882 remainder = do_div(temp, 1000000);
884 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
885 hpetp->hp_which, hpetp->hp_ntimer,
886 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
887 (unsigned) temp, remainder);
889 mcfg = readq(&hpet->hpet_config);
890 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
891 write_counter(0L, &hpet->hpet_mc);
892 mcfg |= HPET_ENABLE_CNF_MASK;
893 writeq(mcfg, &hpet->hpet_config);
896 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
897 struct hpet_timer __iomem *timer;
899 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
901 devp->hd_hpets = hpetp;
902 devp->hd_hpet = hpet;
903 devp->hd_timer = timer;
906 * If the timer was reserved by platform code,
907 * then make timer unavailable for opens.
909 if (hdp->hd_state & (1 << i)) {
910 devp->hd_flags = HPET_OPEN;
914 init_waitqueue_head(&devp->hd_waitqueue);
917 hpetp->hp_delta = hpet_calibrate(hpetp);
919 /* This clocksource driver currently only works on ia64 */
921 if (!hpet_clocksource) {
922 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
923 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
924 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
925 clocksource_hpet.shift);
926 clocksource_register(&clocksource_hpet);
927 hpetp->hp_clocksource = &clocksource_hpet;
928 hpet_clocksource = &clocksource_hpet;
935 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
937 struct hpet_data *hdp;
939 struct acpi_resource_address64 addr;
943 status = acpi_resource_to_address64(res, &addr);
945 if (ACPI_SUCCESS(status)) {
946 hdp->hd_phys_address = addr.minimum;
947 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
949 if (hpet_is_known(hdp)) {
950 iounmap(hdp->hd_address);
951 return AE_ALREADY_EXISTS;
953 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
954 struct acpi_resource_fixed_memory32 *fixmem32;
956 fixmem32 = &res->data.fixed_memory32;
960 hdp->hd_phys_address = fixmem32->address;
961 hdp->hd_address = ioremap(fixmem32->address,
964 if (hpet_is_known(hdp)) {
965 iounmap(hdp->hd_address);
966 return AE_ALREADY_EXISTS;
968 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
969 struct acpi_resource_extended_irq *irqp;
972 irqp = &res->data.extended_irq;
974 for (i = 0; i < irqp->interrupt_count; i++) {
975 irq = acpi_register_gsi(NULL, irqp->interrupts[i],
976 irqp->triggering, irqp->polarity);
980 hdp->hd_irq[hdp->hd_nirqs] = irq;
988 static int hpet_acpi_add(struct acpi_device *device)
991 struct hpet_data data;
993 memset(&data, 0, sizeof(data));
996 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
997 hpet_resources, &data);
999 if (ACPI_FAILURE(result))
1002 if (!data.hd_address || !data.hd_nirqs) {
1003 printk("%s: no address or irqs in _CRS\n", __func__);
1007 return hpet_alloc(&data);
1010 static int hpet_acpi_remove(struct acpi_device *device, int type)
1012 /* XXX need to unregister clocksource, dealloc mem, etc */
1016 static const struct acpi_device_id hpet_device_ids[] = {
1020 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1022 static struct acpi_driver hpet_acpi_driver = {
1024 .ids = hpet_device_ids,
1026 .add = hpet_acpi_add,
1027 .remove = hpet_acpi_remove,
1031 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1033 static int __init hpet_init(void)
1037 result = misc_register(&hpet_misc);
1041 sysctl_header = register_sysctl_table(dev_root);
1043 result = acpi_bus_register_driver(&hpet_acpi_driver);
1046 unregister_sysctl_table(sysctl_header);
1047 misc_deregister(&hpet_misc);
1054 static void __exit hpet_exit(void)
1056 acpi_bus_unregister_driver(&hpet_acpi_driver);
1059 unregister_sysctl_table(sysctl_header);
1060 misc_deregister(&hpet_misc);
1065 module_init(hpet_init);
1066 module_exit(hpet_exit);
1067 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1068 MODULE_LICENSE("GPL");