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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; | |
7726942f RB |
298 | int err = -EINVAL; |
299 | ||
300 | if (!as->suser || !as->writer) | |
301 | return -EPERM; | |
302 | ||
303 | switch (cmd) { | |
304 | case APM_IOC_SUSPEND: | |
305 | mutex_lock(&state_lock); | |
306 | ||
307 | as->suspend_result = -EINTR; | |
308 | ||
309 | if (as->suspend_state == SUSPEND_READ) { | |
310 | int pending; | |
311 | ||
312 | /* | |
313 | * If we read a suspend command from /dev/apm_bios, | |
314 | * then the corresponding APM_IOC_SUSPEND ioctl is | |
315 | * interpreted as an acknowledge. | |
316 | */ | |
317 | as->suspend_state = SUSPEND_ACKED; | |
318 | suspends_pending--; | |
319 | pending = suspends_pending == 0; | |
320 | mutex_unlock(&state_lock); | |
321 | ||
322 | /* | |
323 | * If there are no further acknowledges required, | |
324 | * suspend the system. | |
325 | */ | |
326 | if (pending) | |
327 | apm_suspend(); | |
328 | ||
329 | /* | |
330 | * Wait for the suspend/resume to complete. If there | |
331 | * are pending acknowledges, we wait here for them. | |
7726942f | 332 | */ |
cb43c54c | 333 | freezer_do_not_count(); |
7726942f RB |
334 | |
335 | wait_event(apm_suspend_waitqueue, | |
336 | as->suspend_state == SUSPEND_DONE); | |
cb43c54c RW |
337 | |
338 | /* | |
339 | * Since we are waiting until the suspend is done, the | |
340 | * try_to_freeze() in freezer_count() will not trigger | |
341 | */ | |
342 | freezer_count(); | |
7726942f RB |
343 | } else { |
344 | as->suspend_state = SUSPEND_WAIT; | |
345 | mutex_unlock(&state_lock); | |
346 | ||
347 | /* | |
348 | * Otherwise it is a request to suspend the system. | |
349 | * Queue an event for all readers, and expect an | |
350 | * acknowledge from all writers who haven't already | |
351 | * acknowledged. | |
352 | */ | |
353 | err = queue_suspend_event(APM_USER_SUSPEND, as); | |
354 | if (err < 0) { | |
355 | /* | |
356 | * Avoid taking the lock here - this | |
357 | * should be fine. | |
358 | */ | |
359 | as->suspend_state = SUSPEND_NONE; | |
360 | break; | |
361 | } | |
362 | ||
363 | if (err > 0) | |
364 | apm_suspend(); | |
365 | ||
366 | /* | |
367 | * Wait for the suspend/resume to complete. If there | |
368 | * are pending acknowledges, we wait here for them. | |
7726942f | 369 | */ |
cb43c54c | 370 | wait_event_freezable(apm_suspend_waitqueue, |
7726942f RB |
371 | as->suspend_state == SUSPEND_DONE); |
372 | } | |
373 | ||
7726942f RB |
374 | mutex_lock(&state_lock); |
375 | err = as->suspend_result; | |
376 | as->suspend_state = SUSPEND_NONE; | |
377 | mutex_unlock(&state_lock); | |
378 | break; | |
379 | } | |
380 | ||
381 | return err; | |
382 | } | |
383 | ||
384 | static int apm_release(struct inode * inode, struct file * filp) | |
385 | { | |
386 | struct apm_user *as = filp->private_data; | |
387 | int pending = 0; | |
388 | ||
389 | filp->private_data = NULL; | |
390 | ||
391 | down_write(&user_list_lock); | |
392 | list_del(&as->list); | |
393 | up_write(&user_list_lock); | |
394 | ||
395 | /* | |
396 | * We are now unhooked from the chain. As far as new | |
397 | * events are concerned, we no longer exist. However, we | |
398 | * need to balance suspends_pending, which means the | |
399 | * possibility of sleeping. | |
400 | */ | |
401 | mutex_lock(&state_lock); | |
402 | if (as->suspend_state != SUSPEND_NONE) { | |
403 | suspends_pending -= 1; | |
404 | pending = suspends_pending == 0; | |
405 | } | |
406 | mutex_unlock(&state_lock); | |
407 | if (pending) | |
408 | apm_suspend(); | |
409 | ||
410 | kfree(as); | |
411 | return 0; | |
412 | } | |
413 | ||
414 | static int apm_open(struct inode * inode, struct file * filp) | |
415 | { | |
416 | struct apm_user *as; | |
417 | ||
418 | as = kzalloc(sizeof(*as), GFP_KERNEL); | |
419 | if (as) { | |
420 | /* | |
421 | * XXX - this is a tiny bit broken, when we consider BSD | |
422 | * process accounting. If the device is opened by root, we | |
423 | * instantly flag that we used superuser privs. Who knows, | |
424 | * we might close the device immediately without doing a | |
425 | * privileged operation -- cevans | |
426 | */ | |
427 | as->suser = capable(CAP_SYS_ADMIN); | |
428 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
429 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
430 | ||
431 | down_write(&user_list_lock); | |
432 | list_add(&as->list, &apm_user_list); | |
433 | up_write(&user_list_lock); | |
434 | ||
435 | filp->private_data = as; | |
436 | } | |
437 | ||
438 | return as ? 0 : -ENOMEM; | |
439 | } | |
440 | ||
441 | static struct file_operations apm_bios_fops = { | |
442 | .owner = THIS_MODULE, | |
443 | .read = apm_read, | |
444 | .poll = apm_poll, | |
445 | .ioctl = apm_ioctl, | |
446 | .open = apm_open, | |
447 | .release = apm_release, | |
448 | }; | |
449 | ||
450 | static struct miscdevice apm_device = { | |
451 | .minor = APM_MINOR_DEV, | |
452 | .name = "apm_bios", | |
453 | .fops = &apm_bios_fops | |
454 | }; | |
455 | ||
456 | ||
457 | #ifdef CONFIG_PROC_FS | |
458 | /* | |
459 | * Arguments, with symbols from linux/apm_bios.h. | |
460 | * | |
461 | * 0) Linux driver version (this will change if format changes) | |
462 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
463 | * 2) APM flags from APM Installation Check (0x00): | |
464 | * bit 0: APM_16_BIT_SUPPORT | |
465 | * bit 1: APM_32_BIT_SUPPORT | |
466 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
467 | * bit 3: APM_BIOS_DISABLED | |
468 | * bit 4: APM_BIOS_DISENGAGED | |
469 | * 3) AC line status | |
470 | * 0x00: Off-line | |
471 | * 0x01: On-line | |
472 | * 0x02: On backup power (BIOS >= 1.1 only) | |
473 | * 0xff: Unknown | |
474 | * 4) Battery status | |
475 | * 0x00: High | |
476 | * 0x01: Low | |
477 | * 0x02: Critical | |
478 | * 0x03: Charging | |
479 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
480 | * 0xff: Unknown | |
481 | * 5) Battery flag | |
482 | * bit 0: High | |
483 | * bit 1: Low | |
484 | * bit 2: Critical | |
485 | * bit 3: Charging | |
486 | * bit 7: No system battery | |
487 | * 0xff: Unknown | |
488 | * 6) Remaining battery life (percentage of charge): | |
489 | * 0-100: valid | |
490 | * -1: Unknown | |
491 | * 7) Remaining battery life (time units): | |
492 | * Number of remaining minutes or seconds | |
493 | * -1: Unknown | |
494 | * 8) min = minutes; sec = seconds | |
495 | */ | |
496 | static int apm_get_info(char *buf, char **start, off_t fpos, int length) | |
497 | { | |
498 | struct apm_power_info info; | |
499 | char *units; | |
500 | int ret; | |
501 | ||
502 | info.ac_line_status = 0xff; | |
503 | info.battery_status = 0xff; | |
504 | info.battery_flag = 0xff; | |
505 | info.battery_life = -1; | |
506 | info.time = -1; | |
507 | info.units = -1; | |
508 | ||
509 | if (apm_get_power_status) | |
510 | apm_get_power_status(&info); | |
511 | ||
512 | switch (info.units) { | |
513 | default: units = "?"; break; | |
514 | case 0: units = "min"; break; | |
515 | case 1: units = "sec"; break; | |
516 | } | |
517 | ||
518 | ret = sprintf(buf, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", | |
519 | driver_version, APM_32_BIT_SUPPORT, | |
520 | info.ac_line_status, info.battery_status, | |
521 | info.battery_flag, info.battery_life, | |
522 | info.time, units); | |
523 | ||
524 | return ret; | |
525 | } | |
526 | #endif | |
527 | ||
528 | static int kapmd(void *arg) | |
529 | { | |
530 | do { | |
531 | apm_event_t event; | |
532 | int ret; | |
533 | ||
534 | wait_event_interruptible(kapmd_wait, | |
535 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
536 | ||
537 | if (kthread_should_stop()) | |
538 | break; | |
539 | ||
540 | spin_lock_irq(&kapmd_queue_lock); | |
541 | event = 0; | |
542 | if (!queue_empty(&kapmd_queue)) | |
543 | event = queue_get_event(&kapmd_queue); | |
544 | spin_unlock_irq(&kapmd_queue_lock); | |
545 | ||
546 | switch (event) { | |
547 | case 0: | |
548 | break; | |
549 | ||
550 | case APM_LOW_BATTERY: | |
551 | case APM_POWER_STATUS_CHANGE: | |
552 | queue_event(event); | |
553 | break; | |
554 | ||
555 | case APM_USER_SUSPEND: | |
556 | case APM_SYS_SUSPEND: | |
557 | ret = queue_suspend_event(event, NULL); | |
558 | if (ret < 0) { | |
559 | /* | |
560 | * We were busy. Try again in 50ms. | |
561 | */ | |
562 | queue_add_event(&kapmd_queue, event); | |
563 | msleep(50); | |
564 | } | |
565 | if (ret > 0) | |
566 | apm_suspend(); | |
567 | break; | |
568 | ||
569 | case APM_CRITICAL_SUSPEND: | |
570 | apm_suspend(); | |
571 | break; | |
572 | } | |
573 | } while (1); | |
574 | ||
575 | return 0; | |
576 | } | |
577 | ||
578 | static int __init apm_init(void) | |
579 | { | |
580 | int ret; | |
581 | ||
582 | if (apm_disabled) { | |
583 | printk(KERN_NOTICE "apm: disabled on user request.\n"); | |
584 | return -ENODEV; | |
585 | } | |
586 | ||
587 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); | |
588 | if (IS_ERR(kapmd_tsk)) { | |
589 | ret = PTR_ERR(kapmd_tsk); | |
590 | kapmd_tsk = NULL; | |
591 | return ret; | |
592 | } | |
7726942f RB |
593 | wake_up_process(kapmd_tsk); |
594 | ||
595 | #ifdef CONFIG_PROC_FS | |
596 | create_proc_info_entry("apm", 0, NULL, apm_get_info); | |
597 | #endif | |
598 | ||
599 | ret = misc_register(&apm_device); | |
600 | if (ret != 0) { | |
601 | remove_proc_entry("apm", NULL); | |
602 | kthread_stop(kapmd_tsk); | |
603 | } | |
604 | ||
605 | return ret; | |
606 | } | |
607 | ||
608 | static void __exit apm_exit(void) | |
609 | { | |
610 | misc_deregister(&apm_device); | |
611 | remove_proc_entry("apm", NULL); | |
612 | ||
613 | kthread_stop(kapmd_tsk); | |
614 | } | |
615 | ||
616 | module_init(apm_init); | |
617 | module_exit(apm_exit); | |
618 | ||
619 | MODULE_AUTHOR("Stephen Rothwell"); | |
620 | MODULE_DESCRIPTION("Advanced Power Management"); | |
621 | MODULE_LICENSE("GPL"); | |
622 | ||
623 | #ifndef MODULE | |
624 | static int __init apm_setup(char *str) | |
625 | { | |
626 | while ((str != NULL) && (*str != '\0')) { | |
627 | if (strncmp(str, "off", 3) == 0) | |
628 | apm_disabled = 1; | |
629 | if (strncmp(str, "on", 2) == 0) | |
630 | apm_disabled = 0; | |
631 | str = strchr(str, ','); | |
632 | if (str != NULL) | |
633 | str += strspn(str, ", \t"); | |
634 | } | |
635 | return 1; | |
636 | } | |
637 | ||
638 | __setup("apm=", apm_setup); | |
639 | #endif | |
640 | ||
641 | /** | |
642 | * apm_queue_event - queue an APM event for kapmd | |
643 | * @event: APM event | |
644 | * | |
645 | * Queue an APM event for kapmd to process and ultimately take the | |
646 | * appropriate action. Only a subset of events are handled: | |
647 | * %APM_LOW_BATTERY | |
648 | * %APM_POWER_STATUS_CHANGE | |
649 | * %APM_USER_SUSPEND | |
650 | * %APM_SYS_SUSPEND | |
651 | * %APM_CRITICAL_SUSPEND | |
652 | */ | |
653 | void apm_queue_event(apm_event_t event) | |
654 | { | |
655 | unsigned long flags; | |
656 | ||
657 | spin_lock_irqsave(&kapmd_queue_lock, flags); | |
658 | queue_add_event(&kapmd_queue, event); | |
659 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); | |
660 | ||
661 | wake_up_interruptible(&kapmd_wait); | |
662 | } | |
663 | EXPORT_SYMBOL(apm_queue_event); |