Merge remote-tracking branch 'regulator/topic/core' into regulator-next
[linux-2.6-block.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/kernel.h>
16 #include <linux/types.h>
17 #include <linux/miscdevice.h>
18 #include <linux/major.h>
19 #include <linux/ioport.h>
20 #include <linux/fcntl.h>
21 #include <linux/init.h>
22 #include <linux/poll.h>
23 #include <linux/mm.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 #include <linux/compat.h>
32 #include <linux/clocksource.h>
33 #include <linux/uaccess.h>
34 #include <linux/slab.h>
35 #include <linux/io.h>
36 #include <linux/acpi.h>
37 #include <linux/hpet.h>
38 #include <asm/current.h>
39 #include <asm/irq.h>
40 #include <asm/div64.h>
41
42 /*
43  * The High Precision Event Timer driver.
44  * This driver is closely modelled after the rtc.c driver.
45  * See HPET spec revision 1.
46  */
47 #define HPET_USER_FREQ  (64)
48 #define HPET_DRIFT      (500)
49
50 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
51
52
53 /* WARNING -- don't get confused.  These macros are never used
54  * to write the (single) counter, and rarely to read it.
55  * They're badly named; to fix, someday.
56  */
57 #if BITS_PER_LONG == 64
58 #define write_counter(V, MC)    writeq(V, MC)
59 #define read_counter(MC)        readq(MC)
60 #else
61 #define write_counter(V, MC)    writel(V, MC)
62 #define read_counter(MC)        readl(MC)
63 #endif
64
65 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
66 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
67
68 /* This clocksource driver currently only works on ia64 */
69 #ifdef CONFIG_IA64
70 static void __iomem *hpet_mctr;
71
72 static cycle_t read_hpet(struct clocksource *cs)
73 {
74         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
75 }
76
77 static struct clocksource clocksource_hpet = {
78         .name           = "hpet",
79         .rating         = 250,
80         .read           = read_hpet,
81         .mask           = CLOCKSOURCE_MASK(64),
82         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
83 };
84 static struct clocksource *hpet_clocksource;
85 #endif
86
87 /* A lock for concurrent access by app and isr hpet activity. */
88 static DEFINE_SPINLOCK(hpet_lock);
89
90 #define HPET_DEV_NAME   (7)
91
92 struct hpet_dev {
93         struct hpets *hd_hpets;
94         struct hpet __iomem *hd_hpet;
95         struct hpet_timer __iomem *hd_timer;
96         unsigned long hd_ireqfreq;
97         unsigned long hd_irqdata;
98         wait_queue_head_t hd_waitqueue;
99         struct fasync_struct *hd_async_queue;
100         unsigned int hd_flags;
101         unsigned int hd_irq;
102         unsigned int hd_hdwirq;
103         char hd_name[HPET_DEV_NAME];
104 };
105
106 struct hpets {
107         struct hpets *hp_next;
108         struct hpet __iomem *hp_hpet;
109         unsigned long hp_hpet_phys;
110         struct clocksource *hp_clocksource;
111         unsigned long long hp_tick_freq;
112         unsigned long hp_delta;
113         unsigned int hp_ntimer;
114         unsigned int hp_which;
115         struct hpet_dev hp_dev[1];
116 };
117
118 static struct hpets *hpets;
119
120 #define HPET_OPEN               0x0001
121 #define HPET_IE                 0x0002  /* interrupt enabled */
122 #define HPET_PERIODIC           0x0004
123 #define HPET_SHARED_IRQ         0x0008
124
125
126 #ifndef readq
127 static inline unsigned long long readq(void __iomem *addr)
128 {
129         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
130 }
131 #endif
132
133 #ifndef writeq
134 static inline void writeq(unsigned long long v, void __iomem *addr)
135 {
136         writel(v & 0xffffffff, addr);
137         writel(v >> 32, addr + 4);
138 }
139 #endif
140
141 static irqreturn_t hpet_interrupt(int irq, void *data)
142 {
143         struct hpet_dev *devp;
144         unsigned long isr;
145
146         devp = data;
147         isr = 1 << (devp - devp->hd_hpets->hp_dev);
148
149         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
150             !(isr & readl(&devp->hd_hpet->hpet_isr)))
151                 return IRQ_NONE;
152
153         spin_lock(&hpet_lock);
154         devp->hd_irqdata++;
155
156         /*
157          * For non-periodic timers, increment the accumulator.
158          * This has the effect of treating non-periodic like periodic.
159          */
160         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
161                 unsigned long m, t, mc, base, k;
162                 struct hpet __iomem *hpet = devp->hd_hpet;
163                 struct hpets *hpetp = devp->hd_hpets;
164
165                 t = devp->hd_ireqfreq;
166                 m = read_counter(&devp->hd_timer->hpet_compare);
167                 mc = read_counter(&hpet->hpet_mc);
168                 /* The time for the next interrupt would logically be t + m,
169                  * however, if we are very unlucky and the interrupt is delayed
170                  * for longer than t then we will completely miss the next
171                  * interrupt if we set t + m and an application will hang.
172                  * Therefore we need to make a more complex computation assuming
173                  * that there exists a k for which the following is true:
174                  * k * t + base < mc + delta
175                  * (k + 1) * t + base > mc + delta
176                  * where t is the interval in hpet ticks for the given freq,
177                  * base is the theoretical start value 0 < base < t,
178                  * mc is the main counter value at the time of the interrupt,
179                  * delta is the time it takes to write the a value to the
180                  * comparator.
181                  * k may then be computed as (mc - base + delta) / t .
182                  */
183                 base = mc % t;
184                 k = (mc - base + hpetp->hp_delta) / t;
185                 write_counter(t * (k + 1) + base,
186                               &devp->hd_timer->hpet_compare);
187         }
188
189         if (devp->hd_flags & HPET_SHARED_IRQ)
190                 writel(isr, &devp->hd_hpet->hpet_isr);
191         spin_unlock(&hpet_lock);
192
193         wake_up_interruptible(&devp->hd_waitqueue);
194
195         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
196
197         return IRQ_HANDLED;
198 }
199
200 static void hpet_timer_set_irq(struct hpet_dev *devp)
201 {
202         unsigned long v;
203         int irq, gsi;
204         struct hpet_timer __iomem *timer;
205
206         spin_lock_irq(&hpet_lock);
207         if (devp->hd_hdwirq) {
208                 spin_unlock_irq(&hpet_lock);
209                 return;
210         }
211
212         timer = devp->hd_timer;
213
214         /* we prefer level triggered mode */
215         v = readl(&timer->hpet_config);
216         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
217                 v |= Tn_INT_TYPE_CNF_MASK;
218                 writel(v, &timer->hpet_config);
219         }
220         spin_unlock_irq(&hpet_lock);
221
222         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
223                                  Tn_INT_ROUTE_CAP_SHIFT;
224
225         /*
226          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
227          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
228          */
229         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
230                 v &= ~0xf3df;
231         else
232                 v &= ~0xffff;
233
234         for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
235                 if (irq >= nr_irqs) {
236                         irq = HPET_MAX_IRQ;
237                         break;
238                 }
239
240                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
241                                         ACPI_ACTIVE_LOW);
242                 if (gsi > 0)
243                         break;
244
245                 /* FIXME: Setup interrupt source table */
246         }
247
248         if (irq < HPET_MAX_IRQ) {
249                 spin_lock_irq(&hpet_lock);
250                 v = readl(&timer->hpet_config);
251                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
252                 writel(v, &timer->hpet_config);
253                 devp->hd_hdwirq = gsi;
254                 spin_unlock_irq(&hpet_lock);
255         }
256         return;
257 }
258
259 static int hpet_open(struct inode *inode, struct file *file)
260 {
261         struct hpet_dev *devp;
262         struct hpets *hpetp;
263         int i;
264
265         if (file->f_mode & FMODE_WRITE)
266                 return -EINVAL;
267
268         mutex_lock(&hpet_mutex);
269         spin_lock_irq(&hpet_lock);
270
271         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
272                 for (i = 0; i < hpetp->hp_ntimer; i++)
273                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
274                                 continue;
275                         else {
276                                 devp = &hpetp->hp_dev[i];
277                                 break;
278                         }
279
280         if (!devp) {
281                 spin_unlock_irq(&hpet_lock);
282                 mutex_unlock(&hpet_mutex);
283                 return -EBUSY;
284         }
285
286         file->private_data = devp;
287         devp->hd_irqdata = 0;
288         devp->hd_flags |= HPET_OPEN;
289         spin_unlock_irq(&hpet_lock);
290         mutex_unlock(&hpet_mutex);
291
292         hpet_timer_set_irq(devp);
293
294         return 0;
295 }
296
297 static ssize_t
298 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
299 {
300         DECLARE_WAITQUEUE(wait, current);
301         unsigned long data;
302         ssize_t retval;
303         struct hpet_dev *devp;
304
305         devp = file->private_data;
306         if (!devp->hd_ireqfreq)
307                 return -EIO;
308
309         if (count < sizeof(unsigned long))
310                 return -EINVAL;
311
312         add_wait_queue(&devp->hd_waitqueue, &wait);
313
314         for ( ; ; ) {
315                 set_current_state(TASK_INTERRUPTIBLE);
316
317                 spin_lock_irq(&hpet_lock);
318                 data = devp->hd_irqdata;
319                 devp->hd_irqdata = 0;
320                 spin_unlock_irq(&hpet_lock);
321
322                 if (data)
323                         break;
324                 else if (file->f_flags & O_NONBLOCK) {
325                         retval = -EAGAIN;
326                         goto out;
327                 } else if (signal_pending(current)) {
328                         retval = -ERESTARTSYS;
329                         goto out;
330                 }
331                 schedule();
332         }
333
334         retval = put_user(data, (unsigned long __user *)buf);
335         if (!retval)
336                 retval = sizeof(unsigned long);
337 out:
338         __set_current_state(TASK_RUNNING);
339         remove_wait_queue(&devp->hd_waitqueue, &wait);
340
341         return retval;
342 }
343
344 static unsigned int hpet_poll(struct file *file, poll_table * wait)
345 {
346         unsigned long v;
347         struct hpet_dev *devp;
348
349         devp = file->private_data;
350
351         if (!devp->hd_ireqfreq)
352                 return 0;
353
354         poll_wait(file, &devp->hd_waitqueue, wait);
355
356         spin_lock_irq(&hpet_lock);
357         v = devp->hd_irqdata;
358         spin_unlock_irq(&hpet_lock);
359
360         if (v != 0)
361                 return POLLIN | POLLRDNORM;
362
363         return 0;
364 }
365
366 #ifdef CONFIG_HPET_MMAP
367 #ifdef CONFIG_HPET_MMAP_DEFAULT
368 static int hpet_mmap_enabled = 1;
369 #else
370 static int hpet_mmap_enabled = 0;
371 #endif
372
373 static __init int hpet_mmap_enable(char *str)
374 {
375         get_option(&str, &hpet_mmap_enabled);
376         pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled");
377         return 1;
378 }
379 __setup("hpet_mmap", hpet_mmap_enable);
380
381 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
382 {
383         struct hpet_dev *devp;
384         unsigned long addr;
385
386         if (!hpet_mmap_enabled)
387                 return -EACCES;
388
389         devp = file->private_data;
390         addr = devp->hd_hpets->hp_hpet_phys;
391
392         if (addr & (PAGE_SIZE - 1))
393                 return -ENOSYS;
394
395         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
396         return vm_iomap_memory(vma, addr, PAGE_SIZE);
397 }
398 #else
399 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
400 {
401         return -ENOSYS;
402 }
403 #endif
404
405 static int hpet_fasync(int fd, struct file *file, int on)
406 {
407         struct hpet_dev *devp;
408
409         devp = file->private_data;
410
411         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
412                 return 0;
413         else
414                 return -EIO;
415 }
416
417 static int hpet_release(struct inode *inode, struct file *file)
418 {
419         struct hpet_dev *devp;
420         struct hpet_timer __iomem *timer;
421         int irq = 0;
422
423         devp = file->private_data;
424         timer = devp->hd_timer;
425
426         spin_lock_irq(&hpet_lock);
427
428         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
429                &timer->hpet_config);
430
431         irq = devp->hd_irq;
432         devp->hd_irq = 0;
433
434         devp->hd_ireqfreq = 0;
435
436         if (devp->hd_flags & HPET_PERIODIC
437             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
438                 unsigned long v;
439
440                 v = readq(&timer->hpet_config);
441                 v ^= Tn_TYPE_CNF_MASK;
442                 writeq(v, &timer->hpet_config);
443         }
444
445         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
446         spin_unlock_irq(&hpet_lock);
447
448         if (irq)
449                 free_irq(irq, devp);
450
451         file->private_data = NULL;
452         return 0;
453 }
454
455 static int hpet_ioctl_ieon(struct hpet_dev *devp)
456 {
457         struct hpet_timer __iomem *timer;
458         struct hpet __iomem *hpet;
459         struct hpets *hpetp;
460         int irq;
461         unsigned long g, v, t, m;
462         unsigned long flags, isr;
463
464         timer = devp->hd_timer;
465         hpet = devp->hd_hpet;
466         hpetp = devp->hd_hpets;
467
468         if (!devp->hd_ireqfreq)
469                 return -EIO;
470
471         spin_lock_irq(&hpet_lock);
472
473         if (devp->hd_flags & HPET_IE) {
474                 spin_unlock_irq(&hpet_lock);
475                 return -EBUSY;
476         }
477
478         devp->hd_flags |= HPET_IE;
479
480         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
481                 devp->hd_flags |= HPET_SHARED_IRQ;
482         spin_unlock_irq(&hpet_lock);
483
484         irq = devp->hd_hdwirq;
485
486         if (irq) {
487                 unsigned long irq_flags;
488
489                 if (devp->hd_flags & HPET_SHARED_IRQ) {
490                         /*
491                          * To prevent the interrupt handler from seeing an
492                          * unwanted interrupt status bit, program the timer
493                          * so that it will not fire in the near future ...
494                          */
495                         writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
496                                &timer->hpet_config);
497                         write_counter(read_counter(&hpet->hpet_mc),
498                                       &timer->hpet_compare);
499                         /* ... and clear any left-over status. */
500                         isr = 1 << (devp - devp->hd_hpets->hp_dev);
501                         writel(isr, &hpet->hpet_isr);
502                 }
503
504                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
505                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0;
506                 if (request_irq(irq, hpet_interrupt, irq_flags,
507                                 devp->hd_name, (void *)devp)) {
508                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
509                         irq = 0;
510                 }
511         }
512
513         if (irq == 0) {
514                 spin_lock_irq(&hpet_lock);
515                 devp->hd_flags ^= HPET_IE;
516                 spin_unlock_irq(&hpet_lock);
517                 return -EIO;
518         }
519
520         devp->hd_irq = irq;
521         t = devp->hd_ireqfreq;
522         v = readq(&timer->hpet_config);
523
524         /* 64-bit comparators are not yet supported through the ioctls,
525          * so force this into 32-bit mode if it supports both modes
526          */
527         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
528
529         if (devp->hd_flags & HPET_PERIODIC) {
530                 g |= Tn_TYPE_CNF_MASK;
531                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
532                 writeq(v, &timer->hpet_config);
533                 local_irq_save(flags);
534
535                 /*
536                  * NOTE: First we modify the hidden accumulator
537                  * register supported by periodic-capable comparators.
538                  * We never want to modify the (single) counter; that
539                  * would affect all the comparators. The value written
540                  * is the counter value when the first interrupt is due.
541                  */
542                 m = read_counter(&hpet->hpet_mc);
543                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
544                 /*
545                  * Then we modify the comparator, indicating the period
546                  * for subsequent interrupt.
547                  */
548                 write_counter(t, &timer->hpet_compare);
549         } else {
550                 local_irq_save(flags);
551                 m = read_counter(&hpet->hpet_mc);
552                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
553         }
554
555         if (devp->hd_flags & HPET_SHARED_IRQ) {
556                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
557                 writel(isr, &hpet->hpet_isr);
558         }
559         writeq(g, &timer->hpet_config);
560         local_irq_restore(flags);
561
562         return 0;
563 }
564
565 /* converts Hz to number of timer ticks */
566 static inline unsigned long hpet_time_div(struct hpets *hpets,
567                                           unsigned long dis)
568 {
569         unsigned long long m;
570
571         m = hpets->hp_tick_freq + (dis >> 1);
572         do_div(m, dis);
573         return (unsigned long)m;
574 }
575
576 static int
577 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
578                   struct hpet_info *info)
579 {
580         struct hpet_timer __iomem *timer;
581         struct hpet __iomem *hpet;
582         struct hpets *hpetp;
583         int err;
584         unsigned long v;
585
586         switch (cmd) {
587         case HPET_IE_OFF:
588         case HPET_INFO:
589         case HPET_EPI:
590         case HPET_DPI:
591         case HPET_IRQFREQ:
592                 timer = devp->hd_timer;
593                 hpet = devp->hd_hpet;
594                 hpetp = devp->hd_hpets;
595                 break;
596         case HPET_IE_ON:
597                 return hpet_ioctl_ieon(devp);
598         default:
599                 return -EINVAL;
600         }
601
602         err = 0;
603
604         switch (cmd) {
605         case HPET_IE_OFF:
606                 if ((devp->hd_flags & HPET_IE) == 0)
607                         break;
608                 v = readq(&timer->hpet_config);
609                 v &= ~Tn_INT_ENB_CNF_MASK;
610                 writeq(v, &timer->hpet_config);
611                 if (devp->hd_irq) {
612                         free_irq(devp->hd_irq, devp);
613                         devp->hd_irq = 0;
614                 }
615                 devp->hd_flags ^= HPET_IE;
616                 break;
617         case HPET_INFO:
618                 {
619                         memset(info, 0, sizeof(*info));
620                         if (devp->hd_ireqfreq)
621                                 info->hi_ireqfreq =
622                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
623                         info->hi_flags =
624                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
625                         info->hi_hpet = hpetp->hp_which;
626                         info->hi_timer = devp - hpetp->hp_dev;
627                         break;
628                 }
629         case HPET_EPI:
630                 v = readq(&timer->hpet_config);
631                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
632                         err = -ENXIO;
633                         break;
634                 }
635                 devp->hd_flags |= HPET_PERIODIC;
636                 break;
637         case HPET_DPI:
638                 v = readq(&timer->hpet_config);
639                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
640                         err = -ENXIO;
641                         break;
642                 }
643                 if (devp->hd_flags & HPET_PERIODIC &&
644                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
645                         v = readq(&timer->hpet_config);
646                         v ^= Tn_TYPE_CNF_MASK;
647                         writeq(v, &timer->hpet_config);
648                 }
649                 devp->hd_flags &= ~HPET_PERIODIC;
650                 break;
651         case HPET_IRQFREQ:
652                 if ((arg > hpet_max_freq) &&
653                     !capable(CAP_SYS_RESOURCE)) {
654                         err = -EACCES;
655                         break;
656                 }
657
658                 if (!arg) {
659                         err = -EINVAL;
660                         break;
661                 }
662
663                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
664         }
665
666         return err;
667 }
668
669 static long
670 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
671 {
672         struct hpet_info info;
673         int err;
674
675         mutex_lock(&hpet_mutex);
676         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
677         mutex_unlock(&hpet_mutex);
678
679         if ((cmd == HPET_INFO) && !err &&
680             (copy_to_user((void __user *)arg, &info, sizeof(info))))
681                 err = -EFAULT;
682
683         return err;
684 }
685
686 #ifdef CONFIG_COMPAT
687 struct compat_hpet_info {
688         compat_ulong_t hi_ireqfreq;     /* Hz */
689         compat_ulong_t hi_flags;        /* information */
690         unsigned short hi_hpet;
691         unsigned short hi_timer;
692 };
693
694 static long
695 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
696 {
697         struct hpet_info info;
698         int err;
699
700         mutex_lock(&hpet_mutex);
701         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
702         mutex_unlock(&hpet_mutex);
703
704         if ((cmd == HPET_INFO) && !err) {
705                 struct compat_hpet_info __user *u = compat_ptr(arg);
706                 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
707                     put_user(info.hi_flags, &u->hi_flags) ||
708                     put_user(info.hi_hpet, &u->hi_hpet) ||
709                     put_user(info.hi_timer, &u->hi_timer))
710                         err = -EFAULT;
711         }
712
713         return err;
714 }
715 #endif
716
717 static const struct file_operations hpet_fops = {
718         .owner = THIS_MODULE,
719         .llseek = no_llseek,
720         .read = hpet_read,
721         .poll = hpet_poll,
722         .unlocked_ioctl = hpet_ioctl,
723 #ifdef CONFIG_COMPAT
724         .compat_ioctl = hpet_compat_ioctl,
725 #endif
726         .open = hpet_open,
727         .release = hpet_release,
728         .fasync = hpet_fasync,
729         .mmap = hpet_mmap,
730 };
731
732 static int hpet_is_known(struct hpet_data *hdp)
733 {
734         struct hpets *hpetp;
735
736         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
737                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
738                         return 1;
739
740         return 0;
741 }
742
743 static struct ctl_table hpet_table[] = {
744         {
745          .procname = "max-user-freq",
746          .data = &hpet_max_freq,
747          .maxlen = sizeof(int),
748          .mode = 0644,
749          .proc_handler = proc_dointvec,
750          },
751         {}
752 };
753
754 static struct ctl_table hpet_root[] = {
755         {
756          .procname = "hpet",
757          .maxlen = 0,
758          .mode = 0555,
759          .child = hpet_table,
760          },
761         {}
762 };
763
764 static struct ctl_table dev_root[] = {
765         {
766          .procname = "dev",
767          .maxlen = 0,
768          .mode = 0555,
769          .child = hpet_root,
770          },
771         {}
772 };
773
774 static struct ctl_table_header *sysctl_header;
775
776 /*
777  * Adjustment for when arming the timer with
778  * initial conditions.  That is, main counter
779  * ticks expired before interrupts are enabled.
780  */
781 #define TICK_CALIBRATE  (1000UL)
782
783 static unsigned long __hpet_calibrate(struct hpets *hpetp)
784 {
785         struct hpet_timer __iomem *timer = NULL;
786         unsigned long t, m, count, i, flags, start;
787         struct hpet_dev *devp;
788         int j;
789         struct hpet __iomem *hpet;
790
791         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
792                 if ((devp->hd_flags & HPET_OPEN) == 0) {
793                         timer = devp->hd_timer;
794                         break;
795                 }
796
797         if (!timer)
798                 return 0;
799
800         hpet = hpetp->hp_hpet;
801         t = read_counter(&timer->hpet_compare);
802
803         i = 0;
804         count = hpet_time_div(hpetp, TICK_CALIBRATE);
805
806         local_irq_save(flags);
807
808         start = read_counter(&hpet->hpet_mc);
809
810         do {
811                 m = read_counter(&hpet->hpet_mc);
812                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
813         } while (i++, (m - start) < count);
814
815         local_irq_restore(flags);
816
817         return (m - start) / i;
818 }
819
820 static unsigned long hpet_calibrate(struct hpets *hpetp)
821 {
822         unsigned long ret = ~0UL;
823         unsigned long tmp;
824
825         /*
826          * Try to calibrate until return value becomes stable small value.
827          * If SMI interruption occurs in calibration loop, the return value
828          * will be big. This avoids its impact.
829          */
830         for ( ; ; ) {
831                 tmp = __hpet_calibrate(hpetp);
832                 if (ret <= tmp)
833                         break;
834                 ret = tmp;
835         }
836
837         return ret;
838 }
839
840 int hpet_alloc(struct hpet_data *hdp)
841 {
842         u64 cap, mcfg;
843         struct hpet_dev *devp;
844         u32 i, ntimer;
845         struct hpets *hpetp;
846         size_t siz;
847         struct hpet __iomem *hpet;
848         static struct hpets *last;
849         unsigned long period;
850         unsigned long long temp;
851         u32 remainder;
852
853         /*
854          * hpet_alloc can be called by platform dependent code.
855          * If platform dependent code has allocated the hpet that
856          * ACPI has also reported, then we catch it here.
857          */
858         if (hpet_is_known(hdp)) {
859                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
860                         __func__);
861                 return 0;
862         }
863
864         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
865                                       sizeof(struct hpet_dev));
866
867         hpetp = kzalloc(siz, GFP_KERNEL);
868
869         if (!hpetp)
870                 return -ENOMEM;
871
872         hpetp->hp_which = hpet_nhpet++;
873         hpetp->hp_hpet = hdp->hd_address;
874         hpetp->hp_hpet_phys = hdp->hd_phys_address;
875
876         hpetp->hp_ntimer = hdp->hd_nirqs;
877
878         for (i = 0; i < hdp->hd_nirqs; i++)
879                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
880
881         hpet = hpetp->hp_hpet;
882
883         cap = readq(&hpet->hpet_cap);
884
885         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
886
887         if (hpetp->hp_ntimer != ntimer) {
888                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
889                        " with number of timers\n");
890                 kfree(hpetp);
891                 return -ENODEV;
892         }
893
894         if (last)
895                 last->hp_next = hpetp;
896         else
897                 hpets = hpetp;
898
899         last = hpetp;
900
901         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
902                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
903         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
904         temp += period >> 1; /* round */
905         do_div(temp, period);
906         hpetp->hp_tick_freq = temp; /* ticks per second */
907
908         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
909                 hpetp->hp_which, hdp->hd_phys_address,
910                 hpetp->hp_ntimer > 1 ? "s" : "");
911         for (i = 0; i < hpetp->hp_ntimer; i++)
912                 printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
913         printk(KERN_CONT "\n");
914
915         temp = hpetp->hp_tick_freq;
916         remainder = do_div(temp, 1000000);
917         printk(KERN_INFO
918                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
919                 hpetp->hp_which, hpetp->hp_ntimer,
920                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
921                 (unsigned) temp, remainder);
922
923         mcfg = readq(&hpet->hpet_config);
924         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
925                 write_counter(0L, &hpet->hpet_mc);
926                 mcfg |= HPET_ENABLE_CNF_MASK;
927                 writeq(mcfg, &hpet->hpet_config);
928         }
929
930         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
931                 struct hpet_timer __iomem *timer;
932
933                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
934
935                 devp->hd_hpets = hpetp;
936                 devp->hd_hpet = hpet;
937                 devp->hd_timer = timer;
938
939                 /*
940                  * If the timer was reserved by platform code,
941                  * then make timer unavailable for opens.
942                  */
943                 if (hdp->hd_state & (1 << i)) {
944                         devp->hd_flags = HPET_OPEN;
945                         continue;
946                 }
947
948                 init_waitqueue_head(&devp->hd_waitqueue);
949         }
950
951         hpetp->hp_delta = hpet_calibrate(hpetp);
952
953 /* This clocksource driver currently only works on ia64 */
954 #ifdef CONFIG_IA64
955         if (!hpet_clocksource) {
956                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
957                 clocksource_hpet.archdata.fsys_mmio = hpet_mctr;
958                 clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
959                 hpetp->hp_clocksource = &clocksource_hpet;
960                 hpet_clocksource = &clocksource_hpet;
961         }
962 #endif
963
964         return 0;
965 }
966
967 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
968 {
969         struct hpet_data *hdp;
970         acpi_status status;
971         struct acpi_resource_address64 addr;
972
973         hdp = data;
974
975         status = acpi_resource_to_address64(res, &addr);
976
977         if (ACPI_SUCCESS(status)) {
978                 hdp->hd_phys_address = addr.address.minimum;
979                 hdp->hd_address = ioremap(addr.address.minimum, addr.address.address_length);
980
981                 if (hpet_is_known(hdp)) {
982                         iounmap(hdp->hd_address);
983                         return AE_ALREADY_EXISTS;
984                 }
985         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
986                 struct acpi_resource_fixed_memory32 *fixmem32;
987
988                 fixmem32 = &res->data.fixed_memory32;
989
990                 hdp->hd_phys_address = fixmem32->address;
991                 hdp->hd_address = ioremap(fixmem32->address,
992                                                 HPET_RANGE_SIZE);
993
994                 if (hpet_is_known(hdp)) {
995                         iounmap(hdp->hd_address);
996                         return AE_ALREADY_EXISTS;
997                 }
998         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
999                 struct acpi_resource_extended_irq *irqp;
1000                 int i, irq;
1001
1002                 irqp = &res->data.extended_irq;
1003
1004                 for (i = 0; i < irqp->interrupt_count; i++) {
1005                         if (hdp->hd_nirqs >= HPET_MAX_TIMERS)
1006                                 break;
1007
1008                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
1009                                       irqp->triggering, irqp->polarity);
1010                         if (irq < 0)
1011                                 return AE_ERROR;
1012
1013                         hdp->hd_irq[hdp->hd_nirqs] = irq;
1014                         hdp->hd_nirqs++;
1015                 }
1016         }
1017
1018         return AE_OK;
1019 }
1020
1021 static int hpet_acpi_add(struct acpi_device *device)
1022 {
1023         acpi_status result;
1024         struct hpet_data data;
1025
1026         memset(&data, 0, sizeof(data));
1027
1028         result =
1029             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1030                                 hpet_resources, &data);
1031
1032         if (ACPI_FAILURE(result))
1033                 return -ENODEV;
1034
1035         if (!data.hd_address || !data.hd_nirqs) {
1036                 if (data.hd_address)
1037                         iounmap(data.hd_address);
1038                 printk("%s: no address or irqs in _CRS\n", __func__);
1039                 return -ENODEV;
1040         }
1041
1042         return hpet_alloc(&data);
1043 }
1044
1045 static const struct acpi_device_id hpet_device_ids[] = {
1046         {"PNP0103", 0},
1047         {"", 0},
1048 };
1049
1050 static struct acpi_driver hpet_acpi_driver = {
1051         .name = "hpet",
1052         .ids = hpet_device_ids,
1053         .ops = {
1054                 .add = hpet_acpi_add,
1055                 },
1056 };
1057
1058 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1059
1060 static int __init hpet_init(void)
1061 {
1062         int result;
1063
1064         result = misc_register(&hpet_misc);
1065         if (result < 0)
1066                 return -ENODEV;
1067
1068         sysctl_header = register_sysctl_table(dev_root);
1069
1070         result = acpi_bus_register_driver(&hpet_acpi_driver);
1071         if (result < 0) {
1072                 if (sysctl_header)
1073                         unregister_sysctl_table(sysctl_header);
1074                 misc_deregister(&hpet_misc);
1075                 return result;
1076         }
1077
1078         return 0;
1079 }
1080 device_initcall(hpet_init);
1081
1082 /*
1083 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1084 MODULE_LICENSE("GPL");
1085 */