Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
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> | |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 | 11 | #include <linux/interrupt.h> |
1da177e4 LT |
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> | |
f23f6e08 | 20 | #include <linux/mm.h> |
1da177e4 LT |
21 | #include <linux/proc_fs.h> |
22 | #include <linux/spinlock.h> | |
23 | #include <linux/sysctl.h> | |
24 | #include <linux/wait.h> | |
174cd4b1 | 25 | #include <linux/sched/signal.h> |
1da177e4 LT |
26 | #include <linux/bcd.h> |
27 | #include <linux/seq_file.h> | |
28 | #include <linux/bitops.h> | |
54066a57 | 29 | #include <linux/compat.h> |
0aa366f3 | 30 | #include <linux/clocksource.h> |
0ca01763 | 31 | #include <linux/uaccess.h> |
5a0e3ad6 | 32 | #include <linux/slab.h> |
0ca01763 | 33 | #include <linux/io.h> |
8b48463f LZ |
34 | #include <linux/acpi.h> |
35 | #include <linux/hpet.h> | |
1da177e4 | 36 | #include <asm/current.h> |
1da177e4 LT |
37 | #include <asm/irq.h> |
38 | #include <asm/div64.h> | |
39 | ||
1da177e4 LT |
40 | /* |
41 | * The High Precision Event Timer driver. | |
42 | * This driver is closely modelled after the rtc.c driver. | |
4e7f9df2 | 43 | * See HPET spec revision 1. |
1da177e4 LT |
44 | */ |
45 | #define HPET_USER_FREQ (64) | |
46 | #define HPET_DRIFT (500) | |
47 | ||
757c4724 RD |
48 | #define HPET_RANGE_SIZE 1024 /* from HPET spec */ |
49 | ||
64a76f66 DB |
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 | */ | |
0aa366f3 TL |
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 | ||
54066a57 | 63 | static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */ |
642d30bb | 64 | static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; |
1da177e4 | 65 | |
3dffec45 ÇO |
66 | /* This clocksource driver currently only works on ia64 */ |
67 | #ifdef CONFIG_IA64 | |
0aa366f3 TL |
68 | static void __iomem *hpet_mctr; |
69 | ||
a5a1d1c2 | 70 | static u64 read_hpet(struct clocksource *cs) |
0aa366f3 | 71 | { |
a5a1d1c2 | 72 | return (u64)read_counter((void __iomem *)hpet_mctr); |
0aa366f3 TL |
73 | } |
74 | ||
75 | static struct clocksource clocksource_hpet = { | |
0ca01763 JSR |
76 | .name = "hpet", |
77 | .rating = 250, | |
78 | .read = read_hpet, | |
79 | .mask = CLOCKSOURCE_MASK(64), | |
0ca01763 | 80 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
0aa366f3 TL |
81 | }; |
82 | static struct clocksource *hpet_clocksource; | |
3dffec45 | 83 | #endif |
0aa366f3 | 84 | |
1da177e4 LT |
85 | /* A lock for concurrent access by app and isr hpet activity. */ |
86 | static DEFINE_SPINLOCK(hpet_lock); | |
1da177e4 LT |
87 | |
88 | #define HPET_DEV_NAME (7) | |
89 | ||
90 | struct 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; | |
1da177e4 LT |
98 | unsigned int hd_flags; |
99 | unsigned int hd_irq; | |
100 | unsigned int hd_hdwirq; | |
101 | char hd_name[HPET_DEV_NAME]; | |
102 | }; | |
103 | ||
104 | struct hpets { | |
105 | struct hpets *hp_next; | |
106 | struct hpet __iomem *hp_hpet; | |
107 | unsigned long hp_hpet_phys; | |
0aa366f3 | 108 | struct clocksource *hp_clocksource; |
ba3f213f | 109 | unsigned long long hp_tick_freq; |
1da177e4 LT |
110 | unsigned long hp_delta; |
111 | unsigned int hp_ntimer; | |
112 | unsigned int hp_which; | |
987f028b | 113 | struct hpet_dev hp_dev[]; |
1da177e4 LT |
114 | }; |
115 | ||
116 | static struct hpets *hpets; | |
117 | ||
118 | #define HPET_OPEN 0x0001 | |
119 | #define HPET_IE 0x0002 /* interrupt enabled */ | |
120 | #define HPET_PERIODIC 0x0004 | |
0d290861 | 121 | #define HPET_SHARED_IRQ 0x0008 |
1da177e4 | 122 | |
1da177e4 LT |
123 | |
124 | #ifndef readq | |
887c27f3 | 125 | static inline unsigned long long readq(void __iomem *addr) |
1da177e4 LT |
126 | { |
127 | return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); | |
128 | } | |
129 | #endif | |
130 | ||
131 | #ifndef writeq | |
887c27f3 | 132 | static inline void writeq(unsigned long long v, void __iomem *addr) |
1da177e4 LT |
133 | { |
134 | writel(v & 0xffffffff, addr); | |
135 | writel(v >> 32, addr + 4); | |
136 | } | |
137 | #endif | |
138 | ||
7d12e780 | 139 | static irqreturn_t hpet_interrupt(int irq, void *data) |
1da177e4 LT |
140 | { |
141 | struct hpet_dev *devp; | |
142 | unsigned long isr; | |
143 | ||
144 | devp = data; | |
0d290861 CL |
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; | |
1da177e4 LT |
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) { | |
273ef950 NC |
159 | unsigned long m, t, mc, base, k; |
160 | struct hpet __iomem *hpet = devp->hd_hpet; | |
161 | struct hpets *hpetp = devp->hd_hpets; | |
1da177e4 LT |
162 | |
163 | t = devp->hd_ireqfreq; | |
ae21cf92 | 164 | m = read_counter(&devp->hd_timer->hpet_compare); |
273ef950 NC |
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); | |
1da177e4 LT |
185 | } |
186 | ||
0d290861 CL |
187 | if (devp->hd_flags & HPET_SHARED_IRQ) |
188 | writel(isr, &devp->hd_hpet->hpet_isr); | |
1da177e4 LT |
189 | spin_unlock(&hpet_lock); |
190 | ||
1da177e4 LT |
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 | ||
70ef6d59 KH |
198 | static 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 | ||
e5d61511 | 232 | for_each_set_bit(irq, &v, HPET_MAX_IRQ) { |
1f45f562 | 233 | if (irq >= nr_irqs) { |
70ef6d59 KH |
234 | irq = HPET_MAX_IRQ; |
235 | break; | |
236 | } | |
237 | ||
a2f809b0 | 238 | gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, |
70ef6d59 KH |
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 | ||
1da177e4 LT |
257 | static 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 | ||
54066a57 | 266 | mutex_lock(&hpet_mutex); |
1da177e4 LT |
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++) | |
64a76f66 | 271 | if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) |
1da177e4 LT |
272 | continue; |
273 | else { | |
274 | devp = &hpetp->hp_dev[i]; | |
275 | break; | |
276 | } | |
277 | ||
278 | if (!devp) { | |
279 | spin_unlock_irq(&hpet_lock); | |
54066a57 | 280 | mutex_unlock(&hpet_mutex); |
1da177e4 LT |
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); | |
54066a57 | 288 | mutex_unlock(&hpet_mutex); |
1da177e4 | 289 | |
70ef6d59 KH |
290 | hpet_timer_set_irq(devp); |
291 | ||
1da177e4 LT |
292 | return 0; |
293 | } | |
294 | ||
295 | static ssize_t | |
296 | hpet_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); | |
335 | out: | |
336 | __set_current_state(TASK_RUNNING); | |
337 | remove_wait_queue(&devp->hd_waitqueue, &wait); | |
338 | ||
339 | return retval; | |
340 | } | |
341 | ||
afc9a42b | 342 | static __poll_t hpet_poll(struct file *file, poll_table * wait) |
1da177e4 LT |
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) | |
a9a08845 | 359 | return EPOLLIN | EPOLLRDNORM; |
1da177e4 LT |
360 | |
361 | return 0; | |
362 | } | |
363 | ||
3d035f58 PB |
364 | #ifdef CONFIG_HPET_MMAP |
365 | #ifdef CONFIG_HPET_MMAP_DEFAULT | |
366 | static int hpet_mmap_enabled = 1; | |
367 | #else | |
368 | static int hpet_mmap_enabled = 0; | |
369 | #endif | |
370 | ||
371 | static __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 | } | |
24d48a61 | 377 | __setup("hpet_mmap=", hpet_mmap_enable); |
3d035f58 | 378 | |
1da177e4 LT |
379 | static int hpet_mmap(struct file *file, struct vm_area_struct *vma) |
380 | { | |
1da177e4 LT |
381 | struct hpet_dev *devp; |
382 | unsigned long addr; | |
383 | ||
3d035f58 PB |
384 | if (!hpet_mmap_enabled) |
385 | return -EACCES; | |
386 | ||
1da177e4 LT |
387 | devp = file->private_data; |
388 | addr = devp->hd_hpets->hp_hpet_phys; | |
389 | ||
390 | if (addr & (PAGE_SIZE - 1)) | |
391 | return -ENOSYS; | |
392 | ||
1da177e4 | 393 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
2323036d | 394 | return vm_iomap_memory(vma, addr, PAGE_SIZE); |
3d035f58 | 395 | } |
1da177e4 | 396 | #else |
3d035f58 PB |
397 | static int hpet_mmap(struct file *file, struct vm_area_struct *vma) |
398 | { | |
1da177e4 | 399 | return -ENOSYS; |
1da177e4 | 400 | } |
3d035f58 | 401 | #endif |
1da177e4 LT |
402 | |
403 | static 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 | ||
415 | static 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 | ||
1da177e4 LT |
449 | file->private_data = NULL; |
450 | return 0; | |
451 | } | |
452 | ||
1da177e4 LT |
453 | static 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 | ||
9090e6db CL |
466 | if (!devp->hd_ireqfreq) |
467 | return -EIO; | |
468 | ||
1da177e4 LT |
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; | |
0d290861 CL |
477 | |
478 | if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) | |
479 | devp->hd_flags |= HPET_SHARED_IRQ; | |
1da177e4 LT |
480 | spin_unlock_irq(&hpet_lock); |
481 | ||
1da177e4 LT |
482 | irq = devp->hd_hdwirq; |
483 | ||
484 | if (irq) { | |
0d290861 | 485 | unsigned long irq_flags; |
1da177e4 | 486 | |
96e9694d CL |
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 | ||
0d290861 | 502 | sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); |
158f0bb0 | 503 | irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0; |
0d290861 CL |
504 | if (request_irq(irq, hpet_interrupt, irq_flags, |
505 | devp->hd_name, (void *)devp)) { | |
1da177e4 LT |
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); | |
64a76f66 DB |
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; | |
1da177e4 LT |
526 | |
527 | if (devp->hd_flags & HPET_PERIODIC) { | |
1da177e4 | 528 | g |= Tn_TYPE_CNF_MASK; |
ae21cf92 | 529 | v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; |
1da177e4 LT |
530 | writeq(v, &timer->hpet_config); |
531 | local_irq_save(flags); | |
64a76f66 | 532 | |
ae21cf92 NC |
533 | /* |
534 | * NOTE: First we modify the hidden accumulator | |
64a76f66 DB |
535 | * register supported by periodic-capable comparators. |
536 | * We never want to modify the (single) counter; that | |
ae21cf92 NC |
537 | * would affect all the comparators. The value written |
538 | * is the counter value when the first interrupt is due. | |
64a76f66 | 539 | */ |
1da177e4 LT |
540 | m = read_counter(&hpet->hpet_mc); |
541 | write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); | |
ae21cf92 NC |
542 | /* |
543 | * Then we modify the comparator, indicating the period | |
544 | * for subsequent interrupt. | |
545 | */ | |
546 | write_counter(t, &timer->hpet_compare); | |
1da177e4 LT |
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 | ||
0d290861 | 553 | if (devp->hd_flags & HPET_SHARED_IRQ) { |
3d5640d1 | 554 | isr = 1 << (devp - devp->hd_hpets->hp_dev); |
0d290861 CL |
555 | writel(isr, &hpet->hpet_isr); |
556 | } | |
1da177e4 LT |
557 | writeq(g, &timer->hpet_config); |
558 | local_irq_restore(flags); | |
559 | ||
560 | return 0; | |
561 | } | |
562 | ||
ba3f213f CL |
563 | /* converts Hz to number of timer ticks */ |
564 | static inline unsigned long hpet_time_div(struct hpets *hpets, | |
565 | unsigned long dis) | |
1da177e4 | 566 | { |
ba3f213f | 567 | unsigned long long m; |
1da177e4 | 568 | |
ba3f213f | 569 | m = hpets->hp_tick_freq + (dis >> 1); |
0c7d37f4 | 570 | return div64_ul(m, dis); |
1da177e4 LT |
571 | } |
572 | ||
573 | static int | |
5cd5e6ad | 574 | hpet_ioctl_common(struct hpet_dev *devp, unsigned int cmd, unsigned long arg, |
54066a57 | 575 | struct hpet_info *info) |
1da177e4 LT |
576 | { |
577 | struct hpet_timer __iomem *timer; | |
1da177e4 LT |
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; | |
1da177e4 LT |
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 | { | |
dae512ed | 614 | memset(info, 0, sizeof(*info)); |
af95eade | 615 | if (devp->hd_ireqfreq) |
54066a57 | 616 | info->hi_ireqfreq = |
af95eade | 617 | hpet_time_div(hpetp, devp->hd_ireqfreq); |
54066a57 | 618 | info->hi_flags = |
1da177e4 | 619 | readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; |
54066a57 AB |
620 | info->hi_hpet = hpetp->hp_which; |
621 | info->hi_timer = devp - hpetp->hp_dev; | |
1da177e4 LT |
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: | |
54066a57 | 647 | if ((arg > hpet_max_freq) && |
1da177e4 LT |
648 | !capable(CAP_SYS_RESOURCE)) { |
649 | err = -EACCES; | |
650 | break; | |
651 | } | |
652 | ||
189e2dd1 | 653 | if (!arg) { |
1da177e4 LT |
654 | err = -EINVAL; |
655 | break; | |
656 | } | |
657 | ||
ba3f213f | 658 | devp->hd_ireqfreq = hpet_time_div(hpetp, arg); |
1da177e4 LT |
659 | } |
660 | ||
661 | return err; | |
662 | } | |
663 | ||
54066a57 AB |
664 | static long |
665 | hpet_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 | |
682 | struct 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 | ||
689 | static long | |
690 | hpet_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 | ||
62322d25 | 712 | static const struct file_operations hpet_fops = { |
1da177e4 LT |
713 | .owner = THIS_MODULE, |
714 | .llseek = no_llseek, | |
715 | .read = hpet_read, | |
716 | .poll = hpet_poll, | |
55929332 | 717 | .unlocked_ioctl = hpet_ioctl, |
54066a57 AB |
718 | #ifdef CONFIG_COMPAT |
719 | .compat_ioctl = hpet_compat_ioctl, | |
720 | #endif | |
1da177e4 LT |
721 | .open = hpet_open, |
722 | .release = hpet_release, | |
723 | .fasync = hpet_fasync, | |
724 | .mmap = hpet_mmap, | |
725 | }; | |
726 | ||
3e6716e7 RD |
727 | static 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 | ||
a151427e | 738 | static struct ctl_table hpet_table[] = { |
1da177e4 | 739 | { |
1da177e4 LT |
740 | .procname = "max-user-freq", |
741 | .data = &hpet_max_freq, | |
742 | .maxlen = sizeof(int), | |
743 | .mode = 0644, | |
6d456111 | 744 | .proc_handler = proc_dointvec, |
1da177e4 | 745 | }, |
894d2491 | 746 | {} |
1da177e4 LT |
747 | }; |
748 | ||
a151427e | 749 | static struct ctl_table hpet_root[] = { |
1da177e4 | 750 | { |
1da177e4 LT |
751 | .procname = "hpet", |
752 | .maxlen = 0, | |
753 | .mode = 0555, | |
754 | .child = hpet_table, | |
755 | }, | |
894d2491 | 756 | {} |
1da177e4 LT |
757 | }; |
758 | ||
a151427e | 759 | static struct ctl_table dev_root[] = { |
1da177e4 | 760 | { |
1da177e4 LT |
761 | .procname = "dev", |
762 | .maxlen = 0, | |
763 | .mode = 0555, | |
764 | .child = hpet_root, | |
765 | }, | |
894d2491 | 766 | {} |
1da177e4 LT |
767 | }; |
768 | ||
769 | static struct ctl_table_header *sysctl_header; | |
770 | ||
1da177e4 LT |
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 | ||
303d379c | 778 | static unsigned long __hpet_calibrate(struct hpets *hpetp) |
1da177e4 LT |
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 | ||
3d5640d1 | 795 | hpet = hpetp->hp_hpet; |
1da177e4 LT |
796 | t = read_counter(&timer->hpet_compare); |
797 | ||
798 | i = 0; | |
ba3f213f | 799 | count = hpet_time_div(hpetp, TICK_CALIBRATE); |
1da177e4 LT |
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 | ||
303d379c YG |
815 | static unsigned long hpet_calibrate(struct hpets *hpetp) |
816 | { | |
2cf4e52e | 817 | unsigned long ret = ~0UL; |
303d379c YG |
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 | ||
1da177e4 LT |
835 | int hpet_alloc(struct hpet_data *hdp) |
836 | { | |
5761d64b | 837 | u64 cap, mcfg; |
1da177e4 | 838 | struct hpet_dev *devp; |
5761d64b | 839 | u32 i, ntimer; |
1da177e4 | 840 | struct hpets *hpetp; |
1da177e4 | 841 | struct hpet __iomem *hpet; |
0ca01763 | 842 | static struct hpets *last; |
5761d64b | 843 | unsigned long period; |
ba3f213f | 844 | unsigned long long temp; |
f92a789d | 845 | u32 remainder; |
1da177e4 LT |
846 | |
847 | /* | |
848 | * hpet_alloc can be called by platform dependent code. | |
3e6716e7 RD |
849 | * If platform dependent code has allocated the hpet that |
850 | * ACPI has also reported, then we catch it here. | |
1da177e4 | 851 | */ |
3e6716e7 RD |
852 | if (hpet_is_known(hdp)) { |
853 | printk(KERN_DEBUG "%s: duplicate HPET ignored\n", | |
bf9d8929 | 854 | __func__); |
3e6716e7 RD |
855 | return 0; |
856 | } | |
1da177e4 | 857 | |
98c49f17 | 858 | hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs), |
401c9bd1 | 859 | GFP_KERNEL); |
1da177e4 LT |
860 | |
861 | if (!hpetp) | |
862 | return -ENOMEM; | |
863 | ||
1da177e4 LT |
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; | |
e3f37a54 | 869 | |
5761d64b TG |
870 | for (i = 0; i < hdp->hd_nirqs; i++) |
871 | hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; | |
37a47db8 | 872 | |
5761d64b | 873 | hpet = hpetp->hp_hpet; |
e3f37a54 | 874 | |
1da177e4 LT |
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 | ||
ba3f213f CL |
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 */ | |
1da177e4 | 899 | |
3034d11c AK |
900 | printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", |
901 | hpetp->hp_which, hdp->hd_phys_address, | |
1da177e4 LT |
902 | hpetp->hp_ntimer > 1 ? "s" : ""); |
903 | for (i = 0; i < hpetp->hp_ntimer; i++) | |
5da527aa KS |
904 | printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); |
905 | printk(KERN_CONT "\n"); | |
1da177e4 | 906 | |
f92a789d DB |
907 | temp = hpetp->hp_tick_freq; |
908 | remainder = do_div(temp, 1000000); | |
64a76f66 DB |
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, | |
f92a789d | 913 | (unsigned) temp, remainder); |
1da177e4 LT |
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 | ||
642d30bb | 922 | for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { |
1da177e4 LT |
923 | struct hpet_timer __iomem *timer; |
924 | ||
925 | timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; | |
1da177e4 LT |
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); | |
0aa366f3 | 944 | |
3b2b64fd LT |
945 | /* This clocksource driver currently only works on ia64 */ |
946 | #ifdef CONFIG_IA64 | |
0aa366f3 TL |
947 | if (!hpet_clocksource) { |
948 | hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; | |
574c44fa | 949 | clocksource_hpet.archdata.fsys_mmio = hpet_mctr; |
d60c3041 | 950 | clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); |
0aa366f3 TL |
951 | hpetp->hp_clocksource = &clocksource_hpet; |
952 | hpet_clocksource = &clocksource_hpet; | |
953 | } | |
3b2b64fd | 954 | #endif |
1da177e4 LT |
955 | |
956 | return 0; | |
957 | } | |
958 | ||
959 | static 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; | |
1da177e4 LT |
964 | |
965 | hdp = data; | |
966 | ||
967 | status = acpi_resource_to_address64(res, &addr); | |
968 | ||
969 | if (ACPI_SUCCESS(status)) { | |
a45de93e LZ |
970 | hdp->hd_phys_address = addr.address.minimum; |
971 | hdp->hd_address = ioremap(addr.address.minimum, addr.address.address_length); | |
b11701c9 TS |
972 | if (!hdp->hd_address) |
973 | return AE_ERROR; | |
1da177e4 | 974 | |
3e6716e7 | 975 | if (hpet_is_known(hdp)) { |
3e6716e7 | 976 | iounmap(hdp->hd_address); |
78e1ca49 | 977 | return AE_ALREADY_EXISTS; |
3e6716e7 | 978 | } |
50eca3eb BM |
979 | } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { |
980 | struct acpi_resource_fixed_memory32 *fixmem32; | |
757c4724 RD |
981 | |
982 | fixmem32 = &res->data.fixed_memory32; | |
757c4724 | 983 | |
50eca3eb BM |
984 | hdp->hd_phys_address = fixmem32->address; |
985 | hdp->hd_address = ioremap(fixmem32->address, | |
757c4724 | 986 | HPET_RANGE_SIZE); |
b11701c9 TS |
987 | if (!hdp->hd_address) |
988 | return AE_ERROR; | |
757c4724 | 989 | |
3e6716e7 | 990 | if (hpet_is_known(hdp)) { |
3e6716e7 | 991 | iounmap(hdp->hd_address); |
78e1ca49 | 992 | return AE_ALREADY_EXISTS; |
3e6716e7 | 993 | } |
50eca3eb BM |
994 | } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { |
995 | struct acpi_resource_extended_irq *irqp; | |
be5efffb | 996 | int i, irq; |
1da177e4 LT |
997 | |
998 | irqp = &res->data.extended_irq; | |
999 | ||
be5efffb | 1000 | for (i = 0; i < irqp->interrupt_count; i++) { |
2cf4e52e CG |
1001 | if (hdp->hd_nirqs >= HPET_MAX_TIMERS) |
1002 | break; | |
1003 | ||
a2f809b0 | 1004 | irq = acpi_register_gsi(NULL, irqp->interrupts[i], |
be5efffb BH |
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++; | |
1da177e4 LT |
1011 | } |
1012 | } | |
1013 | ||
1014 | return AE_OK; | |
1015 | } | |
1016 | ||
1017 | static int hpet_acpi_add(struct acpi_device *device) | |
1018 | { | |
1019 | acpi_status result; | |
1020 | struct hpet_data data; | |
1021 | ||
1022 | memset(&data, 0, sizeof(data)); | |
1023 | ||
1024 | result = | |
1025 | acpi_walk_resources(device->handle, METHOD_NAME__CRS, | |
1026 | hpet_resources, &data); | |
1027 | ||
1028 | if (ACPI_FAILURE(result)) | |
1029 | return -ENODEV; | |
1030 | ||
1031 | if (!data.hd_address || !data.hd_nirqs) { | |
a56d5318 JS |
1032 | if (data.hd_address) |
1033 | iounmap(data.hd_address); | |
bf9d8929 | 1034 | printk("%s: no address or irqs in _CRS\n", __func__); |
1da177e4 LT |
1035 | return -ENODEV; |
1036 | } | |
1037 | ||
1038 | return hpet_alloc(&data); | |
1039 | } | |
1040 | ||
1ba90e3a TR |
1041 | static const struct acpi_device_id hpet_device_ids[] = { |
1042 | {"PNP0103", 0}, | |
1043 | {"", 0}, | |
1044 | }; | |
1ba90e3a | 1045 | |
1da177e4 LT |
1046 | static struct acpi_driver hpet_acpi_driver = { |
1047 | .name = "hpet", | |
1ba90e3a | 1048 | .ids = hpet_device_ids, |
1da177e4 LT |
1049 | .ops = { |
1050 | .add = hpet_acpi_add, | |
1da177e4 LT |
1051 | }, |
1052 | }; | |
1053 | ||
1054 | static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; | |
1055 | ||
1056 | static int __init hpet_init(void) | |
1057 | { | |
1058 | int result; | |
1059 | ||
1060 | result = misc_register(&hpet_misc); | |
1061 | if (result < 0) | |
1062 | return -ENODEV; | |
1063 | ||
0b4d4147 | 1064 | sysctl_header = register_sysctl_table(dev_root); |
1da177e4 LT |
1065 | |
1066 | result = acpi_bus_register_driver(&hpet_acpi_driver); | |
1067 | if (result < 0) { | |
1068 | if (sysctl_header) | |
1069 | unregister_sysctl_table(sysctl_header); | |
1070 | misc_deregister(&hpet_misc); | |
1071 | return result; | |
1072 | } | |
1073 | ||
1074 | return 0; | |
1075 | } | |
a8cedfec | 1076 | device_initcall(hpet_init); |
1da177e4 | 1077 | |
a8cedfec | 1078 | /* |
1da177e4 LT |
1079 | MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); |
1080 | MODULE_LICENSE("GPL"); | |
a8cedfec | 1081 | */ |