Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux...
[sfrench/cifs-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 static inline int hpet_tpcheck(struct hpet_task *tp)
604 {
605         struct hpet_dev *devp;
606         struct hpets *hpetp;
607
608         devp = tp->ht_opaque;
609
610         if (!devp)
611                 return -ENXIO;
612
613         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
614                 if (devp >= hpetp->hp_dev
615                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
616                     && devp->hd_hpet == hpetp->hp_hpet)
617                         return 0;
618
619         return -ENXIO;
620 }
621
622 int hpet_unregister(struct hpet_task *tp)
623 {
624         struct hpet_dev *devp;
625         struct hpet_timer __iomem *timer;
626         int err;
627
628         if ((err = hpet_tpcheck(tp)))
629                 return err;
630
631         spin_lock_irq(&hpet_task_lock);
632         spin_lock(&hpet_lock);
633
634         devp = tp->ht_opaque;
635         if (devp->hd_task != tp) {
636                 spin_unlock(&hpet_lock);
637                 spin_unlock_irq(&hpet_task_lock);
638                 return -ENXIO;
639         }
640
641         timer = devp->hd_timer;
642         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
643                &timer->hpet_config);
644         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
645         devp->hd_task = NULL;
646         spin_unlock(&hpet_lock);
647         spin_unlock_irq(&hpet_task_lock);
648
649         return 0;
650 }
651
652 static ctl_table hpet_table[] = {
653         {
654          .ctl_name = CTL_UNNUMBERED,
655          .procname = "max-user-freq",
656          .data = &hpet_max_freq,
657          .maxlen = sizeof(int),
658          .mode = 0644,
659          .proc_handler = &proc_dointvec,
660          },
661         {.ctl_name = 0}
662 };
663
664 static ctl_table hpet_root[] = {
665         {
666          .ctl_name = CTL_UNNUMBERED,
667          .procname = "hpet",
668          .maxlen = 0,
669          .mode = 0555,
670          .child = hpet_table,
671          },
672         {.ctl_name = 0}
673 };
674
675 static ctl_table dev_root[] = {
676         {
677          .ctl_name = CTL_DEV,
678          .procname = "dev",
679          .maxlen = 0,
680          .mode = 0555,
681          .child = hpet_root,
682          },
683         {.ctl_name = 0}
684 };
685
686 static struct ctl_table_header *sysctl_header;
687
688 /*
689  * Adjustment for when arming the timer with
690  * initial conditions.  That is, main counter
691  * ticks expired before interrupts are enabled.
692  */
693 #define TICK_CALIBRATE  (1000UL)
694
695 static unsigned long hpet_calibrate(struct hpets *hpetp)
696 {
697         struct hpet_timer __iomem *timer = NULL;
698         unsigned long t, m, count, i, flags, start;
699         struct hpet_dev *devp;
700         int j;
701         struct hpet __iomem *hpet;
702
703         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
704                 if ((devp->hd_flags & HPET_OPEN) == 0) {
705                         timer = devp->hd_timer;
706                         break;
707                 }
708
709         if (!timer)
710                 return 0;
711
712         hpet = hpetp->hp_hpet;
713         t = read_counter(&timer->hpet_compare);
714
715         i = 0;
716         count = hpet_time_div(hpetp, TICK_CALIBRATE);
717
718         local_irq_save(flags);
719
720         start = read_counter(&hpet->hpet_mc);
721
722         do {
723                 m = read_counter(&hpet->hpet_mc);
724                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
725         } while (i++, (m - start) < count);
726
727         local_irq_restore(flags);
728
729         return (m - start) / i;
730 }
731
732 int hpet_alloc(struct hpet_data *hdp)
733 {
734         u64 cap, mcfg;
735         struct hpet_dev *devp;
736         u32 i, ntimer;
737         struct hpets *hpetp;
738         size_t siz;
739         struct hpet __iomem *hpet;
740         static struct hpets *last = NULL;
741         unsigned long period;
742         unsigned long long temp;
743
744         /*
745          * hpet_alloc can be called by platform dependent code.
746          * If platform dependent code has allocated the hpet that
747          * ACPI has also reported, then we catch it here.
748          */
749         if (hpet_is_known(hdp)) {
750                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
751                         __FUNCTION__);
752                 return 0;
753         }
754
755         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
756                                       sizeof(struct hpet_dev));
757
758         hpetp = kzalloc(siz, GFP_KERNEL);
759
760         if (!hpetp)
761                 return -ENOMEM;
762
763         hpetp->hp_which = hpet_nhpet++;
764         hpetp->hp_hpet = hdp->hd_address;
765         hpetp->hp_hpet_phys = hdp->hd_phys_address;
766
767         hpetp->hp_ntimer = hdp->hd_nirqs;
768
769         for (i = 0; i < hdp->hd_nirqs; i++)
770                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
771
772         hpet = hpetp->hp_hpet;
773
774         cap = readq(&hpet->hpet_cap);
775
776         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
777
778         if (hpetp->hp_ntimer != ntimer) {
779                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
780                        " with number of timers\n");
781                 kfree(hpetp);
782                 return -ENODEV;
783         }
784
785         if (last)
786                 last->hp_next = hpetp;
787         else
788                 hpets = hpetp;
789
790         last = hpetp;
791
792         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
793                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
794         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
795         temp += period >> 1; /* round */
796         do_div(temp, period);
797         hpetp->hp_tick_freq = temp; /* ticks per second */
798
799         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
800                 hpetp->hp_which, hdp->hd_phys_address,
801                 hpetp->hp_ntimer > 1 ? "s" : "");
802         for (i = 0; i < hpetp->hp_ntimer; i++)
803                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
804         printk("\n");
805
806         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
807                hpetp->hp_which, hpetp->hp_ntimer,
808                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
809
810         mcfg = readq(&hpet->hpet_config);
811         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
812                 write_counter(0L, &hpet->hpet_mc);
813                 mcfg |= HPET_ENABLE_CNF_MASK;
814                 writeq(mcfg, &hpet->hpet_config);
815         }
816
817         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
818                 struct hpet_timer __iomem *timer;
819
820                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
821
822                 devp->hd_hpets = hpetp;
823                 devp->hd_hpet = hpet;
824                 devp->hd_timer = timer;
825
826                 /*
827                  * If the timer was reserved by platform code,
828                  * then make timer unavailable for opens.
829                  */
830                 if (hdp->hd_state & (1 << i)) {
831                         devp->hd_flags = HPET_OPEN;
832                         continue;
833                 }
834
835                 init_waitqueue_head(&devp->hd_waitqueue);
836         }
837
838         hpetp->hp_delta = hpet_calibrate(hpetp);
839
840 /* This clocksource driver currently only works on ia64 */
841 #ifdef CONFIG_IA64
842         if (!hpet_clocksource) {
843                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
844                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
845                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
846                                                 clocksource_hpet.shift);
847                 clocksource_register(&clocksource_hpet);
848                 hpetp->hp_clocksource = &clocksource_hpet;
849                 hpet_clocksource = &clocksource_hpet;
850         }
851 #endif
852
853         return 0;
854 }
855
856 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
857 {
858         struct hpet_data *hdp;
859         acpi_status status;
860         struct acpi_resource_address64 addr;
861
862         hdp = data;
863
864         status = acpi_resource_to_address64(res, &addr);
865
866         if (ACPI_SUCCESS(status)) {
867                 hdp->hd_phys_address = addr.minimum;
868                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
869
870                 if (hpet_is_known(hdp)) {
871                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
872                                 __FUNCTION__, hdp->hd_phys_address);
873                         iounmap(hdp->hd_address);
874                         return AE_ALREADY_EXISTS;
875                 }
876         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
877                 struct acpi_resource_fixed_memory32 *fixmem32;
878
879                 fixmem32 = &res->data.fixed_memory32;
880                 if (!fixmem32)
881                         return AE_NO_MEMORY;
882
883                 hdp->hd_phys_address = fixmem32->address;
884                 hdp->hd_address = ioremap(fixmem32->address,
885                                                 HPET_RANGE_SIZE);
886
887                 if (hpet_is_known(hdp)) {
888                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
889                                 __FUNCTION__, hdp->hd_phys_address);
890                         iounmap(hdp->hd_address);
891                         return AE_ALREADY_EXISTS;
892                 }
893         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
894                 struct acpi_resource_extended_irq *irqp;
895                 int i, irq;
896
897                 irqp = &res->data.extended_irq;
898
899                 for (i = 0; i < irqp->interrupt_count; i++) {
900                         irq = acpi_register_gsi(irqp->interrupts[i],
901                                       irqp->triggering, irqp->polarity);
902                         if (irq < 0)
903                                 return AE_ERROR;
904
905                         hdp->hd_irq[hdp->hd_nirqs] = irq;
906                         hdp->hd_nirqs++;
907                 }
908         }
909
910         return AE_OK;
911 }
912
913 static int hpet_acpi_add(struct acpi_device *device)
914 {
915         acpi_status result;
916         struct hpet_data data;
917
918         memset(&data, 0, sizeof(data));
919
920         result =
921             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
922                                 hpet_resources, &data);
923
924         if (ACPI_FAILURE(result))
925                 return -ENODEV;
926
927         if (!data.hd_address || !data.hd_nirqs) {
928                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
929                 return -ENODEV;
930         }
931
932         return hpet_alloc(&data);
933 }
934
935 static int hpet_acpi_remove(struct acpi_device *device, int type)
936 {
937         /* XXX need to unregister clocksource, dealloc mem, etc */
938         return -EINVAL;
939 }
940
941 static const struct acpi_device_id hpet_device_ids[] = {
942         {"PNP0103", 0},
943         {"", 0},
944 };
945 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
946
947 static struct acpi_driver hpet_acpi_driver = {
948         .name = "hpet",
949         .ids = hpet_device_ids,
950         .ops = {
951                 .add = hpet_acpi_add,
952                 .remove = hpet_acpi_remove,
953                 },
954 };
955
956 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
957
958 static int __init hpet_init(void)
959 {
960         int result;
961
962         result = misc_register(&hpet_misc);
963         if (result < 0)
964                 return -ENODEV;
965
966         sysctl_header = register_sysctl_table(dev_root);
967
968         result = acpi_bus_register_driver(&hpet_acpi_driver);
969         if (result < 0) {
970                 if (sysctl_header)
971                         unregister_sysctl_table(sysctl_header);
972                 misc_deregister(&hpet_misc);
973                 return result;
974         }
975
976         return 0;
977 }
978
979 static void __exit hpet_exit(void)
980 {
981         acpi_bus_unregister_driver(&hpet_acpi_driver);
982
983         if (sysctl_header)
984                 unregister_sysctl_table(sysctl_header);
985         misc_deregister(&hpet_misc);
986
987         return;
988 }
989
990 module_init(hpet_init);
991 module_exit(hpet_exit);
992 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
993 MODULE_LICENSE("GPL");