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7726942f RB |
1 | /* |
2 | * bios-less APM driver for ARM Linux | |
3 | * Jamey Hicks <jamey@crl.dec.com> | |
4 | * adapted from the APM BIOS driver for Linux by Stephen Rothwell (sfr@linuxcare.com) | |
5 | * | |
6 | * APM 1.2 Reference: | |
7 | * Intel Corporation, Microsoft Corporation. Advanced Power Management | |
8 | * (APM) BIOS Interface Specification, Revision 1.2, February 1996. | |
9 | * | |
10 | * [This document is available from Microsoft at: | |
11 | * http://www.microsoft.com/hwdev/busbios/amp_12.htm] | |
12 | */ | |
13 | #include <linux/module.h> | |
14 | #include <linux/poll.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/proc_fs.h> | |
17 | #include <linux/miscdevice.h> | |
18 | #include <linux/apm_bios.h> | |
19 | #include <linux/capability.h> | |
20 | #include <linux/sched.h> | |
95d9ffbe | 21 | #include <linux/suspend.h> |
7726942f | 22 | #include <linux/apm-emulation.h> |
83144186 | 23 | #include <linux/freezer.h> |
7726942f RB |
24 | #include <linux/device.h> |
25 | #include <linux/kernel.h> | |
26 | #include <linux/list.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/completion.h> | |
29 | #include <linux/kthread.h> | |
30 | #include <linux/delay.h> | |
31 | ||
32 | #include <asm/system.h> | |
33 | ||
34 | /* | |
35 | * The apm_bios device is one of the misc char devices. | |
36 | * This is its minor number. | |
37 | */ | |
38 | #define APM_MINOR_DEV 134 | |
39 | ||
40 | /* | |
41 | * See Documentation/Config.help for the configuration options. | |
42 | * | |
43 | * Various options can be changed at boot time as follows: | |
44 | * (We allow underscores for compatibility with the modules code) | |
45 | * apm=on/off enable/disable APM | |
46 | */ | |
47 | ||
48 | /* | |
49 | * Maximum number of events stored | |
50 | */ | |
51 | #define APM_MAX_EVENTS 16 | |
52 | ||
53 | struct apm_queue { | |
54 | unsigned int event_head; | |
55 | unsigned int event_tail; | |
56 | apm_event_t events[APM_MAX_EVENTS]; | |
57 | }; | |
58 | ||
59 | /* | |
60 | * The per-file APM data | |
61 | */ | |
62 | struct apm_user { | |
63 | struct list_head list; | |
64 | ||
65 | unsigned int suser: 1; | |
66 | unsigned int writer: 1; | |
67 | unsigned int reader: 1; | |
68 | ||
69 | int suspend_result; | |
70 | unsigned int suspend_state; | |
71 | #define SUSPEND_NONE 0 /* no suspend pending */ | |
72 | #define SUSPEND_PENDING 1 /* suspend pending read */ | |
73 | #define SUSPEND_READ 2 /* suspend read, pending ack */ | |
74 | #define SUSPEND_ACKED 3 /* suspend acked */ | |
75 | #define SUSPEND_WAIT 4 /* waiting for suspend */ | |
76 | #define SUSPEND_DONE 5 /* suspend completed */ | |
77 | ||
78 | struct apm_queue queue; | |
79 | }; | |
80 | ||
81 | /* | |
82 | * Local variables | |
83 | */ | |
84 | static int suspends_pending; | |
85 | static int apm_disabled; | |
86 | static struct task_struct *kapmd_tsk; | |
87 | ||
88 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); | |
89 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); | |
90 | ||
91 | /* | |
92 | * This is a list of everyone who has opened /dev/apm_bios | |
93 | */ | |
94 | static DECLARE_RWSEM(user_list_lock); | |
95 | static LIST_HEAD(apm_user_list); | |
96 | ||
97 | /* | |
98 | * kapmd info. kapmd provides us a process context to handle | |
99 | * "APM" events within - specifically necessary if we're going | |
100 | * to be suspending the system. | |
101 | */ | |
102 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); | |
103 | static DEFINE_SPINLOCK(kapmd_queue_lock); | |
104 | static struct apm_queue kapmd_queue; | |
105 | ||
106 | static DEFINE_MUTEX(state_lock); | |
107 | ||
108 | static const char driver_version[] = "1.13"; /* no spaces */ | |
109 | ||
110 | ||
111 | ||
112 | /* | |
113 | * Compatibility cruft until the IPAQ people move over to the new | |
114 | * interface. | |
115 | */ | |
116 | static void __apm_get_power_status(struct apm_power_info *info) | |
117 | { | |
118 | } | |
119 | ||
120 | /* | |
121 | * This allows machines to provide their own "apm get power status" function. | |
122 | */ | |
123 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; | |
124 | EXPORT_SYMBOL(apm_get_power_status); | |
125 | ||
126 | ||
127 | /* | |
128 | * APM event queue management. | |
129 | */ | |
130 | static inline int queue_empty(struct apm_queue *q) | |
131 | { | |
132 | return q->event_head == q->event_tail; | |
133 | } | |
134 | ||
135 | static inline apm_event_t queue_get_event(struct apm_queue *q) | |
136 | { | |
137 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
138 | return q->events[q->event_tail]; | |
139 | } | |
140 | ||
141 | static void queue_add_event(struct apm_queue *q, apm_event_t event) | |
142 | { | |
143 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; | |
144 | if (q->event_head == q->event_tail) { | |
145 | static int notified; | |
146 | ||
147 | if (notified++ == 0) | |
148 | printk(KERN_ERR "apm: an event queue overflowed\n"); | |
149 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
150 | } | |
151 | q->events[q->event_head] = event; | |
152 | } | |
153 | ||
154 | static void queue_event(apm_event_t event) | |
155 | { | |
156 | struct apm_user *as; | |
157 | ||
158 | down_read(&user_list_lock); | |
159 | list_for_each_entry(as, &apm_user_list, list) { | |
160 | if (as->reader) | |
161 | queue_add_event(&as->queue, event); | |
162 | } | |
163 | up_read(&user_list_lock); | |
164 | wake_up_interruptible(&apm_waitqueue); | |
165 | } | |
166 | ||
167 | /* | |
168 | * queue_suspend_event - queue an APM suspend event. | |
169 | * | |
170 | * Check that we're in a state where we can suspend. If not, | |
171 | * return -EBUSY. Otherwise, queue an event to all "writer" | |
172 | * users. If there are no "writer" users, return '1' to | |
173 | * indicate that we can immediately suspend. | |
174 | */ | |
175 | static int queue_suspend_event(apm_event_t event, struct apm_user *sender) | |
176 | { | |
177 | struct apm_user *as; | |
178 | int ret = 1; | |
179 | ||
180 | mutex_lock(&state_lock); | |
181 | down_read(&user_list_lock); | |
182 | ||
183 | /* | |
184 | * If a thread is still processing, we can't suspend, so reject | |
185 | * the request. | |
186 | */ | |
187 | list_for_each_entry(as, &apm_user_list, list) { | |
188 | if (as != sender && as->reader && as->writer && as->suser && | |
189 | as->suspend_state != SUSPEND_NONE) { | |
190 | ret = -EBUSY; | |
191 | goto out; | |
192 | } | |
193 | } | |
194 | ||
195 | list_for_each_entry(as, &apm_user_list, list) { | |
196 | if (as != sender && as->reader && as->writer && as->suser) { | |
197 | as->suspend_state = SUSPEND_PENDING; | |
198 | suspends_pending++; | |
199 | queue_add_event(&as->queue, event); | |
200 | ret = 0; | |
201 | } | |
202 | } | |
203 | out: | |
204 | up_read(&user_list_lock); | |
205 | mutex_unlock(&state_lock); | |
206 | wake_up_interruptible(&apm_waitqueue); | |
207 | return ret; | |
208 | } | |
209 | ||
210 | static void apm_suspend(void) | |
211 | { | |
212 | struct apm_user *as; | |
213 | int err = pm_suspend(PM_SUSPEND_MEM); | |
214 | ||
215 | /* | |
216 | * Anyone on the APM queues will think we're still suspended. | |
217 | * Send a message so everyone knows we're now awake again. | |
218 | */ | |
219 | queue_event(APM_NORMAL_RESUME); | |
220 | ||
221 | /* | |
222 | * Finally, wake up anyone who is sleeping on the suspend. | |
223 | */ | |
224 | mutex_lock(&state_lock); | |
225 | down_read(&user_list_lock); | |
226 | list_for_each_entry(as, &apm_user_list, list) { | |
227 | if (as->suspend_state == SUSPEND_WAIT || | |
228 | as->suspend_state == SUSPEND_ACKED) { | |
229 | as->suspend_result = err; | |
230 | as->suspend_state = SUSPEND_DONE; | |
231 | } | |
232 | } | |
233 | up_read(&user_list_lock); | |
234 | mutex_unlock(&state_lock); | |
235 | ||
236 | wake_up(&apm_suspend_waitqueue); | |
237 | } | |
238 | ||
239 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) | |
240 | { | |
241 | struct apm_user *as = fp->private_data; | |
242 | apm_event_t event; | |
243 | int i = count, ret = 0; | |
244 | ||
245 | if (count < sizeof(apm_event_t)) | |
246 | return -EINVAL; | |
247 | ||
248 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) | |
249 | return -EAGAIN; | |
250 | ||
251 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); | |
252 | ||
253 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { | |
254 | event = queue_get_event(&as->queue); | |
255 | ||
256 | ret = -EFAULT; | |
257 | if (copy_to_user(buf, &event, sizeof(event))) | |
258 | break; | |
259 | ||
260 | mutex_lock(&state_lock); | |
261 | if (as->suspend_state == SUSPEND_PENDING && | |
262 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) | |
263 | as->suspend_state = SUSPEND_READ; | |
264 | mutex_unlock(&state_lock); | |
265 | ||
266 | buf += sizeof(event); | |
267 | i -= sizeof(event); | |
268 | } | |
269 | ||
270 | if (i < count) | |
271 | ret = count - i; | |
272 | ||
273 | return ret; | |
274 | } | |
275 | ||
276 | static unsigned int apm_poll(struct file *fp, poll_table * wait) | |
277 | { | |
278 | struct apm_user *as = fp->private_data; | |
279 | ||
280 | poll_wait(fp, &apm_waitqueue, wait); | |
281 | return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM; | |
282 | } | |
283 | ||
284 | /* | |
285 | * apm_ioctl - handle APM ioctl | |
286 | * | |
287 | * APM_IOC_SUSPEND | |
288 | * This IOCTL is overloaded, and performs two functions. It is used to: | |
289 | * - initiate a suspend | |
290 | * - acknowledge a suspend read from /dev/apm_bios. | |
291 | * Only when everyone who has opened /dev/apm_bios with write permission | |
292 | * has acknowledge does the actual suspend happen. | |
293 | */ | |
294 | static int | |
295 | apm_ioctl(struct inode * inode, struct file *filp, u_int cmd, u_long arg) | |
296 | { | |
297 | struct apm_user *as = filp->private_data; | |
298 | unsigned long flags; | |
299 | int err = -EINVAL; | |
300 | ||
301 | if (!as->suser || !as->writer) | |
302 | return -EPERM; | |
303 | ||
304 | switch (cmd) { | |
305 | case APM_IOC_SUSPEND: | |
306 | mutex_lock(&state_lock); | |
307 | ||
308 | as->suspend_result = -EINTR; | |
309 | ||
310 | if (as->suspend_state == SUSPEND_READ) { | |
311 | int pending; | |
312 | ||
313 | /* | |
314 | * If we read a suspend command from /dev/apm_bios, | |
315 | * then the corresponding APM_IOC_SUSPEND ioctl is | |
316 | * interpreted as an acknowledge. | |
317 | */ | |
318 | as->suspend_state = SUSPEND_ACKED; | |
319 | suspends_pending--; | |
320 | pending = suspends_pending == 0; | |
321 | mutex_unlock(&state_lock); | |
322 | ||
323 | /* | |
324 | * If there are no further acknowledges required, | |
325 | * suspend the system. | |
326 | */ | |
327 | if (pending) | |
328 | apm_suspend(); | |
329 | ||
330 | /* | |
331 | * Wait for the suspend/resume to complete. If there | |
332 | * are pending acknowledges, we wait here for them. | |
7726942f RB |
333 | */ |
334 | flags = current->flags; | |
7726942f RB |
335 | |
336 | wait_event(apm_suspend_waitqueue, | |
337 | as->suspend_state == SUSPEND_DONE); | |
338 | } else { | |
339 | as->suspend_state = SUSPEND_WAIT; | |
340 | mutex_unlock(&state_lock); | |
341 | ||
342 | /* | |
343 | * Otherwise it is a request to suspend the system. | |
344 | * Queue an event for all readers, and expect an | |
345 | * acknowledge from all writers who haven't already | |
346 | * acknowledged. | |
347 | */ | |
348 | err = queue_suspend_event(APM_USER_SUSPEND, as); | |
349 | if (err < 0) { | |
350 | /* | |
351 | * Avoid taking the lock here - this | |
352 | * should be fine. | |
353 | */ | |
354 | as->suspend_state = SUSPEND_NONE; | |
355 | break; | |
356 | } | |
357 | ||
358 | if (err > 0) | |
359 | apm_suspend(); | |
360 | ||
361 | /* | |
362 | * Wait for the suspend/resume to complete. If there | |
363 | * are pending acknowledges, we wait here for them. | |
7726942f RB |
364 | */ |
365 | flags = current->flags; | |
7726942f RB |
366 | |
367 | wait_event_interruptible(apm_suspend_waitqueue, | |
368 | as->suspend_state == SUSPEND_DONE); | |
369 | } | |
370 | ||
371 | current->flags = flags; | |
372 | ||
373 | mutex_lock(&state_lock); | |
374 | err = as->suspend_result; | |
375 | as->suspend_state = SUSPEND_NONE; | |
376 | mutex_unlock(&state_lock); | |
377 | break; | |
378 | } | |
379 | ||
380 | return err; | |
381 | } | |
382 | ||
383 | static int apm_release(struct inode * inode, struct file * filp) | |
384 | { | |
385 | struct apm_user *as = filp->private_data; | |
386 | int pending = 0; | |
387 | ||
388 | filp->private_data = NULL; | |
389 | ||
390 | down_write(&user_list_lock); | |
391 | list_del(&as->list); | |
392 | up_write(&user_list_lock); | |
393 | ||
394 | /* | |
395 | * We are now unhooked from the chain. As far as new | |
396 | * events are concerned, we no longer exist. However, we | |
397 | * need to balance suspends_pending, which means the | |
398 | * possibility of sleeping. | |
399 | */ | |
400 | mutex_lock(&state_lock); | |
401 | if (as->suspend_state != SUSPEND_NONE) { | |
402 | suspends_pending -= 1; | |
403 | pending = suspends_pending == 0; | |
404 | } | |
405 | mutex_unlock(&state_lock); | |
406 | if (pending) | |
407 | apm_suspend(); | |
408 | ||
409 | kfree(as); | |
410 | return 0; | |
411 | } | |
412 | ||
413 | static int apm_open(struct inode * inode, struct file * filp) | |
414 | { | |
415 | struct apm_user *as; | |
416 | ||
417 | as = kzalloc(sizeof(*as), GFP_KERNEL); | |
418 | if (as) { | |
419 | /* | |
420 | * XXX - this is a tiny bit broken, when we consider BSD | |
421 | * process accounting. If the device is opened by root, we | |
422 | * instantly flag that we used superuser privs. Who knows, | |
423 | * we might close the device immediately without doing a | |
424 | * privileged operation -- cevans | |
425 | */ | |
426 | as->suser = capable(CAP_SYS_ADMIN); | |
427 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
428 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
429 | ||
430 | down_write(&user_list_lock); | |
431 | list_add(&as->list, &apm_user_list); | |
432 | up_write(&user_list_lock); | |
433 | ||
434 | filp->private_data = as; | |
435 | } | |
436 | ||
437 | return as ? 0 : -ENOMEM; | |
438 | } | |
439 | ||
440 | static struct file_operations apm_bios_fops = { | |
441 | .owner = THIS_MODULE, | |
442 | .read = apm_read, | |
443 | .poll = apm_poll, | |
444 | .ioctl = apm_ioctl, | |
445 | .open = apm_open, | |
446 | .release = apm_release, | |
447 | }; | |
448 | ||
449 | static struct miscdevice apm_device = { | |
450 | .minor = APM_MINOR_DEV, | |
451 | .name = "apm_bios", | |
452 | .fops = &apm_bios_fops | |
453 | }; | |
454 | ||
455 | ||
456 | #ifdef CONFIG_PROC_FS | |
457 | /* | |
458 | * Arguments, with symbols from linux/apm_bios.h. | |
459 | * | |
460 | * 0) Linux driver version (this will change if format changes) | |
461 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
462 | * 2) APM flags from APM Installation Check (0x00): | |
463 | * bit 0: APM_16_BIT_SUPPORT | |
464 | * bit 1: APM_32_BIT_SUPPORT | |
465 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
466 | * bit 3: APM_BIOS_DISABLED | |
467 | * bit 4: APM_BIOS_DISENGAGED | |
468 | * 3) AC line status | |
469 | * 0x00: Off-line | |
470 | * 0x01: On-line | |
471 | * 0x02: On backup power (BIOS >= 1.1 only) | |
472 | * 0xff: Unknown | |
473 | * 4) Battery status | |
474 | * 0x00: High | |
475 | * 0x01: Low | |
476 | * 0x02: Critical | |
477 | * 0x03: Charging | |
478 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
479 | * 0xff: Unknown | |
480 | * 5) Battery flag | |
481 | * bit 0: High | |
482 | * bit 1: Low | |
483 | * bit 2: Critical | |
484 | * bit 3: Charging | |
485 | * bit 7: No system battery | |
486 | * 0xff: Unknown | |
487 | * 6) Remaining battery life (percentage of charge): | |
488 | * 0-100: valid | |
489 | * -1: Unknown | |
490 | * 7) Remaining battery life (time units): | |
491 | * Number of remaining minutes or seconds | |
492 | * -1: Unknown | |
493 | * 8) min = minutes; sec = seconds | |
494 | */ | |
495 | static int apm_get_info(char *buf, char **start, off_t fpos, int length) | |
496 | { | |
497 | struct apm_power_info info; | |
498 | char *units; | |
499 | int ret; | |
500 | ||
501 | info.ac_line_status = 0xff; | |
502 | info.battery_status = 0xff; | |
503 | info.battery_flag = 0xff; | |
504 | info.battery_life = -1; | |
505 | info.time = -1; | |
506 | info.units = -1; | |
507 | ||
508 | if (apm_get_power_status) | |
509 | apm_get_power_status(&info); | |
510 | ||
511 | switch (info.units) { | |
512 | default: units = "?"; break; | |
513 | case 0: units = "min"; break; | |
514 | case 1: units = "sec"; break; | |
515 | } | |
516 | ||
517 | ret = sprintf(buf, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", | |
518 | driver_version, APM_32_BIT_SUPPORT, | |
519 | info.ac_line_status, info.battery_status, | |
520 | info.battery_flag, info.battery_life, | |
521 | info.time, units); | |
522 | ||
523 | return ret; | |
524 | } | |
525 | #endif | |
526 | ||
527 | static int kapmd(void *arg) | |
528 | { | |
529 | do { | |
530 | apm_event_t event; | |
531 | int ret; | |
532 | ||
533 | wait_event_interruptible(kapmd_wait, | |
534 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
535 | ||
536 | if (kthread_should_stop()) | |
537 | break; | |
538 | ||
539 | spin_lock_irq(&kapmd_queue_lock); | |
540 | event = 0; | |
541 | if (!queue_empty(&kapmd_queue)) | |
542 | event = queue_get_event(&kapmd_queue); | |
543 | spin_unlock_irq(&kapmd_queue_lock); | |
544 | ||
545 | switch (event) { | |
546 | case 0: | |
547 | break; | |
548 | ||
549 | case APM_LOW_BATTERY: | |
550 | case APM_POWER_STATUS_CHANGE: | |
551 | queue_event(event); | |
552 | break; | |
553 | ||
554 | case APM_USER_SUSPEND: | |
555 | case APM_SYS_SUSPEND: | |
556 | ret = queue_suspend_event(event, NULL); | |
557 | if (ret < 0) { | |
558 | /* | |
559 | * We were busy. Try again in 50ms. | |
560 | */ | |
561 | queue_add_event(&kapmd_queue, event); | |
562 | msleep(50); | |
563 | } | |
564 | if (ret > 0) | |
565 | apm_suspend(); | |
566 | break; | |
567 | ||
568 | case APM_CRITICAL_SUSPEND: | |
569 | apm_suspend(); | |
570 | break; | |
571 | } | |
572 | } while (1); | |
573 | ||
574 | return 0; | |
575 | } | |
576 | ||
577 | static int __init apm_init(void) | |
578 | { | |
579 | int ret; | |
580 | ||
581 | if (apm_disabled) { | |
582 | printk(KERN_NOTICE "apm: disabled on user request.\n"); | |
583 | return -ENODEV; | |
584 | } | |
585 | ||
586 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); | |
587 | if (IS_ERR(kapmd_tsk)) { | |
588 | ret = PTR_ERR(kapmd_tsk); | |
589 | kapmd_tsk = NULL; | |
590 | return ret; | |
591 | } | |
7726942f RB |
592 | wake_up_process(kapmd_tsk); |
593 | ||
594 | #ifdef CONFIG_PROC_FS | |
595 | create_proc_info_entry("apm", 0, NULL, apm_get_info); | |
596 | #endif | |
597 | ||
598 | ret = misc_register(&apm_device); | |
599 | if (ret != 0) { | |
600 | remove_proc_entry("apm", NULL); | |
601 | kthread_stop(kapmd_tsk); | |
602 | } | |
603 | ||
604 | return ret; | |
605 | } | |
606 | ||
607 | static void __exit apm_exit(void) | |
608 | { | |
609 | misc_deregister(&apm_device); | |
610 | remove_proc_entry("apm", NULL); | |
611 | ||
612 | kthread_stop(kapmd_tsk); | |
613 | } | |
614 | ||
615 | module_init(apm_init); | |
616 | module_exit(apm_exit); | |
617 | ||
618 | MODULE_AUTHOR("Stephen Rothwell"); | |
619 | MODULE_DESCRIPTION("Advanced Power Management"); | |
620 | MODULE_LICENSE("GPL"); | |
621 | ||
622 | #ifndef MODULE | |
623 | static int __init apm_setup(char *str) | |
624 | { | |
625 | while ((str != NULL) && (*str != '\0')) { | |
626 | if (strncmp(str, "off", 3) == 0) | |
627 | apm_disabled = 1; | |
628 | if (strncmp(str, "on", 2) == 0) | |
629 | apm_disabled = 0; | |
630 | str = strchr(str, ','); | |
631 | if (str != NULL) | |
632 | str += strspn(str, ", \t"); | |
633 | } | |
634 | return 1; | |
635 | } | |
636 | ||
637 | __setup("apm=", apm_setup); | |
638 | #endif | |
639 | ||
640 | /** | |
641 | * apm_queue_event - queue an APM event for kapmd | |
642 | * @event: APM event | |
643 | * | |
644 | * Queue an APM event for kapmd to process and ultimately take the | |
645 | * appropriate action. Only a subset of events are handled: | |
646 | * %APM_LOW_BATTERY | |
647 | * %APM_POWER_STATUS_CHANGE | |
648 | * %APM_USER_SUSPEND | |
649 | * %APM_SYS_SUSPEND | |
650 | * %APM_CRITICAL_SUSPEND | |
651 | */ | |
652 | void apm_queue_event(apm_event_t event) | |
653 | { | |
654 | unsigned long flags; | |
655 | ||
656 | spin_lock_irqsave(&kapmd_queue_lock, flags); | |
657 | queue_add_event(&kapmd_queue, event); | |
658 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); | |
659 | ||
660 | wake_up_interruptible(&kapmd_wait); | |
661 | } | |
662 | EXPORT_SYMBOL(apm_queue_event); |