[PATCH] sysctl: remove insert_at_head from register_sysctl
[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/mm.h>
25 #include <linux/proc_fs.h>
26 #include <linux/spinlock.h>
27 #include <linux/sysctl.h>
28 #include <linux/wait.h>
29 #include <linux/bcd.h>
30 #include <linux/seq_file.h>
31 #include <linux/bitops.h>
32
33 #include <asm/current.h>
34 #include <asm/uaccess.h>
35 #include <asm/system.h>
36 #include <asm/io.h>
37 #include <asm/irq.h>
38 #include <asm/div64.h>
39
40 #include <linux/acpi.h>
41 #include <acpi/acpi_bus.h>
42 #include <linux/hpet.h>
43
44 /*
45  * The High Precision Event Timer driver.
46  * This driver is closely modelled after the rtc.c driver.
47  * http://www.intel.com/hardwaredesign/hpetspec.htm
48  */
49 #define HPET_USER_FREQ  (64)
50 #define HPET_DRIFT      (500)
51
52 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
53
54 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
55
56 /* A lock for concurrent access by app and isr hpet activity. */
57 static DEFINE_SPINLOCK(hpet_lock);
58 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
59 static DEFINE_SPINLOCK(hpet_task_lock);
60
61 #define HPET_DEV_NAME   (7)
62
63 struct hpet_dev {
64         struct hpets *hd_hpets;
65         struct hpet __iomem *hd_hpet;
66         struct hpet_timer __iomem *hd_timer;
67         unsigned long hd_ireqfreq;
68         unsigned long hd_irqdata;
69         wait_queue_head_t hd_waitqueue;
70         struct fasync_struct *hd_async_queue;
71         struct hpet_task *hd_task;
72         unsigned int hd_flags;
73         unsigned int hd_irq;
74         unsigned int hd_hdwirq;
75         char hd_name[HPET_DEV_NAME];
76 };
77
78 struct hpets {
79         struct hpets *hp_next;
80         struct hpet __iomem *hp_hpet;
81         unsigned long hp_hpet_phys;
82         struct time_interpolator *hp_interpolator;
83         unsigned long long hp_tick_freq;
84         unsigned long hp_delta;
85         unsigned int hp_ntimer;
86         unsigned int hp_which;
87         struct hpet_dev hp_dev[1];
88 };
89
90 static struct hpets *hpets;
91
92 #define HPET_OPEN               0x0001
93 #define HPET_IE                 0x0002  /* interrupt enabled */
94 #define HPET_PERIODIC           0x0004
95 #define HPET_SHARED_IRQ         0x0008
96
97 #if BITS_PER_LONG == 64
98 #define write_counter(V, MC)    writeq(V, MC)
99 #define read_counter(MC)        readq(MC)
100 #else
101 #define write_counter(V, MC)    writel(V, MC)
102 #define read_counter(MC)        readl(MC)
103 #endif
104
105 #ifndef readq
106 static inline unsigned long long readq(void __iomem *addr)
107 {
108         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
109 }
110 #endif
111
112 #ifndef writeq
113 static inline void writeq(unsigned long long v, void __iomem *addr)
114 {
115         writel(v & 0xffffffff, addr);
116         writel(v >> 32, addr + 4);
117 }
118 #endif
119
120 static irqreturn_t hpet_interrupt(int irq, void *data)
121 {
122         struct hpet_dev *devp;
123         unsigned long isr;
124
125         devp = data;
126         isr = 1 << (devp - devp->hd_hpets->hp_dev);
127
128         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
129             !(isr & readl(&devp->hd_hpet->hpet_isr)))
130                 return IRQ_NONE;
131
132         spin_lock(&hpet_lock);
133         devp->hd_irqdata++;
134
135         /*
136          * For non-periodic timers, increment the accumulator.
137          * This has the effect of treating non-periodic like periodic.
138          */
139         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
140                 unsigned long m, t;
141
142                 t = devp->hd_ireqfreq;
143                 m = read_counter(&devp->hd_hpet->hpet_mc);
144                 write_counter(t + m + devp->hd_hpets->hp_delta,
145                               &devp->hd_timer->hpet_compare);
146         }
147
148         if (devp->hd_flags & HPET_SHARED_IRQ)
149                 writel(isr, &devp->hd_hpet->hpet_isr);
150         spin_unlock(&hpet_lock);
151
152         spin_lock(&hpet_task_lock);
153         if (devp->hd_task)
154                 devp->hd_task->ht_func(devp->hd_task->ht_data);
155         spin_unlock(&hpet_task_lock);
156
157         wake_up_interruptible(&devp->hd_waitqueue);
158
159         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
160
161         return IRQ_HANDLED;
162 }
163
164 static int hpet_open(struct inode *inode, struct file *file)
165 {
166         struct hpet_dev *devp;
167         struct hpets *hpetp;
168         int i;
169
170         if (file->f_mode & FMODE_WRITE)
171                 return -EINVAL;
172
173         spin_lock_irq(&hpet_lock);
174
175         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
176                 for (i = 0; i < hpetp->hp_ntimer; i++)
177                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
178                             || hpetp->hp_dev[i].hd_task)
179                                 continue;
180                         else {
181                                 devp = &hpetp->hp_dev[i];
182                                 break;
183                         }
184
185         if (!devp) {
186                 spin_unlock_irq(&hpet_lock);
187                 return -EBUSY;
188         }
189
190         file->private_data = devp;
191         devp->hd_irqdata = 0;
192         devp->hd_flags |= HPET_OPEN;
193         spin_unlock_irq(&hpet_lock);
194
195         return 0;
196 }
197
198 static ssize_t
199 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
200 {
201         DECLARE_WAITQUEUE(wait, current);
202         unsigned long data;
203         ssize_t retval;
204         struct hpet_dev *devp;
205
206         devp = file->private_data;
207         if (!devp->hd_ireqfreq)
208                 return -EIO;
209
210         if (count < sizeof(unsigned long))
211                 return -EINVAL;
212
213         add_wait_queue(&devp->hd_waitqueue, &wait);
214
215         for ( ; ; ) {
216                 set_current_state(TASK_INTERRUPTIBLE);
217
218                 spin_lock_irq(&hpet_lock);
219                 data = devp->hd_irqdata;
220                 devp->hd_irqdata = 0;
221                 spin_unlock_irq(&hpet_lock);
222
223                 if (data)
224                         break;
225                 else if (file->f_flags & O_NONBLOCK) {
226                         retval = -EAGAIN;
227                         goto out;
228                 } else if (signal_pending(current)) {
229                         retval = -ERESTARTSYS;
230                         goto out;
231                 }
232                 schedule();
233         }
234
235         retval = put_user(data, (unsigned long __user *)buf);
236         if (!retval)
237                 retval = sizeof(unsigned long);
238 out:
239         __set_current_state(TASK_RUNNING);
240         remove_wait_queue(&devp->hd_waitqueue, &wait);
241
242         return retval;
243 }
244
245 static unsigned int hpet_poll(struct file *file, poll_table * wait)
246 {
247         unsigned long v;
248         struct hpet_dev *devp;
249
250         devp = file->private_data;
251
252         if (!devp->hd_ireqfreq)
253                 return 0;
254
255         poll_wait(file, &devp->hd_waitqueue, wait);
256
257         spin_lock_irq(&hpet_lock);
258         v = devp->hd_irqdata;
259         spin_unlock_irq(&hpet_lock);
260
261         if (v != 0)
262                 return POLLIN | POLLRDNORM;
263
264         return 0;
265 }
266
267 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
268 {
269 #ifdef  CONFIG_HPET_MMAP
270         struct hpet_dev *devp;
271         unsigned long addr;
272
273         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
274                 return -EINVAL;
275
276         devp = file->private_data;
277         addr = devp->hd_hpets->hp_hpet_phys;
278
279         if (addr & (PAGE_SIZE - 1))
280                 return -ENOSYS;
281
282         vma->vm_flags |= VM_IO;
283         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
284
285         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
286                                         PAGE_SIZE, vma->vm_page_prot)) {
287                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
288                         __FUNCTION__);
289                 return -EAGAIN;
290         }
291
292         return 0;
293 #else
294         return -ENOSYS;
295 #endif
296 }
297
298 static int hpet_fasync(int fd, struct file *file, int on)
299 {
300         struct hpet_dev *devp;
301
302         devp = file->private_data;
303
304         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
305                 return 0;
306         else
307                 return -EIO;
308 }
309
310 static int hpet_release(struct inode *inode, struct file *file)
311 {
312         struct hpet_dev *devp;
313         struct hpet_timer __iomem *timer;
314         int irq = 0;
315
316         devp = file->private_data;
317         timer = devp->hd_timer;
318
319         spin_lock_irq(&hpet_lock);
320
321         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
322                &timer->hpet_config);
323
324         irq = devp->hd_irq;
325         devp->hd_irq = 0;
326
327         devp->hd_ireqfreq = 0;
328
329         if (devp->hd_flags & HPET_PERIODIC
330             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
331                 unsigned long v;
332
333                 v = readq(&timer->hpet_config);
334                 v ^= Tn_TYPE_CNF_MASK;
335                 writeq(v, &timer->hpet_config);
336         }
337
338         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
339         spin_unlock_irq(&hpet_lock);
340
341         if (irq)
342                 free_irq(irq, devp);
343
344         if (file->f_flags & FASYNC)
345                 hpet_fasync(-1, file, 0);
346
347         file->private_data = NULL;
348         return 0;
349 }
350
351 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
352
353 static int
354 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
355            unsigned long arg)
356 {
357         struct hpet_dev *devp;
358
359         devp = file->private_data;
360         return hpet_ioctl_common(devp, cmd, arg, 0);
361 }
362
363 static int hpet_ioctl_ieon(struct hpet_dev *devp)
364 {
365         struct hpet_timer __iomem *timer;
366         struct hpet __iomem *hpet;
367         struct hpets *hpetp;
368         int irq;
369         unsigned long g, v, t, m;
370         unsigned long flags, isr;
371
372         timer = devp->hd_timer;
373         hpet = devp->hd_hpet;
374         hpetp = devp->hd_hpets;
375
376         if (!devp->hd_ireqfreq)
377                 return -EIO;
378
379         spin_lock_irq(&hpet_lock);
380
381         if (devp->hd_flags & HPET_IE) {
382                 spin_unlock_irq(&hpet_lock);
383                 return -EBUSY;
384         }
385
386         devp->hd_flags |= HPET_IE;
387
388         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
389                 devp->hd_flags |= HPET_SHARED_IRQ;
390         spin_unlock_irq(&hpet_lock);
391
392         irq = devp->hd_hdwirq;
393
394         if (irq) {
395                 unsigned long irq_flags;
396
397                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
398                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
399                                                 ? IRQF_SHARED : IRQF_DISABLED;
400                 if (request_irq(irq, hpet_interrupt, irq_flags,
401                                 devp->hd_name, (void *)devp)) {
402                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
403                         irq = 0;
404                 }
405         }
406
407         if (irq == 0) {
408                 spin_lock_irq(&hpet_lock);
409                 devp->hd_flags ^= HPET_IE;
410                 spin_unlock_irq(&hpet_lock);
411                 return -EIO;
412         }
413
414         devp->hd_irq = irq;
415         t = devp->hd_ireqfreq;
416         v = readq(&timer->hpet_config);
417         g = v | Tn_INT_ENB_CNF_MASK;
418
419         if (devp->hd_flags & HPET_PERIODIC) {
420                 write_counter(t, &timer->hpet_compare);
421                 g |= Tn_TYPE_CNF_MASK;
422                 v |= Tn_TYPE_CNF_MASK;
423                 writeq(v, &timer->hpet_config);
424                 v |= Tn_VAL_SET_CNF_MASK;
425                 writeq(v, &timer->hpet_config);
426                 local_irq_save(flags);
427                 m = read_counter(&hpet->hpet_mc);
428                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
429         } else {
430                 local_irq_save(flags);
431                 m = read_counter(&hpet->hpet_mc);
432                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
433         }
434
435         if (devp->hd_flags & HPET_SHARED_IRQ) {
436                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
437                 writel(isr, &hpet->hpet_isr);
438         }
439         writeq(g, &timer->hpet_config);
440         local_irq_restore(flags);
441
442         return 0;
443 }
444
445 /* converts Hz to number of timer ticks */
446 static inline unsigned long hpet_time_div(struct hpets *hpets,
447                                           unsigned long dis)
448 {
449         unsigned long long m;
450
451         m = hpets->hp_tick_freq + (dis >> 1);
452         do_div(m, dis);
453         return (unsigned long)m;
454 }
455
456 static int
457 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
458 {
459         struct hpet_timer __iomem *timer;
460         struct hpet __iomem *hpet;
461         struct hpets *hpetp;
462         int err;
463         unsigned long v;
464
465         switch (cmd) {
466         case HPET_IE_OFF:
467         case HPET_INFO:
468         case HPET_EPI:
469         case HPET_DPI:
470         case HPET_IRQFREQ:
471                 timer = devp->hd_timer;
472                 hpet = devp->hd_hpet;
473                 hpetp = devp->hd_hpets;
474                 break;
475         case HPET_IE_ON:
476                 return hpet_ioctl_ieon(devp);
477         default:
478                 return -EINVAL;
479         }
480
481         err = 0;
482
483         switch (cmd) {
484         case HPET_IE_OFF:
485                 if ((devp->hd_flags & HPET_IE) == 0)
486                         break;
487                 v = readq(&timer->hpet_config);
488                 v &= ~Tn_INT_ENB_CNF_MASK;
489                 writeq(v, &timer->hpet_config);
490                 if (devp->hd_irq) {
491                         free_irq(devp->hd_irq, devp);
492                         devp->hd_irq = 0;
493                 }
494                 devp->hd_flags ^= HPET_IE;
495                 break;
496         case HPET_INFO:
497                 {
498                         struct hpet_info info;
499
500                         if (devp->hd_ireqfreq)
501                                 info.hi_ireqfreq =
502                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
503                         else
504                                 info.hi_ireqfreq = 0;
505                         info.hi_flags =
506                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
507                         info.hi_hpet = hpetp->hp_which;
508                         info.hi_timer = devp - hpetp->hp_dev;
509                         if (kernel)
510                                 memcpy((void *)arg, &info, sizeof(info));
511                         else
512                                 if (copy_to_user((void __user *)arg, &info,
513                                                  sizeof(info)))
514                                         err = -EFAULT;
515                         break;
516                 }
517         case HPET_EPI:
518                 v = readq(&timer->hpet_config);
519                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
520                         err = -ENXIO;
521                         break;
522                 }
523                 devp->hd_flags |= HPET_PERIODIC;
524                 break;
525         case HPET_DPI:
526                 v = readq(&timer->hpet_config);
527                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
528                         err = -ENXIO;
529                         break;
530                 }
531                 if (devp->hd_flags & HPET_PERIODIC &&
532                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
533                         v = readq(&timer->hpet_config);
534                         v ^= Tn_TYPE_CNF_MASK;
535                         writeq(v, &timer->hpet_config);
536                 }
537                 devp->hd_flags &= ~HPET_PERIODIC;
538                 break;
539         case HPET_IRQFREQ:
540                 if (!kernel && (arg > hpet_max_freq) &&
541                     !capable(CAP_SYS_RESOURCE)) {
542                         err = -EACCES;
543                         break;
544                 }
545
546                 if (!arg) {
547                         err = -EINVAL;
548                         break;
549                 }
550
551                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
552         }
553
554         return err;
555 }
556
557 static const struct file_operations hpet_fops = {
558         .owner = THIS_MODULE,
559         .llseek = no_llseek,
560         .read = hpet_read,
561         .poll = hpet_poll,
562         .ioctl = hpet_ioctl,
563         .open = hpet_open,
564         .release = hpet_release,
565         .fasync = hpet_fasync,
566         .mmap = hpet_mmap,
567 };
568
569 static int hpet_is_known(struct hpet_data *hdp)
570 {
571         struct hpets *hpetp;
572
573         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
574                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
575                         return 1;
576
577         return 0;
578 }
579
580 EXPORT_SYMBOL(hpet_alloc);
581 EXPORT_SYMBOL(hpet_register);
582 EXPORT_SYMBOL(hpet_unregister);
583 EXPORT_SYMBOL(hpet_control);
584
585 int hpet_register(struct hpet_task *tp, int periodic)
586 {
587         unsigned int i;
588         u64 mask;
589         struct hpet_timer __iomem *timer;
590         struct hpet_dev *devp;
591         struct hpets *hpetp;
592
593         switch (periodic) {
594         case 1:
595                 mask = Tn_PER_INT_CAP_MASK;
596                 break;
597         case 0:
598                 mask = 0;
599                 break;
600         default:
601                 return -EINVAL;
602         }
603
604         tp->ht_opaque = NULL;
605
606         spin_lock_irq(&hpet_task_lock);
607         spin_lock(&hpet_lock);
608
609         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
610                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
611                      i < hpetp->hp_ntimer; i++, timer++) {
612                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
613                             != mask)
614                                 continue;
615
616                         devp = &hpetp->hp_dev[i];
617
618                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
619                                 devp = NULL;
620                                 continue;
621                         }
622
623                         tp->ht_opaque = devp;
624                         devp->hd_task = tp;
625                         break;
626                 }
627
628         spin_unlock(&hpet_lock);
629         spin_unlock_irq(&hpet_task_lock);
630
631         if (tp->ht_opaque)
632                 return 0;
633         else
634                 return -EBUSY;
635 }
636
637 static inline int hpet_tpcheck(struct hpet_task *tp)
638 {
639         struct hpet_dev *devp;
640         struct hpets *hpetp;
641
642         devp = tp->ht_opaque;
643
644         if (!devp)
645                 return -ENXIO;
646
647         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
648                 if (devp >= hpetp->hp_dev
649                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
650                     && devp->hd_hpet == hpetp->hp_hpet)
651                         return 0;
652
653         return -ENXIO;
654 }
655
656 int hpet_unregister(struct hpet_task *tp)
657 {
658         struct hpet_dev *devp;
659         struct hpet_timer __iomem *timer;
660         int err;
661
662         if ((err = hpet_tpcheck(tp)))
663                 return err;
664
665         spin_lock_irq(&hpet_task_lock);
666         spin_lock(&hpet_lock);
667
668         devp = tp->ht_opaque;
669         if (devp->hd_task != tp) {
670                 spin_unlock(&hpet_lock);
671                 spin_unlock_irq(&hpet_task_lock);
672                 return -ENXIO;
673         }
674
675         timer = devp->hd_timer;
676         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
677                &timer->hpet_config);
678         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
679         devp->hd_task = NULL;
680         spin_unlock(&hpet_lock);
681         spin_unlock_irq(&hpet_task_lock);
682
683         return 0;
684 }
685
686 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
687 {
688         struct hpet_dev *devp;
689         int err;
690
691         if ((err = hpet_tpcheck(tp)))
692                 return err;
693
694         spin_lock_irq(&hpet_lock);
695         devp = tp->ht_opaque;
696         if (devp->hd_task != tp) {
697                 spin_unlock_irq(&hpet_lock);
698                 return -ENXIO;
699         }
700         spin_unlock_irq(&hpet_lock);
701         return hpet_ioctl_common(devp, cmd, arg, 1);
702 }
703
704 static ctl_table hpet_table[] = {
705         {
706          .ctl_name = CTL_UNNUMBERED,
707          .procname = "max-user-freq",
708          .data = &hpet_max_freq,
709          .maxlen = sizeof(int),
710          .mode = 0644,
711          .proc_handler = &proc_dointvec,
712          },
713         {.ctl_name = 0}
714 };
715
716 static ctl_table hpet_root[] = {
717         {
718          .ctl_name = CTL_UNNUMBERED,
719          .procname = "hpet",
720          .maxlen = 0,
721          .mode = 0555,
722          .child = hpet_table,
723          },
724         {.ctl_name = 0}
725 };
726
727 static ctl_table dev_root[] = {
728         {
729          .ctl_name = CTL_DEV,
730          .procname = "dev",
731          .maxlen = 0,
732          .mode = 0555,
733          .child = hpet_root,
734          },
735         {.ctl_name = 0}
736 };
737
738 static struct ctl_table_header *sysctl_header;
739
740 static void hpet_register_interpolator(struct hpets *hpetp)
741 {
742 #ifdef  CONFIG_TIME_INTERPOLATION
743         struct time_interpolator *ti;
744
745         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
746         if (!ti)
747                 return;
748
749         ti->source = TIME_SOURCE_MMIO64;
750         ti->shift = 10;
751         ti->addr = &hpetp->hp_hpet->hpet_mc;
752         ti->frequency = hpetp->hp_tick_freq;
753         ti->drift = HPET_DRIFT;
754         ti->mask = -1;
755
756         hpetp->hp_interpolator = ti;
757         register_time_interpolator(ti);
758 #endif
759 }
760
761 /*
762  * Adjustment for when arming the timer with
763  * initial conditions.  That is, main counter
764  * ticks expired before interrupts are enabled.
765  */
766 #define TICK_CALIBRATE  (1000UL)
767
768 static unsigned long hpet_calibrate(struct hpets *hpetp)
769 {
770         struct hpet_timer __iomem *timer = NULL;
771         unsigned long t, m, count, i, flags, start;
772         struct hpet_dev *devp;
773         int j;
774         struct hpet __iomem *hpet;
775
776         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
777                 if ((devp->hd_flags & HPET_OPEN) == 0) {
778                         timer = devp->hd_timer;
779                         break;
780                 }
781
782         if (!timer)
783                 return 0;
784
785         hpet = hpetp->hp_hpet;
786         t = read_counter(&timer->hpet_compare);
787
788         i = 0;
789         count = hpet_time_div(hpetp, TICK_CALIBRATE);
790
791         local_irq_save(flags);
792
793         start = read_counter(&hpet->hpet_mc);
794
795         do {
796                 m = read_counter(&hpet->hpet_mc);
797                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
798         } while (i++, (m - start) < count);
799
800         local_irq_restore(flags);
801
802         return (m - start) / i;
803 }
804
805 int hpet_alloc(struct hpet_data *hdp)
806 {
807         u64 cap, mcfg;
808         struct hpet_dev *devp;
809         u32 i, ntimer;
810         struct hpets *hpetp;
811         size_t siz;
812         struct hpet __iomem *hpet;
813         static struct hpets *last = NULL;
814         unsigned long period;
815         unsigned long long temp;
816
817         /*
818          * hpet_alloc can be called by platform dependent code.
819          * If platform dependent code has allocated the hpet that
820          * ACPI has also reported, then we catch it here.
821          */
822         if (hpet_is_known(hdp)) {
823                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
824                         __FUNCTION__);
825                 return 0;
826         }
827
828         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
829                                       sizeof(struct hpet_dev));
830
831         hpetp = kzalloc(siz, GFP_KERNEL);
832
833         if (!hpetp)
834                 return -ENOMEM;
835
836         hpetp->hp_which = hpet_nhpet++;
837         hpetp->hp_hpet = hdp->hd_address;
838         hpetp->hp_hpet_phys = hdp->hd_phys_address;
839
840         hpetp->hp_ntimer = hdp->hd_nirqs;
841
842         for (i = 0; i < hdp->hd_nirqs; i++)
843                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
844
845         hpet = hpetp->hp_hpet;
846
847         cap = readq(&hpet->hpet_cap);
848
849         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
850
851         if (hpetp->hp_ntimer != ntimer) {
852                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
853                        " with number of timers\n");
854                 kfree(hpetp);
855                 return -ENODEV;
856         }
857
858         if (last)
859                 last->hp_next = hpetp;
860         else
861                 hpets = hpetp;
862
863         last = hpetp;
864
865         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
866                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
867         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
868         temp += period >> 1; /* round */
869         do_div(temp, period);
870         hpetp->hp_tick_freq = temp; /* ticks per second */
871
872         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
873                 hpetp->hp_which, hdp->hd_phys_address,
874                 hpetp->hp_ntimer > 1 ? "s" : "");
875         for (i = 0; i < hpetp->hp_ntimer; i++)
876                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
877         printk("\n");
878
879         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
880                hpetp->hp_which, hpetp->hp_ntimer,
881                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
882
883         mcfg = readq(&hpet->hpet_config);
884         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
885                 write_counter(0L, &hpet->hpet_mc);
886                 mcfg |= HPET_ENABLE_CNF_MASK;
887                 writeq(mcfg, &hpet->hpet_config);
888         }
889
890         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
891                 struct hpet_timer __iomem *timer;
892
893                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
894
895                 devp->hd_hpets = hpetp;
896                 devp->hd_hpet = hpet;
897                 devp->hd_timer = timer;
898
899                 /*
900                  * If the timer was reserved by platform code,
901                  * then make timer unavailable for opens.
902                  */
903                 if (hdp->hd_state & (1 << i)) {
904                         devp->hd_flags = HPET_OPEN;
905                         continue;
906                 }
907
908                 init_waitqueue_head(&devp->hd_waitqueue);
909         }
910
911         hpetp->hp_delta = hpet_calibrate(hpetp);
912         hpet_register_interpolator(hpetp);
913
914         return 0;
915 }
916
917 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
918 {
919         struct hpet_data *hdp;
920         acpi_status status;
921         struct acpi_resource_address64 addr;
922
923         hdp = data;
924
925         status = acpi_resource_to_address64(res, &addr);
926
927         if (ACPI_SUCCESS(status)) {
928                 hdp->hd_phys_address = addr.minimum;
929                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
930
931                 if (hpet_is_known(hdp)) {
932                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
933                                 __FUNCTION__, hdp->hd_phys_address);
934                         iounmap(hdp->hd_address);
935                         return -EBUSY;
936                 }
937         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
938                 struct acpi_resource_fixed_memory32 *fixmem32;
939
940                 fixmem32 = &res->data.fixed_memory32;
941                 if (!fixmem32)
942                         return -EINVAL;
943
944                 hdp->hd_phys_address = fixmem32->address;
945                 hdp->hd_address = ioremap(fixmem32->address,
946                                                 HPET_RANGE_SIZE);
947
948                 if (hpet_is_known(hdp)) {
949                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
950                                 __FUNCTION__, hdp->hd_phys_address);
951                         iounmap(hdp->hd_address);
952                         return -EBUSY;
953                 }
954         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
955                 struct acpi_resource_extended_irq *irqp;
956                 int i, irq;
957
958                 irqp = &res->data.extended_irq;
959
960                 for (i = 0; i < irqp->interrupt_count; i++) {
961                         irq = acpi_register_gsi(irqp->interrupts[i],
962                                       irqp->triggering, irqp->polarity);
963                         if (irq < 0)
964                                 return AE_ERROR;
965
966                         hdp->hd_irq[hdp->hd_nirqs] = irq;
967                         hdp->hd_nirqs++;
968                 }
969         }
970
971         return AE_OK;
972 }
973
974 static int hpet_acpi_add(struct acpi_device *device)
975 {
976         acpi_status result;
977         struct hpet_data data;
978
979         memset(&data, 0, sizeof(data));
980
981         result =
982             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
983                                 hpet_resources, &data);
984
985         if (ACPI_FAILURE(result))
986                 return -ENODEV;
987
988         if (!data.hd_address || !data.hd_nirqs) {
989                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
990                 return -ENODEV;
991         }
992
993         return hpet_alloc(&data);
994 }
995
996 static int hpet_acpi_remove(struct acpi_device *device, int type)
997 {
998         /* XXX need to unregister interpolator, dealloc mem, etc */
999         return -EINVAL;
1000 }
1001
1002 static struct acpi_driver hpet_acpi_driver = {
1003         .name = "hpet",
1004         .ids = "PNP0103",
1005         .ops = {
1006                 .add = hpet_acpi_add,
1007                 .remove = hpet_acpi_remove,
1008                 },
1009 };
1010
1011 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1012
1013 static int __init hpet_init(void)
1014 {
1015         int result;
1016
1017         result = misc_register(&hpet_misc);
1018         if (result < 0)
1019                 return -ENODEV;
1020
1021         sysctl_header = register_sysctl_table(dev_root);
1022
1023         result = acpi_bus_register_driver(&hpet_acpi_driver);
1024         if (result < 0) {
1025                 if (sysctl_header)
1026                         unregister_sysctl_table(sysctl_header);
1027                 misc_deregister(&hpet_misc);
1028                 return result;
1029         }
1030
1031         return 0;
1032 }
1033
1034 static void __exit hpet_exit(void)
1035 {
1036         acpi_bus_unregister_driver(&hpet_acpi_driver);
1037
1038         if (sysctl_header)
1039                 unregister_sysctl_table(sysctl_header);
1040         misc_deregister(&hpet_misc);
1041
1042         return;
1043 }
1044
1045 module_init(hpet_init);
1046 module_exit(hpet_exit);
1047 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1048 MODULE_LICENSE("GPL");