Root/
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 | #include <linux/slab.h> |
35 | |
36 | #include <asm/current.h> |
37 | #include <asm/uaccess.h> |
38 | #include <asm/system.h> |
39 | #include <asm/io.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 u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; |
71 | |
72 | /* This clocksource driver currently only works on ia64 */ |
73 | #ifdef CONFIG_IA64 |
74 | static void __iomem *hpet_mctr; |
75 | |
76 | static cycle_t read_hpet(struct clocksource *cs) |
77 | { |
78 | return (cycle_t)read_counter((void __iomem *)hpet_mctr); |
79 | } |
80 | |
81 | static struct clocksource clocksource_hpet = { |
82 | .name = "hpet", |
83 | .rating = 250, |
84 | .read = read_hpet, |
85 | .mask = CLOCKSOURCE_MASK(64), |
86 | .mult = 0, /* to be calculated */ |
87 | .shift = 10, |
88 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
89 | }; |
90 | static struct clocksource *hpet_clocksource; |
91 | #endif |
92 | |
93 | /* A lock for concurrent access by app and isr hpet activity. */ |
94 | static DEFINE_SPINLOCK(hpet_lock); |
95 | |
96 | #define HPET_DEV_NAME (7) |
97 | |
98 | struct hpet_dev { |
99 | struct hpets *hd_hpets; |
100 | struct hpet __iomem *hd_hpet; |
101 | struct hpet_timer __iomem *hd_timer; |
102 | unsigned long hd_ireqfreq; |
103 | unsigned long hd_irqdata; |
104 | wait_queue_head_t hd_waitqueue; |
105 | struct fasync_struct *hd_async_queue; |
106 | unsigned int hd_flags; |
107 | unsigned int hd_irq; |
108 | unsigned int hd_hdwirq; |
109 | char hd_name[HPET_DEV_NAME]; |
110 | }; |
111 | |
112 | struct hpets { |
113 | struct hpets *hp_next; |
114 | struct hpet __iomem *hp_hpet; |
115 | unsigned long hp_hpet_phys; |
116 | struct clocksource *hp_clocksource; |
117 | unsigned long long hp_tick_freq; |
118 | unsigned long hp_delta; |
119 | unsigned int hp_ntimer; |
120 | unsigned int hp_which; |
121 | struct hpet_dev hp_dev[1]; |
122 | }; |
123 | |
124 | static struct hpets *hpets; |
125 | |
126 | #define HPET_OPEN 0x0001 |
127 | #define HPET_IE 0x0002 /* interrupt enabled */ |
128 | #define HPET_PERIODIC 0x0004 |
129 | #define HPET_SHARED_IRQ 0x0008 |
130 | |
131 | |
132 | #ifndef readq |
133 | static inline unsigned long long readq(void __iomem *addr) |
134 | { |
135 | return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); |
136 | } |
137 | #endif |
138 | |
139 | #ifndef writeq |
140 | static inline void writeq(unsigned long long v, void __iomem *addr) |
141 | { |
142 | writel(v & 0xffffffff, addr); |
143 | writel(v >> 32, addr + 4); |
144 | } |
145 | #endif |
146 | |
147 | static irqreturn_t hpet_interrupt(int irq, void *data) |
148 | { |
149 | struct hpet_dev *devp; |
150 | unsigned long isr; |
151 | |
152 | devp = data; |
153 | isr = 1 << (devp - devp->hd_hpets->hp_dev); |
154 | |
155 | if ((devp->hd_flags & HPET_SHARED_IRQ) && |
156 | !(isr & readl(&devp->hd_hpet->hpet_isr))) |
157 | return IRQ_NONE; |
158 | |
159 | spin_lock(&hpet_lock); |
160 | devp->hd_irqdata++; |
161 | |
162 | /* |
163 | * For non-periodic timers, increment the accumulator. |
164 | * This has the effect of treating non-periodic like periodic. |
165 | */ |
166 | if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { |
167 | unsigned long m, t; |
168 | |
169 | t = devp->hd_ireqfreq; |
170 | m = read_counter(&devp->hd_timer->hpet_compare); |
171 | write_counter(t + m, &devp->hd_timer->hpet_compare); |
172 | } |
173 | |
174 | if (devp->hd_flags & HPET_SHARED_IRQ) |
175 | writel(isr, &devp->hd_hpet->hpet_isr); |
176 | spin_unlock(&hpet_lock); |
177 | |
178 | wake_up_interruptible(&devp->hd_waitqueue); |
179 | |
180 | kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); |
181 | |
182 | return IRQ_HANDLED; |
183 | } |
184 | |
185 | static void hpet_timer_set_irq(struct hpet_dev *devp) |
186 | { |
187 | unsigned long v; |
188 | int irq, gsi; |
189 | struct hpet_timer __iomem *timer; |
190 | |
191 | spin_lock_irq(&hpet_lock); |
192 | if (devp->hd_hdwirq) { |
193 | spin_unlock_irq(&hpet_lock); |
194 | return; |
195 | } |
196 | |
197 | timer = devp->hd_timer; |
198 | |
199 | /* we prefer level triggered mode */ |
200 | v = readl(&timer->hpet_config); |
201 | if (!(v & Tn_INT_TYPE_CNF_MASK)) { |
202 | v |= Tn_INT_TYPE_CNF_MASK; |
203 | writel(v, &timer->hpet_config); |
204 | } |
205 | spin_unlock_irq(&hpet_lock); |
206 | |
207 | v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >> |
208 | Tn_INT_ROUTE_CAP_SHIFT; |
209 | |
210 | /* |
211 | * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by |
212 | * legacy device. In IO APIC mode, we skip all the legacy IRQS. |
213 | */ |
214 | if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) |
215 | v &= ~0xf3df; |
216 | else |
217 | v &= ~0xffff; |
218 | |
219 | for_each_set_bit(irq, &v, HPET_MAX_IRQ) { |
220 | if (irq >= nr_irqs) { |
221 | irq = HPET_MAX_IRQ; |
222 | break; |
223 | } |
224 | |
225 | gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, |
226 | ACPI_ACTIVE_LOW); |
227 | if (gsi > 0) |
228 | break; |
229 | |
230 | /* FIXME: Setup interrupt source table */ |
231 | } |
232 | |
233 | if (irq < HPET_MAX_IRQ) { |
234 | spin_lock_irq(&hpet_lock); |
235 | v = readl(&timer->hpet_config); |
236 | v |= irq << Tn_INT_ROUTE_CNF_SHIFT; |
237 | writel(v, &timer->hpet_config); |
238 | devp->hd_hdwirq = gsi; |
239 | spin_unlock_irq(&hpet_lock); |
240 | } |
241 | return; |
242 | } |
243 | |
244 | static int hpet_open(struct inode *inode, struct file *file) |
245 | { |
246 | struct hpet_dev *devp; |
247 | struct hpets *hpetp; |
248 | int i; |
249 | |
250 | if (file->f_mode & FMODE_WRITE) |
251 | return -EINVAL; |
252 | |
253 | lock_kernel(); |
254 | spin_lock_irq(&hpet_lock); |
255 | |
256 | for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) |
257 | for (i = 0; i < hpetp->hp_ntimer; i++) |
258 | if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) |
259 | continue; |
260 | else { |
261 | devp = &hpetp->hp_dev[i]; |
262 | break; |
263 | } |
264 | |
265 | if (!devp) { |
266 | spin_unlock_irq(&hpet_lock); |
267 | unlock_kernel(); |
268 | return -EBUSY; |
269 | } |
270 | |
271 | file->private_data = devp; |
272 | devp->hd_irqdata = 0; |
273 | devp->hd_flags |= HPET_OPEN; |
274 | spin_unlock_irq(&hpet_lock); |
275 | unlock_kernel(); |
276 | |
277 | hpet_timer_set_irq(devp); |
278 | |
279 | return 0; |
280 | } |
281 | |
282 | static ssize_t |
283 | hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) |
284 | { |
285 | DECLARE_WAITQUEUE(wait, current); |
286 | unsigned long data; |
287 | ssize_t retval; |
288 | struct hpet_dev *devp; |
289 | |
290 | devp = file->private_data; |
291 | if (!devp->hd_ireqfreq) |
292 | return -EIO; |
293 | |
294 | if (count < sizeof(unsigned long)) |
295 | return -EINVAL; |
296 | |
297 | add_wait_queue(&devp->hd_waitqueue, &wait); |
298 | |
299 | for ( ; ; ) { |
300 | set_current_state(TASK_INTERRUPTIBLE); |
301 | |
302 | spin_lock_irq(&hpet_lock); |
303 | data = devp->hd_irqdata; |
304 | devp->hd_irqdata = 0; |
305 | spin_unlock_irq(&hpet_lock); |
306 | |
307 | if (data) |
308 | break; |
309 | else if (file->f_flags & O_NONBLOCK) { |
310 | retval = -EAGAIN; |
311 | goto out; |
312 | } else if (signal_pending(current)) { |
313 | retval = -ERESTARTSYS; |
314 | goto out; |
315 | } |
316 | schedule(); |
317 | } |
318 | |
319 | retval = put_user(data, (unsigned long __user *)buf); |
320 | if (!retval) |
321 | retval = sizeof(unsigned long); |
322 | out: |
323 | __set_current_state(TASK_RUNNING); |
324 | remove_wait_queue(&devp->hd_waitqueue, &wait); |
325 | |
326 | return retval; |
327 | } |
328 | |
329 | static unsigned int hpet_poll(struct file *file, poll_table * wait) |
330 | { |
331 | unsigned long v; |
332 | struct hpet_dev *devp; |
333 | |
334 | devp = file->private_data; |
335 | |
336 | if (!devp->hd_ireqfreq) |
337 | return 0; |
338 | |
339 | poll_wait(file, &devp->hd_waitqueue, wait); |
340 | |
341 | spin_lock_irq(&hpet_lock); |
342 | v = devp->hd_irqdata; |
343 | spin_unlock_irq(&hpet_lock); |
344 | |
345 | if (v != 0) |
346 | return POLLIN | POLLRDNORM; |
347 | |
348 | return 0; |
349 | } |
350 | |
351 | static int hpet_mmap(struct file *file, struct vm_area_struct *vma) |
352 | { |
353 | #ifdef CONFIG_HPET_MMAP |
354 | struct hpet_dev *devp; |
355 | unsigned long addr; |
356 | |
357 | if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) |
358 | return -EINVAL; |
359 | |
360 | devp = file->private_data; |
361 | addr = devp->hd_hpets->hp_hpet_phys; |
362 | |
363 | if (addr & (PAGE_SIZE - 1)) |
364 | return -ENOSYS; |
365 | |
366 | vma->vm_flags |= VM_IO; |
367 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
368 | |
369 | if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, |
370 | PAGE_SIZE, vma->vm_page_prot)) { |
371 | printk(KERN_ERR "%s: io_remap_pfn_range failed\n", |
372 | __func__); |
373 | return -EAGAIN; |
374 | } |
375 | |
376 | return 0; |
377 | #else |
378 | return -ENOSYS; |
379 | #endif |
380 | } |
381 | |
382 | static int hpet_fasync(int fd, struct file *file, int on) |
383 | { |
384 | struct hpet_dev *devp; |
385 | |
386 | devp = file->private_data; |
387 | |
388 | if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) |
389 | return 0; |
390 | else |
391 | return -EIO; |
392 | } |
393 | |
394 | static int hpet_release(struct inode *inode, struct file *file) |
395 | { |
396 | struct hpet_dev *devp; |
397 | struct hpet_timer __iomem *timer; |
398 | int irq = 0; |
399 | |
400 | devp = file->private_data; |
401 | timer = devp->hd_timer; |
402 | |
403 | spin_lock_irq(&hpet_lock); |
404 | |
405 | writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), |
406 | &timer->hpet_config); |
407 | |
408 | irq = devp->hd_irq; |
409 | devp->hd_irq = 0; |
410 | |
411 | devp->hd_ireqfreq = 0; |
412 | |
413 | if (devp->hd_flags & HPET_PERIODIC |
414 | && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { |
415 | unsigned long v; |
416 | |
417 | v = readq(&timer->hpet_config); |
418 | v ^= Tn_TYPE_CNF_MASK; |
419 | writeq(v, &timer->hpet_config); |
420 | } |
421 | |
422 | devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); |
423 | spin_unlock_irq(&hpet_lock); |
424 | |
425 | if (irq) |
426 | free_irq(irq, devp); |
427 | |
428 | file->private_data = NULL; |
429 | return 0; |
430 | } |
431 | |
432 | static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); |
433 | |
434 | static int |
435 | hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd, |
436 | unsigned long arg) |
437 | { |
438 | struct hpet_dev *devp; |
439 | |
440 | devp = file->private_data; |
441 | return hpet_ioctl_common(devp, cmd, arg, 0); |
442 | } |
443 | |
444 | static int hpet_ioctl_ieon(struct hpet_dev *devp) |
445 | { |
446 | struct hpet_timer __iomem *timer; |
447 | struct hpet __iomem *hpet; |
448 | struct hpets *hpetp; |
449 | int irq; |
450 | unsigned long g, v, t, m; |
451 | unsigned long flags, isr; |
452 | |
453 | timer = devp->hd_timer; |
454 | hpet = devp->hd_hpet; |
455 | hpetp = devp->hd_hpets; |
456 | |
457 | if (!devp->hd_ireqfreq) |
458 | return -EIO; |
459 | |
460 | spin_lock_irq(&hpet_lock); |
461 | |
462 | if (devp->hd_flags & HPET_IE) { |
463 | spin_unlock_irq(&hpet_lock); |
464 | return -EBUSY; |
465 | } |
466 | |
467 | devp->hd_flags |= HPET_IE; |
468 | |
469 | if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) |
470 | devp->hd_flags |= HPET_SHARED_IRQ; |
471 | spin_unlock_irq(&hpet_lock); |
472 | |
473 | irq = devp->hd_hdwirq; |
474 | |
475 | if (irq) { |
476 | unsigned long irq_flags; |
477 | |
478 | sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); |
479 | irq_flags = devp->hd_flags & HPET_SHARED_IRQ |
480 | ? IRQF_SHARED : IRQF_DISABLED; |
481 | if (request_irq(irq, hpet_interrupt, irq_flags, |
482 | devp->hd_name, (void *)devp)) { |
483 | printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); |
484 | irq = 0; |
485 | } |
486 | } |
487 | |
488 | if (irq == 0) { |
489 | spin_lock_irq(&hpet_lock); |
490 | devp->hd_flags ^= HPET_IE; |
491 | spin_unlock_irq(&hpet_lock); |
492 | return -EIO; |
493 | } |
494 | |
495 | devp->hd_irq = irq; |
496 | t = devp->hd_ireqfreq; |
497 | v = readq(&timer->hpet_config); |
498 | |
499 | /* 64-bit comparators are not yet supported through the ioctls, |
500 | * so force this into 32-bit mode if it supports both modes |
501 | */ |
502 | g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; |
503 | |
504 | if (devp->hd_flags & HPET_PERIODIC) { |
505 | g |= Tn_TYPE_CNF_MASK; |
506 | v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; |
507 | writeq(v, &timer->hpet_config); |
508 | local_irq_save(flags); |
509 | |
510 | /* |
511 | * NOTE: First we modify the hidden accumulator |
512 | * register supported by periodic-capable comparators. |
513 | * We never want to modify the (single) counter; that |
514 | * would affect all the comparators. The value written |
515 | * is the counter value when the first interrupt is due. |
516 | */ |
517 | m = read_counter(&hpet->hpet_mc); |
518 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); |
519 | /* |
520 | * Then we modify the comparator, indicating the period |
521 | * for subsequent interrupt. |
522 | */ |
523 | write_counter(t, &timer->hpet_compare); |
524 | } else { |
525 | local_irq_save(flags); |
526 | m = read_counter(&hpet->hpet_mc); |
527 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); |
528 | } |
529 | |
530 | if (devp->hd_flags & HPET_SHARED_IRQ) { |
531 | isr = 1 << (devp - devp->hd_hpets->hp_dev); |
532 | writel(isr, &hpet->hpet_isr); |
533 | } |
534 | writeq(g, &timer->hpet_config); |
535 | local_irq_restore(flags); |
536 | |
537 | return 0; |
538 | } |
539 | |
540 | /* converts Hz to number of timer ticks */ |
541 | static inline unsigned long hpet_time_div(struct hpets *hpets, |
542 | unsigned long dis) |
543 | { |
544 | unsigned long long m; |
545 | |
546 | m = hpets->hp_tick_freq + (dis >> 1); |
547 | do_div(m, dis); |
548 | return (unsigned long)m; |
549 | } |
550 | |
551 | static int |
552 | hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) |
553 | { |
554 | struct hpet_timer __iomem *timer; |
555 | struct hpet __iomem *hpet; |
556 | struct hpets *hpetp; |
557 | int err; |
558 | unsigned long v; |
559 | |
560 | switch (cmd) { |
561 | case HPET_IE_OFF: |
562 | case HPET_INFO: |
563 | case HPET_EPI: |
564 | case HPET_DPI: |
565 | case HPET_IRQFREQ: |
566 | timer = devp->hd_timer; |
567 | hpet = devp->hd_hpet; |
568 | hpetp = devp->hd_hpets; |
569 | break; |
570 | case HPET_IE_ON: |
571 | return hpet_ioctl_ieon(devp); |
572 | default: |
573 | return -EINVAL; |
574 | } |
575 | |
576 | err = 0; |
577 | |
578 | switch (cmd) { |
579 | case HPET_IE_OFF: |
580 | if ((devp->hd_flags & HPET_IE) == 0) |
581 | break; |
582 | v = readq(&timer->hpet_config); |
583 | v &= ~Tn_INT_ENB_CNF_MASK; |
584 | writeq(v, &timer->hpet_config); |
585 | if (devp->hd_irq) { |
586 | free_irq(devp->hd_irq, devp); |
587 | devp->hd_irq = 0; |
588 | } |
589 | devp->hd_flags ^= HPET_IE; |
590 | break; |
591 | case HPET_INFO: |
592 | { |
593 | struct hpet_info info; |
594 | |
595 | if (devp->hd_ireqfreq) |
596 | info.hi_ireqfreq = |
597 | hpet_time_div(hpetp, devp->hd_ireqfreq); |
598 | else |
599 | info.hi_ireqfreq = 0; |
600 | info.hi_flags = |
601 | readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; |
602 | info.hi_hpet = hpetp->hp_which; |
603 | info.hi_timer = devp - hpetp->hp_dev; |
604 | if (kernel) |
605 | memcpy((void *)arg, &info, sizeof(info)); |
606 | else |
607 | if (copy_to_user((void __user *)arg, &info, |
608 | sizeof(info))) |
609 | err = -EFAULT; |
610 | break; |
611 | } |
612 | case HPET_EPI: |
613 | v = readq(&timer->hpet_config); |
614 | if ((v & Tn_PER_INT_CAP_MASK) == 0) { |
615 | err = -ENXIO; |
616 | break; |
617 | } |
618 | devp->hd_flags |= HPET_PERIODIC; |
619 | break; |
620 | case HPET_DPI: |
621 | v = readq(&timer->hpet_config); |
622 | if ((v & Tn_PER_INT_CAP_MASK) == 0) { |
623 | err = -ENXIO; |
624 | break; |
625 | } |
626 | if (devp->hd_flags & HPET_PERIODIC && |
627 | readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { |
628 | v = readq(&timer->hpet_config); |
629 | v ^= Tn_TYPE_CNF_MASK; |
630 | writeq(v, &timer->hpet_config); |
631 | } |
632 | devp->hd_flags &= ~HPET_PERIODIC; |
633 | break; |
634 | case HPET_IRQFREQ: |
635 | if (!kernel && (arg > hpet_max_freq) && |
636 | !capable(CAP_SYS_RESOURCE)) { |
637 | err = -EACCES; |
638 | break; |
639 | } |
640 | |
641 | if (!arg) { |
642 | err = -EINVAL; |
643 | break; |
644 | } |
645 | |
646 | devp->hd_ireqfreq = hpet_time_div(hpetp, arg); |
647 | } |
648 | |
649 | return err; |
650 | } |
651 | |
652 | static const struct file_operations hpet_fops = { |
653 | .owner = THIS_MODULE, |
654 | .llseek = no_llseek, |
655 | .read = hpet_read, |
656 | .poll = hpet_poll, |
657 | .ioctl = hpet_ioctl, |
658 | .open = hpet_open, |
659 | .release = hpet_release, |
660 | .fasync = hpet_fasync, |
661 | .mmap = hpet_mmap, |
662 | }; |
663 | |
664 | static int hpet_is_known(struct hpet_data *hdp) |
665 | { |
666 | struct hpets *hpetp; |
667 | |
668 | for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) |
669 | if (hpetp->hp_hpet_phys == hdp->hd_phys_address) |
670 | return 1; |
671 | |
672 | return 0; |
673 | } |
674 | |
675 | static ctl_table hpet_table[] = { |
676 | { |
677 | .procname = "max-user-freq", |
678 | .data = &hpet_max_freq, |
679 | .maxlen = sizeof(int), |
680 | .mode = 0644, |
681 | .proc_handler = proc_dointvec, |
682 | }, |
683 | {} |
684 | }; |
685 | |
686 | static ctl_table hpet_root[] = { |
687 | { |
688 | .procname = "hpet", |
689 | .maxlen = 0, |
690 | .mode = 0555, |
691 | .child = hpet_table, |
692 | }, |
693 | {} |
694 | }; |
695 | |
696 | static ctl_table dev_root[] = { |
697 | { |
698 | .procname = "dev", |
699 | .maxlen = 0, |
700 | .mode = 0555, |
701 | .child = hpet_root, |
702 | }, |
703 | {} |
704 | }; |
705 | |
706 | static struct ctl_table_header *sysctl_header; |
707 | |
708 | /* |
709 | * Adjustment for when arming the timer with |
710 | * initial conditions. That is, main counter |
711 | * ticks expired before interrupts are enabled. |
712 | */ |
713 | #define TICK_CALIBRATE (1000UL) |
714 | |
715 | static unsigned long __hpet_calibrate(struct hpets *hpetp) |
716 | { |
717 | struct hpet_timer __iomem *timer = NULL; |
718 | unsigned long t, m, count, i, flags, start; |
719 | struct hpet_dev *devp; |
720 | int j; |
721 | struct hpet __iomem *hpet; |
722 | |
723 | for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) |
724 | if ((devp->hd_flags & HPET_OPEN) == 0) { |
725 | timer = devp->hd_timer; |
726 | break; |
727 | } |
728 | |
729 | if (!timer) |
730 | return 0; |
731 | |
732 | hpet = hpetp->hp_hpet; |
733 | t = read_counter(&timer->hpet_compare); |
734 | |
735 | i = 0; |
736 | count = hpet_time_div(hpetp, TICK_CALIBRATE); |
737 | |
738 | local_irq_save(flags); |
739 | |
740 | start = read_counter(&hpet->hpet_mc); |
741 | |
742 | do { |
743 | m = read_counter(&hpet->hpet_mc); |
744 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); |
745 | } while (i++, (m - start) < count); |
746 | |
747 | local_irq_restore(flags); |
748 | |
749 | return (m - start) / i; |
750 | } |
751 | |
752 | static unsigned long hpet_calibrate(struct hpets *hpetp) |
753 | { |
754 | unsigned long ret = -1; |
755 | unsigned long tmp; |
756 | |
757 | /* |
758 | * Try to calibrate until return value becomes stable small value. |
759 | * If SMI interruption occurs in calibration loop, the return value |
760 | * will be big. This avoids its impact. |
761 | */ |
762 | for ( ; ; ) { |
763 | tmp = __hpet_calibrate(hpetp); |
764 | if (ret <= tmp) |
765 | break; |
766 | ret = tmp; |
767 | } |
768 | |
769 | return ret; |
770 | } |
771 | |
772 | int hpet_alloc(struct hpet_data *hdp) |
773 | { |
774 | u64 cap, mcfg; |
775 | struct hpet_dev *devp; |
776 | u32 i, ntimer; |
777 | struct hpets *hpetp; |
778 | size_t siz; |
779 | struct hpet __iomem *hpet; |
780 | static struct hpets *last = NULL; |
781 | unsigned long period; |
782 | unsigned long long temp; |
783 | u32 remainder; |
784 | |
785 | /* |
786 | * hpet_alloc can be called by platform dependent code. |
787 | * If platform dependent code has allocated the hpet that |
788 | * ACPI has also reported, then we catch it here. |
789 | */ |
790 | if (hpet_is_known(hdp)) { |
791 | printk(KERN_DEBUG "%s: duplicate HPET ignored\n", |
792 | __func__); |
793 | return 0; |
794 | } |
795 | |
796 | siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * |
797 | sizeof(struct hpet_dev)); |
798 | |
799 | hpetp = kzalloc(siz, GFP_KERNEL); |
800 | |
801 | if (!hpetp) |
802 | return -ENOMEM; |
803 | |
804 | hpetp->hp_which = hpet_nhpet++; |
805 | hpetp->hp_hpet = hdp->hd_address; |
806 | hpetp->hp_hpet_phys = hdp->hd_phys_address; |
807 | |
808 | hpetp->hp_ntimer = hdp->hd_nirqs; |
809 | |
810 | for (i = 0; i < hdp->hd_nirqs; i++) |
811 | hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; |
812 | |
813 | hpet = hpetp->hp_hpet; |
814 | |
815 | cap = readq(&hpet->hpet_cap); |
816 | |
817 | ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; |
818 | |
819 | if (hpetp->hp_ntimer != ntimer) { |
820 | printk(KERN_WARNING "hpet: number irqs doesn't agree" |
821 | " with number of timers\n"); |
822 | kfree(hpetp); |
823 | return -ENODEV; |
824 | } |
825 | |
826 | if (last) |
827 | last->hp_next = hpetp; |
828 | else |
829 | hpets = hpetp; |
830 | |
831 | last = hpetp; |
832 | |
833 | period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> |
834 | HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ |
835 | temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ |
836 | temp += period >> 1; /* round */ |
837 | do_div(temp, period); |
838 | hpetp->hp_tick_freq = temp; /* ticks per second */ |
839 | |
840 | printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", |
841 | hpetp->hp_which, hdp->hd_phys_address, |
842 | hpetp->hp_ntimer > 1 ? "s" : ""); |
843 | for (i = 0; i < hpetp->hp_ntimer; i++) |
844 | printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); |
845 | printk("\n"); |
846 | |
847 | temp = hpetp->hp_tick_freq; |
848 | remainder = do_div(temp, 1000000); |
849 | printk(KERN_INFO |
850 | "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", |
851 | hpetp->hp_which, hpetp->hp_ntimer, |
852 | cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, |
853 | (unsigned) temp, remainder); |
854 | |
855 | mcfg = readq(&hpet->hpet_config); |
856 | if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { |
857 | write_counter(0L, &hpet->hpet_mc); |
858 | mcfg |= HPET_ENABLE_CNF_MASK; |
859 | writeq(mcfg, &hpet->hpet_config); |
860 | } |
861 | |
862 | for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { |
863 | struct hpet_timer __iomem *timer; |
864 | |
865 | timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; |
866 | |
867 | devp->hd_hpets = hpetp; |
868 | devp->hd_hpet = hpet; |
869 | devp->hd_timer = timer; |
870 | |
871 | /* |
872 | * If the timer was reserved by platform code, |
873 | * then make timer unavailable for opens. |
874 | */ |
875 | if (hdp->hd_state & (1 << i)) { |
876 | devp->hd_flags = HPET_OPEN; |
877 | continue; |
878 | } |
879 | |
880 | init_waitqueue_head(&devp->hd_waitqueue); |
881 | } |
882 | |
883 | hpetp->hp_delta = hpet_calibrate(hpetp); |
884 | |
885 | /* This clocksource driver currently only works on ia64 */ |
886 | #ifdef CONFIG_IA64 |
887 | if (!hpet_clocksource) { |
888 | hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; |
889 | CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); |
890 | clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, |
891 | clocksource_hpet.shift); |
892 | clocksource_register(&clocksource_hpet); |
893 | hpetp->hp_clocksource = &clocksource_hpet; |
894 | hpet_clocksource = &clocksource_hpet; |
895 | } |
896 | #endif |
897 | |
898 | return 0; |
899 | } |
900 | |
901 | static acpi_status hpet_resources(struct acpi_resource *res, void *data) |
902 | { |
903 | struct hpet_data *hdp; |
904 | acpi_status status; |
905 | struct acpi_resource_address64 addr; |
906 | |
907 | hdp = data; |
908 | |
909 | status = acpi_resource_to_address64(res, &addr); |
910 | |
911 | if (ACPI_SUCCESS(status)) { |
912 | hdp->hd_phys_address = addr.minimum; |
913 | hdp->hd_address = ioremap(addr.minimum, addr.address_length); |
914 | |
915 | if (hpet_is_known(hdp)) { |
916 | iounmap(hdp->hd_address); |
917 | return AE_ALREADY_EXISTS; |
918 | } |
919 | } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { |
920 | struct acpi_resource_fixed_memory32 *fixmem32; |
921 | |
922 | fixmem32 = &res->data.fixed_memory32; |
923 | if (!fixmem32) |
924 | return AE_NO_MEMORY; |
925 | |
926 | hdp->hd_phys_address = fixmem32->address; |
927 | hdp->hd_address = ioremap(fixmem32->address, |
928 | HPET_RANGE_SIZE); |
929 | |
930 | if (hpet_is_known(hdp)) { |
931 | iounmap(hdp->hd_address); |
932 | return AE_ALREADY_EXISTS; |
933 | } |
934 | } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { |
935 | struct acpi_resource_extended_irq *irqp; |
936 | int i, irq; |
937 | |
938 | irqp = &res->data.extended_irq; |
939 | |
940 | for (i = 0; i < irqp->interrupt_count; i++) { |
941 | irq = acpi_register_gsi(NULL, irqp->interrupts[i], |
942 | irqp->triggering, irqp->polarity); |
943 | if (irq < 0) |
944 | return AE_ERROR; |
945 | |
946 | hdp->hd_irq[hdp->hd_nirqs] = irq; |
947 | hdp->hd_nirqs++; |
948 | } |
949 | } |
950 | |
951 | return AE_OK; |
952 | } |
953 | |
954 | static int hpet_acpi_add(struct acpi_device *device) |
955 | { |
956 | acpi_status result; |
957 | struct hpet_data data; |
958 | |
959 | memset(&data, 0, sizeof(data)); |
960 | |
961 | result = |
962 | acpi_walk_resources(device->handle, METHOD_NAME__CRS, |
963 | hpet_resources, &data); |
964 | |
965 | if (ACPI_FAILURE(result)) |
966 | return -ENODEV; |
967 | |
968 | if (!data.hd_address || !data.hd_nirqs) { |
969 | printk("%s: no address or irqs in _CRS\n", __func__); |
970 | return -ENODEV; |
971 | } |
972 | |
973 | return hpet_alloc(&data); |
974 | } |
975 | |
976 | static int hpet_acpi_remove(struct acpi_device *device, int type) |
977 | { |
978 | /* XXX need to unregister clocksource, dealloc mem, etc */ |
979 | return -EINVAL; |
980 | } |
981 | |
982 | static const struct acpi_device_id hpet_device_ids[] = { |
983 | {"PNP0103", 0}, |
984 | {"", 0}, |
985 | }; |
986 | MODULE_DEVICE_TABLE(acpi, hpet_device_ids); |
987 | |
988 | static struct acpi_driver hpet_acpi_driver = { |
989 | .name = "hpet", |
990 | .ids = hpet_device_ids, |
991 | .ops = { |
992 | .add = hpet_acpi_add, |
993 | .remove = hpet_acpi_remove, |
994 | }, |
995 | }; |
996 | |
997 | static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; |
998 | |
999 | static int __init hpet_init(void) |
1000 | { |
1001 | int result; |
1002 | |
1003 | result = misc_register(&hpet_misc); |
1004 | if (result < 0) |
1005 | return -ENODEV; |
1006 | |
1007 | sysctl_header = register_sysctl_table(dev_root); |
1008 | |
1009 | result = acpi_bus_register_driver(&hpet_acpi_driver); |
1010 | if (result < 0) { |
1011 | if (sysctl_header) |
1012 | unregister_sysctl_table(sysctl_header); |
1013 | misc_deregister(&hpet_misc); |
1014 | return result; |
1015 | } |
1016 | |
1017 | return 0; |
1018 | } |
1019 | |
1020 | static void __exit hpet_exit(void) |
1021 | { |
1022 | acpi_bus_unregister_driver(&hpet_acpi_driver); |
1023 | |
1024 | if (sysctl_header) |
1025 | unregister_sysctl_table(sysctl_header); |
1026 | misc_deregister(&hpet_misc); |
1027 | |
1028 | return; |
1029 | } |
1030 | |
1031 | module_init(hpet_init); |
1032 | module_exit(hpet_exit); |
1033 | MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); |
1034 | MODULE_LICENSE("GPL"); |
1035 |
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