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Linux 2.6.34-rc3
[pohmelfs.git] / drivers / char / hpet.c
blob9c5eea3ea4deb22b7cb215184b3dd3a9b8a69152
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/smp_lock.h>
18 #include <linux/types.h>
19 #include <linux/miscdevice.h>
20 #include <linux/major.h>
21 #include <linux/ioport.h>
22 #include <linux/fcntl.h>
23 #include <linux/init.h>
24 #include <linux/poll.h>
25 #include <linux/mm.h>
26 #include <linux/proc_fs.h>
27 #include <linux/spinlock.h>
28 #include <linux/sysctl.h>
29 #include <linux/wait.h>
30 #include <linux/bcd.h>
31 #include <linux/seq_file.h>
32 #include <linux/bitops.h>
33 #include <linux/clocksource.h>
34
35 #include <asm/current.h>
36 #include <asm/uaccess.h>
37 #include <asm/system.h>
38 #include <asm/io.h>
39 #include <asm/irq.h>
40 #include <asm/div64.h>
41
42 #include <linux/acpi.h>
43 #include <acpi/acpi_bus.h>
44 #include <linux/hpet.h>
45
46 /*
47 * The High Precision Event Timer driver.
48 * This driver is closely modelled after the rtc.c driver.
49 * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
50 */
51 #define HPET_USER_FREQ (64)
52 #define HPET_DRIFT (500)
53
54 #define HPET_RANGE_SIZE 1024 /* from HPET spec */
55
56
57 /* WARNING -- don't get confused. These macros are never used
58 * to write the (single) counter, and rarely to read it.
59 * They're badly named; to fix, someday.
60 */
61 #if BITS_PER_LONG == 64
62 #define write_counter(V, MC) writeq(V, MC)
63 #define read_counter(MC) readq(MC)
64 #else
65 #define write_counter(V, MC) writel(V, MC)
66 #define read_counter(MC) readl(MC)
67 #endif
68
69 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
70
71 /* This clocksource driver currently only works on ia64 */
72 #ifdef CONFIG_IA64
73 static void __iomem *hpet_mctr;
74
75 static cycle_t read_hpet(struct clocksource *cs)
76 {
77 return (cycle_t)read_counter((void __iomem *)hpet_mctr);
78 }
79
80 static struct clocksource clocksource_hpet = {
81 .name = "hpet",
82 .rating = 250,
83 .read = read_hpet,
84 .mask = CLOCKSOURCE_MASK(64),
85 .mult = 0, /* to be calculated */
86 .shift = 10,
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;
167
168 t = devp->hd_ireqfreq;
169 m = read_counter(&devp->hd_timer->hpet_compare);
170 write_counter(t + m, &devp->hd_timer->hpet_compare);
171 }
172
173 if (devp->hd_flags & HPET_SHARED_IRQ)
174 writel(isr, &devp->hd_hpet->hpet_isr);
175 spin_unlock(&hpet_lock);
176
177 wake_up_interruptible(&devp->hd_waitqueue);
178
179 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
180
181 return IRQ_HANDLED;
182 }
183
184 static void hpet_timer_set_irq(struct hpet_dev *devp)
185 {
186 unsigned long v;
187 int irq, gsi;
188 struct hpet_timer __iomem *timer;
189
190 spin_lock_irq(&hpet_lock);
191 if (devp->hd_hdwirq) {
192 spin_unlock_irq(&hpet_lock);
193 return;
194 }
195
196 timer = devp->hd_timer;
197
198 /* we prefer level triggered mode */
199 v = readl(&timer->hpet_config);
200 if (!(v & Tn_INT_TYPE_CNF_MASK)) {
201 v |= Tn_INT_TYPE_CNF_MASK;
202 writel(v, &timer->hpet_config);
203 }
204 spin_unlock_irq(&hpet_lock);
205
206 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
207 Tn_INT_ROUTE_CAP_SHIFT;
208
209 /*
210 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
211 * legacy device. In IO APIC mode, we skip all the legacy IRQS.
212 */
213 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
214 v &= ~0xf3df;
215 else
216 v &= ~0xffff;
217
218 for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
219 if (irq >= nr_irqs) {
220 irq = HPET_MAX_IRQ;
221 break;
222 }
223
224 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
225 ACPI_ACTIVE_LOW);
226 if (gsi > 0)
227 break;
228
229 /* FIXME: Setup interrupt source table */
230 }
231
232 if (irq < HPET_MAX_IRQ) {
233 spin_lock_irq(&hpet_lock);
234 v = readl(&timer->hpet_config);
235 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
236 writel(v, &timer->hpet_config);
237 devp->hd_hdwirq = gsi;
238 spin_unlock_irq(&hpet_lock);
239 }
240 return;
241 }
242
243 static int hpet_open(struct inode *inode, struct file *file)
244 {
245 struct hpet_dev *devp;
246 struct hpets *hpetp;
247 int i;
248
249 if (file->f_mode & FMODE_WRITE)
250 return -EINVAL;
251
252 lock_kernel();
253 spin_lock_irq(&hpet_lock);
254
255 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
256 for (i = 0; i < hpetp->hp_ntimer; i++)
257 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
258 continue;
259 else {
260 devp = &hpetp->hp_dev[i];
261 break;
262 }
263
264 if (!devp) {
265 spin_unlock_irq(&hpet_lock);
266 unlock_kernel();
267 return -EBUSY;
268 }
269
270 file->private_data = devp;
271 devp->hd_irqdata = 0;
272 devp->hd_flags |= HPET_OPEN;
273 spin_unlock_irq(&hpet_lock);
274 unlock_kernel();
275
276 hpet_timer_set_irq(devp);
277
278 return 0;
279 }
280
281 static ssize_t
282 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
283 {
284 DECLARE_WAITQUEUE(wait, current);
285 unsigned long data;
286 ssize_t retval;
287 struct hpet_dev *devp;
288
289 devp = file->private_data;
290 if (!devp->hd_ireqfreq)
291 return -EIO;
292
293 if (count < sizeof(unsigned long))
294 return -EINVAL;
295
296 add_wait_queue(&devp->hd_waitqueue, &wait);
297
298 for ( ; ; ) {
299 set_current_state(TASK_INTERRUPTIBLE);
300
301 spin_lock_irq(&hpet_lock);
302 data = devp->hd_irqdata;
303 devp->hd_irqdata = 0;
304 spin_unlock_irq(&hpet_lock);
305
306 if (data)
307 break;
308 else if (file->f_flags & O_NONBLOCK) {
309 retval = -EAGAIN;
310 goto out;
311 } else if (signal_pending(current)) {
312 retval = -ERESTARTSYS;
313 goto out;
314 }
315 schedule();
316 }
317
318 retval = put_user(data, (unsigned long __user *)buf);
319 if (!retval)
320 retval = sizeof(unsigned long);
321 out:
322 __set_current_state(TASK_RUNNING);
323 remove_wait_queue(&devp->hd_waitqueue, &wait);
324
325 return retval;
326 }
327
328 static unsigned int hpet_poll(struct file *file, poll_table * wait)
329 {
330 unsigned long v;
331 struct hpet_dev *devp;
332
333 devp = file->private_data;
334
335 if (!devp->hd_ireqfreq)
336 return 0;
337
338 poll_wait(file, &devp->hd_waitqueue, wait);
339
340 spin_lock_irq(&hpet_lock);
341 v = devp->hd_irqdata;
342 spin_unlock_irq(&hpet_lock);
343
344 if (v != 0)
345 return POLLIN | POLLRDNORM;
346
347 return 0;
348 }
349
350 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
351 {
352 #ifdef CONFIG_HPET_MMAP
353 struct hpet_dev *devp;
354 unsigned long addr;
355
356 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
357 return -EINVAL;
358
359 devp = file->private_data;
360 addr = devp->hd_hpets->hp_hpet_phys;
361
362 if (addr & (PAGE_SIZE - 1))
363 return -ENOSYS;
364
365 vma->vm_flags |= VM_IO;
366 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
367
368 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
369 PAGE_SIZE, vma->vm_page_prot)) {
370 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
371 __func__);
372 return -EAGAIN;
373 }
374
375 return 0;
376 #else
377 return -ENOSYS;
378 #endif
379 }
380
381 static int hpet_fasync(int fd, struct file *file, int on)
382 {
383 struct hpet_dev *devp;
384
385 devp = file->private_data;
386
387 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
388 return 0;
389 else
390 return -EIO;
391 }
392
393 static int hpet_release(struct inode *inode, struct file *file)
394 {
395 struct hpet_dev *devp;
396 struct hpet_timer __iomem *timer;
397 int irq = 0;
398
399 devp = file->private_data;
400 timer = devp->hd_timer;
401
402 spin_lock_irq(&hpet_lock);
403
404 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
405 &timer->hpet_config);
406
407 irq = devp->hd_irq;
408 devp->hd_irq = 0;
409
410 devp->hd_ireqfreq = 0;
411
412 if (devp->hd_flags & HPET_PERIODIC
413 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
414 unsigned long v;
415
416 v = readq(&timer->hpet_config);
417 v ^= Tn_TYPE_CNF_MASK;
418 writeq(v, &timer->hpet_config);
419 }
420
421 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
422 spin_unlock_irq(&hpet_lock);
423
424 if (irq)
425 free_irq(irq, devp);
426
427 file->private_data = NULL;
428 return 0;
429 }
430
431 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
432
433 static int
434 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
435 unsigned long arg)
436 {
437 struct hpet_dev *devp;
438
439 devp = file->private_data;
440 return hpet_ioctl_common(devp, cmd, arg, 0);
441 }
442
443 static int hpet_ioctl_ieon(struct hpet_dev *devp)
444 {
445 struct hpet_timer __iomem *timer;
446 struct hpet __iomem *hpet;
447 struct hpets *hpetp;
448 int irq;
449 unsigned long g, v, t, m;
450 unsigned long flags, isr;
451
452 timer = devp->hd_timer;
453 hpet = devp->hd_hpet;
454 hpetp = devp->hd_hpets;
455
456 if (!devp->hd_ireqfreq)
457 return -EIO;
458
459 spin_lock_irq(&hpet_lock);
460
461 if (devp->hd_flags & HPET_IE) {
462 spin_unlock_irq(&hpet_lock);
463 return -EBUSY;
464 }
465
466 devp->hd_flags |= HPET_IE;
467
468 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
469 devp->hd_flags |= HPET_SHARED_IRQ;
470 spin_unlock_irq(&hpet_lock);
471
472 irq = devp->hd_hdwirq;
473
474 if (irq) {
475 unsigned long irq_flags;
476
477 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
478 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
479 ? IRQF_SHARED : IRQF_DISABLED;
480 if (request_irq(irq, hpet_interrupt, irq_flags,
481 devp->hd_name, (void *)devp)) {
482 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
483 irq = 0;
484 }
485 }
486
487 if (irq == 0) {
488 spin_lock_irq(&hpet_lock);
489 devp->hd_flags ^= HPET_IE;
490 spin_unlock_irq(&hpet_lock);
491 return -EIO;
492 }
493
494 devp->hd_irq = irq;
495 t = devp->hd_ireqfreq;
496 v = readq(&timer->hpet_config);
497
498 /* 64-bit comparators are not yet supported through the ioctls,
499 * so force this into 32-bit mode if it supports both modes
500 */
501 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
502
503 if (devp->hd_flags & HPET_PERIODIC) {
504 g |= Tn_TYPE_CNF_MASK;
505 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
506 writeq(v, &timer->hpet_config);
507 local_irq_save(flags);
508
509 /*
510 * NOTE: First we modify the hidden accumulator
511 * register supported by periodic-capable comparators.
512 * We never want to modify the (single) counter; that
513 * would affect all the comparators. The value written
514 * is the counter value when the first interrupt is due.
515 */
516 m = read_counter(&hpet->hpet_mc);
517 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
518 /*
519 * Then we modify the comparator, indicating the period
520 * for subsequent interrupt.
521 */
522 write_counter(t, &timer->hpet_compare);
523 } else {
524 local_irq_save(flags);
525 m = read_counter(&hpet->hpet_mc);
526 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
527 }
528
529 if (devp->hd_flags & HPET_SHARED_IRQ) {
530 isr = 1 << (devp - devp->hd_hpets->hp_dev);
531 writel(isr, &hpet->hpet_isr);
532 }
533 writeq(g, &timer->hpet_config);
534 local_irq_restore(flags);
535
536 return 0;
537 }
538
539 /* converts Hz to number of timer ticks */
540 static inline unsigned long hpet_time_div(struct hpets *hpets,
541 unsigned long dis)
542 {
543 unsigned long long m;
544
545 m = hpets->hp_tick_freq + (dis >> 1);
546 do_div(m, dis);
547 return (unsigned long)m;
548 }
549
550 static int
551 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
552 {
553 struct hpet_timer __iomem *timer;
554 struct hpet __iomem *hpet;
555 struct hpets *hpetp;
556 int err;
557 unsigned long v;
558
559 switch (cmd) {
560 case HPET_IE_OFF:
561 case HPET_INFO:
562 case HPET_EPI:
563 case HPET_DPI:
564 case HPET_IRQFREQ:
565 timer = devp->hd_timer;
566 hpet = devp->hd_hpet;
567 hpetp = devp->hd_hpets;
568 break;
569 case HPET_IE_ON:
570 return hpet_ioctl_ieon(devp);
571 default:
572 return -EINVAL;
573 }
574
575 err = 0;
576
577 switch (cmd) {
578 case HPET_IE_OFF:
579 if ((devp->hd_flags & HPET_IE) == 0)
580 break;
581 v = readq(&timer->hpet_config);
582 v &= ~Tn_INT_ENB_CNF_MASK;
583 writeq(v, &timer->hpet_config);
584 if (devp->hd_irq) {
585 free_irq(devp->hd_irq, devp);
586 devp->hd_irq = 0;
587 }
588 devp->hd_flags ^= HPET_IE;
589 break;
590 case HPET_INFO:
591 {
592 struct hpet_info info;
593
594 if (devp->hd_ireqfreq)
595 info.hi_ireqfreq =
596 hpet_time_div(hpetp, devp->hd_ireqfreq);
597 else
598 info.hi_ireqfreq = 0;
599 info.hi_flags =
600 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
601 info.hi_hpet = hpetp->hp_which;
602 info.hi_timer = devp - hpetp->hp_dev;
603 if (kernel)
604 memcpy((void *)arg, &info, sizeof(info));
605 else
606 if (copy_to_user((void __user *)arg, &info,
607 sizeof(info)))
608 err = -EFAULT;
609 break;
610 }
611 case HPET_EPI:
612 v = readq(&timer->hpet_config);
613 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
614 err = -ENXIO;
615 break;
616 }
617 devp->hd_flags |= HPET_PERIODIC;
618 break;
619 case HPET_DPI:
620 v = readq(&timer->hpet_config);
621 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
622 err = -ENXIO;
623 break;
624 }
625 if (devp->hd_flags & HPET_PERIODIC &&
626 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
627 v = readq(&timer->hpet_config);
628 v ^= Tn_TYPE_CNF_MASK;
629 writeq(v, &timer->hpet_config);
630 }
631 devp->hd_flags &= ~HPET_PERIODIC;
632 break;
633 case HPET_IRQFREQ:
634 if (!kernel && (arg > hpet_max_freq) &&
635 !capable(CAP_SYS_RESOURCE)) {
636 err = -EACCES;
637 break;
638 }
639
640 if (!arg) {
641 err = -EINVAL;
642 break;
643 }
644
645 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
646 }
647
648 return err;
649 }
650
651 static const struct file_operations hpet_fops = {
652 .owner = THIS_MODULE,
653 .llseek = no_llseek,
654 .read = hpet_read,
655 .poll = hpet_poll,
656 .ioctl = hpet_ioctl,
657 .open = hpet_open,
658 .release = hpet_release,
659 .fasync = hpet_fasync,
660 .mmap = hpet_mmap,
661 };
662
663 static int hpet_is_known(struct hpet_data *hdp)
664 {
665 struct hpets *hpetp;
666
667 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
668 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
669 return 1;
670
671 return 0;
672 }
673
674 static ctl_table hpet_table[] = {
675 {
676 .procname = "max-user-freq",
677 .data = &hpet_max_freq,
678 .maxlen = sizeof(int),
679 .mode = 0644,
680 .proc_handler = proc_dointvec,
681 },
682 {}
683 };
684
685 static ctl_table hpet_root[] = {
686 {
687 .procname = "hpet",
688 .maxlen = 0,
689 .mode = 0555,
690 .child = hpet_table,
691 },
692 {}
693 };
694
695 static ctl_table dev_root[] = {
696 {
697 .procname = "dev",
698 .maxlen = 0,
699 .mode = 0555,
700 .child = hpet_root,
701 },
702 {}
703 };
704
705 static struct ctl_table_header *sysctl_header;
706
707 /*
708 * Adjustment for when arming the timer with
709 * initial conditions. That is, main counter
710 * ticks expired before interrupts are enabled.
711 */
712 #define TICK_CALIBRATE (1000UL)
713
714 static unsigned long __hpet_calibrate(struct hpets *hpetp)
715 {
716 struct hpet_timer __iomem *timer = NULL;
717 unsigned long t, m, count, i, flags, start;
718 struct hpet_dev *devp;
719 int j;
720 struct hpet __iomem *hpet;
721
722 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
723 if ((devp->hd_flags & HPET_OPEN) == 0) {
724 timer = devp->hd_timer;
725 break;
726 }
727
728 if (!timer)
729 return 0;
730
731 hpet = hpetp->hp_hpet;
732 t = read_counter(&timer->hpet_compare);
733
734 i = 0;
735 count = hpet_time_div(hpetp, TICK_CALIBRATE);
736
737 local_irq_save(flags);
738
739 start = read_counter(&hpet->hpet_mc);
740
741 do {
742 m = read_counter(&hpet->hpet_mc);
743 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
744 } while (i++, (m - start) < count);
745
746 local_irq_restore(flags);
747
748 return (m - start) / i;
749 }
750
751 static unsigned long hpet_calibrate(struct hpets *hpetp)
752 {
753 unsigned long ret = -1;
754 unsigned long tmp;
755
756 /*
757 * Try to calibrate until return value becomes stable small value.
758 * If SMI interruption occurs in calibration loop, the return value
759 * will be big. This avoids its impact.
760 */
761 for ( ; ; ) {
762 tmp = __hpet_calibrate(hpetp);
763 if (ret <= tmp)
764 break;
765 ret = tmp;
766 }
767
768 return ret;
769 }
770
771 int hpet_alloc(struct hpet_data *hdp)
772 {
773 u64 cap, mcfg;
774 struct hpet_dev *devp;
775 u32 i, ntimer;
776 struct hpets *hpetp;
777 size_t siz;
778 struct hpet __iomem *hpet;
779 static struct hpets *last = NULL;
780 unsigned long period;
781 unsigned long long temp;
782 u32 remainder;
783
784 /*
785 * hpet_alloc can be called by platform dependent code.
786 * If platform dependent code has allocated the hpet that
787 * ACPI has also reported, then we catch it here.
788 */
789 if (hpet_is_known(hdp)) {
790 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
791 __func__);
792 return 0;
793 }
794
795 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
796 sizeof(struct hpet_dev));
797
798 hpetp = kzalloc(siz, GFP_KERNEL);
799
800 if (!hpetp)
801 return -ENOMEM;
802
803 hpetp->hp_which = hpet_nhpet++;
804 hpetp->hp_hpet = hdp->hd_address;
805 hpetp->hp_hpet_phys = hdp->hd_phys_address;
806
807 hpetp->hp_ntimer = hdp->hd_nirqs;
808
809 for (i = 0; i < hdp->hd_nirqs; i++)
810 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
811
812 hpet = hpetp->hp_hpet;
813
814 cap = readq(&hpet->hpet_cap);
815
816 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
817
818 if (hpetp->hp_ntimer != ntimer) {
819 printk(KERN_WARNING "hpet: number irqs doesn't agree"
820 " with number of timers\n");
821 kfree(hpetp);
822 return -ENODEV;
823 }
824
825 if (last)
826 last->hp_next = hpetp;
827 else
828 hpets = hpetp;
829
830 last = hpetp;
831
832 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
833 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
834 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
835 temp += period >> 1; /* round */
836 do_div(temp, period);
837 hpetp->hp_tick_freq = temp; /* ticks per second */
838
839 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
840 hpetp->hp_which, hdp->hd_phys_address,
841 hpetp->hp_ntimer > 1 ? "s" : "");
842 for (i = 0; i < hpetp->hp_ntimer; i++)
843 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
844 printk("\n");
845
846 temp = hpetp->hp_tick_freq;
847 remainder = do_div(temp, 1000000);
848 printk(KERN_INFO
849 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
850 hpetp->hp_which, hpetp->hp_ntimer,
851 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
852 (unsigned) temp, remainder);
853
854 mcfg = readq(&hpet->hpet_config);
855 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
856 write_counter(0L, &hpet->hpet_mc);
857 mcfg |= HPET_ENABLE_CNF_MASK;
858 writeq(mcfg, &hpet->hpet_config);
859 }
860
861 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
862 struct hpet_timer __iomem *timer;
863
864 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
865
866 devp->hd_hpets = hpetp;
867 devp->hd_hpet = hpet;
868 devp->hd_timer = timer;
869
870 /*
871 * If the timer was reserved by platform code,
872 * then make timer unavailable for opens.
873 */
874 if (hdp->hd_state & (1 << i)) {
875 devp->hd_flags = HPET_OPEN;
876 continue;
877 }
878
879 init_waitqueue_head(&devp->hd_waitqueue);
880 }
881
882 hpetp->hp_delta = hpet_calibrate(hpetp);
883
884 /* This clocksource driver currently only works on ia64 */
885 #ifdef CONFIG_IA64
886 if (!hpet_clocksource) {
887 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
888 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
889 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
890 clocksource_hpet.shift);
891 clocksource_register(&clocksource_hpet);
892 hpetp->hp_clocksource = &clocksource_hpet;
893 hpet_clocksource = &clocksource_hpet;
894 }
895 #endif
896
897 return 0;
898 }
899
900 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
901 {
902 struct hpet_data *hdp;
903 acpi_status status;
904 struct acpi_resource_address64 addr;
905
906 hdp = data;
907
908 status = acpi_resource_to_address64(res, &addr);
909
910 if (ACPI_SUCCESS(status)) {
911 hdp->hd_phys_address = addr.minimum;
912 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
913
914 if (hpet_is_known(hdp)) {
915 iounmap(hdp->hd_address);
916 return AE_ALREADY_EXISTS;
917 }
918 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
919 struct acpi_resource_fixed_memory32 *fixmem32;
920
921 fixmem32 = &res->data.fixed_memory32;
922 if (!fixmem32)
923 return AE_NO_MEMORY;
924
925 hdp->hd_phys_address = fixmem32->address;
926 hdp->hd_address = ioremap(fixmem32->address,
927 HPET_RANGE_SIZE);
928
929 if (hpet_is_known(hdp)) {
930 iounmap(hdp->hd_address);
931 return AE_ALREADY_EXISTS;
932 }
933 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
934 struct acpi_resource_extended_irq *irqp;
935 int i, irq;
936
937 irqp = &res->data.extended_irq;
938
939 for (i = 0; i < irqp->interrupt_count; i++) {
940 irq = acpi_register_gsi(NULL, irqp->interrupts[i],
941 irqp->triggering, irqp->polarity);
942 if (irq < 0)
943 return AE_ERROR;
944
945 hdp->hd_irq[hdp->hd_nirqs] = irq;
946 hdp->hd_nirqs++;
947 }
948 }
949
950 return AE_OK;
951 }
952
953 static int hpet_acpi_add(struct acpi_device *device)
954 {
955 acpi_status result;
956 struct hpet_data data;
957
958 memset(&data, 0, sizeof(data));
959
960 result =
961 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
962 hpet_resources, &data);
963
964 if (ACPI_FAILURE(result))
965 return -ENODEV;
966
967 if (!data.hd_address || !data.hd_nirqs) {
968 printk("%s: no address or irqs in _CRS\n", __func__);
969 return -ENODEV;
970 }
971
972 return hpet_alloc(&data);
973 }
974
975 static int hpet_acpi_remove(struct acpi_device *device, int type)
976 {
977 /* XXX need to unregister clocksource, dealloc mem, etc */
978 return -EINVAL;
979 }
980
981 static const struct acpi_device_id hpet_device_ids[] = {
982 {"PNP0103", 0},
983 {"", 0},
984 };
985 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
986
987 static struct acpi_driver hpet_acpi_driver = {
988 .name = "hpet",
989 .ids = hpet_device_ids,
990 .ops = {
991 .add = hpet_acpi_add,
992 .remove = hpet_acpi_remove,
993 },
994 };
995
996 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
997
998 static int __init hpet_init(void)
999 {
1000 int result;
1001
1002 result = misc_register(&hpet_misc);
1003 if (result < 0)
1004 return -ENODEV;
1005
1006 sysctl_header = register_sysctl_table(dev_root);
1007
1008 result = acpi_bus_register_driver(&hpet_acpi_driver);
1009 if (result < 0) {
1010 if (sysctl_header)
1011 unregister_sysctl_table(sysctl_header);
1012 misc_deregister(&hpet_misc);
1013 return result;
1014 }
1015
1016 return 0;
1017 }
1018
1019 static void __exit hpet_exit(void)
1020 {
1021 acpi_bus_unregister_driver(&hpet_acpi_driver);
1022
1023 if (sysctl_header)
1024 unregister_sysctl_table(sysctl_header);
1025 misc_deregister(&hpet_misc);
1026
1027 return;
1028 }
1029
1030 module_init(hpet_init);
1031 module_exit(hpet_exit);
1032 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1033 MODULE_LICENSE("GPL");