Commit | Line | Data |
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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> | |
647634df | 17 | #include <linux/seq_file.h> |
7726942f RB |
18 | #include <linux/miscdevice.h> |
19 | #include <linux/apm_bios.h> | |
20 | #include <linux/capability.h> | |
21 | #include <linux/sched.h> | |
95d9ffbe | 22 | #include <linux/suspend.h> |
7726942f | 23 | #include <linux/apm-emulation.h> |
83144186 | 24 | #include <linux/freezer.h> |
7726942f RB |
25 | #include <linux/device.h> |
26 | #include <linux/kernel.h> | |
27 | #include <linux/list.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/completion.h> | |
30 | #include <linux/kthread.h> | |
31 | #include <linux/delay.h> | |
32 | ||
33 | #include <asm/system.h> | |
34 | ||
35 | /* | |
36 | * The apm_bios device is one of the misc char devices. | |
37 | * This is its minor number. | |
38 | */ | |
39 | #define APM_MINOR_DEV 134 | |
40 | ||
41 | /* | |
42 | * See Documentation/Config.help for the configuration options. | |
43 | * | |
44 | * Various options can be changed at boot time as follows: | |
45 | * (We allow underscores for compatibility with the modules code) | |
46 | * apm=on/off enable/disable APM | |
47 | */ | |
48 | ||
49 | /* | |
50 | * Maximum number of events stored | |
51 | */ | |
52 | #define APM_MAX_EVENTS 16 | |
53 | ||
54 | struct apm_queue { | |
55 | unsigned int event_head; | |
56 | unsigned int event_tail; | |
57 | apm_event_t events[APM_MAX_EVENTS]; | |
58 | }; | |
59 | ||
60 | /* | |
61 | * The per-file APM data | |
62 | */ | |
63 | struct apm_user { | |
64 | struct list_head list; | |
65 | ||
66 | unsigned int suser: 1; | |
67 | unsigned int writer: 1; | |
68 | unsigned int reader: 1; | |
69 | ||
70 | int suspend_result; | |
71 | unsigned int suspend_state; | |
72 | #define SUSPEND_NONE 0 /* no suspend pending */ | |
73 | #define SUSPEND_PENDING 1 /* suspend pending read */ | |
74 | #define SUSPEND_READ 2 /* suspend read, pending ack */ | |
75 | #define SUSPEND_ACKED 3 /* suspend acked */ | |
76 | #define SUSPEND_WAIT 4 /* waiting for suspend */ | |
77 | #define SUSPEND_DONE 5 /* suspend completed */ | |
78 | ||
79 | struct apm_queue queue; | |
80 | }; | |
81 | ||
82 | /* | |
83 | * Local variables | |
84 | */ | |
85 | static int suspends_pending; | |
86 | static int apm_disabled; | |
87 | static struct task_struct *kapmd_tsk; | |
88 | ||
89 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); | |
90 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); | |
91 | ||
92 | /* | |
93 | * This is a list of everyone who has opened /dev/apm_bios | |
94 | */ | |
95 | static DECLARE_RWSEM(user_list_lock); | |
96 | static LIST_HEAD(apm_user_list); | |
97 | ||
98 | /* | |
99 | * kapmd info. kapmd provides us a process context to handle | |
100 | * "APM" events within - specifically necessary if we're going | |
101 | * to be suspending the system. | |
102 | */ | |
103 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); | |
104 | static DEFINE_SPINLOCK(kapmd_queue_lock); | |
105 | static struct apm_queue kapmd_queue; | |
106 | ||
107 | static DEFINE_MUTEX(state_lock); | |
108 | ||
109 | static const char driver_version[] = "1.13"; /* no spaces */ | |
110 | ||
111 | ||
112 | ||
113 | /* | |
114 | * Compatibility cruft until the IPAQ people move over to the new | |
115 | * interface. | |
116 | */ | |
117 | static void __apm_get_power_status(struct apm_power_info *info) | |
118 | { | |
119 | } | |
120 | ||
121 | /* | |
122 | * This allows machines to provide their own "apm get power status" function. | |
123 | */ | |
124 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; | |
125 | EXPORT_SYMBOL(apm_get_power_status); | |
126 | ||
127 | ||
128 | /* | |
129 | * APM event queue management. | |
130 | */ | |
131 | static inline int queue_empty(struct apm_queue *q) | |
132 | { | |
133 | return q->event_head == q->event_tail; | |
134 | } | |
135 | ||
136 | static inline apm_event_t queue_get_event(struct apm_queue *q) | |
137 | { | |
138 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
139 | return q->events[q->event_tail]; | |
140 | } | |
141 | ||
142 | static void queue_add_event(struct apm_queue *q, apm_event_t event) | |
143 | { | |
144 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; | |
145 | if (q->event_head == q->event_tail) { | |
146 | static int notified; | |
147 | ||
148 | if (notified++ == 0) | |
149 | printk(KERN_ERR "apm: an event queue overflowed\n"); | |
150 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
151 | } | |
152 | q->events[q->event_head] = event; | |
153 | } | |
154 | ||
155 | static void queue_event(apm_event_t event) | |
156 | { | |
157 | struct apm_user *as; | |
158 | ||
159 | down_read(&user_list_lock); | |
160 | list_for_each_entry(as, &apm_user_list, list) { | |
161 | if (as->reader) | |
162 | queue_add_event(&as->queue, event); | |
163 | } | |
164 | up_read(&user_list_lock); | |
165 | wake_up_interruptible(&apm_waitqueue); | |
166 | } | |
167 | ||
168 | /* | |
169 | * queue_suspend_event - queue an APM suspend event. | |
170 | * | |
171 | * Check that we're in a state where we can suspend. If not, | |
172 | * return -EBUSY. Otherwise, queue an event to all "writer" | |
173 | * users. If there are no "writer" users, return '1' to | |
174 | * indicate that we can immediately suspend. | |
175 | */ | |
176 | static int queue_suspend_event(apm_event_t event, struct apm_user *sender) | |
177 | { | |
178 | struct apm_user *as; | |
179 | int ret = 1; | |
180 | ||
181 | mutex_lock(&state_lock); | |
182 | down_read(&user_list_lock); | |
183 | ||
184 | /* | |
185 | * If a thread is still processing, we can't suspend, so reject | |
186 | * the request. | |
187 | */ | |
188 | list_for_each_entry(as, &apm_user_list, list) { | |
189 | if (as != sender && as->reader && as->writer && as->suser && | |
190 | as->suspend_state != SUSPEND_NONE) { | |
191 | ret = -EBUSY; | |
192 | goto out; | |
193 | } | |
194 | } | |
195 | ||
196 | list_for_each_entry(as, &apm_user_list, list) { | |
197 | if (as != sender && as->reader && as->writer && as->suser) { | |
198 | as->suspend_state = SUSPEND_PENDING; | |
199 | suspends_pending++; | |
200 | queue_add_event(&as->queue, event); | |
201 | ret = 0; | |
202 | } | |
203 | } | |
204 | out: | |
205 | up_read(&user_list_lock); | |
206 | mutex_unlock(&state_lock); | |
207 | wake_up_interruptible(&apm_waitqueue); | |
208 | return ret; | |
209 | } | |
210 | ||
211 | static void apm_suspend(void) | |
212 | { | |
213 | struct apm_user *as; | |
214 | int err = pm_suspend(PM_SUSPEND_MEM); | |
215 | ||
216 | /* | |
217 | * Anyone on the APM queues will think we're still suspended. | |
218 | * Send a message so everyone knows we're now awake again. | |
219 | */ | |
220 | queue_event(APM_NORMAL_RESUME); | |
221 | ||
222 | /* | |
223 | * Finally, wake up anyone who is sleeping on the suspend. | |
224 | */ | |
225 | mutex_lock(&state_lock); | |
226 | down_read(&user_list_lock); | |
227 | list_for_each_entry(as, &apm_user_list, list) { | |
228 | if (as->suspend_state == SUSPEND_WAIT || | |
229 | as->suspend_state == SUSPEND_ACKED) { | |
230 | as->suspend_result = err; | |
231 | as->suspend_state = SUSPEND_DONE; | |
232 | } | |
233 | } | |
234 | up_read(&user_list_lock); | |
235 | mutex_unlock(&state_lock); | |
236 | ||
237 | wake_up(&apm_suspend_waitqueue); | |
238 | } | |
239 | ||
240 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) | |
241 | { | |
242 | struct apm_user *as = fp->private_data; | |
243 | apm_event_t event; | |
244 | int i = count, ret = 0; | |
245 | ||
246 | if (count < sizeof(apm_event_t)) | |
247 | return -EINVAL; | |
248 | ||
249 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) | |
250 | return -EAGAIN; | |
251 | ||
252 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); | |
253 | ||
254 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { | |
255 | event = queue_get_event(&as->queue); | |
256 | ||
257 | ret = -EFAULT; | |
258 | if (copy_to_user(buf, &event, sizeof(event))) | |
259 | break; | |
260 | ||
261 | mutex_lock(&state_lock); | |
262 | if (as->suspend_state == SUSPEND_PENDING && | |
263 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) | |
264 | as->suspend_state = SUSPEND_READ; | |
265 | mutex_unlock(&state_lock); | |
266 | ||
267 | buf += sizeof(event); | |
268 | i -= sizeof(event); | |
269 | } | |
270 | ||
271 | if (i < count) | |
272 | ret = count - i; | |
273 | ||
274 | return ret; | |
275 | } | |
276 | ||
277 | static unsigned int apm_poll(struct file *fp, poll_table * wait) | |
278 | { | |
279 | struct apm_user *as = fp->private_data; | |
280 | ||
281 | poll_wait(fp, &apm_waitqueue, wait); | |
282 | return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM; | |
283 | } | |
284 | ||
285 | /* | |
286 | * apm_ioctl - handle APM ioctl | |
287 | * | |
288 | * APM_IOC_SUSPEND | |
289 | * This IOCTL is overloaded, and performs two functions. It is used to: | |
290 | * - initiate a suspend | |
291 | * - acknowledge a suspend read from /dev/apm_bios. | |
292 | * Only when everyone who has opened /dev/apm_bios with write permission | |
293 | * has acknowledge does the actual suspend happen. | |
294 | */ | |
295 | static int | |
296 | apm_ioctl(struct inode * inode, struct file *filp, u_int cmd, u_long arg) | |
297 | { | |
298 | struct apm_user *as = filp->private_data; | |
7726942f RB |
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 | 333 | */ |
cb43c54c | 334 | freezer_do_not_count(); |
7726942f RB |
335 | |
336 | wait_event(apm_suspend_waitqueue, | |
337 | as->suspend_state == SUSPEND_DONE); | |
cb43c54c RW |
338 | |
339 | /* | |
340 | * Since we are waiting until the suspend is done, the | |
341 | * try_to_freeze() in freezer_count() will not trigger | |
342 | */ | |
343 | freezer_count(); | |
7726942f RB |
344 | } else { |
345 | as->suspend_state = SUSPEND_WAIT; | |
346 | mutex_unlock(&state_lock); | |
347 | ||
348 | /* | |
349 | * Otherwise it is a request to suspend the system. | |
350 | * Queue an event for all readers, and expect an | |
351 | * acknowledge from all writers who haven't already | |
352 | * acknowledged. | |
353 | */ | |
354 | err = queue_suspend_event(APM_USER_SUSPEND, as); | |
355 | if (err < 0) { | |
356 | /* | |
357 | * Avoid taking the lock here - this | |
358 | * should be fine. | |
359 | */ | |
360 | as->suspend_state = SUSPEND_NONE; | |
361 | break; | |
362 | } | |
363 | ||
364 | if (err > 0) | |
365 | apm_suspend(); | |
366 | ||
367 | /* | |
368 | * Wait for the suspend/resume to complete. If there | |
369 | * are pending acknowledges, we wait here for them. | |
7726942f | 370 | */ |
cb43c54c | 371 | wait_event_freezable(apm_suspend_waitqueue, |
7726942f RB |
372 | as->suspend_state == SUSPEND_DONE); |
373 | } | |
374 | ||
7726942f RB |
375 | mutex_lock(&state_lock); |
376 | err = as->suspend_result; | |
377 | as->suspend_state = SUSPEND_NONE; | |
378 | mutex_unlock(&state_lock); | |
379 | break; | |
380 | } | |
381 | ||
382 | return err; | |
383 | } | |
384 | ||
385 | static int apm_release(struct inode * inode, struct file * filp) | |
386 | { | |
387 | struct apm_user *as = filp->private_data; | |
388 | int pending = 0; | |
389 | ||
390 | filp->private_data = NULL; | |
391 | ||
392 | down_write(&user_list_lock); | |
393 | list_del(&as->list); | |
394 | up_write(&user_list_lock); | |
395 | ||
396 | /* | |
397 | * We are now unhooked from the chain. As far as new | |
398 | * events are concerned, we no longer exist. However, we | |
399 | * need to balance suspends_pending, which means the | |
400 | * possibility of sleeping. | |
401 | */ | |
402 | mutex_lock(&state_lock); | |
403 | if (as->suspend_state != SUSPEND_NONE) { | |
404 | suspends_pending -= 1; | |
405 | pending = suspends_pending == 0; | |
406 | } | |
407 | mutex_unlock(&state_lock); | |
408 | if (pending) | |
409 | apm_suspend(); | |
410 | ||
411 | kfree(as); | |
412 | return 0; | |
413 | } | |
414 | ||
415 | static int apm_open(struct inode * inode, struct file * filp) | |
416 | { | |
417 | struct apm_user *as; | |
418 | ||
419 | as = kzalloc(sizeof(*as), GFP_KERNEL); | |
420 | if (as) { | |
421 | /* | |
422 | * XXX - this is a tiny bit broken, when we consider BSD | |
423 | * process accounting. If the device is opened by root, we | |
424 | * instantly flag that we used superuser privs. Who knows, | |
425 | * we might close the device immediately without doing a | |
426 | * privileged operation -- cevans | |
427 | */ | |
428 | as->suser = capable(CAP_SYS_ADMIN); | |
429 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
430 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
431 | ||
432 | down_write(&user_list_lock); | |
433 | list_add(&as->list, &apm_user_list); | |
434 | up_write(&user_list_lock); | |
435 | ||
436 | filp->private_data = as; | |
437 | } | |
438 | ||
439 | return as ? 0 : -ENOMEM; | |
440 | } | |
441 | ||
442 | static struct file_operations apm_bios_fops = { | |
443 | .owner = THIS_MODULE, | |
444 | .read = apm_read, | |
445 | .poll = apm_poll, | |
446 | .ioctl = apm_ioctl, | |
447 | .open = apm_open, | |
448 | .release = apm_release, | |
449 | }; | |
450 | ||
451 | static struct miscdevice apm_device = { | |
452 | .minor = APM_MINOR_DEV, | |
453 | .name = "apm_bios", | |
454 | .fops = &apm_bios_fops | |
455 | }; | |
456 | ||
457 | ||
458 | #ifdef CONFIG_PROC_FS | |
459 | /* | |
460 | * Arguments, with symbols from linux/apm_bios.h. | |
461 | * | |
462 | * 0) Linux driver version (this will change if format changes) | |
463 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
464 | * 2) APM flags from APM Installation Check (0x00): | |
465 | * bit 0: APM_16_BIT_SUPPORT | |
466 | * bit 1: APM_32_BIT_SUPPORT | |
467 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
468 | * bit 3: APM_BIOS_DISABLED | |
469 | * bit 4: APM_BIOS_DISENGAGED | |
470 | * 3) AC line status | |
471 | * 0x00: Off-line | |
472 | * 0x01: On-line | |
473 | * 0x02: On backup power (BIOS >= 1.1 only) | |
474 | * 0xff: Unknown | |
475 | * 4) Battery status | |
476 | * 0x00: High | |
477 | * 0x01: Low | |
478 | * 0x02: Critical | |
479 | * 0x03: Charging | |
480 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
481 | * 0xff: Unknown | |
482 | * 5) Battery flag | |
483 | * bit 0: High | |
484 | * bit 1: Low | |
485 | * bit 2: Critical | |
486 | * bit 3: Charging | |
487 | * bit 7: No system battery | |
488 | * 0xff: Unknown | |
489 | * 6) Remaining battery life (percentage of charge): | |
490 | * 0-100: valid | |
491 | * -1: Unknown | |
492 | * 7) Remaining battery life (time units): | |
493 | * Number of remaining minutes or seconds | |
494 | * -1: Unknown | |
495 | * 8) min = minutes; sec = seconds | |
496 | */ | |
647634df | 497 | static int proc_apm_show(struct seq_file *m, void *v) |
7726942f RB |
498 | { |
499 | struct apm_power_info info; | |
500 | char *units; | |
7726942f RB |
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 | ||
647634df | 518 | seq_printf(m, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", |
7726942f RB |
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 | ||
647634df | 524 | return 0; |
7726942f | 525 | } |
647634df AD |
526 | |
527 | static int proc_apm_open(struct inode *inode, struct file *file) | |
528 | { | |
529 | return single_open(file, proc_apm_show, NULL); | |
530 | } | |
531 | ||
532 | static const struct file_operations apm_proc_fops = { | |
533 | .owner = THIS_MODULE, | |
534 | .open = proc_apm_open, | |
535 | .read = seq_read, | |
536 | .llseek = seq_lseek, | |
537 | .release = single_release, | |
538 | }; | |
7726942f RB |
539 | #endif |
540 | ||
541 | static int kapmd(void *arg) | |
542 | { | |
543 | do { | |
544 | apm_event_t event; | |
545 | int ret; | |
546 | ||
547 | wait_event_interruptible(kapmd_wait, | |
548 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
549 | ||
550 | if (kthread_should_stop()) | |
551 | break; | |
552 | ||
553 | spin_lock_irq(&kapmd_queue_lock); | |
554 | event = 0; | |
555 | if (!queue_empty(&kapmd_queue)) | |
556 | event = queue_get_event(&kapmd_queue); | |
557 | spin_unlock_irq(&kapmd_queue_lock); | |
558 | ||
559 | switch (event) { | |
560 | case 0: | |
561 | break; | |
562 | ||
563 | case APM_LOW_BATTERY: | |
564 | case APM_POWER_STATUS_CHANGE: | |
565 | queue_event(event); | |
566 | break; | |
567 | ||
568 | case APM_USER_SUSPEND: | |
569 | case APM_SYS_SUSPEND: | |
570 | ret = queue_suspend_event(event, NULL); | |
571 | if (ret < 0) { | |
572 | /* | |
573 | * We were busy. Try again in 50ms. | |
574 | */ | |
575 | queue_add_event(&kapmd_queue, event); | |
576 | msleep(50); | |
577 | } | |
578 | if (ret > 0) | |
579 | apm_suspend(); | |
580 | break; | |
581 | ||
582 | case APM_CRITICAL_SUSPEND: | |
583 | apm_suspend(); | |
584 | break; | |
585 | } | |
586 | } while (1); | |
587 | ||
588 | return 0; | |
589 | } | |
590 | ||
591 | static int __init apm_init(void) | |
592 | { | |
593 | int ret; | |
594 | ||
595 | if (apm_disabled) { | |
596 | printk(KERN_NOTICE "apm: disabled on user request.\n"); | |
597 | return -ENODEV; | |
598 | } | |
599 | ||
600 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); | |
601 | if (IS_ERR(kapmd_tsk)) { | |
602 | ret = PTR_ERR(kapmd_tsk); | |
603 | kapmd_tsk = NULL; | |
604 | return ret; | |
605 | } | |
7726942f RB |
606 | wake_up_process(kapmd_tsk); |
607 | ||
608 | #ifdef CONFIG_PROC_FS | |
647634df | 609 | proc_create("apm", 0, NULL, &apm_proc_fops); |
7726942f RB |
610 | #endif |
611 | ||
612 | ret = misc_register(&apm_device); | |
613 | if (ret != 0) { | |
614 | remove_proc_entry("apm", NULL); | |
615 | kthread_stop(kapmd_tsk); | |
616 | } | |
617 | ||
618 | return ret; | |
619 | } | |
620 | ||
621 | static void __exit apm_exit(void) | |
622 | { | |
623 | misc_deregister(&apm_device); | |
624 | remove_proc_entry("apm", NULL); | |
625 | ||
626 | kthread_stop(kapmd_tsk); | |
627 | } | |
628 | ||
629 | module_init(apm_init); | |
630 | module_exit(apm_exit); | |
631 | ||
632 | MODULE_AUTHOR("Stephen Rothwell"); | |
633 | MODULE_DESCRIPTION("Advanced Power Management"); | |
634 | MODULE_LICENSE("GPL"); | |
635 | ||
636 | #ifndef MODULE | |
637 | static int __init apm_setup(char *str) | |
638 | { | |
639 | while ((str != NULL) && (*str != '\0')) { | |
640 | if (strncmp(str, "off", 3) == 0) | |
641 | apm_disabled = 1; | |
642 | if (strncmp(str, "on", 2) == 0) | |
643 | apm_disabled = 0; | |
644 | str = strchr(str, ','); | |
645 | if (str != NULL) | |
646 | str += strspn(str, ", \t"); | |
647 | } | |
648 | return 1; | |
649 | } | |
650 | ||
651 | __setup("apm=", apm_setup); | |
652 | #endif | |
653 | ||
654 | /** | |
655 | * apm_queue_event - queue an APM event for kapmd | |
656 | * @event: APM event | |
657 | * | |
658 | * Queue an APM event for kapmd to process and ultimately take the | |
659 | * appropriate action. Only a subset of events are handled: | |
660 | * %APM_LOW_BATTERY | |
661 | * %APM_POWER_STATUS_CHANGE | |
662 | * %APM_USER_SUSPEND | |
663 | * %APM_SYS_SUSPEND | |
664 | * %APM_CRITICAL_SUSPEND | |
665 | */ | |
666 | void apm_queue_event(apm_event_t event) | |
667 | { | |
668 | unsigned long flags; | |
669 | ||
670 | spin_lock_irqsave(&kapmd_queue_lock, flags); | |
671 | queue_add_event(&kapmd_queue, event); | |
672 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); | |
673 | ||
674 | wake_up_interruptible(&kapmd_wait); | |
675 | } | |
676 | EXPORT_SYMBOL(apm_queue_event); |