[IA64] Convert to generic timekeeping/clocksource
[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 #include <linux/clocksource.h>
33
34 #include <asm/current.h>
35 #include <asm/uaccess.h>
36 #include <asm/system.h>
37 #include <asm/io.h>
38 #include <asm/irq.h>
39 #include <asm/div64.h>
40
41 #include <linux/acpi.h>
42 #include <acpi/acpi_bus.h>
43 #include <linux/hpet.h>
44
45 /*
46  * The High Precision Event Timer driver.
47  * This driver is closely modelled after the rtc.c driver.
48  * http://www.intel.com/hardwaredesign/hpetspec.htm
49  */
50 #define HPET_USER_FREQ  (64)
51 #define HPET_DRIFT      (500)
52
53 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
54
55 #if BITS_PER_LONG == 64
56 #define write_counter(V, MC)    writeq(V, MC)
57 #define read_counter(MC)        readq(MC)
58 #else
59 #define write_counter(V, MC)    writel(V, MC)
60 #define read_counter(MC)        readl(MC)
61 #endif
62
63 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
64
65 static void __iomem *hpet_mctr;
66
67 static cycle_t read_hpet(void)
68 {
69         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
70 }
71
72 static struct clocksource clocksource_hpet = {
73         .name           = "hpet",
74         .rating         = 250,
75         .read           = read_hpet,
76         .mask           = 0xffffffffffffffff,
77         .mult           = 0, /*to be caluclated*/
78         .shift          = 10,
79         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
80 };
81 static struct clocksource *hpet_clocksource;
82
83 /* A lock for concurrent access by app and isr hpet activity. */
84 static DEFINE_SPINLOCK(hpet_lock);
85 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
86 static DEFINE_SPINLOCK(hpet_task_lock);
87
88 #define HPET_DEV_NAME   (7)
89
90 struct hpet_dev {
91         struct hpets *hd_hpets;
92         struct hpet __iomem *hd_hpet;
93         struct hpet_timer __iomem *hd_timer;
94         unsigned long hd_ireqfreq;
95         unsigned long hd_irqdata;
96         wait_queue_head_t hd_waitqueue;
97         struct fasync_struct *hd_async_queue;
98         struct hpet_task *hd_task;
99         unsigned int hd_flags;
100         unsigned int hd_irq;
101         unsigned int hd_hdwirq;
102         char hd_name[HPET_DEV_NAME];
103 };
104
105 struct hpets {
106         struct hpets *hp_next;
107         struct hpet __iomem *hp_hpet;
108         unsigned long hp_hpet_phys;
109         struct clocksource *hp_clocksource;
110         unsigned long long hp_tick_freq;
111         unsigned long hp_delta;
112         unsigned int hp_ntimer;
113         unsigned int hp_which;
114         struct hpet_dev hp_dev[1];
115 };
116
117 static struct hpets *hpets;
118
119 #define HPET_OPEN               0x0001
120 #define HPET_IE                 0x0002  /* interrupt enabled */
121 #define HPET_PERIODIC           0x0004
122 #define HPET_SHARED_IRQ         0x0008
123
124
125 #ifndef readq
126 static inline unsigned long long readq(void __iomem *addr)
127 {
128         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
129 }
130 #endif
131
132 #ifndef writeq
133 static inline void writeq(unsigned long long v, void __iomem *addr)
134 {
135         writel(v & 0xffffffff, addr);
136         writel(v >> 32, addr + 4);
137 }
138 #endif
139
140 static irqreturn_t hpet_interrupt(int irq, void *data)
141 {
142         struct hpet_dev *devp;
143         unsigned long isr;
144
145         devp = data;
146         isr = 1 << (devp - devp->hd_hpets->hp_dev);
147
148         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
149             !(isr & readl(&devp->hd_hpet->hpet_isr)))
150                 return IRQ_NONE;
151
152         spin_lock(&hpet_lock);
153         devp->hd_irqdata++;
154
155         /*
156          * For non-periodic timers, increment the accumulator.
157          * This has the effect of treating non-periodic like periodic.
158          */
159         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
160                 unsigned long m, t;
161
162                 t = devp->hd_ireqfreq;
163                 m = read_counter(&devp->hd_hpet->hpet_mc);
164                 write_counter(t + m + devp->hd_hpets->hp_delta,
165                               &devp->hd_timer->hpet_compare);
166         }
167
168         if (devp->hd_flags & HPET_SHARED_IRQ)
169                 writel(isr, &devp->hd_hpet->hpet_isr);
170         spin_unlock(&hpet_lock);
171
172         spin_lock(&hpet_task_lock);
173         if (devp->hd_task)
174                 devp->hd_task->ht_func(devp->hd_task->ht_data);
175         spin_unlock(&hpet_task_lock);
176
177         wake_up_interruptible(&devp->hd_waitqueue);
178
179         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
180
181         return IRQ_HANDLED;
182 }
183
184 static int hpet_open(struct inode *inode, struct file *file)
185 {
186         struct hpet_dev *devp;
187         struct hpets *hpetp;
188         int i;
189
190         if (file->f_mode & FMODE_WRITE)
191                 return -EINVAL;
192
193         spin_lock_irq(&hpet_lock);
194
195         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
196                 for (i = 0; i < hpetp->hp_ntimer; i++)
197                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
198                             || hpetp->hp_dev[i].hd_task)
199                                 continue;
200                         else {
201                                 devp = &hpetp->hp_dev[i];
202                                 break;
203                         }
204
205         if (!devp) {
206                 spin_unlock_irq(&hpet_lock);
207                 return -EBUSY;
208         }
209
210         file->private_data = devp;
211         devp->hd_irqdata = 0;
212         devp->hd_flags |= HPET_OPEN;
213         spin_unlock_irq(&hpet_lock);
214
215         return 0;
216 }
217
218 static ssize_t
219 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
220 {
221         DECLARE_WAITQUEUE(wait, current);
222         unsigned long data;
223         ssize_t retval;
224         struct hpet_dev *devp;
225
226         devp = file->private_data;
227         if (!devp->hd_ireqfreq)
228                 return -EIO;
229
230         if (count < sizeof(unsigned long))
231                 return -EINVAL;
232
233         add_wait_queue(&devp->hd_waitqueue, &wait);
234
235         for ( ; ; ) {
236                 set_current_state(TASK_INTERRUPTIBLE);
237
238                 spin_lock_irq(&hpet_lock);
239                 data = devp->hd_irqdata;
240                 devp->hd_irqdata = 0;
241                 spin_unlock_irq(&hpet_lock);
242
243                 if (data)
244                         break;
245                 else if (file->f_flags & O_NONBLOCK) {
246                         retval = -EAGAIN;
247                         goto out;
248                 } else if (signal_pending(current)) {
249                         retval = -ERESTARTSYS;
250                         goto out;
251                 }
252                 schedule();
253         }
254
255         retval = put_user(data, (unsigned long __user *)buf);
256         if (!retval)
257                 retval = sizeof(unsigned long);
258 out:
259         __set_current_state(TASK_RUNNING);
260         remove_wait_queue(&devp->hd_waitqueue, &wait);
261
262         return retval;
263 }
264
265 static unsigned int hpet_poll(struct file *file, poll_table * wait)
266 {
267         unsigned long v;
268         struct hpet_dev *devp;
269
270         devp = file->private_data;
271
272         if (!devp->hd_ireqfreq)
273                 return 0;
274
275         poll_wait(file, &devp->hd_waitqueue, wait);
276
277         spin_lock_irq(&hpet_lock);
278         v = devp->hd_irqdata;
279         spin_unlock_irq(&hpet_lock);
280
281         if (v != 0)
282                 return POLLIN | POLLRDNORM;
283
284         return 0;
285 }
286
287 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
288 {
289 #ifdef  CONFIG_HPET_MMAP
290         struct hpet_dev *devp;
291         unsigned long addr;
292
293         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
294                 return -EINVAL;
295
296         devp = file->private_data;
297         addr = devp->hd_hpets->hp_hpet_phys;
298
299         if (addr & (PAGE_SIZE - 1))
300                 return -ENOSYS;
301
302         vma->vm_flags |= VM_IO;
303         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
304
305         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
306                                         PAGE_SIZE, vma->vm_page_prot)) {
307                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
308                         __FUNCTION__);
309                 return -EAGAIN;
310         }
311
312         return 0;
313 #else
314         return -ENOSYS;
315 #endif
316 }
317
318 static int hpet_fasync(int fd, struct file *file, int on)
319 {
320         struct hpet_dev *devp;
321
322         devp = file->private_data;
323
324         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
325                 return 0;
326         else
327                 return -EIO;
328 }
329
330 static int hpet_release(struct inode *inode, struct file *file)
331 {
332         struct hpet_dev *devp;
333         struct hpet_timer __iomem *timer;
334         int irq = 0;
335
336         devp = file->private_data;
337         timer = devp->hd_timer;
338
339         spin_lock_irq(&hpet_lock);
340
341         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
342                &timer->hpet_config);
343
344         irq = devp->hd_irq;
345         devp->hd_irq = 0;
346
347         devp->hd_ireqfreq = 0;
348
349         if (devp->hd_flags & HPET_PERIODIC
350             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
351                 unsigned long v;
352
353                 v = readq(&timer->hpet_config);
354                 v ^= Tn_TYPE_CNF_MASK;
355                 writeq(v, &timer->hpet_config);
356         }
357
358         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
359         spin_unlock_irq(&hpet_lock);
360
361         if (irq)
362                 free_irq(irq, devp);
363
364         if (file->f_flags & FASYNC)
365                 hpet_fasync(-1, file, 0);
366
367         file->private_data = NULL;
368         return 0;
369 }
370
371 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
372
373 static int
374 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
375            unsigned long arg)
376 {
377         struct hpet_dev *devp;
378
379         devp = file->private_data;
380         return hpet_ioctl_common(devp, cmd, arg, 0);
381 }
382
383 static int hpet_ioctl_ieon(struct hpet_dev *devp)
384 {
385         struct hpet_timer __iomem *timer;
386         struct hpet __iomem *hpet;
387         struct hpets *hpetp;
388         int irq;
389         unsigned long g, v, t, m;
390         unsigned long flags, isr;
391
392         timer = devp->hd_timer;
393         hpet = devp->hd_hpet;
394         hpetp = devp->hd_hpets;
395
396         if (!devp->hd_ireqfreq)
397                 return -EIO;
398
399         spin_lock_irq(&hpet_lock);
400
401         if (devp->hd_flags & HPET_IE) {
402                 spin_unlock_irq(&hpet_lock);
403                 return -EBUSY;
404         }
405
406         devp->hd_flags |= HPET_IE;
407
408         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
409                 devp->hd_flags |= HPET_SHARED_IRQ;
410         spin_unlock_irq(&hpet_lock);
411
412         irq = devp->hd_hdwirq;
413
414         if (irq) {
415                 unsigned long irq_flags;
416
417                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
418                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
419                                                 ? IRQF_SHARED : IRQF_DISABLED;
420                 if (request_irq(irq, hpet_interrupt, irq_flags,
421                                 devp->hd_name, (void *)devp)) {
422                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
423                         irq = 0;
424                 }
425         }
426
427         if (irq == 0) {
428                 spin_lock_irq(&hpet_lock);
429                 devp->hd_flags ^= HPET_IE;
430                 spin_unlock_irq(&hpet_lock);
431                 return -EIO;
432         }
433
434         devp->hd_irq = irq;
435         t = devp->hd_ireqfreq;
436         v = readq(&timer->hpet_config);
437         g = v | Tn_INT_ENB_CNF_MASK;
438
439         if (devp->hd_flags & HPET_PERIODIC) {
440                 write_counter(t, &timer->hpet_compare);
441                 g |= Tn_TYPE_CNF_MASK;
442                 v |= Tn_TYPE_CNF_MASK;
443                 writeq(v, &timer->hpet_config);
444                 v |= Tn_VAL_SET_CNF_MASK;
445                 writeq(v, &timer->hpet_config);
446                 local_irq_save(flags);
447                 m = read_counter(&hpet->hpet_mc);
448                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
449         } else {
450                 local_irq_save(flags);
451                 m = read_counter(&hpet->hpet_mc);
452                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
453         }
454
455         if (devp->hd_flags & HPET_SHARED_IRQ) {
456                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
457                 writel(isr, &hpet->hpet_isr);
458         }
459         writeq(g, &timer->hpet_config);
460         local_irq_restore(flags);
461
462         return 0;
463 }
464
465 /* converts Hz to number of timer ticks */
466 static inline unsigned long hpet_time_div(struct hpets *hpets,
467                                           unsigned long dis)
468 {
469         unsigned long long m;
470
471         m = hpets->hp_tick_freq + (dis >> 1);
472         do_div(m, dis);
473         return (unsigned long)m;
474 }
475
476 static int
477 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
478 {
479         struct hpet_timer __iomem *timer;
480         struct hpet __iomem *hpet;
481         struct hpets *hpetp;
482         int err;
483         unsigned long v;
484
485         switch (cmd) {
486         case HPET_IE_OFF:
487         case HPET_INFO:
488         case HPET_EPI:
489         case HPET_DPI:
490         case HPET_IRQFREQ:
491                 timer = devp->hd_timer;
492                 hpet = devp->hd_hpet;
493                 hpetp = devp->hd_hpets;
494                 break;
495         case HPET_IE_ON:
496                 return hpet_ioctl_ieon(devp);
497         default:
498                 return -EINVAL;
499         }
500
501         err = 0;
502
503         switch (cmd) {
504         case HPET_IE_OFF:
505                 if ((devp->hd_flags & HPET_IE) == 0)
506                         break;
507                 v = readq(&timer->hpet_config);
508                 v &= ~Tn_INT_ENB_CNF_MASK;
509                 writeq(v, &timer->hpet_config);
510                 if (devp->hd_irq) {
511                         free_irq(devp->hd_irq, devp);
512                         devp->hd_irq = 0;
513                 }
514                 devp->hd_flags ^= HPET_IE;
515                 break;
516         case HPET_INFO:
517                 {
518                         struct hpet_info info;
519
520                         if (devp->hd_ireqfreq)
521                                 info.hi_ireqfreq =
522                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
523                         else
524                                 info.hi_ireqfreq = 0;
525                         info.hi_flags =
526                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
527                         info.hi_hpet = hpetp->hp_which;
528                         info.hi_timer = devp - hpetp->hp_dev;
529                         if (kernel)
530                                 memcpy((void *)arg, &info, sizeof(info));
531                         else
532                                 if (copy_to_user((void __user *)arg, &info,
533                                                  sizeof(info)))
534                                         err = -EFAULT;
535                         break;
536                 }
537         case HPET_EPI:
538                 v = readq(&timer->hpet_config);
539                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
540                         err = -ENXIO;
541                         break;
542                 }
543                 devp->hd_flags |= HPET_PERIODIC;
544                 break;
545         case HPET_DPI:
546                 v = readq(&timer->hpet_config);
547                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
548                         err = -ENXIO;
549                         break;
550                 }
551                 if (devp->hd_flags & HPET_PERIODIC &&
552                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
553                         v = readq(&timer->hpet_config);
554                         v ^= Tn_TYPE_CNF_MASK;
555                         writeq(v, &timer->hpet_config);
556                 }
557                 devp->hd_flags &= ~HPET_PERIODIC;
558                 break;
559         case HPET_IRQFREQ:
560                 if (!kernel && (arg > hpet_max_freq) &&
561                     !capable(CAP_SYS_RESOURCE)) {
562                         err = -EACCES;
563                         break;
564                 }
565
566                 if (!arg) {
567                         err = -EINVAL;
568                         break;
569                 }
570
571                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
572         }
573
574         return err;
575 }
576
577 static const struct file_operations hpet_fops = {
578         .owner = THIS_MODULE,
579         .llseek = no_llseek,
580         .read = hpet_read,
581         .poll = hpet_poll,
582         .ioctl = hpet_ioctl,
583         .open = hpet_open,
584         .release = hpet_release,
585         .fasync = hpet_fasync,
586         .mmap = hpet_mmap,
587 };
588
589 static int hpet_is_known(struct hpet_data *hdp)
590 {
591         struct hpets *hpetp;
592
593         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
594                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
595                         return 1;
596
597         return 0;
598 }
599
600 EXPORT_SYMBOL(hpet_alloc);
601 EXPORT_SYMBOL(hpet_register);
602 EXPORT_SYMBOL(hpet_unregister);
603 EXPORT_SYMBOL(hpet_control);
604
605 int hpet_register(struct hpet_task *tp, int periodic)
606 {
607         unsigned int i;
608         u64 mask;
609         struct hpet_timer __iomem *timer;
610         struct hpet_dev *devp;
611         struct hpets *hpetp;
612
613         switch (periodic) {
614         case 1:
615                 mask = Tn_PER_INT_CAP_MASK;
616                 break;
617         case 0:
618                 mask = 0;
619                 break;
620         default:
621                 return -EINVAL;
622         }
623
624         tp->ht_opaque = NULL;
625
626         spin_lock_irq(&hpet_task_lock);
627         spin_lock(&hpet_lock);
628
629         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
630                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
631                      i < hpetp->hp_ntimer; i++, timer++) {
632                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
633                             != mask)
634                                 continue;
635
636                         devp = &hpetp->hp_dev[i];
637
638                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
639                                 devp = NULL;
640                                 continue;
641                         }
642
643                         tp->ht_opaque = devp;
644                         devp->hd_task = tp;
645                         break;
646                 }
647
648         spin_unlock(&hpet_lock);
649         spin_unlock_irq(&hpet_task_lock);
650
651         if (tp->ht_opaque)
652                 return 0;
653         else
654                 return -EBUSY;
655 }
656
657 static inline int hpet_tpcheck(struct hpet_task *tp)
658 {
659         struct hpet_dev *devp;
660         struct hpets *hpetp;
661
662         devp = tp->ht_opaque;
663
664         if (!devp)
665                 return -ENXIO;
666
667         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
668                 if (devp >= hpetp->hp_dev
669                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
670                     && devp->hd_hpet == hpetp->hp_hpet)
671                         return 0;
672
673         return -ENXIO;
674 }
675
676 int hpet_unregister(struct hpet_task *tp)
677 {
678         struct hpet_dev *devp;
679         struct hpet_timer __iomem *timer;
680         int err;
681
682         if ((err = hpet_tpcheck(tp)))
683                 return err;
684
685         spin_lock_irq(&hpet_task_lock);
686         spin_lock(&hpet_lock);
687
688         devp = tp->ht_opaque;
689         if (devp->hd_task != tp) {
690                 spin_unlock(&hpet_lock);
691                 spin_unlock_irq(&hpet_task_lock);
692                 return -ENXIO;
693         }
694
695         timer = devp->hd_timer;
696         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
697                &timer->hpet_config);
698         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
699         devp->hd_task = NULL;
700         spin_unlock(&hpet_lock);
701         spin_unlock_irq(&hpet_task_lock);
702
703         return 0;
704 }
705
706 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
707 {
708         struct hpet_dev *devp;
709         int err;
710
711         if ((err = hpet_tpcheck(tp)))
712                 return err;
713
714         spin_lock_irq(&hpet_lock);
715         devp = tp->ht_opaque;
716         if (devp->hd_task != tp) {
717                 spin_unlock_irq(&hpet_lock);
718                 return -ENXIO;
719         }
720         spin_unlock_irq(&hpet_lock);
721         return hpet_ioctl_common(devp, cmd, arg, 1);
722 }
723
724 static ctl_table hpet_table[] = {
725         {
726          .ctl_name = CTL_UNNUMBERED,
727          .procname = "max-user-freq",
728          .data = &hpet_max_freq,
729          .maxlen = sizeof(int),
730          .mode = 0644,
731          .proc_handler = &proc_dointvec,
732          },
733         {.ctl_name = 0}
734 };
735
736 static ctl_table hpet_root[] = {
737         {
738          .ctl_name = CTL_UNNUMBERED,
739          .procname = "hpet",
740          .maxlen = 0,
741          .mode = 0555,
742          .child = hpet_table,
743          },
744         {.ctl_name = 0}
745 };
746
747 static ctl_table dev_root[] = {
748         {
749          .ctl_name = CTL_DEV,
750          .procname = "dev",
751          .maxlen = 0,
752          .mode = 0555,
753          .child = hpet_root,
754          },
755         {.ctl_name = 0}
756 };
757
758 static struct ctl_table_header *sysctl_header;
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
912         if (!hpet_clocksource) {
913                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
914                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
915                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
916                                                 clocksource_hpet.shift);
917                 clocksource_register(&clocksource_hpet);
918                 hpetp->hp_clocksource = &clocksource_hpet;
919                 hpet_clocksource = &clocksource_hpet;
920         }
921
922         return 0;
923 }
924
925 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
926 {
927         struct hpet_data *hdp;
928         acpi_status status;
929         struct acpi_resource_address64 addr;
930
931         hdp = data;
932
933         status = acpi_resource_to_address64(res, &addr);
934
935         if (ACPI_SUCCESS(status)) {
936                 hdp->hd_phys_address = addr.minimum;
937                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
938
939                 if (hpet_is_known(hdp)) {
940                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
941                                 __FUNCTION__, hdp->hd_phys_address);
942                         iounmap(hdp->hd_address);
943                         return -EBUSY;
944                 }
945         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
946                 struct acpi_resource_fixed_memory32 *fixmem32;
947
948                 fixmem32 = &res->data.fixed_memory32;
949                 if (!fixmem32)
950                         return -EINVAL;
951
952                 hdp->hd_phys_address = fixmem32->address;
953                 hdp->hd_address = ioremap(fixmem32->address,
954                                                 HPET_RANGE_SIZE);
955
956                 if (hpet_is_known(hdp)) {
957                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
958                                 __FUNCTION__, hdp->hd_phys_address);
959                         iounmap(hdp->hd_address);
960                         return -EBUSY;
961                 }
962         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
963                 struct acpi_resource_extended_irq *irqp;
964                 int i, irq;
965
966                 irqp = &res->data.extended_irq;
967
968                 for (i = 0; i < irqp->interrupt_count; i++) {
969                         irq = acpi_register_gsi(irqp->interrupts[i],
970                                       irqp->triggering, irqp->polarity);
971                         if (irq < 0)
972                                 return AE_ERROR;
973
974                         hdp->hd_irq[hdp->hd_nirqs] = irq;
975                         hdp->hd_nirqs++;
976                 }
977         }
978
979         return AE_OK;
980 }
981
982 static int hpet_acpi_add(struct acpi_device *device)
983 {
984         acpi_status result;
985         struct hpet_data data;
986
987         memset(&data, 0, sizeof(data));
988
989         result =
990             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
991                                 hpet_resources, &data);
992
993         if (ACPI_FAILURE(result))
994                 return -ENODEV;
995
996         if (!data.hd_address || !data.hd_nirqs) {
997                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
998                 return -ENODEV;
999         }
1000
1001         return hpet_alloc(&data);
1002 }
1003
1004 static int hpet_acpi_remove(struct acpi_device *device, int type)
1005 {
1006         /* XXX need to unregister clocksource, dealloc mem, etc */
1007         return -EINVAL;
1008 }
1009
1010 static struct acpi_driver hpet_acpi_driver = {
1011         .name = "hpet",
1012         .ids = "PNP0103",
1013         .ops = {
1014                 .add = hpet_acpi_add,
1015                 .remove = hpet_acpi_remove,
1016                 },
1017 };
1018
1019 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1020
1021 static int __init hpet_init(void)
1022 {
1023         int result;
1024
1025         result = misc_register(&hpet_misc);
1026         if (result < 0)
1027                 return -ENODEV;
1028
1029         sysctl_header = register_sysctl_table(dev_root);
1030
1031         result = acpi_bus_register_driver(&hpet_acpi_driver);
1032         if (result < 0) {
1033                 if (sysctl_header)
1034                         unregister_sysctl_table(sysctl_header);
1035                 misc_deregister(&hpet_misc);
1036                 return result;
1037         }
1038
1039         return 0;
1040 }
1041
1042 static void __exit hpet_exit(void)
1043 {
1044         acpi_bus_unregister_driver(&hpet_acpi_driver);
1045
1046         if (sysctl_header)
1047                 unregister_sysctl_table(sysctl_header);
1048         misc_deregister(&hpet_misc);
1049
1050         return;
1051 }
1052
1053 module_init(hpet_init);
1054 module_exit(hpet_exit);
1055 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1056 MODULE_LICENSE("GPL");