ia64/linux-2.6.18-xen.hg

view drivers/char/hpet.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * Intel & MS High Precision Event Timer Implementation.
3 *
4 * Copyright (C) 2003 Intel Corporation
5 * Venki Pallipadi
6 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
7 * Bob Picco <robert.picco@hp.com>
8 *
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.
12 */
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/miscdevice.h>
19 #include <linux/major.h>
20 #include <linux/ioport.h>
21 #include <linux/fcntl.h>
22 #include <linux/init.h>
23 #include <linux/poll.h>
24 #include <linux/proc_fs.h>
25 #include <linux/spinlock.h>
26 #include <linux/sysctl.h>
27 #include <linux/wait.h>
28 #include <linux/bcd.h>
29 #include <linux/seq_file.h>
30 #include <linux/bitops.h>
32 #include <asm/current.h>
33 #include <asm/uaccess.h>
34 #include <asm/system.h>
35 #include <asm/io.h>
36 #include <asm/irq.h>
37 #include <asm/div64.h>
39 #include <linux/acpi.h>
40 #include <acpi/acpi_bus.h>
41 #include <linux/hpet.h>
43 /*
44 * The High Precision Event Timer driver.
45 * This driver is closely modelled after the rtc.c driver.
46 * http://www.intel.com/hardwaredesign/hpetspec.htm
47 */
48 #define HPET_USER_FREQ (64)
49 #define HPET_DRIFT (500)
51 #define HPET_RANGE_SIZE 1024 /* from HPET spec */
53 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
55 /* A lock for concurrent access by app and isr hpet activity. */
56 static DEFINE_SPINLOCK(hpet_lock);
57 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
58 static DEFINE_SPINLOCK(hpet_task_lock);
60 #define HPET_DEV_NAME (7)
62 struct hpet_dev {
63 struct hpets *hd_hpets;
64 struct hpet __iomem *hd_hpet;
65 struct hpet_timer __iomem *hd_timer;
66 unsigned long hd_ireqfreq;
67 unsigned long hd_irqdata;
68 wait_queue_head_t hd_waitqueue;
69 struct fasync_struct *hd_async_queue;
70 struct hpet_task *hd_task;
71 unsigned int hd_flags;
72 unsigned int hd_irq;
73 unsigned int hd_hdwirq;
74 char hd_name[HPET_DEV_NAME];
75 };
77 struct hpets {
78 struct hpets *hp_next;
79 struct hpet __iomem *hp_hpet;
80 unsigned long hp_hpet_phys;
81 struct time_interpolator *hp_interpolator;
82 unsigned long long hp_tick_freq;
83 unsigned long hp_delta;
84 unsigned int hp_ntimer;
85 unsigned int hp_which;
86 struct hpet_dev hp_dev[1];
87 };
89 static struct hpets *hpets;
91 #define HPET_OPEN 0x0001
92 #define HPET_IE 0x0002 /* interrupt enabled */
93 #define HPET_PERIODIC 0x0004
94 #define HPET_SHARED_IRQ 0x0008
96 #if BITS_PER_LONG == 64
97 #define write_counter(V, MC) writeq(V, MC)
98 #define read_counter(MC) readq(MC)
99 #else
100 #define write_counter(V, MC) writel(V, MC)
101 #define read_counter(MC) readl(MC)
102 #endif
104 #ifndef readq
105 static inline unsigned long long readq(void __iomem *addr)
106 {
107 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
108 }
109 #endif
111 #ifndef writeq
112 static inline void writeq(unsigned long long v, void __iomem *addr)
113 {
114 writel(v & 0xffffffff, addr);
115 writel(v >> 32, addr + 4);
116 }
117 #endif
119 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
120 {
121 struct hpet_dev *devp;
122 unsigned long isr;
124 devp = data;
125 isr = 1 << (devp - devp->hd_hpets->hp_dev);
127 if ((devp->hd_flags & HPET_SHARED_IRQ) &&
128 !(isr & readl(&devp->hd_hpet->hpet_isr)))
129 return IRQ_NONE;
131 spin_lock(&hpet_lock);
132 devp->hd_irqdata++;
134 /*
135 * For non-periodic timers, increment the accumulator.
136 * This has the effect of treating non-periodic like periodic.
137 */
138 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
139 unsigned long m, t;
141 t = devp->hd_ireqfreq;
142 m = read_counter(&devp->hd_hpet->hpet_mc);
143 write_counter(t + m + devp->hd_hpets->hp_delta,
144 &devp->hd_timer->hpet_compare);
145 }
147 if (devp->hd_flags & HPET_SHARED_IRQ)
148 writel(isr, &devp->hd_hpet->hpet_isr);
149 spin_unlock(&hpet_lock);
151 spin_lock(&hpet_task_lock);
152 if (devp->hd_task)
153 devp->hd_task->ht_func(devp->hd_task->ht_data);
154 spin_unlock(&hpet_task_lock);
156 wake_up_interruptible(&devp->hd_waitqueue);
158 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
160 return IRQ_HANDLED;
161 }
163 static int hpet_open(struct inode *inode, struct file *file)
164 {
165 struct hpet_dev *devp;
166 struct hpets *hpetp;
167 int i;
169 if (file->f_mode & FMODE_WRITE)
170 return -EINVAL;
172 spin_lock_irq(&hpet_lock);
174 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
175 for (i = 0; i < hpetp->hp_ntimer; i++)
176 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
177 || hpetp->hp_dev[i].hd_task)
178 continue;
179 else {
180 devp = &hpetp->hp_dev[i];
181 break;
182 }
184 if (!devp) {
185 spin_unlock_irq(&hpet_lock);
186 return -EBUSY;
187 }
189 file->private_data = devp;
190 devp->hd_irqdata = 0;
191 devp->hd_flags |= HPET_OPEN;
192 spin_unlock_irq(&hpet_lock);
194 return 0;
195 }
197 static ssize_t
198 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
199 {
200 DECLARE_WAITQUEUE(wait, current);
201 unsigned long data;
202 ssize_t retval;
203 struct hpet_dev *devp;
205 devp = file->private_data;
206 if (!devp->hd_ireqfreq)
207 return -EIO;
209 if (count < sizeof(unsigned long))
210 return -EINVAL;
212 add_wait_queue(&devp->hd_waitqueue, &wait);
214 for ( ; ; ) {
215 set_current_state(TASK_INTERRUPTIBLE);
217 spin_lock_irq(&hpet_lock);
218 data = devp->hd_irqdata;
219 devp->hd_irqdata = 0;
220 spin_unlock_irq(&hpet_lock);
222 if (data)
223 break;
224 else if (file->f_flags & O_NONBLOCK) {
225 retval = -EAGAIN;
226 goto out;
227 } else if (signal_pending(current)) {
228 retval = -ERESTARTSYS;
229 goto out;
230 }
231 schedule();
232 }
234 retval = put_user(data, (unsigned long __user *)buf);
235 if (!retval)
236 retval = sizeof(unsigned long);
237 out:
238 __set_current_state(TASK_RUNNING);
239 remove_wait_queue(&devp->hd_waitqueue, &wait);
241 return retval;
242 }
244 static unsigned int hpet_poll(struct file *file, poll_table * wait)
245 {
246 unsigned long v;
247 struct hpet_dev *devp;
249 devp = file->private_data;
251 if (!devp->hd_ireqfreq)
252 return 0;
254 poll_wait(file, &devp->hd_waitqueue, wait);
256 spin_lock_irq(&hpet_lock);
257 v = devp->hd_irqdata;
258 spin_unlock_irq(&hpet_lock);
260 if (v != 0)
261 return POLLIN | POLLRDNORM;
263 return 0;
264 }
266 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
267 {
268 #ifdef CONFIG_HPET_MMAP
269 struct hpet_dev *devp;
270 unsigned long addr;
272 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
273 return -EINVAL;
275 devp = file->private_data;
276 addr = devp->hd_hpets->hp_hpet_phys;
278 if (addr & (PAGE_SIZE - 1))
279 return -ENOSYS;
281 vma->vm_flags |= VM_IO;
282 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
284 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
285 PAGE_SIZE, vma->vm_page_prot)) {
286 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
287 __FUNCTION__);
288 return -EAGAIN;
289 }
291 return 0;
292 #else
293 return -ENOSYS;
294 #endif
295 }
297 static int hpet_fasync(int fd, struct file *file, int on)
298 {
299 struct hpet_dev *devp;
301 devp = file->private_data;
303 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
304 return 0;
305 else
306 return -EIO;
307 }
309 static int hpet_release(struct inode *inode, struct file *file)
310 {
311 struct hpet_dev *devp;
312 struct hpet_timer __iomem *timer;
313 int irq = 0;
315 devp = file->private_data;
316 timer = devp->hd_timer;
318 spin_lock_irq(&hpet_lock);
320 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
321 &timer->hpet_config);
323 irq = devp->hd_irq;
324 devp->hd_irq = 0;
326 devp->hd_ireqfreq = 0;
328 if (devp->hd_flags & HPET_PERIODIC
329 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
330 unsigned long v;
332 v = readq(&timer->hpet_config);
333 v ^= Tn_TYPE_CNF_MASK;
334 writeq(v, &timer->hpet_config);
335 }
337 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
338 spin_unlock_irq(&hpet_lock);
340 if (irq)
341 free_irq(irq, devp);
343 if (file->f_flags & FASYNC)
344 hpet_fasync(-1, file, 0);
346 file->private_data = NULL;
347 return 0;
348 }
350 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
352 static int
353 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
354 unsigned long arg)
355 {
356 struct hpet_dev *devp;
358 devp = file->private_data;
359 return hpet_ioctl_common(devp, cmd, arg, 0);
360 }
362 static int hpet_ioctl_ieon(struct hpet_dev *devp)
363 {
364 struct hpet_timer __iomem *timer;
365 struct hpet __iomem *hpet;
366 struct hpets *hpetp;
367 int irq;
368 unsigned long g, v, t, m;
369 unsigned long flags, isr;
371 timer = devp->hd_timer;
372 hpet = devp->hd_hpet;
373 hpetp = devp->hd_hpets;
375 if (!devp->hd_ireqfreq)
376 return -EIO;
378 spin_lock_irq(&hpet_lock);
380 if (devp->hd_flags & HPET_IE) {
381 spin_unlock_irq(&hpet_lock);
382 return -EBUSY;
383 }
385 devp->hd_flags |= HPET_IE;
387 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
388 devp->hd_flags |= HPET_SHARED_IRQ;
389 spin_unlock_irq(&hpet_lock);
391 irq = devp->hd_hdwirq;
393 if (irq) {
394 unsigned long irq_flags;
396 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
397 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
398 ? IRQF_SHARED : IRQF_DISABLED;
399 if (request_irq(irq, hpet_interrupt, irq_flags,
400 devp->hd_name, (void *)devp)) {
401 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
402 irq = 0;
403 }
404 }
406 if (irq == 0) {
407 spin_lock_irq(&hpet_lock);
408 devp->hd_flags ^= HPET_IE;
409 spin_unlock_irq(&hpet_lock);
410 return -EIO;
411 }
413 devp->hd_irq = irq;
414 t = devp->hd_ireqfreq;
415 v = readq(&timer->hpet_config);
416 g = v | Tn_INT_ENB_CNF_MASK;
418 if (devp->hd_flags & HPET_PERIODIC) {
419 write_counter(t, &timer->hpet_compare);
420 g |= Tn_TYPE_CNF_MASK;
421 v |= Tn_TYPE_CNF_MASK;
422 writeq(v, &timer->hpet_config);
423 v |= Tn_VAL_SET_CNF_MASK;
424 writeq(v, &timer->hpet_config);
425 local_irq_save(flags);
426 m = read_counter(&hpet->hpet_mc);
427 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
428 } else {
429 local_irq_save(flags);
430 m = read_counter(&hpet->hpet_mc);
431 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
432 }
434 if (devp->hd_flags & HPET_SHARED_IRQ) {
435 isr = 1 << (devp - devp->hd_hpets->hp_dev);
436 writel(isr, &hpet->hpet_isr);
437 }
438 writeq(g, &timer->hpet_config);
439 local_irq_restore(flags);
441 return 0;
442 }
444 /* converts Hz to number of timer ticks */
445 static inline unsigned long hpet_time_div(struct hpets *hpets,
446 unsigned long dis)
447 {
448 unsigned long long m;
450 m = hpets->hp_tick_freq + (dis >> 1);
451 do_div(m, dis);
452 return (unsigned long)m;
453 }
455 static int
456 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
457 {
458 struct hpet_timer __iomem *timer;
459 struct hpet __iomem *hpet;
460 struct hpets *hpetp;
461 int err;
462 unsigned long v;
464 switch (cmd) {
465 case HPET_IE_OFF:
466 case HPET_INFO:
467 case HPET_EPI:
468 case HPET_DPI:
469 case HPET_IRQFREQ:
470 timer = devp->hd_timer;
471 hpet = devp->hd_hpet;
472 hpetp = devp->hd_hpets;
473 break;
474 case HPET_IE_ON:
475 return hpet_ioctl_ieon(devp);
476 default:
477 return -EINVAL;
478 }
480 err = 0;
482 switch (cmd) {
483 case HPET_IE_OFF:
484 if ((devp->hd_flags & HPET_IE) == 0)
485 break;
486 v = readq(&timer->hpet_config);
487 v &= ~Tn_INT_ENB_CNF_MASK;
488 writeq(v, &timer->hpet_config);
489 if (devp->hd_irq) {
490 free_irq(devp->hd_irq, devp);
491 devp->hd_irq = 0;
492 }
493 devp->hd_flags ^= HPET_IE;
494 break;
495 case HPET_INFO:
496 {
497 struct hpet_info info;
499 if (devp->hd_ireqfreq)
500 info.hi_ireqfreq =
501 hpet_time_div(hpetp, devp->hd_ireqfreq);
502 else
503 info.hi_ireqfreq = 0;
504 info.hi_flags =
505 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
506 info.hi_hpet = hpetp->hp_which;
507 info.hi_timer = devp - hpetp->hp_dev;
508 if (kernel)
509 memcpy((void *)arg, &info, sizeof(info));
510 else
511 if (copy_to_user((void __user *)arg, &info,
512 sizeof(info)))
513 err = -EFAULT;
514 break;
515 }
516 case HPET_EPI:
517 v = readq(&timer->hpet_config);
518 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
519 err = -ENXIO;
520 break;
521 }
522 devp->hd_flags |= HPET_PERIODIC;
523 break;
524 case HPET_DPI:
525 v = readq(&timer->hpet_config);
526 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
527 err = -ENXIO;
528 break;
529 }
530 if (devp->hd_flags & HPET_PERIODIC &&
531 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
532 v = readq(&timer->hpet_config);
533 v ^= Tn_TYPE_CNF_MASK;
534 writeq(v, &timer->hpet_config);
535 }
536 devp->hd_flags &= ~HPET_PERIODIC;
537 break;
538 case HPET_IRQFREQ:
539 if (!kernel && (arg > hpet_max_freq) &&
540 !capable(CAP_SYS_RESOURCE)) {
541 err = -EACCES;
542 break;
543 }
545 if (!arg) {
546 err = -EINVAL;
547 break;
548 }
550 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
551 }
553 return err;
554 }
556 static const struct file_operations hpet_fops = {
557 .owner = THIS_MODULE,
558 .llseek = no_llseek,
559 .read = hpet_read,
560 .poll = hpet_poll,
561 .ioctl = hpet_ioctl,
562 .open = hpet_open,
563 .release = hpet_release,
564 .fasync = hpet_fasync,
565 .mmap = hpet_mmap,
566 };
568 static int hpet_is_known(struct hpet_data *hdp)
569 {
570 struct hpets *hpetp;
572 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
573 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
574 return 1;
576 return 0;
577 }
579 EXPORT_SYMBOL(hpet_alloc);
580 EXPORT_SYMBOL(hpet_register);
581 EXPORT_SYMBOL(hpet_unregister);
582 EXPORT_SYMBOL(hpet_control);
584 int hpet_register(struct hpet_task *tp, int periodic)
585 {
586 unsigned int i;
587 u64 mask;
588 struct hpet_timer __iomem *timer;
589 struct hpet_dev *devp;
590 struct hpets *hpetp;
592 switch (periodic) {
593 case 1:
594 mask = Tn_PER_INT_CAP_MASK;
595 break;
596 case 0:
597 mask = 0;
598 break;
599 default:
600 return -EINVAL;
601 }
603 tp->ht_opaque = NULL;
605 spin_lock_irq(&hpet_task_lock);
606 spin_lock(&hpet_lock);
608 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
609 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
610 i < hpetp->hp_ntimer; i++, timer++) {
611 if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
612 != mask)
613 continue;
615 devp = &hpetp->hp_dev[i];
617 if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
618 devp = NULL;
619 continue;
620 }
622 tp->ht_opaque = devp;
623 devp->hd_task = tp;
624 break;
625 }
627 spin_unlock(&hpet_lock);
628 spin_unlock_irq(&hpet_task_lock);
630 if (tp->ht_opaque)
631 return 0;
632 else
633 return -EBUSY;
634 }
636 static inline int hpet_tpcheck(struct hpet_task *tp)
637 {
638 struct hpet_dev *devp;
639 struct hpets *hpetp;
641 devp = tp->ht_opaque;
643 if (!devp)
644 return -ENXIO;
646 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
647 if (devp >= hpetp->hp_dev
648 && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
649 && devp->hd_hpet == hpetp->hp_hpet)
650 return 0;
652 return -ENXIO;
653 }
655 int hpet_unregister(struct hpet_task *tp)
656 {
657 struct hpet_dev *devp;
658 struct hpet_timer __iomem *timer;
659 int err;
661 if ((err = hpet_tpcheck(tp)))
662 return err;
664 spin_lock_irq(&hpet_task_lock);
665 spin_lock(&hpet_lock);
667 devp = tp->ht_opaque;
668 if (devp->hd_task != tp) {
669 spin_unlock(&hpet_lock);
670 spin_unlock_irq(&hpet_task_lock);
671 return -ENXIO;
672 }
674 timer = devp->hd_timer;
675 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
676 &timer->hpet_config);
677 devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
678 devp->hd_task = NULL;
679 spin_unlock(&hpet_lock);
680 spin_unlock_irq(&hpet_task_lock);
682 return 0;
683 }
685 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
686 {
687 struct hpet_dev *devp;
688 int err;
690 if ((err = hpet_tpcheck(tp)))
691 return err;
693 spin_lock_irq(&hpet_lock);
694 devp = tp->ht_opaque;
695 if (devp->hd_task != tp) {
696 spin_unlock_irq(&hpet_lock);
697 return -ENXIO;
698 }
699 spin_unlock_irq(&hpet_lock);
700 return hpet_ioctl_common(devp, cmd, arg, 1);
701 }
703 static ctl_table hpet_table[] = {
704 {
705 .ctl_name = 1,
706 .procname = "max-user-freq",
707 .data = &hpet_max_freq,
708 .maxlen = sizeof(int),
709 .mode = 0644,
710 .proc_handler = &proc_dointvec,
711 },
712 {.ctl_name = 0}
713 };
715 static ctl_table hpet_root[] = {
716 {
717 .ctl_name = 1,
718 .procname = "hpet",
719 .maxlen = 0,
720 .mode = 0555,
721 .child = hpet_table,
722 },
723 {.ctl_name = 0}
724 };
726 static ctl_table dev_root[] = {
727 {
728 .ctl_name = CTL_DEV,
729 .procname = "dev",
730 .maxlen = 0,
731 .mode = 0555,
732 .child = hpet_root,
733 },
734 {.ctl_name = 0}
735 };
737 static struct ctl_table_header *sysctl_header;
739 static void hpet_register_interpolator(struct hpets *hpetp)
740 {
741 #ifdef CONFIG_TIME_INTERPOLATION
742 struct time_interpolator *ti;
744 ti = kzalloc(sizeof(*ti), GFP_KERNEL);
745 if (!ti)
746 return;
748 ti->source = TIME_SOURCE_MMIO64;
749 ti->shift = 10;
750 ti->addr = &hpetp->hp_hpet->hpet_mc;
751 ti->frequency = hpetp->hp_tick_freq;
752 ti->drift = HPET_DRIFT;
753 ti->mask = -1;
755 hpetp->hp_interpolator = ti;
756 register_time_interpolator(ti);
757 #endif
758 }
760 /*
761 * Adjustment for when arming the timer with
762 * initial conditions. That is, main counter
763 * ticks expired before interrupts are enabled.
764 */
765 #define TICK_CALIBRATE (1000UL)
767 static unsigned long hpet_calibrate(struct hpets *hpetp)
768 {
769 struct hpet_timer __iomem *timer = NULL;
770 unsigned long t, m, count, i, flags, start;
771 struct hpet_dev *devp;
772 int j;
773 struct hpet __iomem *hpet;
775 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
776 if ((devp->hd_flags & HPET_OPEN) == 0) {
777 timer = devp->hd_timer;
778 break;
779 }
781 if (!timer)
782 return 0;
784 hpet = hpetp->hp_hpet;
785 t = read_counter(&timer->hpet_compare);
787 i = 0;
788 count = hpet_time_div(hpetp, TICK_CALIBRATE);
790 local_irq_save(flags);
792 start = read_counter(&hpet->hpet_mc);
794 do {
795 m = read_counter(&hpet->hpet_mc);
796 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
797 } while (i++, (m - start) < count);
799 local_irq_restore(flags);
801 return (m - start) / i;
802 }
804 int hpet_alloc(struct hpet_data *hdp)
805 {
806 u64 cap, mcfg;
807 struct hpet_dev *devp;
808 u32 i, ntimer;
809 struct hpets *hpetp;
810 size_t siz;
811 struct hpet __iomem *hpet;
812 static struct hpets *last = NULL;
813 unsigned long period;
814 unsigned long long temp;
816 /*
817 * hpet_alloc can be called by platform dependent code.
818 * If platform dependent code has allocated the hpet that
819 * ACPI has also reported, then we catch it here.
820 */
821 if (hpet_is_known(hdp)) {
822 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
823 __FUNCTION__);
824 return 0;
825 }
827 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
828 sizeof(struct hpet_dev));
830 hpetp = kzalloc(siz, GFP_KERNEL);
832 if (!hpetp)
833 return -ENOMEM;
835 hpetp->hp_which = hpet_nhpet++;
836 hpetp->hp_hpet = hdp->hd_address;
837 hpetp->hp_hpet_phys = hdp->hd_phys_address;
839 hpetp->hp_ntimer = hdp->hd_nirqs;
841 for (i = 0; i < hdp->hd_nirqs; i++)
842 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
844 hpet = hpetp->hp_hpet;
846 cap = readq(&hpet->hpet_cap);
848 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
850 if (hpetp->hp_ntimer != ntimer) {
851 printk(KERN_WARNING "hpet: number irqs doesn't agree"
852 " with number of timers\n");
853 kfree(hpetp);
854 return -ENODEV;
855 }
857 if (last)
858 last->hp_next = hpetp;
859 else
860 hpets = hpetp;
862 last = hpetp;
864 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
865 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
866 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
867 temp += period >> 1; /* round */
868 do_div(temp, period);
869 hpetp->hp_tick_freq = temp; /* ticks per second */
871 printk(KERN_INFO "hpet%d: at MMIO 0x%lx (virtual 0x%p), IRQ%s",
872 hpetp->hp_which, hdp->hd_phys_address, hdp->hd_address,
873 hpetp->hp_ntimer > 1 ? "s" : "");
874 for (i = 0; i < hpetp->hp_ntimer; i++)
875 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
876 printk("\n");
878 printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
879 hpetp->hp_which, hpetp->hp_ntimer,
880 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
882 mcfg = readq(&hpet->hpet_config);
883 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
884 write_counter(0L, &hpet->hpet_mc);
885 mcfg |= HPET_ENABLE_CNF_MASK;
886 writeq(mcfg, &hpet->hpet_config);
887 }
889 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
890 struct hpet_timer __iomem *timer;
892 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
894 devp->hd_hpets = hpetp;
895 devp->hd_hpet = hpet;
896 devp->hd_timer = timer;
898 /*
899 * If the timer was reserved by platform code,
900 * then make timer unavailable for opens.
901 */
902 if (hdp->hd_state & (1 << i)) {
903 devp->hd_flags = HPET_OPEN;
904 continue;
905 }
907 init_waitqueue_head(&devp->hd_waitqueue);
908 }
910 hpetp->hp_delta = hpet_calibrate(hpetp);
911 hpet_register_interpolator(hpetp);
913 return 0;
914 }
916 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
917 {
918 struct hpet_data *hdp;
919 acpi_status status;
920 struct acpi_resource_address64 addr;
922 hdp = data;
924 status = acpi_resource_to_address64(res, &addr);
926 if (ACPI_SUCCESS(status)) {
927 hdp->hd_phys_address = addr.minimum;
928 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
930 if (hpet_is_known(hdp)) {
931 printk(KERN_DEBUG "%s: 0x%lx is busy\n",
932 __FUNCTION__, hdp->hd_phys_address);
933 iounmap(hdp->hd_address);
934 return -EBUSY;
935 }
936 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
937 struct acpi_resource_fixed_memory32 *fixmem32;
939 fixmem32 = &res->data.fixed_memory32;
940 if (!fixmem32)
941 return -EINVAL;
943 hdp->hd_phys_address = fixmem32->address;
944 hdp->hd_address = ioremap(fixmem32->address,
945 HPET_RANGE_SIZE);
947 if (hpet_is_known(hdp)) {
948 printk(KERN_DEBUG "%s: 0x%lx is busy\n",
949 __FUNCTION__, hdp->hd_phys_address);
950 iounmap(hdp->hd_address);
951 return -EBUSY;
952 }
953 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
954 struct acpi_resource_extended_irq *irqp;
955 int i, irq;
957 irqp = &res->data.extended_irq;
959 for (i = 0; i < irqp->interrupt_count; i++) {
960 irq = acpi_register_gsi(irqp->interrupts[i],
961 irqp->triggering, irqp->polarity);
962 if (irq < 0)
963 return AE_ERROR;
965 hdp->hd_irq[hdp->hd_nirqs] = irq;
966 hdp->hd_nirqs++;
967 }
968 }
970 return AE_OK;
971 }
973 static int hpet_acpi_add(struct acpi_device *device)
974 {
975 acpi_status result;
976 struct hpet_data data;
978 memset(&data, 0, sizeof(data));
980 result =
981 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
982 hpet_resources, &data);
984 if (ACPI_FAILURE(result))
985 return -ENODEV;
987 if (!data.hd_address || !data.hd_nirqs) {
988 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
989 return -ENODEV;
990 }
992 return hpet_alloc(&data);
993 }
995 static int hpet_acpi_remove(struct acpi_device *device, int type)
996 {
997 /* XXX need to unregister interpolator, dealloc mem, etc */
998 return -EINVAL;
999 }
1001 static struct acpi_driver hpet_acpi_driver = {
1002 .name = "hpet",
1003 .ids = "PNP0103",
1004 .ops = {
1005 .add = hpet_acpi_add,
1006 .remove = hpet_acpi_remove,
1007 },
1008 };
1010 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1012 static int __init hpet_init(void)
1014 int result;
1016 result = misc_register(&hpet_misc);
1017 if (result < 0)
1018 return -ENODEV;
1020 sysctl_header = register_sysctl_table(dev_root, 0);
1022 result = acpi_bus_register_driver(&hpet_acpi_driver);
1023 if (result < 0) {
1024 if (sysctl_header)
1025 unregister_sysctl_table(sysctl_header);
1026 misc_deregister(&hpet_misc);
1027 return result;
1030 return 0;
1033 static void __exit hpet_exit(void)
1035 acpi_bus_unregister_driver(&hpet_acpi_driver);
1037 if (sysctl_header)
1038 unregister_sysctl_table(sysctl_header);
1039 misc_deregister(&hpet_misc);
1041 return;
1044 module_init(hpet_init);
1045 module_exit(hpet_exit);
1046 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1047 MODULE_LICENSE("GPL");