x86: assign IRQs to HPET timers, fix
[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 /* This clocksource driver currently only works on ia64 */
66 #ifdef CONFIG_IA64
67 static void __iomem *hpet_mctr;
68
69 static cycle_t read_hpet(void)
70 {
71         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
72 }
73
74 static struct clocksource clocksource_hpet = {
75         .name           = "hpet",
76         .rating         = 250,
77         .read           = read_hpet,
78         .mask           = CLOCKSOURCE_MASK(64),
79         .mult           = 0, /*to be caluclated*/
80         .shift          = 10,
81         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
82 };
83 static struct clocksource *hpet_clocksource;
84 #endif
85
86 /* A lock for concurrent access by app and isr hpet activity. */
87 static DEFINE_SPINLOCK(hpet_lock);
88 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
89 static DEFINE_SPINLOCK(hpet_task_lock);
90
91 #define HPET_DEV_NAME   (7)
92
93 struct hpet_dev {
94         struct hpets *hd_hpets;
95         struct hpet __iomem *hd_hpet;
96         struct hpet_timer __iomem *hd_timer;
97         unsigned long hd_ireqfreq;
98         unsigned long hd_irqdata;
99         wait_queue_head_t hd_waitqueue;
100         struct fasync_struct *hd_async_queue;
101         struct hpet_task *hd_task;
102         unsigned int hd_flags;
103         unsigned int hd_irq;
104         unsigned int hd_hdwirq;
105         char hd_name[HPET_DEV_NAME];
106 };
107
108 struct hpets {
109         struct hpets *hp_next;
110         struct hpet __iomem *hp_hpet;
111         unsigned long hp_hpet_phys;
112         struct clocksource *hp_clocksource;
113         unsigned long long hp_tick_freq;
114         unsigned long hp_delta;
115         unsigned int hp_ntimer;
116         unsigned int hp_which;
117         struct hpet_dev hp_dev[1];
118 };
119
120 static struct hpets *hpets;
121
122 #define HPET_OPEN               0x0001
123 #define HPET_IE                 0x0002  /* interrupt enabled */
124 #define HPET_PERIODIC           0x0004
125 #define HPET_SHARED_IRQ         0x0008
126
127
128 #ifndef readq
129 static inline unsigned long long readq(void __iomem *addr)
130 {
131         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
132 }
133 #endif
134
135 #ifndef writeq
136 static inline void writeq(unsigned long long v, void __iomem *addr)
137 {
138         writel(v & 0xffffffff, addr);
139         writel(v >> 32, addr + 4);
140 }
141 #endif
142
143 static irqreturn_t hpet_interrupt(int irq, void *data)
144 {
145         struct hpet_dev *devp;
146         unsigned long isr;
147
148         devp = data;
149         isr = 1 << (devp - devp->hd_hpets->hp_dev);
150
151         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
152             !(isr & readl(&devp->hd_hpet->hpet_isr)))
153                 return IRQ_NONE;
154
155         spin_lock(&hpet_lock);
156         devp->hd_irqdata++;
157
158         /*
159          * For non-periodic timers, increment the accumulator.
160          * This has the effect of treating non-periodic like periodic.
161          */
162         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
163                 unsigned long m, t;
164
165                 t = devp->hd_ireqfreq;
166                 m = read_counter(&devp->hd_hpet->hpet_mc);
167                 write_counter(t + m + devp->hd_hpets->hp_delta,
168                               &devp->hd_timer->hpet_compare);
169         }
170
171         if (devp->hd_flags & HPET_SHARED_IRQ)
172                 writel(isr, &devp->hd_hpet->hpet_isr);
173         spin_unlock(&hpet_lock);
174
175         spin_lock(&hpet_task_lock);
176         if (devp->hd_task)
177                 devp->hd_task->ht_func(devp->hd_task->ht_data);
178         spin_unlock(&hpet_task_lock);
179
180         wake_up_interruptible(&devp->hd_waitqueue);
181
182         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
183
184         return IRQ_HANDLED;
185 }
186
187 static int hpet_open(struct inode *inode, struct file *file)
188 {
189         struct hpet_dev *devp;
190         struct hpets *hpetp;
191         int i;
192
193         if (file->f_mode & FMODE_WRITE)
194                 return -EINVAL;
195
196         spin_lock_irq(&hpet_lock);
197
198         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
199                 for (i = 0; i < hpetp->hp_ntimer; i++)
200                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
201                             || hpetp->hp_dev[i].hd_task)
202                                 continue;
203                         else {
204                                 devp = &hpetp->hp_dev[i];
205                                 break;
206                         }
207
208         if (!devp) {
209                 spin_unlock_irq(&hpet_lock);
210                 return -EBUSY;
211         }
212
213         file->private_data = devp;
214         devp->hd_irqdata = 0;
215         devp->hd_flags |= HPET_OPEN;
216         spin_unlock_irq(&hpet_lock);
217
218         return 0;
219 }
220
221 static ssize_t
222 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
223 {
224         DECLARE_WAITQUEUE(wait, current);
225         unsigned long data;
226         ssize_t retval;
227         struct hpet_dev *devp;
228
229         devp = file->private_data;
230         if (!devp->hd_ireqfreq)
231                 return -EIO;
232
233         if (count < sizeof(unsigned long))
234                 return -EINVAL;
235
236         add_wait_queue(&devp->hd_waitqueue, &wait);
237
238         for ( ; ; ) {
239                 set_current_state(TASK_INTERRUPTIBLE);
240
241                 spin_lock_irq(&hpet_lock);
242                 data = devp->hd_irqdata;
243                 devp->hd_irqdata = 0;
244                 spin_unlock_irq(&hpet_lock);
245
246                 if (data)
247                         break;
248                 else if (file->f_flags & O_NONBLOCK) {
249                         retval = -EAGAIN;
250                         goto out;
251                 } else if (signal_pending(current)) {
252                         retval = -ERESTARTSYS;
253                         goto out;
254                 }
255                 schedule();
256         }
257
258         retval = put_user(data, (unsigned long __user *)buf);
259         if (!retval)
260                 retval = sizeof(unsigned long);
261 out:
262         __set_current_state(TASK_RUNNING);
263         remove_wait_queue(&devp->hd_waitqueue, &wait);
264
265         return retval;
266 }
267
268 static unsigned int hpet_poll(struct file *file, poll_table * wait)
269 {
270         unsigned long v;
271         struct hpet_dev *devp;
272
273         devp = file->private_data;
274
275         if (!devp->hd_ireqfreq)
276                 return 0;
277
278         poll_wait(file, &devp->hd_waitqueue, wait);
279
280         spin_lock_irq(&hpet_lock);
281         v = devp->hd_irqdata;
282         spin_unlock_irq(&hpet_lock);
283
284         if (v != 0)
285                 return POLLIN | POLLRDNORM;
286
287         return 0;
288 }
289
290 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
291 {
292 #ifdef  CONFIG_HPET_MMAP
293         struct hpet_dev *devp;
294         unsigned long addr;
295
296         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
297                 return -EINVAL;
298
299         devp = file->private_data;
300         addr = devp->hd_hpets->hp_hpet_phys;
301
302         if (addr & (PAGE_SIZE - 1))
303                 return -ENOSYS;
304
305         vma->vm_flags |= VM_IO;
306         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
307
308         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
309                                         PAGE_SIZE, vma->vm_page_prot)) {
310                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
311                         __FUNCTION__);
312                 return -EAGAIN;
313         }
314
315         return 0;
316 #else
317         return -ENOSYS;
318 #endif
319 }
320
321 static int hpet_fasync(int fd, struct file *file, int on)
322 {
323         struct hpet_dev *devp;
324
325         devp = file->private_data;
326
327         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
328                 return 0;
329         else
330                 return -EIO;
331 }
332
333 static int hpet_release(struct inode *inode, struct file *file)
334 {
335         struct hpet_dev *devp;
336         struct hpet_timer __iomem *timer;
337         int irq = 0;
338
339         devp = file->private_data;
340         timer = devp->hd_timer;
341
342         spin_lock_irq(&hpet_lock);
343
344         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
345                &timer->hpet_config);
346
347         irq = devp->hd_irq;
348         devp->hd_irq = 0;
349
350         devp->hd_ireqfreq = 0;
351
352         if (devp->hd_flags & HPET_PERIODIC
353             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
354                 unsigned long v;
355
356                 v = readq(&timer->hpet_config);
357                 v ^= Tn_TYPE_CNF_MASK;
358                 writeq(v, &timer->hpet_config);
359         }
360
361         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
362         spin_unlock_irq(&hpet_lock);
363
364         if (irq)
365                 free_irq(irq, devp);
366
367         if (file->f_flags & FASYNC)
368                 hpet_fasync(-1, file, 0);
369
370         file->private_data = NULL;
371         return 0;
372 }
373
374 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
375
376 static int
377 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
378            unsigned long arg)
379 {
380         struct hpet_dev *devp;
381
382         devp = file->private_data;
383         return hpet_ioctl_common(devp, cmd, arg, 0);
384 }
385
386 static int hpet_ioctl_ieon(struct hpet_dev *devp)
387 {
388         struct hpet_timer __iomem *timer;
389         struct hpet __iomem *hpet;
390         struct hpets *hpetp;
391         int irq;
392         unsigned long g, v, t, m;
393         unsigned long flags, isr;
394
395         timer = devp->hd_timer;
396         hpet = devp->hd_hpet;
397         hpetp = devp->hd_hpets;
398
399         if (!devp->hd_ireqfreq)
400                 return -EIO;
401
402         spin_lock_irq(&hpet_lock);
403
404         if (devp->hd_flags & HPET_IE) {
405                 spin_unlock_irq(&hpet_lock);
406                 return -EBUSY;
407         }
408
409         devp->hd_flags |= HPET_IE;
410
411         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
412                 devp->hd_flags |= HPET_SHARED_IRQ;
413         spin_unlock_irq(&hpet_lock);
414
415         irq = devp->hd_hdwirq;
416
417         if (irq) {
418                 unsigned long irq_flags;
419
420                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
421                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
422                                                 ? IRQF_SHARED : IRQF_DISABLED;
423                 if (request_irq(irq, hpet_interrupt, irq_flags,
424                                 devp->hd_name, (void *)devp)) {
425                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
426                         irq = 0;
427                 }
428         }
429
430         if (irq == 0) {
431                 spin_lock_irq(&hpet_lock);
432                 devp->hd_flags ^= HPET_IE;
433                 spin_unlock_irq(&hpet_lock);
434                 return -EIO;
435         }
436
437         devp->hd_irq = irq;
438         t = devp->hd_ireqfreq;
439         v = readq(&timer->hpet_config);
440         g = v | Tn_INT_ENB_CNF_MASK;
441
442         if (devp->hd_flags & HPET_PERIODIC) {
443                 write_counter(t, &timer->hpet_compare);
444                 g |= Tn_TYPE_CNF_MASK;
445                 v |= Tn_TYPE_CNF_MASK;
446                 writeq(v, &timer->hpet_config);
447                 v |= Tn_VAL_SET_CNF_MASK;
448                 writeq(v, &timer->hpet_config);
449                 local_irq_save(flags);
450                 m = read_counter(&hpet->hpet_mc);
451                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
452         } else {
453                 local_irq_save(flags);
454                 m = read_counter(&hpet->hpet_mc);
455                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
456         }
457
458         if (devp->hd_flags & HPET_SHARED_IRQ) {
459                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
460                 writel(isr, &hpet->hpet_isr);
461         }
462         writeq(g, &timer->hpet_config);
463         local_irq_restore(flags);
464
465         return 0;
466 }
467
468 /* converts Hz to number of timer ticks */
469 static inline unsigned long hpet_time_div(struct hpets *hpets,
470                                           unsigned long dis)
471 {
472         unsigned long long m;
473
474         m = hpets->hp_tick_freq + (dis >> 1);
475         do_div(m, dis);
476         return (unsigned long)m;
477 }
478
479 static int
480 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
481 {
482         struct hpet_timer __iomem *timer;
483         struct hpet __iomem *hpet;
484         struct hpets *hpetp;
485         int err;
486         unsigned long v;
487
488         switch (cmd) {
489         case HPET_IE_OFF:
490         case HPET_INFO:
491         case HPET_EPI:
492         case HPET_DPI:
493         case HPET_IRQFREQ:
494                 timer = devp->hd_timer;
495                 hpet = devp->hd_hpet;
496                 hpetp = devp->hd_hpets;
497                 break;
498         case HPET_IE_ON:
499                 return hpet_ioctl_ieon(devp);
500         default:
501                 return -EINVAL;
502         }
503
504         err = 0;
505
506         switch (cmd) {
507         case HPET_IE_OFF:
508                 if ((devp->hd_flags & HPET_IE) == 0)
509                         break;
510                 v = readq(&timer->hpet_config);
511                 v &= ~Tn_INT_ENB_CNF_MASK;
512                 writeq(v, &timer->hpet_config);
513                 if (devp->hd_irq) {
514                         free_irq(devp->hd_irq, devp);
515                         devp->hd_irq = 0;
516                 }
517                 devp->hd_flags ^= HPET_IE;
518                 break;
519         case HPET_INFO:
520                 {
521                         struct hpet_info info;
522
523                         if (devp->hd_ireqfreq)
524                                 info.hi_ireqfreq =
525                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
526                         else
527                                 info.hi_ireqfreq = 0;
528                         info.hi_flags =
529                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
530                         info.hi_hpet = hpetp->hp_which;
531                         info.hi_timer = devp - hpetp->hp_dev;
532                         if (kernel)
533                                 memcpy((void *)arg, &info, sizeof(info));
534                         else
535                                 if (copy_to_user((void __user *)arg, &info,
536                                                  sizeof(info)))
537                                         err = -EFAULT;
538                         break;
539                 }
540         case HPET_EPI:
541                 v = readq(&timer->hpet_config);
542                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
543                         err = -ENXIO;
544                         break;
545                 }
546                 devp->hd_flags |= HPET_PERIODIC;
547                 break;
548         case HPET_DPI:
549                 v = readq(&timer->hpet_config);
550                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
551                         err = -ENXIO;
552                         break;
553                 }
554                 if (devp->hd_flags & HPET_PERIODIC &&
555                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
556                         v = readq(&timer->hpet_config);
557                         v ^= Tn_TYPE_CNF_MASK;
558                         writeq(v, &timer->hpet_config);
559                 }
560                 devp->hd_flags &= ~HPET_PERIODIC;
561                 break;
562         case HPET_IRQFREQ:
563                 if (!kernel && (arg > hpet_max_freq) &&
564                     !capable(CAP_SYS_RESOURCE)) {
565                         err = -EACCES;
566                         break;
567                 }
568
569                 if (!arg) {
570                         err = -EINVAL;
571                         break;
572                 }
573
574                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
575         }
576
577         return err;
578 }
579
580 static const struct file_operations hpet_fops = {
581         .owner = THIS_MODULE,
582         .llseek = no_llseek,
583         .read = hpet_read,
584         .poll = hpet_poll,
585         .ioctl = hpet_ioctl,
586         .open = hpet_open,
587         .release = hpet_release,
588         .fasync = hpet_fasync,
589         .mmap = hpet_mmap,
590 };
591
592 static int hpet_is_known(struct hpet_data *hdp)
593 {
594         struct hpets *hpetp;
595
596         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
597                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
598                         return 1;
599
600         return 0;
601 }
602
603 EXPORT_SYMBOL(hpet_alloc);
604 EXPORT_SYMBOL(hpet_register);
605 EXPORT_SYMBOL(hpet_unregister);
606 EXPORT_SYMBOL(hpet_control);
607
608 int hpet_register(struct hpet_task *tp, int periodic)
609 {
610         unsigned int i;
611         u64 mask;
612         struct hpet_timer __iomem *timer;
613         struct hpet_dev *devp;
614         struct hpets *hpetp;
615
616         switch (periodic) {
617         case 1:
618                 mask = Tn_PER_INT_CAP_MASK;
619                 break;
620         case 0:
621                 mask = 0;
622                 break;
623         default:
624                 return -EINVAL;
625         }
626
627         tp->ht_opaque = NULL;
628
629         spin_lock_irq(&hpet_task_lock);
630         spin_lock(&hpet_lock);
631
632         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
633                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
634                      i < hpetp->hp_ntimer; i++, timer++) {
635                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
636                             != mask)
637                                 continue;
638
639                         devp = &hpetp->hp_dev[i];
640
641                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
642                                 devp = NULL;
643                                 continue;
644                         }
645
646                         tp->ht_opaque = devp;
647                         devp->hd_task = tp;
648                         break;
649                 }
650
651         spin_unlock(&hpet_lock);
652         spin_unlock_irq(&hpet_task_lock);
653
654         if (tp->ht_opaque)
655                 return 0;
656         else
657                 return -EBUSY;
658 }
659
660 static inline int hpet_tpcheck(struct hpet_task *tp)
661 {
662         struct hpet_dev *devp;
663         struct hpets *hpetp;
664
665         devp = tp->ht_opaque;
666
667         if (!devp)
668                 return -ENXIO;
669
670         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
671                 if (devp >= hpetp->hp_dev
672                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
673                     && devp->hd_hpet == hpetp->hp_hpet)
674                         return 0;
675
676         return -ENXIO;
677 }
678
679 int hpet_unregister(struct hpet_task *tp)
680 {
681         struct hpet_dev *devp;
682         struct hpet_timer __iomem *timer;
683         int err;
684
685         if ((err = hpet_tpcheck(tp)))
686                 return err;
687
688         spin_lock_irq(&hpet_task_lock);
689         spin_lock(&hpet_lock);
690
691         devp = tp->ht_opaque;
692         if (devp->hd_task != tp) {
693                 spin_unlock(&hpet_lock);
694                 spin_unlock_irq(&hpet_task_lock);
695                 return -ENXIO;
696         }
697
698         timer = devp->hd_timer;
699         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
700                &timer->hpet_config);
701         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
702         devp->hd_task = NULL;
703         spin_unlock(&hpet_lock);
704         spin_unlock_irq(&hpet_task_lock);
705
706         return 0;
707 }
708
709 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
710 {
711         struct hpet_dev *devp;
712         int err;
713
714         if ((err = hpet_tpcheck(tp)))
715                 return err;
716
717         spin_lock_irq(&hpet_lock);
718         devp = tp->ht_opaque;
719         if (devp->hd_task != tp) {
720                 spin_unlock_irq(&hpet_lock);
721                 return -ENXIO;
722         }
723         spin_unlock_irq(&hpet_lock);
724         return hpet_ioctl_common(devp, cmd, arg, 1);
725 }
726
727 static ctl_table hpet_table[] = {
728         {
729          .ctl_name = CTL_UNNUMBERED,
730          .procname = "max-user-freq",
731          .data = &hpet_max_freq,
732          .maxlen = sizeof(int),
733          .mode = 0644,
734          .proc_handler = &proc_dointvec,
735          },
736         {.ctl_name = 0}
737 };
738
739 static ctl_table hpet_root[] = {
740         {
741          .ctl_name = CTL_UNNUMBERED,
742          .procname = "hpet",
743          .maxlen = 0,
744          .mode = 0555,
745          .child = hpet_table,
746          },
747         {.ctl_name = 0}
748 };
749
750 static ctl_table dev_root[] = {
751         {
752          .ctl_name = CTL_DEV,
753          .procname = "dev",
754          .maxlen = 0,
755          .mode = 0555,
756          .child = hpet_root,
757          },
758         {.ctl_name = 0}
759 };
760
761 static struct ctl_table_header *sysctl_header;
762
763 /*
764  * Adjustment for when arming the timer with
765  * initial conditions.  That is, main counter
766  * ticks expired before interrupts are enabled.
767  */
768 #define TICK_CALIBRATE  (1000UL)
769
770 static unsigned long hpet_calibrate(struct hpets *hpetp)
771 {
772         struct hpet_timer __iomem *timer = NULL;
773         unsigned long t, m, count, i, flags, start;
774         struct hpet_dev *devp;
775         int j;
776         struct hpet __iomem *hpet;
777
778         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
779                 if ((devp->hd_flags & HPET_OPEN) == 0) {
780                         timer = devp->hd_timer;
781                         break;
782                 }
783
784         if (!timer)
785                 return 0;
786
787         hpet = hpetp->hp_hpet;
788         t = read_counter(&timer->hpet_compare);
789
790         i = 0;
791         count = hpet_time_div(hpetp, TICK_CALIBRATE);
792
793         local_irq_save(flags);
794
795         start = read_counter(&hpet->hpet_mc);
796
797         do {
798                 m = read_counter(&hpet->hpet_mc);
799                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
800         } while (i++, (m - start) < count);
801
802         local_irq_restore(flags);
803
804         return (m - start) / i;
805 }
806
807 int hpet_alloc(struct hpet_data *hdp)
808 {
809         u64 cap, mcfg, hpet_config;
810         struct hpet_dev *devp;
811         u32 i, ntimer, irq;
812         struct hpets *hpetp;
813         size_t siz;
814         struct hpet __iomem *hpet;
815         static struct hpets *last = NULL;
816         unsigned long period, irq_bitmap;
817         unsigned long long temp;
818
819         /*
820          * hpet_alloc can be called by platform dependent code.
821          * If platform dependent code has allocated the hpet that
822          * ACPI has also reported, then we catch it here.
823          */
824         if (hpet_is_known(hdp)) {
825                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
826                         __FUNCTION__);
827                 return 0;
828         }
829
830         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
831                                       sizeof(struct hpet_dev));
832
833         hpetp = kzalloc(siz, GFP_KERNEL);
834
835         if (!hpetp)
836                 return -ENOMEM;
837
838         hpetp->hp_which = hpet_nhpet++;
839         hpetp->hp_hpet = hdp->hd_address;
840         hpetp->hp_hpet_phys = hdp->hd_phys_address;
841
842         hpetp->hp_ntimer = hdp->hd_nirqs;
843         hpet = hpetp->hp_hpet;
844
845         /* Assign IRQs statically for legacy devices */
846         hpetp->hp_dev[0].hd_hdwirq = hdp->hd_irq[0];
847         hpetp->hp_dev[1].hd_hdwirq = hdp->hd_irq[1];
848
849         /* Assign IRQs dynamically for the others */
850         for (i = 2, devp = &hpetp->hp_dev[2]; i < hdp->hd_nirqs; i++, devp++) {
851                 struct hpet_timer __iomem *timer;
852
853                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
854
855                 /* Check if there's already an IRQ assigned to the timer */
856                 if (hdp->hd_irq[i]) {
857                         hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
858                         continue;
859                 }
860
861                 hpet_config = readq(&timer->hpet_config);
862                 irq_bitmap = (hpet_config & Tn_INT_ROUTE_CAP_MASK)
863                         >> Tn_INT_ROUTE_CAP_SHIFT;
864                 if (!irq_bitmap)
865                         irq = 0;        /* No valid IRQ Assignable */
866                 else {
867                         irq = find_first_bit(&irq_bitmap, 32);
868                         do {
869                                 hpet_config |= irq << Tn_INT_ROUTE_CNF_SHIFT;
870                                 writeq(hpet_config, &timer->hpet_config);
871
872                                 /*
873                                  * Verify whether we have written a valid
874                                  * IRQ number by reading it back again
875                                  */
876                                 hpet_config = readq(&timer->hpet_config);
877                                 if (irq == (hpet_config & Tn_INT_ROUTE_CNF_MASK)
878                                                 >> Tn_INT_ROUTE_CNF_SHIFT)
879                                         break;  /* Success */
880                         } while ((irq = (find_next_bit(&irq_bitmap, 32, irq))));
881                 }
882                 hpetp->hp_dev[i].hd_hdwirq = irq;
883         }
884
885         cap = readq(&hpet->hpet_cap);
886
887         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
888
889         if (hpetp->hp_ntimer != ntimer) {
890                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
891                        " with number of timers\n");
892                 kfree(hpetp);
893                 return -ENODEV;
894         }
895
896         if (last)
897                 last->hp_next = hpetp;
898         else
899                 hpets = hpetp;
900
901         last = hpetp;
902
903         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
904                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
905         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
906         temp += period >> 1; /* round */
907         do_div(temp, period);
908         hpetp->hp_tick_freq = temp; /* ticks per second */
909
910         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
911                 hpetp->hp_which, hdp->hd_phys_address,
912                 hpetp->hp_ntimer > 1 ? "s" : "");
913         for (i = 0; i < hpetp->hp_ntimer; i++)
914                 printk("%s %d", i > 0 ? "," : "",
915                                 hpetp->hp_dev[i].hd_hdwirq);
916         printk("\n");
917
918         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
919                hpetp->hp_which, hpetp->hp_ntimer,
920                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
921
922         mcfg = readq(&hpet->hpet_config);
923         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
924                 write_counter(0L, &hpet->hpet_mc);
925                 mcfg |= HPET_ENABLE_CNF_MASK;
926                 writeq(mcfg, &hpet->hpet_config);
927         }
928
929         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
930                 struct hpet_timer __iomem *timer;
931
932                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
933
934                 devp->hd_hpets = hpetp;
935                 devp->hd_hpet = hpet;
936                 devp->hd_timer = timer;
937
938                 /*
939                  * If the timer was reserved by platform code,
940                  * then make timer unavailable for opens.
941                  */
942                 if (hdp->hd_state & (1 << i)) {
943                         devp->hd_flags = HPET_OPEN;
944                         continue;
945                 }
946
947                 init_waitqueue_head(&devp->hd_waitqueue);
948         }
949
950         hpetp->hp_delta = hpet_calibrate(hpetp);
951
952 /* This clocksource driver currently only works on ia64 */
953 #ifdef CONFIG_IA64
954         if (!hpet_clocksource) {
955                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
956                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
957                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
958                                                 clocksource_hpet.shift);
959                 clocksource_register(&clocksource_hpet);
960                 hpetp->hp_clocksource = &clocksource_hpet;
961                 hpet_clocksource = &clocksource_hpet;
962         }
963 #endif
964
965         return 0;
966 }
967
968 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
969 {
970         struct hpet_data *hdp;
971         acpi_status status;
972         struct acpi_resource_address64 addr;
973
974         hdp = data;
975
976         status = acpi_resource_to_address64(res, &addr);
977
978         if (ACPI_SUCCESS(status)) {
979                 hdp->hd_phys_address = addr.minimum;
980                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
981
982                 if (hpet_is_known(hdp)) {
983                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
984                                 __FUNCTION__, hdp->hd_phys_address);
985                         iounmap(hdp->hd_address);
986                         return AE_ALREADY_EXISTS;
987                 }
988         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
989                 struct acpi_resource_fixed_memory32 *fixmem32;
990
991                 fixmem32 = &res->data.fixed_memory32;
992                 if (!fixmem32)
993                         return AE_NO_MEMORY;
994
995                 hdp->hd_phys_address = fixmem32->address;
996                 hdp->hd_address = ioremap(fixmem32->address,
997                                                 HPET_RANGE_SIZE);
998
999                 if (hpet_is_known(hdp)) {
1000                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
1001                                 __FUNCTION__, hdp->hd_phys_address);
1002                         iounmap(hdp->hd_address);
1003                         return AE_ALREADY_EXISTS;
1004                 }
1005         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
1006                 struct acpi_resource_extended_irq *irqp;
1007                 int i, irq;
1008
1009                 irqp = &res->data.extended_irq;
1010
1011                 for (i = 0; i < irqp->interrupt_count; i++) {
1012                         irq = acpi_register_gsi(irqp->interrupts[i],
1013                                       irqp->triggering, irqp->polarity);
1014                         if (irq < 0)
1015                                 return AE_ERROR;
1016
1017                         hdp->hd_irq[hdp->hd_nirqs] = irq;
1018                         hdp->hd_nirqs++;
1019                 }
1020         }
1021
1022         return AE_OK;
1023 }
1024
1025 static int hpet_acpi_add(struct acpi_device *device)
1026 {
1027         acpi_status result;
1028         struct hpet_data data;
1029
1030         memset(&data, 0, sizeof(data));
1031
1032         result =
1033             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1034                                 hpet_resources, &data);
1035
1036         if (ACPI_FAILURE(result))
1037                 return -ENODEV;
1038
1039         if (!data.hd_address || !data.hd_nirqs) {
1040                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
1041                 return -ENODEV;
1042         }
1043
1044         return hpet_alloc(&data);
1045 }
1046
1047 static int hpet_acpi_remove(struct acpi_device *device, int type)
1048 {
1049         /* XXX need to unregister clocksource, dealloc mem, etc */
1050         return -EINVAL;
1051 }
1052
1053 static const struct acpi_device_id hpet_device_ids[] = {
1054         {"PNP0103", 0},
1055         {"", 0},
1056 };
1057 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1058
1059 static struct acpi_driver hpet_acpi_driver = {
1060         .name = "hpet",
1061         .ids = hpet_device_ids,
1062         .ops = {
1063                 .add = hpet_acpi_add,
1064                 .remove = hpet_acpi_remove,
1065                 },
1066 };
1067
1068 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1069
1070 static int __init hpet_init(void)
1071 {
1072         int result;
1073
1074         result = misc_register(&hpet_misc);
1075         if (result < 0)
1076                 return -ENODEV;
1077
1078         sysctl_header = register_sysctl_table(dev_root);
1079
1080         result = acpi_bus_register_driver(&hpet_acpi_driver);
1081         if (result < 0) {
1082                 if (sysctl_header)
1083                         unregister_sysctl_table(sysctl_header);
1084                 misc_deregister(&hpet_misc);
1085                 return result;
1086         }
1087
1088         return 0;
1089 }
1090
1091 static void __exit hpet_exit(void)
1092 {
1093         acpi_bus_unregister_driver(&hpet_acpi_driver);
1094
1095         if (sysctl_header)
1096                 unregister_sysctl_table(sysctl_header);
1097         misc_deregister(&hpet_misc);
1098
1099         return;
1100 }
1101
1102 module_init(hpet_init);
1103 module_exit(hpet_exit);
1104 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1105 MODULE_LICENSE("GPL");