Merge commit 'v3.0' into x86/vdso
[linux-2.6.git] / drivers / char / hpet.c
1 /*
2  * Intel & MS High Precision Event Timer Implementation.
3  *
4  * Copyright (C) 2003 Intel Corporation
5  *      Venki Pallipadi
6  * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
7  *      Bob Picco <robert.picco@hp.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/miscdevice.h>
19 #include <linux/major.h>
20 #include <linux/ioport.h>
21 #include <linux/fcntl.h>
22 #include <linux/init.h>
23 #include <linux/poll.h>
24 #include <linux/mm.h>
25 #include <linux/proc_fs.h>
26 #include <linux/spinlock.h>
27 #include <linux/sysctl.h>
28 #include <linux/wait.h>
29 #include <linux/bcd.h>
30 #include <linux/seq_file.h>
31 #include <linux/bitops.h>
32 #include <linux/compat.h>
33 #include <linux/clocksource.h>
34 #include <linux/uaccess.h>
35 #include <linux/slab.h>
36 #include <linux/io.h>
37
38 #include <asm/current.h>
39 #include <asm/system.h>
40 #include <asm/irq.h>
41 #include <asm/div64.h>
42
43 #include <linux/acpi.h>
44 #include <acpi/acpi_bus.h>
45 #include <linux/hpet.h>
46
47 /*
48  * The High Precision Event Timer driver.
49  * This driver is closely modelled after the rtc.c driver.
50  * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
51  */
52 #define HPET_USER_FREQ  (64)
53 #define HPET_DRIFT      (500)
54
55 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
56
57
58 /* WARNING -- don't get confused.  These macros are never used
59  * to write the (single) counter, and rarely to read it.
60  * They're badly named; to fix, someday.
61  */
62 #if BITS_PER_LONG == 64
63 #define write_counter(V, MC)    writeq(V, MC)
64 #define read_counter(MC)        readq(MC)
65 #else
66 #define write_counter(V, MC)    writel(V, MC)
67 #define read_counter(MC)        readl(MC)
68 #endif
69
70 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
71 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
72
73 /* This clocksource driver currently only works on ia64 */
74 #ifdef CONFIG_IA64
75 static void __iomem *hpet_mctr;
76
77 static cycle_t read_hpet(struct clocksource *cs)
78 {
79         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
80 }
81
82 static struct clocksource clocksource_hpet = {
83         .name           = "hpet",
84         .rating         = 250,
85         .read           = read_hpet,
86         .mask           = CLOCKSOURCE_MASK(64),
87         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
88 };
89 static struct clocksource *hpet_clocksource;
90 #endif
91
92 /* A lock for concurrent access by app and isr hpet activity. */
93 static DEFINE_SPINLOCK(hpet_lock);
94
95 #define HPET_DEV_NAME   (7)
96
97 struct hpet_dev {
98         struct hpets *hd_hpets;
99         struct hpet __iomem *hd_hpet;
100         struct hpet_timer __iomem *hd_timer;
101         unsigned long hd_ireqfreq;
102         unsigned long hd_irqdata;
103         wait_queue_head_t hd_waitqueue;
104         struct fasync_struct *hd_async_queue;
105         unsigned int hd_flags;
106         unsigned int hd_irq;
107         unsigned int hd_hdwirq;
108         char hd_name[HPET_DEV_NAME];
109 };
110
111 struct hpets {
112         struct hpets *hp_next;
113         struct hpet __iomem *hp_hpet;
114         unsigned long hp_hpet_phys;
115         struct clocksource *hp_clocksource;
116         unsigned long long hp_tick_freq;
117         unsigned long hp_delta;
118         unsigned int hp_ntimer;
119         unsigned int hp_which;
120         struct hpet_dev hp_dev[1];
121 };
122
123 static struct hpets *hpets;
124
125 #define HPET_OPEN               0x0001
126 #define HPET_IE                 0x0002  /* interrupt enabled */
127 #define HPET_PERIODIC           0x0004
128 #define HPET_SHARED_IRQ         0x0008
129
130
131 #ifndef readq
132 static inline unsigned long long readq(void __iomem *addr)
133 {
134         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
135 }
136 #endif
137
138 #ifndef writeq
139 static inline void writeq(unsigned long long v, void __iomem *addr)
140 {
141         writel(v & 0xffffffff, addr);
142         writel(v >> 32, addr + 4);
143 }
144 #endif
145
146 static irqreturn_t hpet_interrupt(int irq, void *data)
147 {
148         struct hpet_dev *devp;
149         unsigned long isr;
150
151         devp = data;
152         isr = 1 << (devp - devp->hd_hpets->hp_dev);
153
154         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
155             !(isr & readl(&devp->hd_hpet->hpet_isr)))
156                 return IRQ_NONE;
157
158         spin_lock(&hpet_lock);
159         devp->hd_irqdata++;
160
161         /*
162          * For non-periodic timers, increment the accumulator.
163          * This has the effect of treating non-periodic like periodic.
164          */
165         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
166                 unsigned long m, t, mc, base, k;
167                 struct hpet __iomem *hpet = devp->hd_hpet;
168                 struct hpets *hpetp = devp->hd_hpets;
169
170                 t = devp->hd_ireqfreq;
171                 m = read_counter(&devp->hd_timer->hpet_compare);
172                 mc = read_counter(&hpet->hpet_mc);
173                 /* The time for the next interrupt would logically be t + m,
174                  * however, if we are very unlucky and the interrupt is delayed
175                  * for longer than t then we will completely miss the next
176                  * interrupt if we set t + m and an application will hang.
177                  * Therefore we need to make a more complex computation assuming
178                  * that there exists a k for which the following is true:
179                  * k * t + base < mc + delta
180                  * (k + 1) * t + base > mc + delta
181                  * where t is the interval in hpet ticks for the given freq,
182                  * base is the theoretical start value 0 < base < t,
183                  * mc is the main counter value at the time of the interrupt,
184                  * delta is the time it takes to write the a value to the
185                  * comparator.
186                  * k may then be computed as (mc - base + delta) / t .
187                  */
188                 base = mc % t;
189                 k = (mc - base + hpetp->hp_delta) / t;
190                 write_counter(t * (k + 1) + base,
191                               &devp->hd_timer->hpet_compare);
192         }
193
194         if (devp->hd_flags & HPET_SHARED_IRQ)
195                 writel(isr, &devp->hd_hpet->hpet_isr);
196         spin_unlock(&hpet_lock);
197
198         wake_up_interruptible(&devp->hd_waitqueue);
199
200         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
201
202         return IRQ_HANDLED;
203 }
204
205 static void hpet_timer_set_irq(struct hpet_dev *devp)
206 {
207         unsigned long v;
208         int irq, gsi;
209         struct hpet_timer __iomem *timer;
210
211         spin_lock_irq(&hpet_lock);
212         if (devp->hd_hdwirq) {
213                 spin_unlock_irq(&hpet_lock);
214                 return;
215         }
216
217         timer = devp->hd_timer;
218
219         /* we prefer level triggered mode */
220         v = readl(&timer->hpet_config);
221         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
222                 v |= Tn_INT_TYPE_CNF_MASK;
223                 writel(v, &timer->hpet_config);
224         }
225         spin_unlock_irq(&hpet_lock);
226
227         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
228                                  Tn_INT_ROUTE_CAP_SHIFT;
229
230         /*
231          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
232          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
233          */
234         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
235                 v &= ~0xf3df;
236         else
237                 v &= ~0xffff;
238
239         for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
240                 if (irq >= nr_irqs) {
241                         irq = HPET_MAX_IRQ;
242                         break;
243                 }
244
245                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
246                                         ACPI_ACTIVE_LOW);
247                 if (gsi > 0)
248                         break;
249
250                 /* FIXME: Setup interrupt source table */
251         }
252
253         if (irq < HPET_MAX_IRQ) {
254                 spin_lock_irq(&hpet_lock);
255                 v = readl(&timer->hpet_config);
256                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
257                 writel(v, &timer->hpet_config);
258                 devp->hd_hdwirq = gsi;
259                 spin_unlock_irq(&hpet_lock);
260         }
261         return;
262 }
263
264 static int hpet_open(struct inode *inode, struct file *file)
265 {
266         struct hpet_dev *devp;
267         struct hpets *hpetp;
268         int i;
269
270         if (file->f_mode & FMODE_WRITE)
271                 return -EINVAL;
272
273         mutex_lock(&hpet_mutex);
274         spin_lock_irq(&hpet_lock);
275
276         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
277                 for (i = 0; i < hpetp->hp_ntimer; i++)
278                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
279                                 continue;
280                         else {
281                                 devp = &hpetp->hp_dev[i];
282                                 break;
283                         }
284
285         if (!devp) {
286                 spin_unlock_irq(&hpet_lock);
287                 mutex_unlock(&hpet_mutex);
288                 return -EBUSY;
289         }
290
291         file->private_data = devp;
292         devp->hd_irqdata = 0;
293         devp->hd_flags |= HPET_OPEN;
294         spin_unlock_irq(&hpet_lock);
295         mutex_unlock(&hpet_mutex);
296
297         hpet_timer_set_irq(devp);
298
299         return 0;
300 }
301
302 static ssize_t
303 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
304 {
305         DECLARE_WAITQUEUE(wait, current);
306         unsigned long data;
307         ssize_t retval;
308         struct hpet_dev *devp;
309
310         devp = file->private_data;
311         if (!devp->hd_ireqfreq)
312                 return -EIO;
313
314         if (count < sizeof(unsigned long))
315                 return -EINVAL;
316
317         add_wait_queue(&devp->hd_waitqueue, &wait);
318
319         for ( ; ; ) {
320                 set_current_state(TASK_INTERRUPTIBLE);
321
322                 spin_lock_irq(&hpet_lock);
323                 data = devp->hd_irqdata;
324                 devp->hd_irqdata = 0;
325                 spin_unlock_irq(&hpet_lock);
326
327                 if (data)
328                         break;
329                 else if (file->f_flags & O_NONBLOCK) {
330                         retval = -EAGAIN;
331                         goto out;
332                 } else if (signal_pending(current)) {
333                         retval = -ERESTARTSYS;
334                         goto out;
335                 }
336                 schedule();
337         }
338
339         retval = put_user(data, (unsigned long __user *)buf);
340         if (!retval)
341                 retval = sizeof(unsigned long);
342 out:
343         __set_current_state(TASK_RUNNING);
344         remove_wait_queue(&devp->hd_waitqueue, &wait);
345
346         return retval;
347 }
348
349 static unsigned int hpet_poll(struct file *file, poll_table * wait)
350 {
351         unsigned long v;
352         struct hpet_dev *devp;
353
354         devp = file->private_data;
355
356         if (!devp->hd_ireqfreq)
357                 return 0;
358
359         poll_wait(file, &devp->hd_waitqueue, wait);
360
361         spin_lock_irq(&hpet_lock);
362         v = devp->hd_irqdata;
363         spin_unlock_irq(&hpet_lock);
364
365         if (v != 0)
366                 return POLLIN | POLLRDNORM;
367
368         return 0;
369 }
370
371 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
372 {
373 #ifdef  CONFIG_HPET_MMAP
374         struct hpet_dev *devp;
375         unsigned long addr;
376
377         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
378                 return -EINVAL;
379
380         devp = file->private_data;
381         addr = devp->hd_hpets->hp_hpet_phys;
382
383         if (addr & (PAGE_SIZE - 1))
384                 return -ENOSYS;
385
386         vma->vm_flags |= VM_IO;
387         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
388
389         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
390                                         PAGE_SIZE, vma->vm_page_prot)) {
391                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
392                         __func__);
393                 return -EAGAIN;
394         }
395
396         return 0;
397 #else
398         return -ENOSYS;
399 #endif
400 }
401
402 static int hpet_fasync(int fd, struct file *file, int on)
403 {
404         struct hpet_dev *devp;
405
406         devp = file->private_data;
407
408         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
409                 return 0;
410         else
411                 return -EIO;
412 }
413
414 static int hpet_release(struct inode *inode, struct file *file)
415 {
416         struct hpet_dev *devp;
417         struct hpet_timer __iomem *timer;
418         int irq = 0;
419
420         devp = file->private_data;
421         timer = devp->hd_timer;
422
423         spin_lock_irq(&hpet_lock);
424
425         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
426                &timer->hpet_config);
427
428         irq = devp->hd_irq;
429         devp->hd_irq = 0;
430
431         devp->hd_ireqfreq = 0;
432
433         if (devp->hd_flags & HPET_PERIODIC
434             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
435                 unsigned long v;
436
437                 v = readq(&timer->hpet_config);
438                 v ^= Tn_TYPE_CNF_MASK;
439                 writeq(v, &timer->hpet_config);
440         }
441
442         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
443         spin_unlock_irq(&hpet_lock);
444
445         if (irq)
446                 free_irq(irq, devp);
447
448         file->private_data = NULL;
449         return 0;
450 }
451
452 static int hpet_ioctl_ieon(struct hpet_dev *devp)
453 {
454         struct hpet_timer __iomem *timer;
455         struct hpet __iomem *hpet;
456         struct hpets *hpetp;
457         int irq;
458         unsigned long g, v, t, m;
459         unsigned long flags, isr;
460
461         timer = devp->hd_timer;
462         hpet = devp->hd_hpet;
463         hpetp = devp->hd_hpets;
464
465         if (!devp->hd_ireqfreq)
466                 return -EIO;
467
468         spin_lock_irq(&hpet_lock);
469
470         if (devp->hd_flags & HPET_IE) {
471                 spin_unlock_irq(&hpet_lock);
472                 return -EBUSY;
473         }
474
475         devp->hd_flags |= HPET_IE;
476
477         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
478                 devp->hd_flags |= HPET_SHARED_IRQ;
479         spin_unlock_irq(&hpet_lock);
480
481         irq = devp->hd_hdwirq;
482
483         if (irq) {
484                 unsigned long irq_flags;
485
486                 if (devp->hd_flags & HPET_SHARED_IRQ) {
487                         /*
488                          * To prevent the interrupt handler from seeing an
489                          * unwanted interrupt status bit, program the timer
490                          * so that it will not fire in the near future ...
491                          */
492                         writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
493                                &timer->hpet_config);
494                         write_counter(read_counter(&hpet->hpet_mc),
495                                       &timer->hpet_compare);
496                         /* ... and clear any left-over status. */
497                         isr = 1 << (devp - devp->hd_hpets->hp_dev);
498                         writel(isr, &hpet->hpet_isr);
499                 }
500
501                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
502                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
503                                                 ? IRQF_SHARED : IRQF_DISABLED;
504                 if (request_irq(irq, hpet_interrupt, irq_flags,
505                                 devp->hd_name, (void *)devp)) {
506                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
507                         irq = 0;
508                 }
509         }
510
511         if (irq == 0) {
512                 spin_lock_irq(&hpet_lock);
513                 devp->hd_flags ^= HPET_IE;
514                 spin_unlock_irq(&hpet_lock);
515                 return -EIO;
516         }
517
518         devp->hd_irq = irq;
519         t = devp->hd_ireqfreq;
520         v = readq(&timer->hpet_config);
521
522         /* 64-bit comparators are not yet supported through the ioctls,
523          * so force this into 32-bit mode if it supports both modes
524          */
525         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
526
527         if (devp->hd_flags & HPET_PERIODIC) {
528                 g |= Tn_TYPE_CNF_MASK;
529                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
530                 writeq(v, &timer->hpet_config);
531                 local_irq_save(flags);
532
533                 /*
534                  * NOTE: First we modify the hidden accumulator
535                  * register supported by periodic-capable comparators.
536                  * We never want to modify the (single) counter; that
537                  * would affect all the comparators. The value written
538                  * is the counter value when the first interrupt is due.
539                  */
540                 m = read_counter(&hpet->hpet_mc);
541                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
542                 /*
543                  * Then we modify the comparator, indicating the period
544                  * for subsequent interrupt.
545                  */
546                 write_counter(t, &timer->hpet_compare);
547         } else {
548                 local_irq_save(flags);
549                 m = read_counter(&hpet->hpet_mc);
550                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
551         }
552
553         if (devp->hd_flags & HPET_SHARED_IRQ) {
554                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
555                 writel(isr, &hpet->hpet_isr);
556         }
557         writeq(g, &timer->hpet_config);
558         local_irq_restore(flags);
559
560         return 0;
561 }
562
563 /* converts Hz to number of timer ticks */
564 static inline unsigned long hpet_time_div(struct hpets *hpets,
565                                           unsigned long dis)
566 {
567         unsigned long long m;
568
569         m = hpets->hp_tick_freq + (dis >> 1);
570         do_div(m, dis);
571         return (unsigned long)m;
572 }
573
574 static int
575 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
576                   struct hpet_info *info)
577 {
578         struct hpet_timer __iomem *timer;
579         struct hpet __iomem *hpet;
580         struct hpets *hpetp;
581         int err;
582         unsigned long v;
583
584         switch (cmd) {
585         case HPET_IE_OFF:
586         case HPET_INFO:
587         case HPET_EPI:
588         case HPET_DPI:
589         case HPET_IRQFREQ:
590                 timer = devp->hd_timer;
591                 hpet = devp->hd_hpet;
592                 hpetp = devp->hd_hpets;
593                 break;
594         case HPET_IE_ON:
595                 return hpet_ioctl_ieon(devp);
596         default:
597                 return -EINVAL;
598         }
599
600         err = 0;
601
602         switch (cmd) {
603         case HPET_IE_OFF:
604                 if ((devp->hd_flags & HPET_IE) == 0)
605                         break;
606                 v = readq(&timer->hpet_config);
607                 v &= ~Tn_INT_ENB_CNF_MASK;
608                 writeq(v, &timer->hpet_config);
609                 if (devp->hd_irq) {
610                         free_irq(devp->hd_irq, devp);
611                         devp->hd_irq = 0;
612                 }
613                 devp->hd_flags ^= HPET_IE;
614                 break;
615         case HPET_INFO:
616                 {
617                         memset(info, 0, sizeof(*info));
618                         if (devp->hd_ireqfreq)
619                                 info->hi_ireqfreq =
620                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
621                         info->hi_flags =
622                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
623                         info->hi_hpet = hpetp->hp_which;
624                         info->hi_timer = devp - hpetp->hp_dev;
625                         break;
626                 }
627         case HPET_EPI:
628                 v = readq(&timer->hpet_config);
629                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
630                         err = -ENXIO;
631                         break;
632                 }
633                 devp->hd_flags |= HPET_PERIODIC;
634                 break;
635         case HPET_DPI:
636                 v = readq(&timer->hpet_config);
637                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
638                         err = -ENXIO;
639                         break;
640                 }
641                 if (devp->hd_flags & HPET_PERIODIC &&
642                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
643                         v = readq(&timer->hpet_config);
644                         v ^= Tn_TYPE_CNF_MASK;
645                         writeq(v, &timer->hpet_config);
646                 }
647                 devp->hd_flags &= ~HPET_PERIODIC;
648                 break;
649         case HPET_IRQFREQ:
650                 if ((arg > hpet_max_freq) &&
651                     !capable(CAP_SYS_RESOURCE)) {
652                         err = -EACCES;
653                         break;
654                 }
655
656                 if (!arg) {
657                         err = -EINVAL;
658                         break;
659                 }
660
661                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
662         }
663
664         return err;
665 }
666
667 static long
668 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
669 {
670         struct hpet_info info;
671         int err;
672
673         mutex_lock(&hpet_mutex);
674         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
675         mutex_unlock(&hpet_mutex);
676
677         if ((cmd == HPET_INFO) && !err &&
678             (copy_to_user((void __user *)arg, &info, sizeof(info))))
679                 err = -EFAULT;
680
681         return err;
682 }
683
684 #ifdef CONFIG_COMPAT
685 struct compat_hpet_info {
686         compat_ulong_t hi_ireqfreq;     /* Hz */
687         compat_ulong_t hi_flags;        /* information */
688         unsigned short hi_hpet;
689         unsigned short hi_timer;
690 };
691
692 static long
693 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
694 {
695         struct hpet_info info;
696         int err;
697
698         mutex_lock(&hpet_mutex);
699         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
700         mutex_unlock(&hpet_mutex);
701
702         if ((cmd == HPET_INFO) && !err) {
703                 struct compat_hpet_info __user *u = compat_ptr(arg);
704                 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
705                     put_user(info.hi_flags, &u->hi_flags) ||
706                     put_user(info.hi_hpet, &u->hi_hpet) ||
707                     put_user(info.hi_timer, &u->hi_timer))
708                         err = -EFAULT;
709         }
710
711         return err;
712 }
713 #endif
714
715 static const struct file_operations hpet_fops = {
716         .owner = THIS_MODULE,
717         .llseek = no_llseek,
718         .read = hpet_read,
719         .poll = hpet_poll,
720         .unlocked_ioctl = hpet_ioctl,
721 #ifdef CONFIG_COMPAT
722         .compat_ioctl = hpet_compat_ioctl,
723 #endif
724         .open = hpet_open,
725         .release = hpet_release,
726         .fasync = hpet_fasync,
727         .mmap = hpet_mmap,
728 };
729
730 static int hpet_is_known(struct hpet_data *hdp)
731 {
732         struct hpets *hpetp;
733
734         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
735                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
736                         return 1;
737
738         return 0;
739 }
740
741 static ctl_table hpet_table[] = {
742         {
743          .procname = "max-user-freq",
744          .data = &hpet_max_freq,
745          .maxlen = sizeof(int),
746          .mode = 0644,
747          .proc_handler = proc_dointvec,
748          },
749         {}
750 };
751
752 static ctl_table hpet_root[] = {
753         {
754          .procname = "hpet",
755          .maxlen = 0,
756          .mode = 0555,
757          .child = hpet_table,
758          },
759         {}
760 };
761
762 static ctl_table dev_root[] = {
763         {
764          .procname = "dev",
765          .maxlen = 0,
766          .mode = 0555,
767          .child = hpet_root,
768          },
769         {}
770 };
771
772 static struct ctl_table_header *sysctl_header;
773
774 /*
775  * Adjustment for when arming the timer with
776  * initial conditions.  That is, main counter
777  * ticks expired before interrupts are enabled.
778  */
779 #define TICK_CALIBRATE  (1000UL)
780
781 static unsigned long __hpet_calibrate(struct hpets *hpetp)
782 {
783         struct hpet_timer __iomem *timer = NULL;
784         unsigned long t, m, count, i, flags, start;
785         struct hpet_dev *devp;
786         int j;
787         struct hpet __iomem *hpet;
788
789         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
790                 if ((devp->hd_flags & HPET_OPEN) == 0) {
791                         timer = devp->hd_timer;
792                         break;
793                 }
794
795         if (!timer)
796                 return 0;
797
798         hpet = hpetp->hp_hpet;
799         t = read_counter(&timer->hpet_compare);
800
801         i = 0;
802         count = hpet_time_div(hpetp, TICK_CALIBRATE);
803
804         local_irq_save(flags);
805
806         start = read_counter(&hpet->hpet_mc);
807
808         do {
809                 m = read_counter(&hpet->hpet_mc);
810                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
811         } while (i++, (m - start) < count);
812
813         local_irq_restore(flags);
814
815         return (m - start) / i;
816 }
817
818 static unsigned long hpet_calibrate(struct hpets *hpetp)
819 {
820         unsigned long ret = -1;
821         unsigned long tmp;
822
823         /*
824          * Try to calibrate until return value becomes stable small value.
825          * If SMI interruption occurs in calibration loop, the return value
826          * will be big. This avoids its impact.
827          */
828         for ( ; ; ) {
829                 tmp = __hpet_calibrate(hpetp);
830                 if (ret <= tmp)
831                         break;
832                 ret = tmp;
833         }
834
835         return ret;
836 }
837
838 int hpet_alloc(struct hpet_data *hdp)
839 {
840         u64 cap, mcfg;
841         struct hpet_dev *devp;
842         u32 i, ntimer;
843         struct hpets *hpetp;
844         size_t siz;
845         struct hpet __iomem *hpet;
846         static struct hpets *last;
847         unsigned long period;
848         unsigned long long temp;
849         u32 remainder;
850
851         /*
852          * hpet_alloc can be called by platform dependent code.
853          * If platform dependent code has allocated the hpet that
854          * ACPI has also reported, then we catch it here.
855          */
856         if (hpet_is_known(hdp)) {
857                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
858                         __func__);
859                 return 0;
860         }
861
862         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
863                                       sizeof(struct hpet_dev));
864
865         hpetp = kzalloc(siz, GFP_KERNEL);
866
867         if (!hpetp)
868                 return -ENOMEM;
869
870         hpetp->hp_which = hpet_nhpet++;
871         hpetp->hp_hpet = hdp->hd_address;
872         hpetp->hp_hpet_phys = hdp->hd_phys_address;
873
874         hpetp->hp_ntimer = hdp->hd_nirqs;
875
876         for (i = 0; i < hdp->hd_nirqs; i++)
877                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
878
879         hpet = hpetp->hp_hpet;
880
881         cap = readq(&hpet->hpet_cap);
882
883         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
884
885         if (hpetp->hp_ntimer != ntimer) {
886                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
887                        " with number of timers\n");
888                 kfree(hpetp);
889                 return -ENODEV;
890         }
891
892         if (last)
893                 last->hp_next = hpetp;
894         else
895                 hpets = hpetp;
896
897         last = hpetp;
898
899         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
900                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
901         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
902         temp += period >> 1; /* round */
903         do_div(temp, period);
904         hpetp->hp_tick_freq = temp; /* ticks per second */
905
906         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
907                 hpetp->hp_which, hdp->hd_phys_address,
908                 hpetp->hp_ntimer > 1 ? "s" : "");
909         for (i = 0; i < hpetp->hp_ntimer; i++)
910                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
911         printk("\n");
912
913         temp = hpetp->hp_tick_freq;
914         remainder = do_div(temp, 1000000);
915         printk(KERN_INFO
916                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
917                 hpetp->hp_which, hpetp->hp_ntimer,
918                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
919                 (unsigned) temp, remainder);
920
921         mcfg = readq(&hpet->hpet_config);
922         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
923                 write_counter(0L, &hpet->hpet_mc);
924                 mcfg |= HPET_ENABLE_CNF_MASK;
925                 writeq(mcfg, &hpet->hpet_config);
926         }
927
928         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
929                 struct hpet_timer __iomem *timer;
930
931                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
932
933                 devp->hd_hpets = hpetp;
934                 devp->hd_hpet = hpet;
935                 devp->hd_timer = timer;
936
937                 /*
938                  * If the timer was reserved by platform code,
939                  * then make timer unavailable for opens.
940                  */
941                 if (hdp->hd_state & (1 << i)) {
942                         devp->hd_flags = HPET_OPEN;
943                         continue;
944                 }
945
946                 init_waitqueue_head(&devp->hd_waitqueue);
947         }
948
949         hpetp->hp_delta = hpet_calibrate(hpetp);
950
951 /* This clocksource driver currently only works on ia64 */
952 #ifdef CONFIG_IA64
953         if (!hpet_clocksource) {
954                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
955                 clocksource_hpet.archdata.fsys_mmio = hpet_mctr;
956                 clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
957                 hpetp->hp_clocksource = &clocksource_hpet;
958                 hpet_clocksource = &clocksource_hpet;
959         }
960 #endif
961
962         return 0;
963 }
964
965 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
966 {
967         struct hpet_data *hdp;
968         acpi_status status;
969         struct acpi_resource_address64 addr;
970
971         hdp = data;
972
973         status = acpi_resource_to_address64(res, &addr);
974
975         if (ACPI_SUCCESS(status)) {
976                 hdp->hd_phys_address = addr.minimum;
977                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
978
979                 if (hpet_is_known(hdp)) {
980                         iounmap(hdp->hd_address);
981                         return AE_ALREADY_EXISTS;
982                 }
983         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
984                 struct acpi_resource_fixed_memory32 *fixmem32;
985
986                 fixmem32 = &res->data.fixed_memory32;
987                 if (!fixmem32)
988                         return AE_NO_MEMORY;
989
990                 hdp->hd_phys_address = fixmem32->address;
991                 hdp->hd_address = ioremap(fixmem32->address,
992                                                 HPET_RANGE_SIZE);
993
994                 if (hpet_is_known(hdp)) {
995                         iounmap(hdp->hd_address);
996                         return AE_ALREADY_EXISTS;
997                 }
998         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
999                 struct acpi_resource_extended_irq *irqp;
1000                 int i, irq;
1001
1002                 irqp = &res->data.extended_irq;
1003
1004                 for (i = 0; i < irqp->interrupt_count; i++) {
1005                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
1006                                       irqp->triggering, irqp->polarity);
1007                         if (irq < 0)
1008                                 return AE_ERROR;
1009
1010                         hdp->hd_irq[hdp->hd_nirqs] = irq;
1011                         hdp->hd_nirqs++;
1012                 }
1013         }
1014
1015         return AE_OK;
1016 }
1017
1018 static int hpet_acpi_add(struct acpi_device *device)
1019 {
1020         acpi_status result;
1021         struct hpet_data data;
1022
1023         memset(&data, 0, sizeof(data));
1024
1025         result =
1026             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1027                                 hpet_resources, &data);
1028
1029         if (ACPI_FAILURE(result))
1030                 return -ENODEV;
1031
1032         if (!data.hd_address || !data.hd_nirqs) {
1033                 if (data.hd_address)
1034                         iounmap(data.hd_address);
1035                 printk("%s: no address or irqs in _CRS\n", __func__);
1036                 return -ENODEV;
1037         }
1038
1039         return hpet_alloc(&data);
1040 }
1041
1042 static int hpet_acpi_remove(struct acpi_device *device, int type)
1043 {
1044         /* XXX need to unregister clocksource, dealloc mem, etc */
1045         return -EINVAL;
1046 }
1047
1048 static const struct acpi_device_id hpet_device_ids[] = {
1049         {"PNP0103", 0},
1050         {"", 0},
1051 };
1052 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1053
1054 static struct acpi_driver hpet_acpi_driver = {
1055         .name = "hpet",
1056         .ids = hpet_device_ids,
1057         .ops = {
1058                 .add = hpet_acpi_add,
1059                 .remove = hpet_acpi_remove,
1060                 },
1061 };
1062
1063 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1064
1065 static int __init hpet_init(void)
1066 {
1067         int result;
1068
1069         result = misc_register(&hpet_misc);
1070         if (result < 0)
1071                 return -ENODEV;
1072
1073         sysctl_header = register_sysctl_table(dev_root);
1074
1075         result = acpi_bus_register_driver(&hpet_acpi_driver);
1076         if (result < 0) {
1077                 if (sysctl_header)
1078                         unregister_sysctl_table(sysctl_header);
1079                 misc_deregister(&hpet_misc);
1080                 return result;
1081         }
1082
1083         return 0;
1084 }
1085
1086 static void __exit hpet_exit(void)
1087 {
1088         acpi_bus_unregister_driver(&hpet_acpi_driver);
1089
1090         if (sysctl_header)
1091                 unregister_sysctl_table(sysctl_header);
1092         misc_deregister(&hpet_misc);
1093
1094         return;
1095 }
1096
1097 module_init(hpet_init);
1098 module_exit(hpet_exit);
1099 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1100 MODULE_LICENSE("GPL");