IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
[linux-2.6.git] / drivers / char / hpet.c
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  */
13
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>
31
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>
38
39 #include <linux/acpi.h>
40 #include <acpi/acpi_bus.h>
41 #include <linux/hpet.h>
42
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)
50
51 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
52
53 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
54
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);
59
60 #define HPET_DEV_NAME   (7)
61
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 };
76
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 };
88
89 static struct hpets *hpets;
90
91 #define HPET_OPEN               0x0001
92 #define HPET_IE                 0x0002  /* interrupt enabled */
93 #define HPET_PERIODIC           0x0004
94 #define HPET_SHARED_IRQ         0x0008
95
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
103
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
110
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
118
119 static irqreturn_t hpet_interrupt(int irq, void *data)
120 {
121         struct hpet_dev *devp;
122         unsigned long isr;
123
124         devp = data;
125         isr = 1 << (devp - devp->hd_hpets->hp_dev);
126
127         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
128             !(isr & readl(&devp->hd_hpet->hpet_isr)))
129                 return IRQ_NONE;
130
131         spin_lock(&hpet_lock);
132         devp->hd_irqdata++;
133
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;
140
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         }
146
147         if (devp->hd_flags & HPET_SHARED_IRQ)
148                 writel(isr, &devp->hd_hpet->hpet_isr);
149         spin_unlock(&hpet_lock);
150
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);
155
156         wake_up_interruptible(&devp->hd_waitqueue);
157
158         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
159
160         return IRQ_HANDLED;
161 }
162
163 static int hpet_open(struct inode *inode, struct file *file)
164 {
165         struct hpet_dev *devp;
166         struct hpets *hpetp;
167         int i;
168
169         if (file->f_mode & FMODE_WRITE)
170                 return -EINVAL;
171
172         spin_lock_irq(&hpet_lock);
173
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                         }
183
184         if (!devp) {
185                 spin_unlock_irq(&hpet_lock);
186                 return -EBUSY;
187         }
188
189         file->private_data = devp;
190         devp->hd_irqdata = 0;
191         devp->hd_flags |= HPET_OPEN;
192         spin_unlock_irq(&hpet_lock);
193
194         return 0;
195 }
196
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;
204
205         devp = file->private_data;
206         if (!devp->hd_ireqfreq)
207                 return -EIO;
208
209         if (count < sizeof(unsigned long))
210                 return -EINVAL;
211
212         add_wait_queue(&devp->hd_waitqueue, &wait);
213
214         for ( ; ; ) {
215                 set_current_state(TASK_INTERRUPTIBLE);
216
217                 spin_lock_irq(&hpet_lock);
218                 data = devp->hd_irqdata;
219                 devp->hd_irqdata = 0;
220                 spin_unlock_irq(&hpet_lock);
221
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         }
233
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);
240
241         return retval;
242 }
243
244 static unsigned int hpet_poll(struct file *file, poll_table * wait)
245 {
246         unsigned long v;
247         struct hpet_dev *devp;
248
249         devp = file->private_data;
250
251         if (!devp->hd_ireqfreq)
252                 return 0;
253
254         poll_wait(file, &devp->hd_waitqueue, wait);
255
256         spin_lock_irq(&hpet_lock);
257         v = devp->hd_irqdata;
258         spin_unlock_irq(&hpet_lock);
259
260         if (v != 0)
261                 return POLLIN | POLLRDNORM;
262
263         return 0;
264 }
265
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;
271
272         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
273                 return -EINVAL;
274
275         devp = file->private_data;
276         addr = devp->hd_hpets->hp_hpet_phys;
277
278         if (addr & (PAGE_SIZE - 1))
279                 return -ENOSYS;
280
281         vma->vm_flags |= VM_IO;
282         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
283
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         }
290
291         return 0;
292 #else
293         return -ENOSYS;
294 #endif
295 }
296
297 static int hpet_fasync(int fd, struct file *file, int on)
298 {
299         struct hpet_dev *devp;
300
301         devp = file->private_data;
302
303         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
304                 return 0;
305         else
306                 return -EIO;
307 }
308
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;
314
315         devp = file->private_data;
316         timer = devp->hd_timer;
317
318         spin_lock_irq(&hpet_lock);
319
320         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
321                &timer->hpet_config);
322
323         irq = devp->hd_irq;
324         devp->hd_irq = 0;
325
326         devp->hd_ireqfreq = 0;
327
328         if (devp->hd_flags & HPET_PERIODIC
329             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
330                 unsigned long v;
331
332                 v = readq(&timer->hpet_config);
333                 v ^= Tn_TYPE_CNF_MASK;
334                 writeq(v, &timer->hpet_config);
335         }
336
337         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
338         spin_unlock_irq(&hpet_lock);
339
340         if (irq)
341                 free_irq(irq, devp);
342
343         if (file->f_flags & FASYNC)
344                 hpet_fasync(-1, file, 0);
345
346         file->private_data = NULL;
347         return 0;
348 }
349
350 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
351
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;
357
358         devp = file->private_data;
359         return hpet_ioctl_common(devp, cmd, arg, 0);
360 }
361
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;
370
371         timer = devp->hd_timer;
372         hpet = devp->hd_hpet;
373         hpetp = devp->hd_hpets;
374
375         if (!devp->hd_ireqfreq)
376                 return -EIO;
377
378         spin_lock_irq(&hpet_lock);
379
380         if (devp->hd_flags & HPET_IE) {
381                 spin_unlock_irq(&hpet_lock);
382                 return -EBUSY;
383         }
384
385         devp->hd_flags |= HPET_IE;
386
387         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
388                 devp->hd_flags |= HPET_SHARED_IRQ;
389         spin_unlock_irq(&hpet_lock);
390
391         irq = devp->hd_hdwirq;
392
393         if (irq) {
394                 unsigned long irq_flags;
395
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         }
405
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         }
412
413         devp->hd_irq = irq;
414         t = devp->hd_ireqfreq;
415         v = readq(&timer->hpet_config);
416         g = v | Tn_INT_ENB_CNF_MASK;
417
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         }
433
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);
440
441         return 0;
442 }
443
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;
449
450         m = hpets->hp_tick_freq + (dis >> 1);
451         do_div(m, dis);
452         return (unsigned long)m;
453 }
454
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;
463
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         }
479
480         err = 0;
481
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;
498
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                 }
544
545                 if (!arg) {
546                         err = -EINVAL;
547                         break;
548                 }
549
550                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
551         }
552
553         return err;
554 }
555
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 };
567
568 static int hpet_is_known(struct hpet_data *hdp)
569 {
570         struct hpets *hpetp;
571
572         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
573                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
574                         return 1;
575
576         return 0;
577 }
578
579 EXPORT_SYMBOL(hpet_alloc);
580 EXPORT_SYMBOL(hpet_register);
581 EXPORT_SYMBOL(hpet_unregister);
582 EXPORT_SYMBOL(hpet_control);
583
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;
591
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         }
602
603         tp->ht_opaque = NULL;
604
605         spin_lock_irq(&hpet_task_lock);
606         spin_lock(&hpet_lock);
607
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;
614
615                         devp = &hpetp->hp_dev[i];
616
617                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
618                                 devp = NULL;
619                                 continue;
620                         }
621
622                         tp->ht_opaque = devp;
623                         devp->hd_task = tp;
624                         break;
625                 }
626
627         spin_unlock(&hpet_lock);
628         spin_unlock_irq(&hpet_task_lock);
629
630         if (tp->ht_opaque)
631                 return 0;
632         else
633                 return -EBUSY;
634 }
635
636 static inline int hpet_tpcheck(struct hpet_task *tp)
637 {
638         struct hpet_dev *devp;
639         struct hpets *hpetp;
640
641         devp = tp->ht_opaque;
642
643         if (!devp)
644                 return -ENXIO;
645
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;
651
652         return -ENXIO;
653 }
654
655 int hpet_unregister(struct hpet_task *tp)
656 {
657         struct hpet_dev *devp;
658         struct hpet_timer __iomem *timer;
659         int err;
660
661         if ((err = hpet_tpcheck(tp)))
662                 return err;
663
664         spin_lock_irq(&hpet_task_lock);
665         spin_lock(&hpet_lock);
666
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         }
673
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);
681
682         return 0;
683 }
684
685 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
686 {
687         struct hpet_dev *devp;
688         int err;
689
690         if ((err = hpet_tpcheck(tp)))
691                 return err;
692
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 }
702
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 };
714
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 };
725
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 };
736
737 static struct ctl_table_header *sysctl_header;
738
739 static void hpet_register_interpolator(struct hpets *hpetp)
740 {
741 #ifdef  CONFIG_TIME_INTERPOLATION
742         struct time_interpolator *ti;
743
744         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
745         if (!ti)
746                 return;
747
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;
754
755         hpetp->hp_interpolator = ti;
756         register_time_interpolator(ti);
757 #endif
758 }
759
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)
766
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;
774
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                 }
780
781         if (!timer)
782                 return 0;
783
784         hpet = hpetp->hp_hpet;
785         t = read_counter(&timer->hpet_compare);
786
787         i = 0;
788         count = hpet_time_div(hpetp, TICK_CALIBRATE);
789
790         local_irq_save(flags);
791
792         start = read_counter(&hpet->hpet_mc);
793
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);
798
799         local_irq_restore(flags);
800
801         return (m - start) / i;
802 }
803
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;
815
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         }
826
827         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
828                                       sizeof(struct hpet_dev));
829
830         hpetp = kzalloc(siz, GFP_KERNEL);
831
832         if (!hpetp)
833                 return -ENOMEM;
834
835         hpetp->hp_which = hpet_nhpet++;
836         hpetp->hp_hpet = hdp->hd_address;
837         hpetp->hp_hpet_phys = hdp->hd_phys_address;
838
839         hpetp->hp_ntimer = hdp->hd_nirqs;
840
841         for (i = 0; i < hdp->hd_nirqs; i++)
842                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
843
844         hpet = hpetp->hp_hpet;
845
846         cap = readq(&hpet->hpet_cap);
847
848         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
849
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         }
856
857         if (last)
858                 last->hp_next = hpetp;
859         else
860                 hpets = hpetp;
861
862         last = hpetp;
863
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 */
870
871         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
872                 hpetp->hp_which, hdp->hd_phys_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");
877
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);
881
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         }
888
889         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
890                 struct hpet_timer __iomem *timer;
891
892                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
893
894                 devp->hd_hpets = hpetp;
895                 devp->hd_hpet = hpet;
896                 devp->hd_timer = timer;
897
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                 }
906
907                 init_waitqueue_head(&devp->hd_waitqueue);
908         }
909
910         hpetp->hp_delta = hpet_calibrate(hpetp);
911         hpet_register_interpolator(hpetp);
912
913         return 0;
914 }
915
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;
921
922         hdp = data;
923
924         status = acpi_resource_to_address64(res, &addr);
925
926         if (ACPI_SUCCESS(status)) {
927                 hdp->hd_phys_address = addr.minimum;
928                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
929
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;
938
939                 fixmem32 = &res->data.fixed_memory32;
940                 if (!fixmem32)
941                         return -EINVAL;
942
943                 hdp->hd_phys_address = fixmem32->address;
944                 hdp->hd_address = ioremap(fixmem32->address,
945                                                 HPET_RANGE_SIZE);
946
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;
956
957                 irqp = &res->data.extended_irq;
958
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;
964
965                         hdp->hd_irq[hdp->hd_nirqs] = irq;
966                         hdp->hd_nirqs++;
967                 }
968         }
969
970         return AE_OK;
971 }
972
973 static int hpet_acpi_add(struct acpi_device *device)
974 {
975         acpi_status result;
976         struct hpet_data data;
977
978         memset(&data, 0, sizeof(data));
979
980         result =
981             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
982                                 hpet_resources, &data);
983
984         if (ACPI_FAILURE(result))
985                 return -ENODEV;
986
987         if (!data.hd_address || !data.hd_nirqs) {
988                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
989                 return -ENODEV;
990         }
991
992         return hpet_alloc(&data);
993 }
994
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 }
1000
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 };
1009
1010 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1011
1012 static int __init hpet_init(void)
1013 {
1014         int result;
1015
1016         result = misc_register(&hpet_misc);
1017         if (result < 0)
1018                 return -ENODEV;
1019
1020         sysctl_header = register_sysctl_table(dev_root, 0);
1021
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;
1028         }
1029
1030         return 0;
1031 }
1032
1033 static void __exit hpet_exit(void)
1034 {
1035         acpi_bus_unregister_driver(&hpet_acpi_driver);
1036
1037         if (sysctl_header)
1038                 unregister_sysctl_table(sysctl_header);
1039         misc_deregister(&hpet_misc);
1040
1041         return;
1042 }
1043
1044 module_init(hpet_init);
1045 module_exit(hpet_exit);
1046 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1047 MODULE_LICENSE("GPL");