intel-gtt: switch i81x to the common initialization helpers
[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/compat.h>
33 #include <linux/clocksource.h>
34 #include <linux/uaccess.h>
35 #include <linux/slab.h>
36 #include <linux/io.h>
37
38 #include <asm/current.h>
39 #include <asm/system.h>
40 #include <asm/irq.h>
41 #include <asm/div64.h>
42
43 #include <linux/acpi.h>
44 #include <acpi/acpi_bus.h>
45 #include <linux/hpet.h>
46
47 /*
48  * The High Precision Event Timer driver.
49  * This driver is closely modelled after the rtc.c driver.
50  * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
51  */
52 #define HPET_USER_FREQ  (64)
53 #define HPET_DRIFT      (500)
54
55 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
56
57
58 /* WARNING -- don't get confused.  These macros are never used
59  * to write the (single) counter, and rarely to read it.
60  * They're badly named; to fix, someday.
61  */
62 #if BITS_PER_LONG == 64
63 #define write_counter(V, MC)    writeq(V, MC)
64 #define read_counter(MC)        readq(MC)
65 #else
66 #define write_counter(V, MC)    writel(V, MC)
67 #define read_counter(MC)        readl(MC)
68 #endif
69
70 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
71 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
72
73 /* This clocksource driver currently only works on ia64 */
74 #ifdef CONFIG_IA64
75 static void __iomem *hpet_mctr;
76
77 static cycle_t read_hpet(struct clocksource *cs)
78 {
79         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
80 }
81
82 static struct clocksource clocksource_hpet = {
83         .name           = "hpet",
84         .rating         = 250,
85         .read           = read_hpet,
86         .mask           = CLOCKSOURCE_MASK(64),
87         .mult           = 0,            /* to be calculated */
88         .shift          = 10,
89         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
90 };
91 static struct clocksource *hpet_clocksource;
92 #endif
93
94 /* A lock for concurrent access by app and isr hpet activity. */
95 static DEFINE_SPINLOCK(hpet_lock);
96
97 #define HPET_DEV_NAME   (7)
98
99 struct hpet_dev {
100         struct hpets *hd_hpets;
101         struct hpet __iomem *hd_hpet;
102         struct hpet_timer __iomem *hd_timer;
103         unsigned long hd_ireqfreq;
104         unsigned long hd_irqdata;
105         wait_queue_head_t hd_waitqueue;
106         struct fasync_struct *hd_async_queue;
107         unsigned int hd_flags;
108         unsigned int hd_irq;
109         unsigned int hd_hdwirq;
110         char hd_name[HPET_DEV_NAME];
111 };
112
113 struct hpets {
114         struct hpets *hp_next;
115         struct hpet __iomem *hp_hpet;
116         unsigned long hp_hpet_phys;
117         struct clocksource *hp_clocksource;
118         unsigned long long hp_tick_freq;
119         unsigned long hp_delta;
120         unsigned int hp_ntimer;
121         unsigned int hp_which;
122         struct hpet_dev hp_dev[1];
123 };
124
125 static struct hpets *hpets;
126
127 #define HPET_OPEN               0x0001
128 #define HPET_IE                 0x0002  /* interrupt enabled */
129 #define HPET_PERIODIC           0x0004
130 #define HPET_SHARED_IRQ         0x0008
131
132
133 #ifndef readq
134 static inline unsigned long long readq(void __iomem *addr)
135 {
136         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
137 }
138 #endif
139
140 #ifndef writeq
141 static inline void writeq(unsigned long long v, void __iomem *addr)
142 {
143         writel(v & 0xffffffff, addr);
144         writel(v >> 32, addr + 4);
145 }
146 #endif
147
148 static irqreturn_t hpet_interrupt(int irq, void *data)
149 {
150         struct hpet_dev *devp;
151         unsigned long isr;
152
153         devp = data;
154         isr = 1 << (devp - devp->hd_hpets->hp_dev);
155
156         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
157             !(isr & readl(&devp->hd_hpet->hpet_isr)))
158                 return IRQ_NONE;
159
160         spin_lock(&hpet_lock);
161         devp->hd_irqdata++;
162
163         /*
164          * For non-periodic timers, increment the accumulator.
165          * This has the effect of treating non-periodic like periodic.
166          */
167         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
168                 unsigned long m, t;
169
170                 t = devp->hd_ireqfreq;
171                 m = read_counter(&devp->hd_timer->hpet_compare);
172                 write_counter(t + m, &devp->hd_timer->hpet_compare);
173         }
174
175         if (devp->hd_flags & HPET_SHARED_IRQ)
176                 writel(isr, &devp->hd_hpet->hpet_isr);
177         spin_unlock(&hpet_lock);
178
179         wake_up_interruptible(&devp->hd_waitqueue);
180
181         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
182
183         return IRQ_HANDLED;
184 }
185
186 static void hpet_timer_set_irq(struct hpet_dev *devp)
187 {
188         unsigned long v;
189         int irq, gsi;
190         struct hpet_timer __iomem *timer;
191
192         spin_lock_irq(&hpet_lock);
193         if (devp->hd_hdwirq) {
194                 spin_unlock_irq(&hpet_lock);
195                 return;
196         }
197
198         timer = devp->hd_timer;
199
200         /* we prefer level triggered mode */
201         v = readl(&timer->hpet_config);
202         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
203                 v |= Tn_INT_TYPE_CNF_MASK;
204                 writel(v, &timer->hpet_config);
205         }
206         spin_unlock_irq(&hpet_lock);
207
208         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
209                                  Tn_INT_ROUTE_CAP_SHIFT;
210
211         /*
212          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
213          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
214          */
215         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
216                 v &= ~0xf3df;
217         else
218                 v &= ~0xffff;
219
220         for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
221                 if (irq >= nr_irqs) {
222                         irq = HPET_MAX_IRQ;
223                         break;
224                 }
225
226                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
227                                         ACPI_ACTIVE_LOW);
228                 if (gsi > 0)
229                         break;
230
231                 /* FIXME: Setup interrupt source table */
232         }
233
234         if (irq < HPET_MAX_IRQ) {
235                 spin_lock_irq(&hpet_lock);
236                 v = readl(&timer->hpet_config);
237                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
238                 writel(v, &timer->hpet_config);
239                 devp->hd_hdwirq = gsi;
240                 spin_unlock_irq(&hpet_lock);
241         }
242         return;
243 }
244
245 static int hpet_open(struct inode *inode, struct file *file)
246 {
247         struct hpet_dev *devp;
248         struct hpets *hpetp;
249         int i;
250
251         if (file->f_mode & FMODE_WRITE)
252                 return -EINVAL;
253
254         mutex_lock(&hpet_mutex);
255         spin_lock_irq(&hpet_lock);
256
257         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
258                 for (i = 0; i < hpetp->hp_ntimer; i++)
259                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
260                                 continue;
261                         else {
262                                 devp = &hpetp->hp_dev[i];
263                                 break;
264                         }
265
266         if (!devp) {
267                 spin_unlock_irq(&hpet_lock);
268                 mutex_unlock(&hpet_mutex);
269                 return -EBUSY;
270         }
271
272         file->private_data = devp;
273         devp->hd_irqdata = 0;
274         devp->hd_flags |= HPET_OPEN;
275         spin_unlock_irq(&hpet_lock);
276         mutex_unlock(&hpet_mutex);
277
278         hpet_timer_set_irq(devp);
279
280         return 0;
281 }
282
283 static ssize_t
284 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
285 {
286         DECLARE_WAITQUEUE(wait, current);
287         unsigned long data;
288         ssize_t retval;
289         struct hpet_dev *devp;
290
291         devp = file->private_data;
292         if (!devp->hd_ireqfreq)
293                 return -EIO;
294
295         if (count < sizeof(unsigned long))
296                 return -EINVAL;
297
298         add_wait_queue(&devp->hd_waitqueue, &wait);
299
300         for ( ; ; ) {
301                 set_current_state(TASK_INTERRUPTIBLE);
302
303                 spin_lock_irq(&hpet_lock);
304                 data = devp->hd_irqdata;
305                 devp->hd_irqdata = 0;
306                 spin_unlock_irq(&hpet_lock);
307
308                 if (data)
309                         break;
310                 else if (file->f_flags & O_NONBLOCK) {
311                         retval = -EAGAIN;
312                         goto out;
313                 } else if (signal_pending(current)) {
314                         retval = -ERESTARTSYS;
315                         goto out;
316                 }
317                 schedule();
318         }
319
320         retval = put_user(data, (unsigned long __user *)buf);
321         if (!retval)
322                 retval = sizeof(unsigned long);
323 out:
324         __set_current_state(TASK_RUNNING);
325         remove_wait_queue(&devp->hd_waitqueue, &wait);
326
327         return retval;
328 }
329
330 static unsigned int hpet_poll(struct file *file, poll_table * wait)
331 {
332         unsigned long v;
333         struct hpet_dev *devp;
334
335         devp = file->private_data;
336
337         if (!devp->hd_ireqfreq)
338                 return 0;
339
340         poll_wait(file, &devp->hd_waitqueue, wait);
341
342         spin_lock_irq(&hpet_lock);
343         v = devp->hd_irqdata;
344         spin_unlock_irq(&hpet_lock);
345
346         if (v != 0)
347                 return POLLIN | POLLRDNORM;
348
349         return 0;
350 }
351
352 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
353 {
354 #ifdef  CONFIG_HPET_MMAP
355         struct hpet_dev *devp;
356         unsigned long addr;
357
358         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
359                 return -EINVAL;
360
361         devp = file->private_data;
362         addr = devp->hd_hpets->hp_hpet_phys;
363
364         if (addr & (PAGE_SIZE - 1))
365                 return -ENOSYS;
366
367         vma->vm_flags |= VM_IO;
368         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
369
370         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
371                                         PAGE_SIZE, vma->vm_page_prot)) {
372                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
373                         __func__);
374                 return -EAGAIN;
375         }
376
377         return 0;
378 #else
379         return -ENOSYS;
380 #endif
381 }
382
383 static int hpet_fasync(int fd, struct file *file, int on)
384 {
385         struct hpet_dev *devp;
386
387         devp = file->private_data;
388
389         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
390                 return 0;
391         else
392                 return -EIO;
393 }
394
395 static int hpet_release(struct inode *inode, struct file *file)
396 {
397         struct hpet_dev *devp;
398         struct hpet_timer __iomem *timer;
399         int irq = 0;
400
401         devp = file->private_data;
402         timer = devp->hd_timer;
403
404         spin_lock_irq(&hpet_lock);
405
406         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
407                &timer->hpet_config);
408
409         irq = devp->hd_irq;
410         devp->hd_irq = 0;
411
412         devp->hd_ireqfreq = 0;
413
414         if (devp->hd_flags & HPET_PERIODIC
415             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
416                 unsigned long v;
417
418                 v = readq(&timer->hpet_config);
419                 v ^= Tn_TYPE_CNF_MASK;
420                 writeq(v, &timer->hpet_config);
421         }
422
423         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
424         spin_unlock_irq(&hpet_lock);
425
426         if (irq)
427                 free_irq(irq, devp);
428
429         file->private_data = NULL;
430         return 0;
431 }
432
433 static int hpet_ioctl_ieon(struct hpet_dev *devp)
434 {
435         struct hpet_timer __iomem *timer;
436         struct hpet __iomem *hpet;
437         struct hpets *hpetp;
438         int irq;
439         unsigned long g, v, t, m;
440         unsigned long flags, isr;
441
442         timer = devp->hd_timer;
443         hpet = devp->hd_hpet;
444         hpetp = devp->hd_hpets;
445
446         if (!devp->hd_ireqfreq)
447                 return -EIO;
448
449         spin_lock_irq(&hpet_lock);
450
451         if (devp->hd_flags & HPET_IE) {
452                 spin_unlock_irq(&hpet_lock);
453                 return -EBUSY;
454         }
455
456         devp->hd_flags |= HPET_IE;
457
458         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
459                 devp->hd_flags |= HPET_SHARED_IRQ;
460         spin_unlock_irq(&hpet_lock);
461
462         irq = devp->hd_hdwirq;
463
464         if (irq) {
465                 unsigned long irq_flags;
466
467                 if (devp->hd_flags & HPET_SHARED_IRQ) {
468                         /*
469                          * To prevent the interrupt handler from seeing an
470                          * unwanted interrupt status bit, program the timer
471                          * so that it will not fire in the near future ...
472                          */
473                         writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
474                                &timer->hpet_config);
475                         write_counter(read_counter(&hpet->hpet_mc),
476                                       &timer->hpet_compare);
477                         /* ... and clear any left-over status. */
478                         isr = 1 << (devp - devp->hd_hpets->hp_dev);
479                         writel(isr, &hpet->hpet_isr);
480                 }
481
482                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
483                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
484                                                 ? IRQF_SHARED : IRQF_DISABLED;
485                 if (request_irq(irq, hpet_interrupt, irq_flags,
486                                 devp->hd_name, (void *)devp)) {
487                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
488                         irq = 0;
489                 }
490         }
491
492         if (irq == 0) {
493                 spin_lock_irq(&hpet_lock);
494                 devp->hd_flags ^= HPET_IE;
495                 spin_unlock_irq(&hpet_lock);
496                 return -EIO;
497         }
498
499         devp->hd_irq = irq;
500         t = devp->hd_ireqfreq;
501         v = readq(&timer->hpet_config);
502
503         /* 64-bit comparators are not yet supported through the ioctls,
504          * so force this into 32-bit mode if it supports both modes
505          */
506         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
507
508         if (devp->hd_flags & HPET_PERIODIC) {
509                 g |= Tn_TYPE_CNF_MASK;
510                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
511                 writeq(v, &timer->hpet_config);
512                 local_irq_save(flags);
513
514                 /*
515                  * NOTE: First we modify the hidden accumulator
516                  * register supported by periodic-capable comparators.
517                  * We never want to modify the (single) counter; that
518                  * would affect all the comparators. The value written
519                  * is the counter value when the first interrupt is due.
520                  */
521                 m = read_counter(&hpet->hpet_mc);
522                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
523                 /*
524                  * Then we modify the comparator, indicating the period
525                  * for subsequent interrupt.
526                  */
527                 write_counter(t, &timer->hpet_compare);
528         } else {
529                 local_irq_save(flags);
530                 m = read_counter(&hpet->hpet_mc);
531                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
532         }
533
534         if (devp->hd_flags & HPET_SHARED_IRQ) {
535                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
536                 writel(isr, &hpet->hpet_isr);
537         }
538         writeq(g, &timer->hpet_config);
539         local_irq_restore(flags);
540
541         return 0;
542 }
543
544 /* converts Hz to number of timer ticks */
545 static inline unsigned long hpet_time_div(struct hpets *hpets,
546                                           unsigned long dis)
547 {
548         unsigned long long m;
549
550         m = hpets->hp_tick_freq + (dis >> 1);
551         do_div(m, dis);
552         return (unsigned long)m;
553 }
554
555 static int
556 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
557                   struct hpet_info *info)
558 {
559         struct hpet_timer __iomem *timer;
560         struct hpet __iomem *hpet;
561         struct hpets *hpetp;
562         int err;
563         unsigned long v;
564
565         switch (cmd) {
566         case HPET_IE_OFF:
567         case HPET_INFO:
568         case HPET_EPI:
569         case HPET_DPI:
570         case HPET_IRQFREQ:
571                 timer = devp->hd_timer;
572                 hpet = devp->hd_hpet;
573                 hpetp = devp->hd_hpets;
574                 break;
575         case HPET_IE_ON:
576                 return hpet_ioctl_ieon(devp);
577         default:
578                 return -EINVAL;
579         }
580
581         err = 0;
582
583         switch (cmd) {
584         case HPET_IE_OFF:
585                 if ((devp->hd_flags & HPET_IE) == 0)
586                         break;
587                 v = readq(&timer->hpet_config);
588                 v &= ~Tn_INT_ENB_CNF_MASK;
589                 writeq(v, &timer->hpet_config);
590                 if (devp->hd_irq) {
591                         free_irq(devp->hd_irq, devp);
592                         devp->hd_irq = 0;
593                 }
594                 devp->hd_flags ^= HPET_IE;
595                 break;
596         case HPET_INFO:
597                 {
598                         memset(info, 0, sizeof(*info));
599                         if (devp->hd_ireqfreq)
600                                 info->hi_ireqfreq =
601                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
602                         info->hi_flags =
603                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
604                         info->hi_hpet = hpetp->hp_which;
605                         info->hi_timer = devp - hpetp->hp_dev;
606                         break;
607                 }
608         case HPET_EPI:
609                 v = readq(&timer->hpet_config);
610                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
611                         err = -ENXIO;
612                         break;
613                 }
614                 devp->hd_flags |= HPET_PERIODIC;
615                 break;
616         case HPET_DPI:
617                 v = readq(&timer->hpet_config);
618                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
619                         err = -ENXIO;
620                         break;
621                 }
622                 if (devp->hd_flags & HPET_PERIODIC &&
623                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
624                         v = readq(&timer->hpet_config);
625                         v ^= Tn_TYPE_CNF_MASK;
626                         writeq(v, &timer->hpet_config);
627                 }
628                 devp->hd_flags &= ~HPET_PERIODIC;
629                 break;
630         case HPET_IRQFREQ:
631                 if ((arg > hpet_max_freq) &&
632                     !capable(CAP_SYS_RESOURCE)) {
633                         err = -EACCES;
634                         break;
635                 }
636
637                 if (!arg) {
638                         err = -EINVAL;
639                         break;
640                 }
641
642                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
643         }
644
645         return err;
646 }
647
648 static long
649 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
650 {
651         struct hpet_info info;
652         int err;
653
654         mutex_lock(&hpet_mutex);
655         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
656         mutex_unlock(&hpet_mutex);
657
658         if ((cmd == HPET_INFO) && !err &&
659             (copy_to_user((void __user *)arg, &info, sizeof(info))))
660                 err = -EFAULT;
661
662         return err;
663 }
664
665 #ifdef CONFIG_COMPAT
666 struct compat_hpet_info {
667         compat_ulong_t hi_ireqfreq;     /* Hz */
668         compat_ulong_t hi_flags;        /* information */
669         unsigned short hi_hpet;
670         unsigned short hi_timer;
671 };
672
673 static long
674 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
675 {
676         struct hpet_info info;
677         int err;
678
679         mutex_lock(&hpet_mutex);
680         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
681         mutex_unlock(&hpet_mutex);
682
683         if ((cmd == HPET_INFO) && !err) {
684                 struct compat_hpet_info __user *u = compat_ptr(arg);
685                 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
686                     put_user(info.hi_flags, &u->hi_flags) ||
687                     put_user(info.hi_hpet, &u->hi_hpet) ||
688                     put_user(info.hi_timer, &u->hi_timer))
689                         err = -EFAULT;
690         }
691
692         return err;
693 }
694 #endif
695
696 static const struct file_operations hpet_fops = {
697         .owner = THIS_MODULE,
698         .llseek = no_llseek,
699         .read = hpet_read,
700         .poll = hpet_poll,
701         .unlocked_ioctl = hpet_ioctl,
702 #ifdef CONFIG_COMPAT
703         .compat_ioctl = hpet_compat_ioctl,
704 #endif
705         .open = hpet_open,
706         .release = hpet_release,
707         .fasync = hpet_fasync,
708         .mmap = hpet_mmap,
709 };
710
711 static int hpet_is_known(struct hpet_data *hdp)
712 {
713         struct hpets *hpetp;
714
715         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
716                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
717                         return 1;
718
719         return 0;
720 }
721
722 static ctl_table hpet_table[] = {
723         {
724          .procname = "max-user-freq",
725          .data = &hpet_max_freq,
726          .maxlen = sizeof(int),
727          .mode = 0644,
728          .proc_handler = proc_dointvec,
729          },
730         {}
731 };
732
733 static ctl_table hpet_root[] = {
734         {
735          .procname = "hpet",
736          .maxlen = 0,
737          .mode = 0555,
738          .child = hpet_table,
739          },
740         {}
741 };
742
743 static ctl_table dev_root[] = {
744         {
745          .procname = "dev",
746          .maxlen = 0,
747          .mode = 0555,
748          .child = hpet_root,
749          },
750         {}
751 };
752
753 static struct ctl_table_header *sysctl_header;
754
755 /*
756  * Adjustment for when arming the timer with
757  * initial conditions.  That is, main counter
758  * ticks expired before interrupts are enabled.
759  */
760 #define TICK_CALIBRATE  (1000UL)
761
762 static unsigned long __hpet_calibrate(struct hpets *hpetp)
763 {
764         struct hpet_timer __iomem *timer = NULL;
765         unsigned long t, m, count, i, flags, start;
766         struct hpet_dev *devp;
767         int j;
768         struct hpet __iomem *hpet;
769
770         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
771                 if ((devp->hd_flags & HPET_OPEN) == 0) {
772                         timer = devp->hd_timer;
773                         break;
774                 }
775
776         if (!timer)
777                 return 0;
778
779         hpet = hpetp->hp_hpet;
780         t = read_counter(&timer->hpet_compare);
781
782         i = 0;
783         count = hpet_time_div(hpetp, TICK_CALIBRATE);
784
785         local_irq_save(flags);
786
787         start = read_counter(&hpet->hpet_mc);
788
789         do {
790                 m = read_counter(&hpet->hpet_mc);
791                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
792         } while (i++, (m - start) < count);
793
794         local_irq_restore(flags);
795
796         return (m - start) / i;
797 }
798
799 static unsigned long hpet_calibrate(struct hpets *hpetp)
800 {
801         unsigned long ret = -1;
802         unsigned long tmp;
803
804         /*
805          * Try to calibrate until return value becomes stable small value.
806          * If SMI interruption occurs in calibration loop, the return value
807          * will be big. This avoids its impact.
808          */
809         for ( ; ; ) {
810                 tmp = __hpet_calibrate(hpetp);
811                 if (ret <= tmp)
812                         break;
813                 ret = tmp;
814         }
815
816         return ret;
817 }
818
819 int hpet_alloc(struct hpet_data *hdp)
820 {
821         u64 cap, mcfg;
822         struct hpet_dev *devp;
823         u32 i, ntimer;
824         struct hpets *hpetp;
825         size_t siz;
826         struct hpet __iomem *hpet;
827         static struct hpets *last;
828         unsigned long period;
829         unsigned long long temp;
830         u32 remainder;
831
832         /*
833          * hpet_alloc can be called by platform dependent code.
834          * If platform dependent code has allocated the hpet that
835          * ACPI has also reported, then we catch it here.
836          */
837         if (hpet_is_known(hdp)) {
838                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
839                         __func__);
840                 return 0;
841         }
842
843         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
844                                       sizeof(struct hpet_dev));
845
846         hpetp = kzalloc(siz, GFP_KERNEL);
847
848         if (!hpetp)
849                 return -ENOMEM;
850
851         hpetp->hp_which = hpet_nhpet++;
852         hpetp->hp_hpet = hdp->hd_address;
853         hpetp->hp_hpet_phys = hdp->hd_phys_address;
854
855         hpetp->hp_ntimer = hdp->hd_nirqs;
856
857         for (i = 0; i < hdp->hd_nirqs; i++)
858                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
859
860         hpet = hpetp->hp_hpet;
861
862         cap = readq(&hpet->hpet_cap);
863
864         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
865
866         if (hpetp->hp_ntimer != ntimer) {
867                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
868                        " with number of timers\n");
869                 kfree(hpetp);
870                 return -ENODEV;
871         }
872
873         if (last)
874                 last->hp_next = hpetp;
875         else
876                 hpets = hpetp;
877
878         last = hpetp;
879
880         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
881                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
882         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
883         temp += period >> 1; /* round */
884         do_div(temp, period);
885         hpetp->hp_tick_freq = temp; /* ticks per second */
886
887         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
888                 hpetp->hp_which, hdp->hd_phys_address,
889                 hpetp->hp_ntimer > 1 ? "s" : "");
890         for (i = 0; i < hpetp->hp_ntimer; i++)
891                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
892         printk("\n");
893
894         temp = hpetp->hp_tick_freq;
895         remainder = do_div(temp, 1000000);
896         printk(KERN_INFO
897                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
898                 hpetp->hp_which, hpetp->hp_ntimer,
899                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
900                 (unsigned) temp, remainder);
901
902         mcfg = readq(&hpet->hpet_config);
903         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
904                 write_counter(0L, &hpet->hpet_mc);
905                 mcfg |= HPET_ENABLE_CNF_MASK;
906                 writeq(mcfg, &hpet->hpet_config);
907         }
908
909         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
910                 struct hpet_timer __iomem *timer;
911
912                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
913
914                 devp->hd_hpets = hpetp;
915                 devp->hd_hpet = hpet;
916                 devp->hd_timer = timer;
917
918                 /*
919                  * If the timer was reserved by platform code,
920                  * then make timer unavailable for opens.
921                  */
922                 if (hdp->hd_state & (1 << i)) {
923                         devp->hd_flags = HPET_OPEN;
924                         continue;
925                 }
926
927                 init_waitqueue_head(&devp->hd_waitqueue);
928         }
929
930         hpetp->hp_delta = hpet_calibrate(hpetp);
931
932 /* This clocksource driver currently only works on ia64 */
933 #ifdef CONFIG_IA64
934         if (!hpet_clocksource) {
935                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
936                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
937                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
938                                                 clocksource_hpet.shift);
939                 clocksource_register(&clocksource_hpet);
940                 hpetp->hp_clocksource = &clocksource_hpet;
941                 hpet_clocksource = &clocksource_hpet;
942         }
943 #endif
944
945         return 0;
946 }
947
948 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
949 {
950         struct hpet_data *hdp;
951         acpi_status status;
952         struct acpi_resource_address64 addr;
953
954         hdp = data;
955
956         status = acpi_resource_to_address64(res, &addr);
957
958         if (ACPI_SUCCESS(status)) {
959                 hdp->hd_phys_address = addr.minimum;
960                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
961
962                 if (hpet_is_known(hdp)) {
963                         iounmap(hdp->hd_address);
964                         return AE_ALREADY_EXISTS;
965                 }
966         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
967                 struct acpi_resource_fixed_memory32 *fixmem32;
968
969                 fixmem32 = &res->data.fixed_memory32;
970                 if (!fixmem32)
971                         return AE_NO_MEMORY;
972
973                 hdp->hd_phys_address = fixmem32->address;
974                 hdp->hd_address = ioremap(fixmem32->address,
975                                                 HPET_RANGE_SIZE);
976
977                 if (hpet_is_known(hdp)) {
978                         iounmap(hdp->hd_address);
979                         return AE_ALREADY_EXISTS;
980                 }
981         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
982                 struct acpi_resource_extended_irq *irqp;
983                 int i, irq;
984
985                 irqp = &res->data.extended_irq;
986
987                 for (i = 0; i < irqp->interrupt_count; i++) {
988                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
989                                       irqp->triggering, irqp->polarity);
990                         if (irq < 0)
991                                 return AE_ERROR;
992
993                         hdp->hd_irq[hdp->hd_nirqs] = irq;
994                         hdp->hd_nirqs++;
995                 }
996         }
997
998         return AE_OK;
999 }
1000
1001 static int hpet_acpi_add(struct acpi_device *device)
1002 {
1003         acpi_status result;
1004         struct hpet_data data;
1005
1006         memset(&data, 0, sizeof(data));
1007
1008         result =
1009             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1010                                 hpet_resources, &data);
1011
1012         if (ACPI_FAILURE(result))
1013                 return -ENODEV;
1014
1015         if (!data.hd_address || !data.hd_nirqs) {
1016                 if (data.hd_address)
1017                         iounmap(data.hd_address);
1018                 printk("%s: no address or irqs in _CRS\n", __func__);
1019                 return -ENODEV;
1020         }
1021
1022         return hpet_alloc(&data);
1023 }
1024
1025 static int hpet_acpi_remove(struct acpi_device *device, int type)
1026 {
1027         /* XXX need to unregister clocksource, dealloc mem, etc */
1028         return -EINVAL;
1029 }
1030
1031 static const struct acpi_device_id hpet_device_ids[] = {
1032         {"PNP0103", 0},
1033         {"", 0},
1034 };
1035 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1036
1037 static struct acpi_driver hpet_acpi_driver = {
1038         .name = "hpet",
1039         .ids = hpet_device_ids,
1040         .ops = {
1041                 .add = hpet_acpi_add,
1042                 .remove = hpet_acpi_remove,
1043                 },
1044 };
1045
1046 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1047
1048 static int __init hpet_init(void)
1049 {
1050         int result;
1051
1052         result = misc_register(&hpet_misc);
1053         if (result < 0)
1054                 return -ENODEV;
1055
1056         sysctl_header = register_sysctl_table(dev_root);
1057
1058         result = acpi_bus_register_driver(&hpet_acpi_driver);
1059         if (result < 0) {
1060                 if (sysctl_header)
1061                         unregister_sysctl_table(sysctl_header);
1062                 misc_deregister(&hpet_misc);
1063                 return result;
1064         }
1065
1066         return 0;
1067 }
1068
1069 static void __exit hpet_exit(void)
1070 {
1071         acpi_bus_unregister_driver(&hpet_acpi_driver);
1072
1073         if (sysctl_header)
1074                 unregister_sysctl_table(sysctl_header);
1075         misc_deregister(&hpet_misc);
1076
1077         return;
1078 }
1079
1080 module_init(hpet_init);
1081 module_exit(hpet_exit);
1082 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1083 MODULE_LICENSE("GPL");