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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/whdc/archive/amp_12.mspx | |
12 | */ | |
13 | #include <linux/module.h> | |
14 | #include <linux/poll.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/proc_fs.h> | |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/miscdevice.h> | |
20 | #include <linux/apm_bios.h> | |
21 | #include <linux/capability.h> | |
22 | #include <linux/sched.h> | |
23 | #include <linux/suspend.h> | |
24 | #include <linux/apm-emulation.h> | |
25 | #include <linux/freezer.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/list.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/completion.h> | |
31 | #include <linux/kthread.h> | |
32 | #include <linux/delay.h> | |
33 | ||
34 | /* | |
35 | * One option can be changed at boot time as follows: | |
36 | * apm=on/off enable/disable APM | |
37 | */ | |
38 | ||
39 | /* | |
40 | * Maximum number of events stored | |
41 | */ | |
42 | #define APM_MAX_EVENTS 16 | |
43 | ||
44 | struct apm_queue { | |
45 | unsigned int event_head; | |
46 | unsigned int event_tail; | |
47 | apm_event_t events[APM_MAX_EVENTS]; | |
48 | }; | |
49 | ||
50 | /* | |
51 | * thread states (for threads using a writable /dev/apm_bios fd): | |
52 | * | |
53 | * SUSPEND_NONE: nothing happening | |
54 | * SUSPEND_PENDING: suspend event queued for thread and pending to be read | |
55 | * SUSPEND_READ: suspend event read, pending acknowledgement | |
56 | * SUSPEND_ACKED: acknowledgement received from thread (via ioctl), | |
57 | * waiting for resume | |
58 | * SUSPEND_ACKTO: acknowledgement timeout | |
59 | * SUSPEND_DONE: thread had acked suspend and is now notified of | |
60 | * resume | |
61 | * | |
62 | * SUSPEND_WAIT: this thread invoked suspend and is waiting for resume | |
63 | * | |
64 | * A thread migrates in one of three paths: | |
65 | * NONE -1-> PENDING -2-> READ -3-> ACKED -4-> DONE -5-> NONE | |
66 | * -6-> ACKTO -7-> NONE | |
67 | * NONE -8-> WAIT -9-> NONE | |
68 | * | |
69 | * While in PENDING or READ, the thread is accounted for in the | |
70 | * suspend_acks_pending counter. | |
71 | * | |
72 | * The transitions are invoked as follows: | |
73 | * 1: suspend event is signalled from the core PM code | |
74 | * 2: the suspend event is read from the fd by the userspace thread | |
75 | * 3: userspace thread issues the APM_IOC_SUSPEND ioctl (as ack) | |
76 | * 4: core PM code signals that we have resumed | |
77 | * 5: APM_IOC_SUSPEND ioctl returns | |
78 | * | |
79 | * 6: the notifier invoked from the core PM code timed out waiting | |
80 | * for all relevant threds to enter ACKED state and puts those | |
81 | * that haven't into ACKTO | |
82 | * 7: those threads issue APM_IOC_SUSPEND ioctl too late, | |
83 | * get an error | |
84 | * | |
85 | * 8: userspace thread issues the APM_IOC_SUSPEND ioctl (to suspend), | |
86 | * ioctl code invokes pm_suspend() | |
87 | * 9: pm_suspend() returns indicating resume | |
88 | */ | |
89 | enum apm_suspend_state { | |
90 | SUSPEND_NONE, | |
91 | SUSPEND_PENDING, | |
92 | SUSPEND_READ, | |
93 | SUSPEND_ACKED, | |
94 | SUSPEND_ACKTO, | |
95 | SUSPEND_WAIT, | |
96 | SUSPEND_DONE, | |
97 | }; | |
98 | ||
99 | /* | |
100 | * The per-file APM data | |
101 | */ | |
102 | struct apm_user { | |
103 | struct list_head list; | |
104 | ||
105 | unsigned int suser: 1; | |
106 | unsigned int writer: 1; | |
107 | unsigned int reader: 1; | |
108 | ||
109 | int suspend_result; | |
110 | enum apm_suspend_state suspend_state; | |
111 | ||
112 | struct apm_queue queue; | |
113 | }; | |
114 | ||
115 | /* | |
116 | * Local variables | |
117 | */ | |
118 | static atomic_t suspend_acks_pending = ATOMIC_INIT(0); | |
119 | static atomic_t userspace_notification_inhibit = ATOMIC_INIT(0); | |
120 | static int apm_disabled; | |
121 | static struct task_struct *kapmd_tsk; | |
122 | ||
123 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); | |
124 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); | |
125 | ||
126 | /* | |
127 | * This is a list of everyone who has opened /dev/apm_bios | |
128 | */ | |
129 | static DECLARE_RWSEM(user_list_lock); | |
130 | static LIST_HEAD(apm_user_list); | |
131 | ||
132 | /* | |
133 | * kapmd info. kapmd provides us a process context to handle | |
134 | * "APM" events within - specifically necessary if we're going | |
135 | * to be suspending the system. | |
136 | */ | |
137 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); | |
138 | static DEFINE_SPINLOCK(kapmd_queue_lock); | |
139 | static struct apm_queue kapmd_queue; | |
140 | ||
141 | static DEFINE_MUTEX(state_lock); | |
142 | ||
143 | static const char driver_version[] = "1.13"; /* no spaces */ | |
144 | ||
145 | ||
146 | ||
147 | /* | |
148 | * Compatibility cruft until the IPAQ people move over to the new | |
149 | * interface. | |
150 | */ | |
151 | static void __apm_get_power_status(struct apm_power_info *info) | |
152 | { | |
153 | } | |
154 | ||
155 | /* | |
156 | * This allows machines to provide their own "apm get power status" function. | |
157 | */ | |
158 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; | |
159 | EXPORT_SYMBOL(apm_get_power_status); | |
160 | ||
161 | ||
162 | /* | |
163 | * APM event queue management. | |
164 | */ | |
165 | static inline int queue_empty(struct apm_queue *q) | |
166 | { | |
167 | return q->event_head == q->event_tail; | |
168 | } | |
169 | ||
170 | static inline apm_event_t queue_get_event(struct apm_queue *q) | |
171 | { | |
172 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
173 | return q->events[q->event_tail]; | |
174 | } | |
175 | ||
176 | static void queue_add_event(struct apm_queue *q, apm_event_t event) | |
177 | { | |
178 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; | |
179 | if (q->event_head == q->event_tail) { | |
180 | static int notified; | |
181 | ||
182 | if (notified++ == 0) | |
183 | printk(KERN_ERR "apm: an event queue overflowed\n"); | |
184 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
185 | } | |
186 | q->events[q->event_head] = event; | |
187 | } | |
188 | ||
189 | static void queue_event(apm_event_t event) | |
190 | { | |
191 | struct apm_user *as; | |
192 | ||
193 | down_read(&user_list_lock); | |
194 | list_for_each_entry(as, &apm_user_list, list) { | |
195 | if (as->reader) | |
196 | queue_add_event(&as->queue, event); | |
197 | } | |
198 | up_read(&user_list_lock); | |
199 | wake_up_interruptible(&apm_waitqueue); | |
200 | } | |
201 | ||
202 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) | |
203 | { | |
204 | struct apm_user *as = fp->private_data; | |
205 | apm_event_t event; | |
206 | int i = count, ret = 0; | |
207 | ||
208 | if (count < sizeof(apm_event_t)) | |
209 | return -EINVAL; | |
210 | ||
211 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) | |
212 | return -EAGAIN; | |
213 | ||
214 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); | |
215 | ||
216 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { | |
217 | event = queue_get_event(&as->queue); | |
218 | ||
219 | ret = -EFAULT; | |
220 | if (copy_to_user(buf, &event, sizeof(event))) | |
221 | break; | |
222 | ||
223 | mutex_lock(&state_lock); | |
224 | if (as->suspend_state == SUSPEND_PENDING && | |
225 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) | |
226 | as->suspend_state = SUSPEND_READ; | |
227 | mutex_unlock(&state_lock); | |
228 | ||
229 | buf += sizeof(event); | |
230 | i -= sizeof(event); | |
231 | } | |
232 | ||
233 | if (i < count) | |
234 | ret = count - i; | |
235 | ||
236 | return ret; | |
237 | } | |
238 | ||
239 | static unsigned int apm_poll(struct file *fp, poll_table * wait) | |
240 | { | |
241 | struct apm_user *as = fp->private_data; | |
242 | ||
243 | poll_wait(fp, &apm_waitqueue, wait); | |
244 | return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM; | |
245 | } | |
246 | ||
247 | /* | |
248 | * apm_ioctl - handle APM ioctl | |
249 | * | |
250 | * APM_IOC_SUSPEND | |
251 | * This IOCTL is overloaded, and performs two functions. It is used to: | |
252 | * - initiate a suspend | |
253 | * - acknowledge a suspend read from /dev/apm_bios. | |
254 | * Only when everyone who has opened /dev/apm_bios with write permission | |
255 | * has acknowledge does the actual suspend happen. | |
256 | */ | |
257 | static long | |
258 | apm_ioctl(struct file *filp, u_int cmd, u_long arg) | |
259 | { | |
260 | struct apm_user *as = filp->private_data; | |
261 | int err = -EINVAL; | |
262 | ||
263 | if (!as->suser || !as->writer) | |
264 | return -EPERM; | |
265 | ||
266 | switch (cmd) { | |
267 | case APM_IOC_SUSPEND: | |
268 | mutex_lock(&state_lock); | |
269 | ||
270 | as->suspend_result = -EINTR; | |
271 | ||
272 | switch (as->suspend_state) { | |
273 | case SUSPEND_READ: | |
274 | /* | |
275 | * If we read a suspend command from /dev/apm_bios, | |
276 | * then the corresponding APM_IOC_SUSPEND ioctl is | |
277 | * interpreted as an acknowledge. | |
278 | */ | |
279 | as->suspend_state = SUSPEND_ACKED; | |
280 | atomic_dec(&suspend_acks_pending); | |
281 | mutex_unlock(&state_lock); | |
282 | ||
283 | /* | |
284 | * suspend_acks_pending changed, the notifier needs to | |
285 | * be woken up for this | |
286 | */ | |
287 | wake_up(&apm_suspend_waitqueue); | |
288 | ||
289 | /* | |
290 | * Wait for the suspend/resume to complete. If there | |
291 | * are pending acknowledges, we wait here for them. | |
292 | * wait_event_freezable() is interruptible and pending | |
293 | * signal can cause busy looping. We aren't doing | |
294 | * anything critical, chill a bit on each iteration. | |
295 | */ | |
296 | while (wait_event_freezable(apm_suspend_waitqueue, | |
297 | as->suspend_state != SUSPEND_ACKED)) | |
298 | msleep(10); | |
299 | break; | |
300 | case SUSPEND_ACKTO: | |
301 | as->suspend_result = -ETIMEDOUT; | |
302 | mutex_unlock(&state_lock); | |
303 | break; | |
304 | default: | |
305 | as->suspend_state = SUSPEND_WAIT; | |
306 | mutex_unlock(&state_lock); | |
307 | ||
308 | /* | |
309 | * Otherwise it is a request to suspend the system. | |
310 | * Just invoke pm_suspend(), we'll handle it from | |
311 | * there via the notifier. | |
312 | */ | |
313 | as->suspend_result = pm_suspend(PM_SUSPEND_MEM); | |
314 | } | |
315 | ||
316 | mutex_lock(&state_lock); | |
317 | err = as->suspend_result; | |
318 | as->suspend_state = SUSPEND_NONE; | |
319 | mutex_unlock(&state_lock); | |
320 | break; | |
321 | } | |
322 | ||
323 | return err; | |
324 | } | |
325 | ||
326 | static int apm_release(struct inode * inode, struct file * filp) | |
327 | { | |
328 | struct apm_user *as = filp->private_data; | |
329 | ||
330 | filp->private_data = NULL; | |
331 | ||
332 | down_write(&user_list_lock); | |
333 | list_del(&as->list); | |
334 | up_write(&user_list_lock); | |
335 | ||
336 | /* | |
337 | * We are now unhooked from the chain. As far as new | |
338 | * events are concerned, we no longer exist. | |
339 | */ | |
340 | mutex_lock(&state_lock); | |
341 | if (as->suspend_state == SUSPEND_PENDING || | |
342 | as->suspend_state == SUSPEND_READ) | |
343 | atomic_dec(&suspend_acks_pending); | |
344 | mutex_unlock(&state_lock); | |
345 | ||
346 | wake_up(&apm_suspend_waitqueue); | |
347 | ||
348 | kfree(as); | |
349 | return 0; | |
350 | } | |
351 | ||
352 | static int apm_open(struct inode * inode, struct file * filp) | |
353 | { | |
354 | struct apm_user *as; | |
355 | ||
356 | as = kzalloc(sizeof(*as), GFP_KERNEL); | |
357 | if (as) { | |
358 | /* | |
359 | * XXX - this is a tiny bit broken, when we consider BSD | |
360 | * process accounting. If the device is opened by root, we | |
361 | * instantly flag that we used superuser privs. Who knows, | |
362 | * we might close the device immediately without doing a | |
363 | * privileged operation -- cevans | |
364 | */ | |
365 | as->suser = capable(CAP_SYS_ADMIN); | |
366 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
367 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
368 | ||
369 | down_write(&user_list_lock); | |
370 | list_add(&as->list, &apm_user_list); | |
371 | up_write(&user_list_lock); | |
372 | ||
373 | filp->private_data = as; | |
374 | } | |
375 | ||
376 | return as ? 0 : -ENOMEM; | |
377 | } | |
378 | ||
379 | static const struct file_operations apm_bios_fops = { | |
380 | .owner = THIS_MODULE, | |
381 | .read = apm_read, | |
382 | .poll = apm_poll, | |
383 | .unlocked_ioctl = apm_ioctl, | |
384 | .open = apm_open, | |
385 | .release = apm_release, | |
386 | .llseek = noop_llseek, | |
387 | }; | |
388 | ||
389 | static struct miscdevice apm_device = { | |
390 | .minor = APM_MINOR_DEV, | |
391 | .name = "apm_bios", | |
392 | .fops = &apm_bios_fops | |
393 | }; | |
394 | ||
395 | ||
396 | #ifdef CONFIG_PROC_FS | |
397 | /* | |
398 | * Arguments, with symbols from linux/apm_bios.h. | |
399 | * | |
400 | * 0) Linux driver version (this will change if format changes) | |
401 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
402 | * 2) APM flags from APM Installation Check (0x00): | |
403 | * bit 0: APM_16_BIT_SUPPORT | |
404 | * bit 1: APM_32_BIT_SUPPORT | |
405 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
406 | * bit 3: APM_BIOS_DISABLED | |
407 | * bit 4: APM_BIOS_DISENGAGED | |
408 | * 3) AC line status | |
409 | * 0x00: Off-line | |
410 | * 0x01: On-line | |
411 | * 0x02: On backup power (BIOS >= 1.1 only) | |
412 | * 0xff: Unknown | |
413 | * 4) Battery status | |
414 | * 0x00: High | |
415 | * 0x01: Low | |
416 | * 0x02: Critical | |
417 | * 0x03: Charging | |
418 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
419 | * 0xff: Unknown | |
420 | * 5) Battery flag | |
421 | * bit 0: High | |
422 | * bit 1: Low | |
423 | * bit 2: Critical | |
424 | * bit 3: Charging | |
425 | * bit 7: No system battery | |
426 | * 0xff: Unknown | |
427 | * 6) Remaining battery life (percentage of charge): | |
428 | * 0-100: valid | |
429 | * -1: Unknown | |
430 | * 7) Remaining battery life (time units): | |
431 | * Number of remaining minutes or seconds | |
432 | * -1: Unknown | |
433 | * 8) min = minutes; sec = seconds | |
434 | */ | |
435 | static int proc_apm_show(struct seq_file *m, void *v) | |
436 | { | |
437 | struct apm_power_info info; | |
438 | char *units; | |
439 | ||
440 | info.ac_line_status = 0xff; | |
441 | info.battery_status = 0xff; | |
442 | info.battery_flag = 0xff; | |
443 | info.battery_life = -1; | |
444 | info.time = -1; | |
445 | info.units = -1; | |
446 | ||
447 | if (apm_get_power_status) | |
448 | apm_get_power_status(&info); | |
449 | ||
450 | switch (info.units) { | |
451 | default: units = "?"; break; | |
452 | case 0: units = "min"; break; | |
453 | case 1: units = "sec"; break; | |
454 | } | |
455 | ||
456 | seq_printf(m, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", | |
457 | driver_version, APM_32_BIT_SUPPORT, | |
458 | info.ac_line_status, info.battery_status, | |
459 | info.battery_flag, info.battery_life, | |
460 | info.time, units); | |
461 | ||
462 | return 0; | |
463 | } | |
464 | ||
465 | static int proc_apm_open(struct inode *inode, struct file *file) | |
466 | { | |
467 | return single_open(file, proc_apm_show, NULL); | |
468 | } | |
469 | ||
470 | static const struct file_operations apm_proc_fops = { | |
471 | .owner = THIS_MODULE, | |
472 | .open = proc_apm_open, | |
473 | .read = seq_read, | |
474 | .llseek = seq_lseek, | |
475 | .release = single_release, | |
476 | }; | |
477 | #endif | |
478 | ||
479 | static int kapmd(void *arg) | |
480 | { | |
481 | do { | |
482 | apm_event_t event; | |
483 | ||
484 | wait_event_interruptible(kapmd_wait, | |
485 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
486 | ||
487 | if (kthread_should_stop()) | |
488 | break; | |
489 | ||
490 | spin_lock_irq(&kapmd_queue_lock); | |
491 | event = 0; | |
492 | if (!queue_empty(&kapmd_queue)) | |
493 | event = queue_get_event(&kapmd_queue); | |
494 | spin_unlock_irq(&kapmd_queue_lock); | |
495 | ||
496 | switch (event) { | |
497 | case 0: | |
498 | break; | |
499 | ||
500 | case APM_LOW_BATTERY: | |
501 | case APM_POWER_STATUS_CHANGE: | |
502 | queue_event(event); | |
503 | break; | |
504 | ||
505 | case APM_USER_SUSPEND: | |
506 | case APM_SYS_SUSPEND: | |
507 | pm_suspend(PM_SUSPEND_MEM); | |
508 | break; | |
509 | ||
510 | case APM_CRITICAL_SUSPEND: | |
511 | atomic_inc(&userspace_notification_inhibit); | |
512 | pm_suspend(PM_SUSPEND_MEM); | |
513 | atomic_dec(&userspace_notification_inhibit); | |
514 | break; | |
515 | } | |
516 | } while (1); | |
517 | ||
518 | return 0; | |
519 | } | |
520 | ||
521 | static int apm_suspend_notifier(struct notifier_block *nb, | |
522 | unsigned long event, | |
523 | void *dummy) | |
524 | { | |
525 | struct apm_user *as; | |
526 | int err; | |
527 | unsigned long apm_event; | |
528 | ||
529 | /* short-cut emergency suspends */ | |
530 | if (atomic_read(&userspace_notification_inhibit)) | |
531 | return NOTIFY_DONE; | |
532 | ||
533 | switch (event) { | |
534 | case PM_SUSPEND_PREPARE: | |
535 | case PM_HIBERNATION_PREPARE: | |
536 | apm_event = (event == PM_SUSPEND_PREPARE) ? | |
537 | APM_USER_SUSPEND : APM_USER_HIBERNATION; | |
538 | /* | |
539 | * Queue an event to all "writer" users that we want | |
540 | * to suspend and need their ack. | |
541 | */ | |
542 | mutex_lock(&state_lock); | |
543 | down_read(&user_list_lock); | |
544 | ||
545 | list_for_each_entry(as, &apm_user_list, list) { | |
546 | if (as->suspend_state != SUSPEND_WAIT && as->reader && | |
547 | as->writer && as->suser) { | |
548 | as->suspend_state = SUSPEND_PENDING; | |
549 | atomic_inc(&suspend_acks_pending); | |
550 | queue_add_event(&as->queue, apm_event); | |
551 | } | |
552 | } | |
553 | ||
554 | up_read(&user_list_lock); | |
555 | mutex_unlock(&state_lock); | |
556 | wake_up_interruptible(&apm_waitqueue); | |
557 | ||
558 | /* | |
559 | * Wait for the the suspend_acks_pending variable to drop to | |
560 | * zero, meaning everybody acked the suspend event (or the | |
561 | * process was killed.) | |
562 | * | |
563 | * If the app won't answer within a short while we assume it | |
564 | * locked up and ignore it. | |
565 | */ | |
566 | err = wait_event_interruptible_timeout( | |
567 | apm_suspend_waitqueue, | |
568 | atomic_read(&suspend_acks_pending) == 0, | |
569 | 5*HZ); | |
570 | ||
571 | /* timed out */ | |
572 | if (err == 0) { | |
573 | /* | |
574 | * Move anybody who timed out to "ack timeout" state. | |
575 | * | |
576 | * We could time out and the userspace does the ACK | |
577 | * right after we time out but before we enter the | |
578 | * locked section here, but that's fine. | |
579 | */ | |
580 | mutex_lock(&state_lock); | |
581 | down_read(&user_list_lock); | |
582 | list_for_each_entry(as, &apm_user_list, list) { | |
583 | if (as->suspend_state == SUSPEND_PENDING || | |
584 | as->suspend_state == SUSPEND_READ) { | |
585 | as->suspend_state = SUSPEND_ACKTO; | |
586 | atomic_dec(&suspend_acks_pending); | |
587 | } | |
588 | } | |
589 | up_read(&user_list_lock); | |
590 | mutex_unlock(&state_lock); | |
591 | } | |
592 | ||
593 | /* let suspend proceed */ | |
594 | if (err >= 0) | |
595 | return NOTIFY_OK; | |
596 | ||
597 | /* interrupted by signal */ | |
598 | return notifier_from_errno(err); | |
599 | ||
600 | case PM_POST_SUSPEND: | |
601 | case PM_POST_HIBERNATION: | |
602 | apm_event = (event == PM_POST_SUSPEND) ? | |
603 | APM_NORMAL_RESUME : APM_HIBERNATION_RESUME; | |
604 | /* | |
605 | * Anyone on the APM queues will think we're still suspended. | |
606 | * Send a message so everyone knows we're now awake again. | |
607 | */ | |
608 | queue_event(apm_event); | |
609 | ||
610 | /* | |
611 | * Finally, wake up anyone who is sleeping on the suspend. | |
612 | */ | |
613 | mutex_lock(&state_lock); | |
614 | down_read(&user_list_lock); | |
615 | list_for_each_entry(as, &apm_user_list, list) { | |
616 | if (as->suspend_state == SUSPEND_ACKED) { | |
617 | /* | |
618 | * TODO: maybe grab error code, needs core | |
619 | * changes to push the error to the notifier | |
620 | * chain (could use the second parameter if | |
621 | * implemented) | |
622 | */ | |
623 | as->suspend_result = 0; | |
624 | as->suspend_state = SUSPEND_DONE; | |
625 | } | |
626 | } | |
627 | up_read(&user_list_lock); | |
628 | mutex_unlock(&state_lock); | |
629 | ||
630 | wake_up(&apm_suspend_waitqueue); | |
631 | return NOTIFY_OK; | |
632 | ||
633 | default: | |
634 | return NOTIFY_DONE; | |
635 | } | |
636 | } | |
637 | ||
638 | static struct notifier_block apm_notif_block = { | |
639 | .notifier_call = apm_suspend_notifier, | |
640 | }; | |
641 | ||
642 | static int __init apm_init(void) | |
643 | { | |
644 | int ret; | |
645 | ||
646 | if (apm_disabled) { | |
647 | printk(KERN_NOTICE "apm: disabled on user request.\n"); | |
648 | return -ENODEV; | |
649 | } | |
650 | ||
651 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); | |
652 | if (IS_ERR(kapmd_tsk)) { | |
653 | ret = PTR_ERR(kapmd_tsk); | |
654 | kapmd_tsk = NULL; | |
655 | goto out; | |
656 | } | |
657 | wake_up_process(kapmd_tsk); | |
658 | ||
659 | #ifdef CONFIG_PROC_FS | |
660 | proc_create("apm", 0, NULL, &apm_proc_fops); | |
661 | #endif | |
662 | ||
663 | ret = misc_register(&apm_device); | |
664 | if (ret) | |
665 | goto out_stop; | |
666 | ||
667 | ret = register_pm_notifier(&apm_notif_block); | |
668 | if (ret) | |
669 | goto out_unregister; | |
670 | ||
671 | return 0; | |
672 | ||
673 | out_unregister: | |
674 | misc_deregister(&apm_device); | |
675 | out_stop: | |
676 | remove_proc_entry("apm", NULL); | |
677 | kthread_stop(kapmd_tsk); | |
678 | out: | |
679 | return ret; | |
680 | } | |
681 | ||
682 | static void __exit apm_exit(void) | |
683 | { | |
684 | unregister_pm_notifier(&apm_notif_block); | |
685 | misc_deregister(&apm_device); | |
686 | remove_proc_entry("apm", NULL); | |
687 | ||
688 | kthread_stop(kapmd_tsk); | |
689 | } | |
690 | ||
691 | module_init(apm_init); | |
692 | module_exit(apm_exit); | |
693 | ||
694 | MODULE_AUTHOR("Stephen Rothwell"); | |
695 | MODULE_DESCRIPTION("Advanced Power Management"); | |
696 | MODULE_LICENSE("GPL"); | |
697 | ||
698 | #ifndef MODULE | |
699 | static int __init apm_setup(char *str) | |
700 | { | |
701 | while ((str != NULL) && (*str != '\0')) { | |
702 | if (strncmp(str, "off", 3) == 0) | |
703 | apm_disabled = 1; | |
704 | if (strncmp(str, "on", 2) == 0) | |
705 | apm_disabled = 0; | |
706 | str = strchr(str, ','); | |
707 | if (str != NULL) | |
708 | str += strspn(str, ", \t"); | |
709 | } | |
710 | return 1; | |
711 | } | |
712 | ||
713 | __setup("apm=", apm_setup); | |
714 | #endif | |
715 | ||
716 | /** | |
717 | * apm_queue_event - queue an APM event for kapmd | |
718 | * @event: APM event | |
719 | * | |
720 | * Queue an APM event for kapmd to process and ultimately take the | |
721 | * appropriate action. Only a subset of events are handled: | |
722 | * %APM_LOW_BATTERY | |
723 | * %APM_POWER_STATUS_CHANGE | |
724 | * %APM_USER_SUSPEND | |
725 | * %APM_SYS_SUSPEND | |
726 | * %APM_CRITICAL_SUSPEND | |
727 | */ | |
728 | void apm_queue_event(apm_event_t event) | |
729 | { | |
730 | unsigned long flags; | |
731 | ||
732 | spin_lock_irqsave(&kapmd_queue_lock, flags); | |
733 | queue_add_event(&kapmd_queue, event); | |
734 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); | |
735 | ||
736 | wake_up_interruptible(&kapmd_wait); | |
737 | } | |
738 | EXPORT_SYMBOL(apm_queue_event); |