random: add tracepoints for easier debugging and verification
[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/irq.h>
40 #include <asm/div64.h>
41
42 #include <linux/acpi.h>
43 #include <acpi/acpi_bus.h>
44 #include <linux/hpet.h>
45
46 /*
47  * The High Precision Event Timer driver.
48  * This driver is closely modelled after the rtc.c driver.
49  * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
50  */
51 #define HPET_USER_FREQ  (64)
52 #define HPET_DRIFT      (500)
53
54 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
55
56
57 /* WARNING -- don't get confused.  These macros are never used
58  * to write the (single) counter, and rarely to read it.
59  * They're badly named; to fix, someday.
60  */
61 #if BITS_PER_LONG == 64
62 #define write_counter(V, MC)    writeq(V, MC)
63 #define read_counter(MC)        readq(MC)
64 #else
65 #define write_counter(V, MC)    writel(V, MC)
66 #define read_counter(MC)        readl(MC)
67 #endif
68
69 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
70 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
71
72 /* This clocksource driver currently only works on ia64 */
73 #ifdef CONFIG_IA64
74 static void __iomem *hpet_mctr;
75
76 static cycle_t read_hpet(struct clocksource *cs)
77 {
78         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
79 }
80
81 static struct clocksource clocksource_hpet = {
82         .name           = "hpet",
83         .rating         = 250,
84         .read           = read_hpet,
85         .mask           = CLOCKSOURCE_MASK(64),
86         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
87 };
88 static struct clocksource *hpet_clocksource;
89 #endif
90
91 /* A lock for concurrent access by app and isr hpet activity. */
92 static DEFINE_SPINLOCK(hpet_lock);
93
94 #define HPET_DEV_NAME   (7)
95
96 struct hpet_dev {
97         struct hpets *hd_hpets;
98         struct hpet __iomem *hd_hpet;
99         struct hpet_timer __iomem *hd_timer;
100         unsigned long hd_ireqfreq;
101         unsigned long hd_irqdata;
102         wait_queue_head_t hd_waitqueue;
103         struct fasync_struct *hd_async_queue;
104         unsigned int hd_flags;
105         unsigned int hd_irq;
106         unsigned int hd_hdwirq;
107         char hd_name[HPET_DEV_NAME];
108 };
109
110 struct hpets {
111         struct hpets *hp_next;
112         struct hpet __iomem *hp_hpet;
113         unsigned long hp_hpet_phys;
114         struct clocksource *hp_clocksource;
115         unsigned long long hp_tick_freq;
116         unsigned long hp_delta;
117         unsigned int hp_ntimer;
118         unsigned int hp_which;
119         struct hpet_dev hp_dev[1];
120 };
121
122 static struct hpets *hpets;
123
124 #define HPET_OPEN               0x0001
125 #define HPET_IE                 0x0002  /* interrupt enabled */
126 #define HPET_PERIODIC           0x0004
127 #define HPET_SHARED_IRQ         0x0008
128
129
130 #ifndef readq
131 static inline unsigned long long readq(void __iomem *addr)
132 {
133         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
134 }
135 #endif
136
137 #ifndef writeq
138 static inline void writeq(unsigned long long v, void __iomem *addr)
139 {
140         writel(v & 0xffffffff, addr);
141         writel(v >> 32, addr + 4);
142 }
143 #endif
144
145 static irqreturn_t hpet_interrupt(int irq, void *data)
146 {
147         struct hpet_dev *devp;
148         unsigned long isr;
149
150         devp = data;
151         isr = 1 << (devp - devp->hd_hpets->hp_dev);
152
153         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
154             !(isr & readl(&devp->hd_hpet->hpet_isr)))
155                 return IRQ_NONE;
156
157         spin_lock(&hpet_lock);
158         devp->hd_irqdata++;
159
160         /*
161          * For non-periodic timers, increment the accumulator.
162          * This has the effect of treating non-periodic like periodic.
163          */
164         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
165                 unsigned long m, t, mc, base, k;
166                 struct hpet __iomem *hpet = devp->hd_hpet;
167                 struct hpets *hpetp = devp->hd_hpets;
168
169                 t = devp->hd_ireqfreq;
170                 m = read_counter(&devp->hd_timer->hpet_compare);
171                 mc = read_counter(&hpet->hpet_mc);
172                 /* The time for the next interrupt would logically be t + m,
173                  * however, if we are very unlucky and the interrupt is delayed
174                  * for longer than t then we will completely miss the next
175                  * interrupt if we set t + m and an application will hang.
176                  * Therefore we need to make a more complex computation assuming
177                  * that there exists a k for which the following is true:
178                  * k * t + base < mc + delta
179                  * (k + 1) * t + base > mc + delta
180                  * where t is the interval in hpet ticks for the given freq,
181                  * base is the theoretical start value 0 < base < t,
182                  * mc is the main counter value at the time of the interrupt,
183                  * delta is the time it takes to write the a value to the
184                  * comparator.
185                  * k may then be computed as (mc - base + delta) / t .
186                  */
187                 base = mc % t;
188                 k = (mc - base + hpetp->hp_delta) / t;
189                 write_counter(t * (k + 1) + base,
190                               &devp->hd_timer->hpet_compare);
191         }
192
193         if (devp->hd_flags & HPET_SHARED_IRQ)
194                 writel(isr, &devp->hd_hpet->hpet_isr);
195         spin_unlock(&hpet_lock);
196
197         wake_up_interruptible(&devp->hd_waitqueue);
198
199         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
200
201         return IRQ_HANDLED;
202 }
203
204 static void hpet_timer_set_irq(struct hpet_dev *devp)
205 {
206         unsigned long v;
207         int irq, gsi;
208         struct hpet_timer __iomem *timer;
209
210         spin_lock_irq(&hpet_lock);
211         if (devp->hd_hdwirq) {
212                 spin_unlock_irq(&hpet_lock);
213                 return;
214         }
215
216         timer = devp->hd_timer;
217
218         /* we prefer level triggered mode */
219         v = readl(&timer->hpet_config);
220         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
221                 v |= Tn_INT_TYPE_CNF_MASK;
222                 writel(v, &timer->hpet_config);
223         }
224         spin_unlock_irq(&hpet_lock);
225
226         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
227                                  Tn_INT_ROUTE_CAP_SHIFT;
228
229         /*
230          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
231          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
232          */
233         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
234                 v &= ~0xf3df;
235         else
236                 v &= ~0xffff;
237
238         for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
239                 if (irq >= nr_irqs) {
240                         irq = HPET_MAX_IRQ;
241                         break;
242                 }
243
244                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
245                                         ACPI_ACTIVE_LOW);
246                 if (gsi > 0)
247                         break;
248
249                 /* FIXME: Setup interrupt source table */
250         }
251
252         if (irq < HPET_MAX_IRQ) {
253                 spin_lock_irq(&hpet_lock);
254                 v = readl(&timer->hpet_config);
255                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
256                 writel(v, &timer->hpet_config);
257                 devp->hd_hdwirq = gsi;
258                 spin_unlock_irq(&hpet_lock);
259         }
260         return;
261 }
262
263 static int hpet_open(struct inode *inode, struct file *file)
264 {
265         struct hpet_dev *devp;
266         struct hpets *hpetp;
267         int i;
268
269         if (file->f_mode & FMODE_WRITE)
270                 return -EINVAL;
271
272         mutex_lock(&hpet_mutex);
273         spin_lock_irq(&hpet_lock);
274
275         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
276                 for (i = 0; i < hpetp->hp_ntimer; i++)
277                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
278                                 continue;
279                         else {
280                                 devp = &hpetp->hp_dev[i];
281                                 break;
282                         }
283
284         if (!devp) {
285                 spin_unlock_irq(&hpet_lock);
286                 mutex_unlock(&hpet_mutex);
287                 return -EBUSY;
288         }
289
290         file->private_data = devp;
291         devp->hd_irqdata = 0;
292         devp->hd_flags |= HPET_OPEN;
293         spin_unlock_irq(&hpet_lock);
294         mutex_unlock(&hpet_mutex);
295
296         hpet_timer_set_irq(devp);
297
298         return 0;
299 }
300
301 static ssize_t
302 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
303 {
304         DECLARE_WAITQUEUE(wait, current);
305         unsigned long data;
306         ssize_t retval;
307         struct hpet_dev *devp;
308
309         devp = file->private_data;
310         if (!devp->hd_ireqfreq)
311                 return -EIO;
312
313         if (count < sizeof(unsigned long))
314                 return -EINVAL;
315
316         add_wait_queue(&devp->hd_waitqueue, &wait);
317
318         for ( ; ; ) {
319                 set_current_state(TASK_INTERRUPTIBLE);
320
321                 spin_lock_irq(&hpet_lock);
322                 data = devp->hd_irqdata;
323                 devp->hd_irqdata = 0;
324                 spin_unlock_irq(&hpet_lock);
325
326                 if (data)
327                         break;
328                 else if (file->f_flags & O_NONBLOCK) {
329                         retval = -EAGAIN;
330                         goto out;
331                 } else if (signal_pending(current)) {
332                         retval = -ERESTARTSYS;
333                         goto out;
334                 }
335                 schedule();
336         }
337
338         retval = put_user(data, (unsigned long __user *)buf);
339         if (!retval)
340                 retval = sizeof(unsigned long);
341 out:
342         __set_current_state(TASK_RUNNING);
343         remove_wait_queue(&devp->hd_waitqueue, &wait);
344
345         return retval;
346 }
347
348 static unsigned int hpet_poll(struct file *file, poll_table * wait)
349 {
350         unsigned long v;
351         struct hpet_dev *devp;
352
353         devp = file->private_data;
354
355         if (!devp->hd_ireqfreq)
356                 return 0;
357
358         poll_wait(file, &devp->hd_waitqueue, wait);
359
360         spin_lock_irq(&hpet_lock);
361         v = devp->hd_irqdata;
362         spin_unlock_irq(&hpet_lock);
363
364         if (v != 0)
365                 return POLLIN | POLLRDNORM;
366
367         return 0;
368 }
369
370 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
371 {
372 #ifdef  CONFIG_HPET_MMAP
373         struct hpet_dev *devp;
374         unsigned long addr;
375
376         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
377                 return -EINVAL;
378
379         devp = file->private_data;
380         addr = devp->hd_hpets->hp_hpet_phys;
381
382         if (addr & (PAGE_SIZE - 1))
383                 return -ENOSYS;
384
385         vma->vm_flags |= VM_IO;
386         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
387
388         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
389                                         PAGE_SIZE, vma->vm_page_prot)) {
390                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
391                         __func__);
392                 return -EAGAIN;
393         }
394
395         return 0;
396 #else
397         return -ENOSYS;
398 #endif
399 }
400
401 static int hpet_fasync(int fd, struct file *file, int on)
402 {
403         struct hpet_dev *devp;
404
405         devp = file->private_data;
406
407         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
408                 return 0;
409         else
410                 return -EIO;
411 }
412
413 static int hpet_release(struct inode *inode, struct file *file)
414 {
415         struct hpet_dev *devp;
416         struct hpet_timer __iomem *timer;
417         int irq = 0;
418
419         devp = file->private_data;
420         timer = devp->hd_timer;
421
422         spin_lock_irq(&hpet_lock);
423
424         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
425                &timer->hpet_config);
426
427         irq = devp->hd_irq;
428         devp->hd_irq = 0;
429
430         devp->hd_ireqfreq = 0;
431
432         if (devp->hd_flags & HPET_PERIODIC
433             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
434                 unsigned long v;
435
436                 v = readq(&timer->hpet_config);
437                 v ^= Tn_TYPE_CNF_MASK;
438                 writeq(v, &timer->hpet_config);
439         }
440
441         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
442         spin_unlock_irq(&hpet_lock);
443
444         if (irq)
445                 free_irq(irq, devp);
446
447         file->private_data = NULL;
448         return 0;
449 }
450
451 static int hpet_ioctl_ieon(struct hpet_dev *devp)
452 {
453         struct hpet_timer __iomem *timer;
454         struct hpet __iomem *hpet;
455         struct hpets *hpetp;
456         int irq;
457         unsigned long g, v, t, m;
458         unsigned long flags, isr;
459
460         timer = devp->hd_timer;
461         hpet = devp->hd_hpet;
462         hpetp = devp->hd_hpets;
463
464         if (!devp->hd_ireqfreq)
465                 return -EIO;
466
467         spin_lock_irq(&hpet_lock);
468
469         if (devp->hd_flags & HPET_IE) {
470                 spin_unlock_irq(&hpet_lock);
471                 return -EBUSY;
472         }
473
474         devp->hd_flags |= HPET_IE;
475
476         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
477                 devp->hd_flags |= HPET_SHARED_IRQ;
478         spin_unlock_irq(&hpet_lock);
479
480         irq = devp->hd_hdwirq;
481
482         if (irq) {
483                 unsigned long irq_flags;
484
485                 if (devp->hd_flags & HPET_SHARED_IRQ) {
486                         /*
487                          * To prevent the interrupt handler from seeing an
488                          * unwanted interrupt status bit, program the timer
489                          * so that it will not fire in the near future ...
490                          */
491                         writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
492                                &timer->hpet_config);
493                         write_counter(read_counter(&hpet->hpet_mc),
494                                       &timer->hpet_compare);
495                         /* ... and clear any left-over status. */
496                         isr = 1 << (devp - devp->hd_hpets->hp_dev);
497                         writel(isr, &hpet->hpet_isr);
498                 }
499
500                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
501                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
502                                                 ? IRQF_SHARED : IRQF_DISABLED;
503                 if (request_irq(irq, hpet_interrupt, irq_flags,
504                                 devp->hd_name, (void *)devp)) {
505                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
506                         irq = 0;
507                 }
508         }
509
510         if (irq == 0) {
511                 spin_lock_irq(&hpet_lock);
512                 devp->hd_flags ^= HPET_IE;
513                 spin_unlock_irq(&hpet_lock);
514                 return -EIO;
515         }
516
517         devp->hd_irq = irq;
518         t = devp->hd_ireqfreq;
519         v = readq(&timer->hpet_config);
520
521         /* 64-bit comparators are not yet supported through the ioctls,
522          * so force this into 32-bit mode if it supports both modes
523          */
524         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
525
526         if (devp->hd_flags & HPET_PERIODIC) {
527                 g |= Tn_TYPE_CNF_MASK;
528                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
529                 writeq(v, &timer->hpet_config);
530                 local_irq_save(flags);
531
532                 /*
533                  * NOTE: First we modify the hidden accumulator
534                  * register supported by periodic-capable comparators.
535                  * We never want to modify the (single) counter; that
536                  * would affect all the comparators. The value written
537                  * is the counter value when the first interrupt is due.
538                  */
539                 m = read_counter(&hpet->hpet_mc);
540                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
541                 /*
542                  * Then we modify the comparator, indicating the period
543                  * for subsequent interrupt.
544                  */
545                 write_counter(t, &timer->hpet_compare);
546         } else {
547                 local_irq_save(flags);
548                 m = read_counter(&hpet->hpet_mc);
549                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
550         }
551
552         if (devp->hd_flags & HPET_SHARED_IRQ) {
553                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
554                 writel(isr, &hpet->hpet_isr);
555         }
556         writeq(g, &timer->hpet_config);
557         local_irq_restore(flags);
558
559         return 0;
560 }
561
562 /* converts Hz to number of timer ticks */
563 static inline unsigned long hpet_time_div(struct hpets *hpets,
564                                           unsigned long dis)
565 {
566         unsigned long long m;
567
568         m = hpets->hp_tick_freq + (dis >> 1);
569         do_div(m, dis);
570         return (unsigned long)m;
571 }
572
573 static int
574 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
575                   struct hpet_info *info)
576 {
577         struct hpet_timer __iomem *timer;
578         struct hpet __iomem *hpet;
579         struct hpets *hpetp;
580         int err;
581         unsigned long v;
582
583         switch (cmd) {
584         case HPET_IE_OFF:
585         case HPET_INFO:
586         case HPET_EPI:
587         case HPET_DPI:
588         case HPET_IRQFREQ:
589                 timer = devp->hd_timer;
590                 hpet = devp->hd_hpet;
591                 hpetp = devp->hd_hpets;
592                 break;
593         case HPET_IE_ON:
594                 return hpet_ioctl_ieon(devp);
595         default:
596                 return -EINVAL;
597         }
598
599         err = 0;
600
601         switch (cmd) {
602         case HPET_IE_OFF:
603                 if ((devp->hd_flags & HPET_IE) == 0)
604                         break;
605                 v = readq(&timer->hpet_config);
606                 v &= ~Tn_INT_ENB_CNF_MASK;
607                 writeq(v, &timer->hpet_config);
608                 if (devp->hd_irq) {
609                         free_irq(devp->hd_irq, devp);
610                         devp->hd_irq = 0;
611                 }
612                 devp->hd_flags ^= HPET_IE;
613                 break;
614         case HPET_INFO:
615                 {
616                         memset(info, 0, sizeof(*info));
617                         if (devp->hd_ireqfreq)
618                                 info->hi_ireqfreq =
619                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
620                         info->hi_flags =
621                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
622                         info->hi_hpet = hpetp->hp_which;
623                         info->hi_timer = devp - hpetp->hp_dev;
624                         break;
625                 }
626         case HPET_EPI:
627                 v = readq(&timer->hpet_config);
628                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
629                         err = -ENXIO;
630                         break;
631                 }
632                 devp->hd_flags |= HPET_PERIODIC;
633                 break;
634         case HPET_DPI:
635                 v = readq(&timer->hpet_config);
636                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
637                         err = -ENXIO;
638                         break;
639                 }
640                 if (devp->hd_flags & HPET_PERIODIC &&
641                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
642                         v = readq(&timer->hpet_config);
643                         v ^= Tn_TYPE_CNF_MASK;
644                         writeq(v, &timer->hpet_config);
645                 }
646                 devp->hd_flags &= ~HPET_PERIODIC;
647                 break;
648         case HPET_IRQFREQ:
649                 if ((arg > hpet_max_freq) &&
650                     !capable(CAP_SYS_RESOURCE)) {
651                         err = -EACCES;
652                         break;
653                 }
654
655                 if (!arg) {
656                         err = -EINVAL;
657                         break;
658                 }
659
660                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
661         }
662
663         return err;
664 }
665
666 static long
667 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
668 {
669         struct hpet_info info;
670         int err;
671
672         mutex_lock(&hpet_mutex);
673         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
674         mutex_unlock(&hpet_mutex);
675
676         if ((cmd == HPET_INFO) && !err &&
677             (copy_to_user((void __user *)arg, &info, sizeof(info))))
678                 err = -EFAULT;
679
680         return err;
681 }
682
683 #ifdef CONFIG_COMPAT
684 struct compat_hpet_info {
685         compat_ulong_t hi_ireqfreq;     /* Hz */
686         compat_ulong_t hi_flags;        /* information */
687         unsigned short hi_hpet;
688         unsigned short hi_timer;
689 };
690
691 static long
692 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
693 {
694         struct hpet_info info;
695         int err;
696
697         mutex_lock(&hpet_mutex);
698         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
699         mutex_unlock(&hpet_mutex);
700
701         if ((cmd == HPET_INFO) && !err) {
702                 struct compat_hpet_info __user *u = compat_ptr(arg);
703                 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
704                     put_user(info.hi_flags, &u->hi_flags) ||
705                     put_user(info.hi_hpet, &u->hi_hpet) ||
706                     put_user(info.hi_timer, &u->hi_timer))
707                         err = -EFAULT;
708         }
709
710         return err;
711 }
712 #endif
713
714 static const struct file_operations hpet_fops = {
715         .owner = THIS_MODULE,
716         .llseek = no_llseek,
717         .read = hpet_read,
718         .poll = hpet_poll,
719         .unlocked_ioctl = hpet_ioctl,
720 #ifdef CONFIG_COMPAT
721         .compat_ioctl = hpet_compat_ioctl,
722 #endif
723         .open = hpet_open,
724         .release = hpet_release,
725         .fasync = hpet_fasync,
726         .mmap = hpet_mmap,
727 };
728
729 static int hpet_is_known(struct hpet_data *hdp)
730 {
731         struct hpets *hpetp;
732
733         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
734                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
735                         return 1;
736
737         return 0;
738 }
739
740 static ctl_table hpet_table[] = {
741         {
742          .procname = "max-user-freq",
743          .data = &hpet_max_freq,
744          .maxlen = sizeof(int),
745          .mode = 0644,
746          .proc_handler = proc_dointvec,
747          },
748         {}
749 };
750
751 static ctl_table hpet_root[] = {
752         {
753          .procname = "hpet",
754          .maxlen = 0,
755          .mode = 0555,
756          .child = hpet_table,
757          },
758         {}
759 };
760
761 static ctl_table dev_root[] = {
762         {
763          .procname = "dev",
764          .maxlen = 0,
765          .mode = 0555,
766          .child = hpet_root,
767          },
768         {}
769 };
770
771 static struct ctl_table_header *sysctl_header;
772
773 /*
774  * Adjustment for when arming the timer with
775  * initial conditions.  That is, main counter
776  * ticks expired before interrupts are enabled.
777  */
778 #define TICK_CALIBRATE  (1000UL)
779
780 static unsigned long __hpet_calibrate(struct hpets *hpetp)
781 {
782         struct hpet_timer __iomem *timer = NULL;
783         unsigned long t, m, count, i, flags, start;
784         struct hpet_dev *devp;
785         int j;
786         struct hpet __iomem *hpet;
787
788         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
789                 if ((devp->hd_flags & HPET_OPEN) == 0) {
790                         timer = devp->hd_timer;
791                         break;
792                 }
793
794         if (!timer)
795                 return 0;
796
797         hpet = hpetp->hp_hpet;
798         t = read_counter(&timer->hpet_compare);
799
800         i = 0;
801         count = hpet_time_div(hpetp, TICK_CALIBRATE);
802
803         local_irq_save(flags);
804
805         start = read_counter(&hpet->hpet_mc);
806
807         do {
808                 m = read_counter(&hpet->hpet_mc);
809                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
810         } while (i++, (m - start) < count);
811
812         local_irq_restore(flags);
813
814         return (m - start) / i;
815 }
816
817 static unsigned long hpet_calibrate(struct hpets *hpetp)
818 {
819         unsigned long ret = -1;
820         unsigned long tmp;
821
822         /*
823          * Try to calibrate until return value becomes stable small value.
824          * If SMI interruption occurs in calibration loop, the return value
825          * will be big. This avoids its impact.
826          */
827         for ( ; ; ) {
828                 tmp = __hpet_calibrate(hpetp);
829                 if (ret <= tmp)
830                         break;
831                 ret = tmp;
832         }
833
834         return ret;
835 }
836
837 int hpet_alloc(struct hpet_data *hdp)
838 {
839         u64 cap, mcfg;
840         struct hpet_dev *devp;
841         u32 i, ntimer;
842         struct hpets *hpetp;
843         size_t siz;
844         struct hpet __iomem *hpet;
845         static struct hpets *last;
846         unsigned long period;
847         unsigned long long temp;
848         u32 remainder;
849
850         /*
851          * hpet_alloc can be called by platform dependent code.
852          * If platform dependent code has allocated the hpet that
853          * ACPI has also reported, then we catch it here.
854          */
855         if (hpet_is_known(hdp)) {
856                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
857                         __func__);
858                 return 0;
859         }
860
861         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
862                                       sizeof(struct hpet_dev));
863
864         hpetp = kzalloc(siz, GFP_KERNEL);
865
866         if (!hpetp)
867                 return -ENOMEM;
868
869         hpetp->hp_which = hpet_nhpet++;
870         hpetp->hp_hpet = hdp->hd_address;
871         hpetp->hp_hpet_phys = hdp->hd_phys_address;
872
873         hpetp->hp_ntimer = hdp->hd_nirqs;
874
875         for (i = 0; i < hdp->hd_nirqs; i++)
876                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
877
878         hpet = hpetp->hp_hpet;
879
880         cap = readq(&hpet->hpet_cap);
881
882         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
883
884         if (hpetp->hp_ntimer != ntimer) {
885                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
886                        " with number of timers\n");
887                 kfree(hpetp);
888                 return -ENODEV;
889         }
890
891         if (last)
892                 last->hp_next = hpetp;
893         else
894                 hpets = hpetp;
895
896         last = hpetp;
897
898         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
899                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
900         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
901         temp += period >> 1; /* round */
902         do_div(temp, period);
903         hpetp->hp_tick_freq = temp; /* ticks per second */
904
905         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
906                 hpetp->hp_which, hdp->hd_phys_address,
907                 hpetp->hp_ntimer > 1 ? "s" : "");
908         for (i = 0; i < hpetp->hp_ntimer; i++)
909                 printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
910         printk(KERN_CONT "\n");
911
912         temp = hpetp->hp_tick_freq;
913         remainder = do_div(temp, 1000000);
914         printk(KERN_INFO
915                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
916                 hpetp->hp_which, hpetp->hp_ntimer,
917                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
918                 (unsigned) temp, remainder);
919
920         mcfg = readq(&hpet->hpet_config);
921         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
922                 write_counter(0L, &hpet->hpet_mc);
923                 mcfg |= HPET_ENABLE_CNF_MASK;
924                 writeq(mcfg, &hpet->hpet_config);
925         }
926
927         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
928                 struct hpet_timer __iomem *timer;
929
930                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
931
932                 devp->hd_hpets = hpetp;
933                 devp->hd_hpet = hpet;
934                 devp->hd_timer = timer;
935
936                 /*
937                  * If the timer was reserved by platform code,
938                  * then make timer unavailable for opens.
939                  */
940                 if (hdp->hd_state & (1 << i)) {
941                         devp->hd_flags = HPET_OPEN;
942                         continue;
943                 }
944
945                 init_waitqueue_head(&devp->hd_waitqueue);
946         }
947
948         hpetp->hp_delta = hpet_calibrate(hpetp);
949
950 /* This clocksource driver currently only works on ia64 */
951 #ifdef CONFIG_IA64
952         if (!hpet_clocksource) {
953                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
954                 clocksource_hpet.archdata.fsys_mmio = hpet_mctr;
955                 clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
956                 hpetp->hp_clocksource = &clocksource_hpet;
957                 hpet_clocksource = &clocksource_hpet;
958         }
959 #endif
960
961         return 0;
962 }
963
964 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
965 {
966         struct hpet_data *hdp;
967         acpi_status status;
968         struct acpi_resource_address64 addr;
969
970         hdp = data;
971
972         status = acpi_resource_to_address64(res, &addr);
973
974         if (ACPI_SUCCESS(status)) {
975                 hdp->hd_phys_address = addr.minimum;
976                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
977
978                 if (hpet_is_known(hdp)) {
979                         iounmap(hdp->hd_address);
980                         return AE_ALREADY_EXISTS;
981                 }
982         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
983                 struct acpi_resource_fixed_memory32 *fixmem32;
984
985                 fixmem32 = &res->data.fixed_memory32;
986                 if (!fixmem32)
987                         return AE_NO_MEMORY;
988
989                 hdp->hd_phys_address = fixmem32->address;
990                 hdp->hd_address = ioremap(fixmem32->address,
991                                                 HPET_RANGE_SIZE);
992
993                 if (hpet_is_known(hdp)) {
994                         iounmap(hdp->hd_address);
995                         return AE_ALREADY_EXISTS;
996                 }
997         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
998                 struct acpi_resource_extended_irq *irqp;
999                 int i, irq;
1000
1001                 irqp = &res->data.extended_irq;
1002
1003                 for (i = 0; i < irqp->interrupt_count; i++) {
1004                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
1005                                       irqp->triggering, irqp->polarity);
1006                         if (irq < 0)
1007                                 return AE_ERROR;
1008
1009                         hdp->hd_irq[hdp->hd_nirqs] = irq;
1010                         hdp->hd_nirqs++;
1011                 }
1012         }
1013
1014         return AE_OK;
1015 }
1016
1017 static int hpet_acpi_add(struct acpi_device *device)
1018 {
1019         acpi_status result;
1020         struct hpet_data data;
1021
1022         memset(&data, 0, sizeof(data));
1023
1024         result =
1025             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1026                                 hpet_resources, &data);
1027
1028         if (ACPI_FAILURE(result))
1029                 return -ENODEV;
1030
1031         if (!data.hd_address || !data.hd_nirqs) {
1032                 if (data.hd_address)
1033                         iounmap(data.hd_address);
1034                 printk("%s: no address or irqs in _CRS\n", __func__);
1035                 return -ENODEV;
1036         }
1037
1038         return hpet_alloc(&data);
1039 }
1040
1041 static int hpet_acpi_remove(struct acpi_device *device, int type)
1042 {
1043         /* XXX need to unregister clocksource, dealloc mem, etc */
1044         return -EINVAL;
1045 }
1046
1047 static const struct acpi_device_id hpet_device_ids[] = {
1048         {"PNP0103", 0},
1049         {"", 0},
1050 };
1051 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1052
1053 static struct acpi_driver hpet_acpi_driver = {
1054         .name = "hpet",
1055         .ids = hpet_device_ids,
1056         .ops = {
1057                 .add = hpet_acpi_add,
1058                 .remove = hpet_acpi_remove,
1059                 },
1060 };
1061
1062 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1063
1064 static int __init hpet_init(void)
1065 {
1066         int result;
1067
1068         result = misc_register(&hpet_misc);
1069         if (result < 0)
1070                 return -ENODEV;
1071
1072         sysctl_header = register_sysctl_table(dev_root);
1073
1074         result = acpi_bus_register_driver(&hpet_acpi_driver);
1075         if (result < 0) {
1076                 if (sysctl_header)
1077                         unregister_sysctl_table(sysctl_header);
1078                 misc_deregister(&hpet_misc);
1079                 return result;
1080         }
1081
1082         return 0;
1083 }
1084
1085 static void __exit hpet_exit(void)
1086 {
1087         acpi_bus_unregister_driver(&hpet_acpi_driver);
1088
1089         if (sysctl_header)
1090                 unregister_sysctl_table(sysctl_header);
1091         misc_deregister(&hpet_misc);
1092
1093         return;
1094 }
1095
1096 module_init(hpet_init);
1097 module_exit(hpet_exit);
1098 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1099 MODULE_LICENSE("GPL");