Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Intel & MS High Precision Event Timer Implementation.
4 *
5 * Copyright (C) 2003 Intel Corporation
6 * Venki Pallipadi
7 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
8 * Bob Picco <robert.picco@hp.com>
9 */
10
11#include <linux/interrupt.h>
12#include <linux/kernel.h>
13#include <linux/types.h>
14#include <linux/miscdevice.h>
15#include <linux/major.h>
16#include <linux/ioport.h>
17#include <linux/fcntl.h>
18#include <linux/init.h>
19#include <linux/poll.h>
20#include <linux/mm.h>
21#include <linux/proc_fs.h>
22#include <linux/spinlock.h>
23#include <linux/sysctl.h>
24#include <linux/wait.h>
25#include <linux/sched/signal.h>
26#include <linux/bcd.h>
27#include <linux/seq_file.h>
28#include <linux/bitops.h>
29#include <linux/compat.h>
30#include <linux/clocksource.h>
31#include <linux/uaccess.h>
32#include <linux/slab.h>
33#include <linux/io.h>
34#include <linux/acpi.h>
35#include <linux/hpet.h>
36#include <asm/current.h>
37#include <asm/irq.h>
38#include <asm/div64.h>
39
40/*
41 * The High Precision Event Timer driver.
42 * This driver is closely modelled after the rtc.c driver.
43 * See HPET spec revision 1.
44 */
45#define HPET_USER_FREQ (64)
46#define HPET_DRIFT (500)
47
48#define HPET_RANGE_SIZE 1024 /* from HPET spec */
49
50
51/* WARNING -- don't get confused. These macros are never used
52 * to write the (single) counter, and rarely to read it.
53 * They're badly named; to fix, someday.
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
63static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
64static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
65
66/* This clocksource driver currently only works on ia64 */
67#ifdef CONFIG_IA64
68static void __iomem *hpet_mctr;
69
70static u64 read_hpet(struct clocksource *cs)
71{
72 return (u64)read_counter((void __iomem *)hpet_mctr);
73}
74
75static struct clocksource clocksource_hpet = {
76 .name = "hpet",
77 .rating = 250,
78 .read = read_hpet,
79 .mask = CLOCKSOURCE_MASK(64),
80 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
81};
82static struct clocksource *hpet_clocksource;
83#endif
84
85/* A lock for concurrent access by app and isr hpet activity. */
86static DEFINE_SPINLOCK(hpet_lock);
87
88#define HPET_DEV_NAME (7)
89
90struct hpet_dev {
91 struct hpets *hd_hpets;
92 struct hpet __iomem *hd_hpet;
93 struct hpet_timer __iomem *hd_timer;
94 unsigned long hd_ireqfreq;
95 unsigned long hd_irqdata;
96 wait_queue_head_t hd_waitqueue;
97 struct fasync_struct *hd_async_queue;
98 unsigned int hd_flags;
99 unsigned int hd_irq;
100 unsigned int hd_hdwirq;
101 char hd_name[HPET_DEV_NAME];
102};
103
104struct hpets {
105 struct hpets *hp_next;
106 struct hpet __iomem *hp_hpet;
107 unsigned long hp_hpet_phys;
108 struct clocksource *hp_clocksource;
109 unsigned long long hp_tick_freq;
110 unsigned long hp_delta;
111 unsigned int hp_ntimer;
112 unsigned int hp_which;
113 struct hpet_dev hp_dev[];
114};
115
116static struct hpets *hpets;
117
118#define HPET_OPEN 0x0001
119#define HPET_IE 0x0002 /* interrupt enabled */
120#define HPET_PERIODIC 0x0004
121#define HPET_SHARED_IRQ 0x0008
122
123
124#ifndef readq
125static inline unsigned long long readq(void __iomem *addr)
126{
127 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
128}
129#endif
130
131#ifndef writeq
132static inline void writeq(unsigned long long v, void __iomem *addr)
133{
134 writel(v & 0xffffffff, addr);
135 writel(v >> 32, addr + 4);
136}
137#endif
138
139static irqreturn_t hpet_interrupt(int irq, void *data)
140{
141 struct hpet_dev *devp;
142 unsigned long isr;
143
144 devp = data;
145 isr = 1 << (devp - devp->hd_hpets->hp_dev);
146
147 if ((devp->hd_flags & HPET_SHARED_IRQ) &&
148 !(isr & readl(&devp->hd_hpet->hpet_isr)))
149 return IRQ_NONE;
150
151 spin_lock(&hpet_lock);
152 devp->hd_irqdata++;
153
154 /*
155 * For non-periodic timers, increment the accumulator.
156 * This has the effect of treating non-periodic like periodic.
157 */
158 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
159 unsigned long m, t, mc, base, k;
160 struct hpet __iomem *hpet = devp->hd_hpet;
161 struct hpets *hpetp = devp->hd_hpets;
162
163 t = devp->hd_ireqfreq;
164 m = read_counter(&devp->hd_timer->hpet_compare);
165 mc = read_counter(&hpet->hpet_mc);
166 /* The time for the next interrupt would logically be t + m,
167 * however, if we are very unlucky and the interrupt is delayed
168 * for longer than t then we will completely miss the next
169 * interrupt if we set t + m and an application will hang.
170 * Therefore we need to make a more complex computation assuming
171 * that there exists a k for which the following is true:
172 * k * t + base < mc + delta
173 * (k + 1) * t + base > mc + delta
174 * where t is the interval in hpet ticks for the given freq,
175 * base is the theoretical start value 0 < base < t,
176 * mc is the main counter value at the time of the interrupt,
177 * delta is the time it takes to write the a value to the
178 * comparator.
179 * k may then be computed as (mc - base + delta) / t .
180 */
181 base = mc % t;
182 k = (mc - base + hpetp->hp_delta) / t;
183 write_counter(t * (k + 1) + base,
184 &devp->hd_timer->hpet_compare);
185 }
186
187 if (devp->hd_flags & HPET_SHARED_IRQ)
188 writel(isr, &devp->hd_hpet->hpet_isr);
189 spin_unlock(&hpet_lock);
190
191 wake_up_interruptible(&devp->hd_waitqueue);
192
193 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
194
195 return IRQ_HANDLED;
196}
197
198static void hpet_timer_set_irq(struct hpet_dev *devp)
199{
200 unsigned long v;
201 int irq, gsi;
202 struct hpet_timer __iomem *timer;
203
204 spin_lock_irq(&hpet_lock);
205 if (devp->hd_hdwirq) {
206 spin_unlock_irq(&hpet_lock);
207 return;
208 }
209
210 timer = devp->hd_timer;
211
212 /* we prefer level triggered mode */
213 v = readl(&timer->hpet_config);
214 if (!(v & Tn_INT_TYPE_CNF_MASK)) {
215 v |= Tn_INT_TYPE_CNF_MASK;
216 writel(v, &timer->hpet_config);
217 }
218 spin_unlock_irq(&hpet_lock);
219
220 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
221 Tn_INT_ROUTE_CAP_SHIFT;
222
223 /*
224 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
225 * legacy device. In IO APIC mode, we skip all the legacy IRQS.
226 */
227 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
228 v &= ~0xf3df;
229 else
230 v &= ~0xffff;
231
232 for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
233 if (irq >= nr_irqs) {
234 irq = HPET_MAX_IRQ;
235 break;
236 }
237
238 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
239 ACPI_ACTIVE_LOW);
240 if (gsi > 0)
241 break;
242
243 /* FIXME: Setup interrupt source table */
244 }
245
246 if (irq < HPET_MAX_IRQ) {
247 spin_lock_irq(&hpet_lock);
248 v = readl(&timer->hpet_config);
249 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
250 writel(v, &timer->hpet_config);
251 devp->hd_hdwirq = gsi;
252 spin_unlock_irq(&hpet_lock);
253 }
254 return;
255}
256
257static int hpet_open(struct inode *inode, struct file *file)
258{
259 struct hpet_dev *devp;
260 struct hpets *hpetp;
261 int i;
262
263 if (file->f_mode & FMODE_WRITE)
264 return -EINVAL;
265
266 mutex_lock(&hpet_mutex);
267 spin_lock_irq(&hpet_lock);
268
269 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
270 for (i = 0; i < hpetp->hp_ntimer; i++)
271 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
272 continue;
273 else {
274 devp = &hpetp->hp_dev[i];
275 break;
276 }
277
278 if (!devp) {
279 spin_unlock_irq(&hpet_lock);
280 mutex_unlock(&hpet_mutex);
281 return -EBUSY;
282 }
283
284 file->private_data = devp;
285 devp->hd_irqdata = 0;
286 devp->hd_flags |= HPET_OPEN;
287 spin_unlock_irq(&hpet_lock);
288 mutex_unlock(&hpet_mutex);
289
290 hpet_timer_set_irq(devp);
291
292 return 0;
293}
294
295static ssize_t
296hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
297{
298 DECLARE_WAITQUEUE(wait, current);
299 unsigned long data;
300 ssize_t retval;
301 struct hpet_dev *devp;
302
303 devp = file->private_data;
304 if (!devp->hd_ireqfreq)
305 return -EIO;
306
307 if (count < sizeof(unsigned long))
308 return -EINVAL;
309
310 add_wait_queue(&devp->hd_waitqueue, &wait);
311
312 for ( ; ; ) {
313 set_current_state(TASK_INTERRUPTIBLE);
314
315 spin_lock_irq(&hpet_lock);
316 data = devp->hd_irqdata;
317 devp->hd_irqdata = 0;
318 spin_unlock_irq(&hpet_lock);
319
320 if (data)
321 break;
322 else if (file->f_flags & O_NONBLOCK) {
323 retval = -EAGAIN;
324 goto out;
325 } else if (signal_pending(current)) {
326 retval = -ERESTARTSYS;
327 goto out;
328 }
329 schedule();
330 }
331
332 retval = put_user(data, (unsigned long __user *)buf);
333 if (!retval)
334 retval = sizeof(unsigned long);
335out:
336 __set_current_state(TASK_RUNNING);
337 remove_wait_queue(&devp->hd_waitqueue, &wait);
338
339 return retval;
340}
341
342static __poll_t hpet_poll(struct file *file, poll_table * wait)
343{
344 unsigned long v;
345 struct hpet_dev *devp;
346
347 devp = file->private_data;
348
349 if (!devp->hd_ireqfreq)
350 return 0;
351
352 poll_wait(file, &devp->hd_waitqueue, wait);
353
354 spin_lock_irq(&hpet_lock);
355 v = devp->hd_irqdata;
356 spin_unlock_irq(&hpet_lock);
357
358 if (v != 0)
359 return EPOLLIN | EPOLLRDNORM;
360
361 return 0;
362}
363
364#ifdef CONFIG_HPET_MMAP
365#ifdef CONFIG_HPET_MMAP_DEFAULT
366static int hpet_mmap_enabled = 1;
367#else
368static int hpet_mmap_enabled = 0;
369#endif
370
371static __init int hpet_mmap_enable(char *str)
372{
373 get_option(&str, &hpet_mmap_enabled);
374 pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled");
375 return 1;
376}
377__setup("hpet_mmap=", hpet_mmap_enable);
378
379static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
380{
381 struct hpet_dev *devp;
382 unsigned long addr;
383
384 if (!hpet_mmap_enabled)
385 return -EACCES;
386
387 devp = file->private_data;
388 addr = devp->hd_hpets->hp_hpet_phys;
389
390 if (addr & (PAGE_SIZE - 1))
391 return -ENOSYS;
392
393 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
394 return vm_iomap_memory(vma, addr, PAGE_SIZE);
395}
396#else
397static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
398{
399 return -ENOSYS;
400}
401#endif
402
403static int hpet_fasync(int fd, struct file *file, int on)
404{
405 struct hpet_dev *devp;
406
407 devp = file->private_data;
408
409 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
410 return 0;
411 else
412 return -EIO;
413}
414
415static int hpet_release(struct inode *inode, struct file *file)
416{
417 struct hpet_dev *devp;
418 struct hpet_timer __iomem *timer;
419 int irq = 0;
420
421 devp = file->private_data;
422 timer = devp->hd_timer;
423
424 spin_lock_irq(&hpet_lock);
425
426 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
427 &timer->hpet_config);
428
429 irq = devp->hd_irq;
430 devp->hd_irq = 0;
431
432 devp->hd_ireqfreq = 0;
433
434 if (devp->hd_flags & HPET_PERIODIC
435 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
436 unsigned long v;
437
438 v = readq(&timer->hpet_config);
439 v ^= Tn_TYPE_CNF_MASK;
440 writeq(v, &timer->hpet_config);
441 }
442
443 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
444 spin_unlock_irq(&hpet_lock);
445
446 if (irq)
447 free_irq(irq, devp);
448
449 file->private_data = NULL;
450 return 0;
451}
452
453static int hpet_ioctl_ieon(struct hpet_dev *devp)
454{
455 struct hpet_timer __iomem *timer;
456 struct hpet __iomem *hpet;
457 struct hpets *hpetp;
458 int irq;
459 unsigned long g, v, t, m;
460 unsigned long flags, isr;
461
462 timer = devp->hd_timer;
463 hpet = devp->hd_hpet;
464 hpetp = devp->hd_hpets;
465
466 if (!devp->hd_ireqfreq)
467 return -EIO;
468
469 spin_lock_irq(&hpet_lock);
470
471 if (devp->hd_flags & HPET_IE) {
472 spin_unlock_irq(&hpet_lock);
473 return -EBUSY;
474 }
475
476 devp->hd_flags |= HPET_IE;
477
478 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
479 devp->hd_flags |= HPET_SHARED_IRQ;
480 spin_unlock_irq(&hpet_lock);
481
482 irq = devp->hd_hdwirq;
483
484 if (irq) {
485 unsigned long irq_flags;
486
487 if (devp->hd_flags & HPET_SHARED_IRQ) {
488 /*
489 * To prevent the interrupt handler from seeing an
490 * unwanted interrupt status bit, program the timer
491 * so that it will not fire in the near future ...
492 */
493 writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
494 &timer->hpet_config);
495 write_counter(read_counter(&hpet->hpet_mc),
496 &timer->hpet_compare);
497 /* ... and clear any left-over status. */
498 isr = 1 << (devp - devp->hd_hpets->hp_dev);
499 writel(isr, &hpet->hpet_isr);
500 }
501
502 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
503 irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0;
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 */
564static 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 return div64_ul(m, dis);
571}
572
573static int
574hpet_ioctl_common(struct hpet_dev *devp, unsigned int cmd, unsigned long arg,
575 struct hpet_info *info)
576{
577 struct hpet_timer __iomem *timer;
578 struct hpets *hpetp;
579 int err;
580 unsigned long v;
581
582 switch (cmd) {
583 case HPET_IE_OFF:
584 case HPET_INFO:
585 case HPET_EPI:
586 case HPET_DPI:
587 case HPET_IRQFREQ:
588 timer = devp->hd_timer;
589 hpetp = devp->hd_hpets;
590 break;
591 case HPET_IE_ON:
592 return hpet_ioctl_ieon(devp);
593 default:
594 return -EINVAL;
595 }
596
597 err = 0;
598
599 switch (cmd) {
600 case HPET_IE_OFF:
601 if ((devp->hd_flags & HPET_IE) == 0)
602 break;
603 v = readq(&timer->hpet_config);
604 v &= ~Tn_INT_ENB_CNF_MASK;
605 writeq(v, &timer->hpet_config);
606 if (devp->hd_irq) {
607 free_irq(devp->hd_irq, devp);
608 devp->hd_irq = 0;
609 }
610 devp->hd_flags ^= HPET_IE;
611 break;
612 case HPET_INFO:
613 {
614 memset(info, 0, sizeof(*info));
615 if (devp->hd_ireqfreq)
616 info->hi_ireqfreq =
617 hpet_time_div(hpetp, devp->hd_ireqfreq);
618 info->hi_flags =
619 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
620 info->hi_hpet = hpetp->hp_which;
621 info->hi_timer = devp - hpetp->hp_dev;
622 break;
623 }
624 case HPET_EPI:
625 v = readq(&timer->hpet_config);
626 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
627 err = -ENXIO;
628 break;
629 }
630 devp->hd_flags |= HPET_PERIODIC;
631 break;
632 case HPET_DPI:
633 v = readq(&timer->hpet_config);
634 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
635 err = -ENXIO;
636 break;
637 }
638 if (devp->hd_flags & HPET_PERIODIC &&
639 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
640 v = readq(&timer->hpet_config);
641 v ^= Tn_TYPE_CNF_MASK;
642 writeq(v, &timer->hpet_config);
643 }
644 devp->hd_flags &= ~HPET_PERIODIC;
645 break;
646 case HPET_IRQFREQ:
647 if ((arg > hpet_max_freq) &&
648 !capable(CAP_SYS_RESOURCE)) {
649 err = -EACCES;
650 break;
651 }
652
653 if (!arg) {
654 err = -EINVAL;
655 break;
656 }
657
658 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
659 }
660
661 return err;
662}
663
664static long
665hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
666{
667 struct hpet_info info;
668 int err;
669
670 mutex_lock(&hpet_mutex);
671 err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
672 mutex_unlock(&hpet_mutex);
673
674 if ((cmd == HPET_INFO) && !err &&
675 (copy_to_user((void __user *)arg, &info, sizeof(info))))
676 err = -EFAULT;
677
678 return err;
679}
680
681#ifdef CONFIG_COMPAT
682struct compat_hpet_info {
683 compat_ulong_t hi_ireqfreq; /* Hz */
684 compat_ulong_t hi_flags; /* information */
685 unsigned short hi_hpet;
686 unsigned short hi_timer;
687};
688
689static long
690hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
691{
692 struct hpet_info info;
693 int err;
694
695 mutex_lock(&hpet_mutex);
696 err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
697 mutex_unlock(&hpet_mutex);
698
699 if ((cmd == HPET_INFO) && !err) {
700 struct compat_hpet_info __user *u = compat_ptr(arg);
701 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
702 put_user(info.hi_flags, &u->hi_flags) ||
703 put_user(info.hi_hpet, &u->hi_hpet) ||
704 put_user(info.hi_timer, &u->hi_timer))
705 err = -EFAULT;
706 }
707
708 return err;
709}
710#endif
711
712static const struct file_operations hpet_fops = {
713 .owner = THIS_MODULE,
714 .llseek = no_llseek,
715 .read = hpet_read,
716 .poll = hpet_poll,
717 .unlocked_ioctl = hpet_ioctl,
718#ifdef CONFIG_COMPAT
719 .compat_ioctl = hpet_compat_ioctl,
720#endif
721 .open = hpet_open,
722 .release = hpet_release,
723 .fasync = hpet_fasync,
724 .mmap = hpet_mmap,
725};
726
727static int hpet_is_known(struct hpet_data *hdp)
728{
729 struct hpets *hpetp;
730
731 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
732 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
733 return 1;
734
735 return 0;
736}
737
738static struct ctl_table hpet_table[] = {
739 {
740 .procname = "max-user-freq",
741 .data = &hpet_max_freq,
742 .maxlen = sizeof(int),
743 .mode = 0644,
744 .proc_handler = proc_dointvec,
745 },
746 {}
747};
748
749static struct ctl_table hpet_root[] = {
750 {
751 .procname = "hpet",
752 .maxlen = 0,
753 .mode = 0555,
754 .child = hpet_table,
755 },
756 {}
757};
758
759static struct ctl_table dev_root[] = {
760 {
761 .procname = "dev",
762 .maxlen = 0,
763 .mode = 0555,
764 .child = hpet_root,
765 },
766 {}
767};
768
769static struct ctl_table_header *sysctl_header;
770
771/*
772 * Adjustment for when arming the timer with
773 * initial conditions. That is, main counter
774 * ticks expired before interrupts are enabled.
775 */
776#define TICK_CALIBRATE (1000UL)
777
778static unsigned long __hpet_calibrate(struct hpets *hpetp)
779{
780 struct hpet_timer __iomem *timer = NULL;
781 unsigned long t, m, count, i, flags, start;
782 struct hpet_dev *devp;
783 int j;
784 struct hpet __iomem *hpet;
785
786 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
787 if ((devp->hd_flags & HPET_OPEN) == 0) {
788 timer = devp->hd_timer;
789 break;
790 }
791
792 if (!timer)
793 return 0;
794
795 hpet = hpetp->hp_hpet;
796 t = read_counter(&timer->hpet_compare);
797
798 i = 0;
799 count = hpet_time_div(hpetp, TICK_CALIBRATE);
800
801 local_irq_save(flags);
802
803 start = read_counter(&hpet->hpet_mc);
804
805 do {
806 m = read_counter(&hpet->hpet_mc);
807 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
808 } while (i++, (m - start) < count);
809
810 local_irq_restore(flags);
811
812 return (m - start) / i;
813}
814
815static unsigned long hpet_calibrate(struct hpets *hpetp)
816{
817 unsigned long ret = ~0UL;
818 unsigned long tmp;
819
820 /*
821 * Try to calibrate until return value becomes stable small value.
822 * If SMI interruption occurs in calibration loop, the return value
823 * will be big. This avoids its impact.
824 */
825 for ( ; ; ) {
826 tmp = __hpet_calibrate(hpetp);
827 if (ret <= tmp)
828 break;
829 ret = tmp;
830 }
831
832 return ret;
833}
834
835int hpet_alloc(struct hpet_data *hdp)
836{
837 u64 cap, mcfg;
838 struct hpet_dev *devp;
839 u32 i, ntimer;
840 struct hpets *hpetp;
841 struct hpet __iomem *hpet;
842 static struct hpets *last;
843 unsigned long period;
844 unsigned long long temp;
845 u32 remainder;
846
847 /*
848 * hpet_alloc can be called by platform dependent code.
849 * If platform dependent code has allocated the hpet that
850 * ACPI has also reported, then we catch it here.
851 */
852 if (hpet_is_known(hdp)) {
853 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
854 __func__);
855 return 0;
856 }
857
858 hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs),
859 GFP_KERNEL);
860
861 if (!hpetp)
862 return -ENOMEM;
863
864 hpetp->hp_which = hpet_nhpet++;
865 hpetp->hp_hpet = hdp->hd_address;
866 hpetp->hp_hpet_phys = hdp->hd_phys_address;
867
868 hpetp->hp_ntimer = hdp->hd_nirqs;
869
870 for (i = 0; i < hdp->hd_nirqs; i++)
871 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
872
873 hpet = hpetp->hp_hpet;
874
875 cap = readq(&hpet->hpet_cap);
876
877 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
878
879 if (hpetp->hp_ntimer != ntimer) {
880 printk(KERN_WARNING "hpet: number irqs doesn't agree"
881 " with number of timers\n");
882 kfree(hpetp);
883 return -ENODEV;
884 }
885
886 if (last)
887 last->hp_next = hpetp;
888 else
889 hpets = hpetp;
890
891 last = hpetp;
892
893 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
894 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
895 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
896 temp += period >> 1; /* round */
897 do_div(temp, period);
898 hpetp->hp_tick_freq = temp; /* ticks per second */
899
900 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
901 hpetp->hp_which, hdp->hd_phys_address,
902 hpetp->hp_ntimer > 1 ? "s" : "");
903 for (i = 0; i < hpetp->hp_ntimer; i++)
904 printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
905 printk(KERN_CONT "\n");
906
907 temp = hpetp->hp_tick_freq;
908 remainder = do_div(temp, 1000000);
909 printk(KERN_INFO
910 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
911 hpetp->hp_which, hpetp->hp_ntimer,
912 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
913 (unsigned) temp, remainder);
914
915 mcfg = readq(&hpet->hpet_config);
916 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
917 write_counter(0L, &hpet->hpet_mc);
918 mcfg |= HPET_ENABLE_CNF_MASK;
919 writeq(mcfg, &hpet->hpet_config);
920 }
921
922 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
923 struct hpet_timer __iomem *timer;
924
925 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
926
927 devp->hd_hpets = hpetp;
928 devp->hd_hpet = hpet;
929 devp->hd_timer = timer;
930
931 /*
932 * If the timer was reserved by platform code,
933 * then make timer unavailable for opens.
934 */
935 if (hdp->hd_state & (1 << i)) {
936 devp->hd_flags = HPET_OPEN;
937 continue;
938 }
939
940 init_waitqueue_head(&devp->hd_waitqueue);
941 }
942
943 hpetp->hp_delta = hpet_calibrate(hpetp);
944
945/* This clocksource driver currently only works on ia64 */
946#ifdef CONFIG_IA64
947 if (!hpet_clocksource) {
948 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
949 clocksource_hpet.archdata.fsys_mmio = hpet_mctr;
950 clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
951 hpetp->hp_clocksource = &clocksource_hpet;
952 hpet_clocksource = &clocksource_hpet;
953 }
954#endif
955
956 return 0;
957}
958
959static acpi_status hpet_resources(struct acpi_resource *res, void *data)
960{
961 struct hpet_data *hdp;
962 acpi_status status;
963 struct acpi_resource_address64 addr;
964
965 hdp = data;
966
967 status = acpi_resource_to_address64(res, &addr);
968
969 if (ACPI_SUCCESS(status)) {
970 hdp->hd_phys_address = addr.address.minimum;
971 hdp->hd_address = ioremap(addr.address.minimum, addr.address.address_length);
972 if (!hdp->hd_address)
973 return AE_ERROR;
974
975 if (hpet_is_known(hdp)) {
976 iounmap(hdp->hd_address);
977 return AE_ALREADY_EXISTS;
978 }
979 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
980 struct acpi_resource_fixed_memory32 *fixmem32;
981
982 fixmem32 = &res->data.fixed_memory32;
983
984 hdp->hd_phys_address = fixmem32->address;
985 hdp->hd_address = ioremap(fixmem32->address,
986 HPET_RANGE_SIZE);
987
988 if (hpet_is_known(hdp)) {
989 iounmap(hdp->hd_address);
990 return AE_ALREADY_EXISTS;
991 }
992 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
993 struct acpi_resource_extended_irq *irqp;
994 int i, irq;
995
996 irqp = &res->data.extended_irq;
997
998 for (i = 0; i < irqp->interrupt_count; i++) {
999 if (hdp->hd_nirqs >= HPET_MAX_TIMERS)
1000 break;
1001
1002 irq = acpi_register_gsi(NULL, irqp->interrupts[i],
1003 irqp->triggering, irqp->polarity);
1004 if (irq < 0)
1005 return AE_ERROR;
1006
1007 hdp->hd_irq[hdp->hd_nirqs] = irq;
1008 hdp->hd_nirqs++;
1009 }
1010 }
1011
1012 return AE_OK;
1013}
1014
1015static int hpet_acpi_add(struct acpi_device *device)
1016{
1017 acpi_status result;
1018 struct hpet_data data;
1019
1020 memset(&data, 0, sizeof(data));
1021
1022 result =
1023 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1024 hpet_resources, &data);
1025
1026 if (ACPI_FAILURE(result))
1027 return -ENODEV;
1028
1029 if (!data.hd_address || !data.hd_nirqs) {
1030 if (data.hd_address)
1031 iounmap(data.hd_address);
1032 printk("%s: no address or irqs in _CRS\n", __func__);
1033 return -ENODEV;
1034 }
1035
1036 return hpet_alloc(&data);
1037}
1038
1039static const struct acpi_device_id hpet_device_ids[] = {
1040 {"PNP0103", 0},
1041 {"", 0},
1042};
1043
1044static struct acpi_driver hpet_acpi_driver = {
1045 .name = "hpet",
1046 .ids = hpet_device_ids,
1047 .ops = {
1048 .add = hpet_acpi_add,
1049 },
1050};
1051
1052static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1053
1054static int __init hpet_init(void)
1055{
1056 int result;
1057
1058 result = misc_register(&hpet_misc);
1059 if (result < 0)
1060 return -ENODEV;
1061
1062 sysctl_header = register_sysctl_table(dev_root);
1063
1064 result = acpi_bus_register_driver(&hpet_acpi_driver);
1065 if (result < 0) {
1066 if (sysctl_header)
1067 unregister_sysctl_table(sysctl_header);
1068 misc_deregister(&hpet_misc);
1069 return result;
1070 }
1071
1072 return 0;
1073}
1074device_initcall(hpet_init);
1075
1076/*
1077MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1078MODULE_LICENSE("GPL");
1079*/
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
69static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
70static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
71
72/* This clocksource driver currently only works on ia64 */
73#ifdef CONFIG_IA64
74static void __iomem *hpet_mctr;
75
76static cycle_t read_hpet(struct clocksource *cs)
77{
78 return (cycle_t)read_counter((void __iomem *)hpet_mctr);
79}
80
81static 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};
88static struct clocksource *hpet_clocksource;
89#endif
90
91/* A lock for concurrent access by app and isr hpet activity. */
92static DEFINE_SPINLOCK(hpet_lock);
93
94#define HPET_DEV_NAME (7)
95
96struct 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
110struct 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
122static 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
131static 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
138static 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
145static 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
204static 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
263static 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
301static ssize_t
302hpet_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);
341out:
342 __set_current_state(TASK_RUNNING);
343 remove_wait_queue(&devp->hd_waitqueue, &wait);
344
345 return retval;
346}
347
348static 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
370static 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
401static 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
413static 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
451static 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 */
563static 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
573static int
574hpet_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
666static long
667hpet_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
684struct 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
691static long
692hpet_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
714static 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
729static 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
740static 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
751static ctl_table hpet_root[] = {
752 {
753 .procname = "hpet",
754 .maxlen = 0,
755 .mode = 0555,
756 .child = hpet_table,
757 },
758 {}
759};
760
761static ctl_table dev_root[] = {
762 {
763 .procname = "dev",
764 .maxlen = 0,
765 .mode = 0555,
766 .child = hpet_root,
767 },
768 {}
769};
770
771static 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
780static 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
817static 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
837int 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
964static 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
1017static 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
1041static 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
1047static const struct acpi_device_id hpet_device_ids[] = {
1048 {"PNP0103", 0},
1049 {"", 0},
1050};
1051MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1052
1053static 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
1062static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1063
1064static 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
1085static 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
1096module_init(hpet_init);
1097module_exit(hpet_exit);
1098MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1099MODULE_LICENSE("GPL");