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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 | * | |
631dd1a8 JM |
10 | * This document is available from Microsoft at: |
11 | * http://www.microsoft.com/whdc/archive/amp_12.mspx | |
7726942f RB |
12 | */ |
13 | #include <linux/module.h> | |
14 | #include <linux/poll.h> | |
15 | #include <linux/slab.h> | |
613655fa | 16 | #include <linux/mutex.h> |
7726942f | 17 | #include <linux/proc_fs.h> |
647634df | 18 | #include <linux/seq_file.h> |
7726942f RB |
19 | #include <linux/miscdevice.h> |
20 | #include <linux/apm_bios.h> | |
21 | #include <linux/capability.h> | |
22 | #include <linux/sched.h> | |
95d9ffbe | 23 | #include <linux/suspend.h> |
7726942f | 24 | #include <linux/apm-emulation.h> |
83144186 | 25 | #include <linux/freezer.h> |
7726942f RB |
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 | #include <asm/system.h> | |
35 | ||
36 | /* | |
37 | * The apm_bios device is one of the misc char devices. | |
38 | * This is its minor number. | |
39 | */ | |
40 | #define APM_MINOR_DEV 134 | |
41 | ||
42 | /* | |
43 | * See Documentation/Config.help for the configuration options. | |
44 | * | |
45 | * Various options can be changed at boot time as follows: | |
46 | * (We allow underscores for compatibility with the modules code) | |
47 | * apm=on/off enable/disable APM | |
48 | */ | |
49 | ||
50 | /* | |
51 | * Maximum number of events stored | |
52 | */ | |
53 | #define APM_MAX_EVENTS 16 | |
54 | ||
55 | struct apm_queue { | |
56 | unsigned int event_head; | |
57 | unsigned int event_tail; | |
58 | apm_event_t events[APM_MAX_EVENTS]; | |
59 | }; | |
60 | ||
d20a4dca JB |
61 | /* |
62 | * thread states (for threads using a writable /dev/apm_bios fd): | |
63 | * | |
64 | * SUSPEND_NONE: nothing happening | |
65 | * SUSPEND_PENDING: suspend event queued for thread and pending to be read | |
66 | * SUSPEND_READ: suspend event read, pending acknowledgement | |
67 | * SUSPEND_ACKED: acknowledgement received from thread (via ioctl), | |
68 | * waiting for resume | |
69 | * SUSPEND_ACKTO: acknowledgement timeout | |
70 | * SUSPEND_DONE: thread had acked suspend and is now notified of | |
71 | * resume | |
72 | * | |
73 | * SUSPEND_WAIT: this thread invoked suspend and is waiting for resume | |
74 | * | |
75 | * A thread migrates in one of three paths: | |
76 | * NONE -1-> PENDING -2-> READ -3-> ACKED -4-> DONE -5-> NONE | |
77 | * -6-> ACKTO -7-> NONE | |
78 | * NONE -8-> WAIT -9-> NONE | |
79 | * | |
80 | * While in PENDING or READ, the thread is accounted for in the | |
81 | * suspend_acks_pending counter. | |
82 | * | |
83 | * The transitions are invoked as follows: | |
84 | * 1: suspend event is signalled from the core PM code | |
85 | * 2: the suspend event is read from the fd by the userspace thread | |
86 | * 3: userspace thread issues the APM_IOC_SUSPEND ioctl (as ack) | |
87 | * 4: core PM code signals that we have resumed | |
88 | * 5: APM_IOC_SUSPEND ioctl returns | |
89 | * | |
90 | * 6: the notifier invoked from the core PM code timed out waiting | |
91 | * for all relevant threds to enter ACKED state and puts those | |
92 | * that haven't into ACKTO | |
93 | * 7: those threads issue APM_IOC_SUSPEND ioctl too late, | |
94 | * get an error | |
95 | * | |
96 | * 8: userspace thread issues the APM_IOC_SUSPEND ioctl (to suspend), | |
97 | * ioctl code invokes pm_suspend() | |
98 | * 9: pm_suspend() returns indicating resume | |
99 | */ | |
100 | enum apm_suspend_state { | |
101 | SUSPEND_NONE, | |
102 | SUSPEND_PENDING, | |
103 | SUSPEND_READ, | |
104 | SUSPEND_ACKED, | |
105 | SUSPEND_ACKTO, | |
106 | SUSPEND_WAIT, | |
107 | SUSPEND_DONE, | |
108 | }; | |
109 | ||
7726942f RB |
110 | /* |
111 | * The per-file APM data | |
112 | */ | |
113 | struct apm_user { | |
114 | struct list_head list; | |
115 | ||
116 | unsigned int suser: 1; | |
117 | unsigned int writer: 1; | |
118 | unsigned int reader: 1; | |
119 | ||
120 | int suspend_result; | |
d20a4dca | 121 | enum apm_suspend_state suspend_state; |
7726942f RB |
122 | |
123 | struct apm_queue queue; | |
124 | }; | |
125 | ||
126 | /* | |
127 | * Local variables | |
128 | */ | |
613655fa | 129 | static DEFINE_MUTEX(apm_mutex); |
d20a4dca JB |
130 | static atomic_t suspend_acks_pending = ATOMIC_INIT(0); |
131 | static atomic_t userspace_notification_inhibit = ATOMIC_INIT(0); | |
7726942f RB |
132 | static int apm_disabled; |
133 | static struct task_struct *kapmd_tsk; | |
134 | ||
135 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); | |
136 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); | |
137 | ||
138 | /* | |
139 | * This is a list of everyone who has opened /dev/apm_bios | |
140 | */ | |
141 | static DECLARE_RWSEM(user_list_lock); | |
142 | static LIST_HEAD(apm_user_list); | |
143 | ||
144 | /* | |
145 | * kapmd info. kapmd provides us a process context to handle | |
146 | * "APM" events within - specifically necessary if we're going | |
147 | * to be suspending the system. | |
148 | */ | |
149 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); | |
150 | static DEFINE_SPINLOCK(kapmd_queue_lock); | |
151 | static struct apm_queue kapmd_queue; | |
152 | ||
153 | static DEFINE_MUTEX(state_lock); | |
154 | ||
155 | static const char driver_version[] = "1.13"; /* no spaces */ | |
156 | ||
157 | ||
158 | ||
159 | /* | |
160 | * Compatibility cruft until the IPAQ people move over to the new | |
161 | * interface. | |
162 | */ | |
163 | static void __apm_get_power_status(struct apm_power_info *info) | |
164 | { | |
165 | } | |
166 | ||
167 | /* | |
168 | * This allows machines to provide their own "apm get power status" function. | |
169 | */ | |
170 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; | |
171 | EXPORT_SYMBOL(apm_get_power_status); | |
172 | ||
173 | ||
174 | /* | |
175 | * APM event queue management. | |
176 | */ | |
177 | static inline int queue_empty(struct apm_queue *q) | |
178 | { | |
179 | return q->event_head == q->event_tail; | |
180 | } | |
181 | ||
182 | static inline apm_event_t queue_get_event(struct apm_queue *q) | |
183 | { | |
184 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
185 | return q->events[q->event_tail]; | |
186 | } | |
187 | ||
188 | static void queue_add_event(struct apm_queue *q, apm_event_t event) | |
189 | { | |
190 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; | |
191 | if (q->event_head == q->event_tail) { | |
192 | static int notified; | |
193 | ||
194 | if (notified++ == 0) | |
195 | printk(KERN_ERR "apm: an event queue overflowed\n"); | |
196 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
197 | } | |
198 | q->events[q->event_head] = event; | |
199 | } | |
200 | ||
201 | static void queue_event(apm_event_t event) | |
202 | { | |
203 | struct apm_user *as; | |
204 | ||
205 | down_read(&user_list_lock); | |
206 | list_for_each_entry(as, &apm_user_list, list) { | |
207 | if (as->reader) | |
208 | queue_add_event(&as->queue, event); | |
209 | } | |
210 | up_read(&user_list_lock); | |
211 | wake_up_interruptible(&apm_waitqueue); | |
212 | } | |
213 | ||
7726942f RB |
214 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) |
215 | { | |
216 | struct apm_user *as = fp->private_data; | |
217 | apm_event_t event; | |
218 | int i = count, ret = 0; | |
219 | ||
220 | if (count < sizeof(apm_event_t)) | |
221 | return -EINVAL; | |
222 | ||
223 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) | |
224 | return -EAGAIN; | |
225 | ||
226 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); | |
227 | ||
228 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { | |
229 | event = queue_get_event(&as->queue); | |
230 | ||
231 | ret = -EFAULT; | |
232 | if (copy_to_user(buf, &event, sizeof(event))) | |
233 | break; | |
234 | ||
235 | mutex_lock(&state_lock); | |
236 | if (as->suspend_state == SUSPEND_PENDING && | |
237 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) | |
238 | as->suspend_state = SUSPEND_READ; | |
239 | mutex_unlock(&state_lock); | |
240 | ||
241 | buf += sizeof(event); | |
242 | i -= sizeof(event); | |
243 | } | |
244 | ||
245 | if (i < count) | |
246 | ret = count - i; | |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | static unsigned int apm_poll(struct file *fp, poll_table * wait) | |
252 | { | |
253 | struct apm_user *as = fp->private_data; | |
254 | ||
255 | poll_wait(fp, &apm_waitqueue, wait); | |
256 | return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM; | |
257 | } | |
258 | ||
259 | /* | |
260 | * apm_ioctl - handle APM ioctl | |
261 | * | |
262 | * APM_IOC_SUSPEND | |
263 | * This IOCTL is overloaded, and performs two functions. It is used to: | |
264 | * - initiate a suspend | |
265 | * - acknowledge a suspend read from /dev/apm_bios. | |
266 | * Only when everyone who has opened /dev/apm_bios with write permission | |
267 | * has acknowledge does the actual suspend happen. | |
268 | */ | |
55929332 AB |
269 | static long |
270 | apm_ioctl(struct file *filp, u_int cmd, u_long arg) | |
7726942f RB |
271 | { |
272 | struct apm_user *as = filp->private_data; | |
7726942f RB |
273 | int err = -EINVAL; |
274 | ||
275 | if (!as->suser || !as->writer) | |
276 | return -EPERM; | |
277 | ||
613655fa | 278 | mutex_lock(&apm_mutex); |
7726942f RB |
279 | switch (cmd) { |
280 | case APM_IOC_SUSPEND: | |
281 | mutex_lock(&state_lock); | |
282 | ||
283 | as->suspend_result = -EINTR; | |
284 | ||
d20a4dca JB |
285 | switch (as->suspend_state) { |
286 | case SUSPEND_READ: | |
7726942f RB |
287 | /* |
288 | * If we read a suspend command from /dev/apm_bios, | |
289 | * then the corresponding APM_IOC_SUSPEND ioctl is | |
290 | * interpreted as an acknowledge. | |
291 | */ | |
292 | as->suspend_state = SUSPEND_ACKED; | |
d20a4dca | 293 | atomic_dec(&suspend_acks_pending); |
7726942f RB |
294 | mutex_unlock(&state_lock); |
295 | ||
296 | /* | |
d20a4dca JB |
297 | * suspend_acks_pending changed, the notifier needs to |
298 | * be woken up for this | |
7726942f | 299 | */ |
d20a4dca | 300 | wake_up(&apm_suspend_waitqueue); |
7726942f RB |
301 | |
302 | /* | |
303 | * Wait for the suspend/resume to complete. If there | |
304 | * are pending acknowledges, we wait here for them. | |
7726942f | 305 | */ |
cb43c54c | 306 | freezer_do_not_count(); |
7726942f RB |
307 | |
308 | wait_event(apm_suspend_waitqueue, | |
309 | as->suspend_state == SUSPEND_DONE); | |
cb43c54c RW |
310 | |
311 | /* | |
312 | * Since we are waiting until the suspend is done, the | |
313 | * try_to_freeze() in freezer_count() will not trigger | |
314 | */ | |
315 | freezer_count(); | |
d20a4dca JB |
316 | break; |
317 | case SUSPEND_ACKTO: | |
318 | as->suspend_result = -ETIMEDOUT; | |
319 | mutex_unlock(&state_lock); | |
320 | break; | |
321 | default: | |
7726942f RB |
322 | as->suspend_state = SUSPEND_WAIT; |
323 | mutex_unlock(&state_lock); | |
324 | ||
325 | /* | |
326 | * Otherwise it is a request to suspend the system. | |
d20a4dca JB |
327 | * Just invoke pm_suspend(), we'll handle it from |
328 | * there via the notifier. | |
7726942f | 329 | */ |
d20a4dca | 330 | as->suspend_result = pm_suspend(PM_SUSPEND_MEM); |
7726942f RB |
331 | } |
332 | ||
7726942f RB |
333 | mutex_lock(&state_lock); |
334 | err = as->suspend_result; | |
335 | as->suspend_state = SUSPEND_NONE; | |
336 | mutex_unlock(&state_lock); | |
337 | break; | |
338 | } | |
613655fa | 339 | mutex_unlock(&apm_mutex); |
7726942f RB |
340 | |
341 | return err; | |
342 | } | |
343 | ||
344 | static int apm_release(struct inode * inode, struct file * filp) | |
345 | { | |
346 | struct apm_user *as = filp->private_data; | |
7726942f RB |
347 | |
348 | filp->private_data = NULL; | |
349 | ||
350 | down_write(&user_list_lock); | |
351 | list_del(&as->list); | |
352 | up_write(&user_list_lock); | |
353 | ||
354 | /* | |
355 | * We are now unhooked from the chain. As far as new | |
d20a4dca | 356 | * events are concerned, we no longer exist. |
7726942f RB |
357 | */ |
358 | mutex_lock(&state_lock); | |
d20a4dca JB |
359 | if (as->suspend_state == SUSPEND_PENDING || |
360 | as->suspend_state == SUSPEND_READ) | |
361 | atomic_dec(&suspend_acks_pending); | |
7726942f | 362 | mutex_unlock(&state_lock); |
d20a4dca JB |
363 | |
364 | wake_up(&apm_suspend_waitqueue); | |
7726942f RB |
365 | |
366 | kfree(as); | |
367 | return 0; | |
368 | } | |
369 | ||
370 | static int apm_open(struct inode * inode, struct file * filp) | |
371 | { | |
372 | struct apm_user *as; | |
373 | ||
613655fa | 374 | mutex_lock(&apm_mutex); |
7726942f RB |
375 | as = kzalloc(sizeof(*as), GFP_KERNEL); |
376 | if (as) { | |
377 | /* | |
378 | * XXX - this is a tiny bit broken, when we consider BSD | |
379 | * process accounting. If the device is opened by root, we | |
380 | * instantly flag that we used superuser privs. Who knows, | |
381 | * we might close the device immediately without doing a | |
382 | * privileged operation -- cevans | |
383 | */ | |
384 | as->suser = capable(CAP_SYS_ADMIN); | |
385 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
386 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
387 | ||
388 | down_write(&user_list_lock); | |
389 | list_add(&as->list, &apm_user_list); | |
390 | up_write(&user_list_lock); | |
391 | ||
392 | filp->private_data = as; | |
393 | } | |
613655fa | 394 | mutex_unlock(&apm_mutex); |
7726942f RB |
395 | |
396 | return as ? 0 : -ENOMEM; | |
397 | } | |
398 | ||
828c0950 | 399 | static const struct file_operations apm_bios_fops = { |
7726942f RB |
400 | .owner = THIS_MODULE, |
401 | .read = apm_read, | |
402 | .poll = apm_poll, | |
55929332 | 403 | .unlocked_ioctl = apm_ioctl, |
7726942f RB |
404 | .open = apm_open, |
405 | .release = apm_release, | |
6038f373 | 406 | .llseek = noop_llseek, |
7726942f RB |
407 | }; |
408 | ||
409 | static struct miscdevice apm_device = { | |
410 | .minor = APM_MINOR_DEV, | |
411 | .name = "apm_bios", | |
412 | .fops = &apm_bios_fops | |
413 | }; | |
414 | ||
415 | ||
416 | #ifdef CONFIG_PROC_FS | |
417 | /* | |
418 | * Arguments, with symbols from linux/apm_bios.h. | |
419 | * | |
420 | * 0) Linux driver version (this will change if format changes) | |
421 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
422 | * 2) APM flags from APM Installation Check (0x00): | |
423 | * bit 0: APM_16_BIT_SUPPORT | |
424 | * bit 1: APM_32_BIT_SUPPORT | |
425 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
426 | * bit 3: APM_BIOS_DISABLED | |
427 | * bit 4: APM_BIOS_DISENGAGED | |
428 | * 3) AC line status | |
429 | * 0x00: Off-line | |
430 | * 0x01: On-line | |
431 | * 0x02: On backup power (BIOS >= 1.1 only) | |
432 | * 0xff: Unknown | |
433 | * 4) Battery status | |
434 | * 0x00: High | |
435 | * 0x01: Low | |
436 | * 0x02: Critical | |
437 | * 0x03: Charging | |
438 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
439 | * 0xff: Unknown | |
440 | * 5) Battery flag | |
441 | * bit 0: High | |
442 | * bit 1: Low | |
443 | * bit 2: Critical | |
444 | * bit 3: Charging | |
445 | * bit 7: No system battery | |
446 | * 0xff: Unknown | |
447 | * 6) Remaining battery life (percentage of charge): | |
448 | * 0-100: valid | |
449 | * -1: Unknown | |
450 | * 7) Remaining battery life (time units): | |
451 | * Number of remaining minutes or seconds | |
452 | * -1: Unknown | |
453 | * 8) min = minutes; sec = seconds | |
454 | */ | |
647634df | 455 | static int proc_apm_show(struct seq_file *m, void *v) |
7726942f RB |
456 | { |
457 | struct apm_power_info info; | |
458 | char *units; | |
7726942f RB |
459 | |
460 | info.ac_line_status = 0xff; | |
461 | info.battery_status = 0xff; | |
462 | info.battery_flag = 0xff; | |
463 | info.battery_life = -1; | |
464 | info.time = -1; | |
465 | info.units = -1; | |
466 | ||
467 | if (apm_get_power_status) | |
468 | apm_get_power_status(&info); | |
469 | ||
470 | switch (info.units) { | |
471 | default: units = "?"; break; | |
472 | case 0: units = "min"; break; | |
473 | case 1: units = "sec"; break; | |
474 | } | |
475 | ||
647634df | 476 | seq_printf(m, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", |
7726942f RB |
477 | driver_version, APM_32_BIT_SUPPORT, |
478 | info.ac_line_status, info.battery_status, | |
479 | info.battery_flag, info.battery_life, | |
480 | info.time, units); | |
481 | ||
647634df | 482 | return 0; |
7726942f | 483 | } |
647634df AD |
484 | |
485 | static int proc_apm_open(struct inode *inode, struct file *file) | |
486 | { | |
487 | return single_open(file, proc_apm_show, NULL); | |
488 | } | |
489 | ||
490 | static const struct file_operations apm_proc_fops = { | |
491 | .owner = THIS_MODULE, | |
492 | .open = proc_apm_open, | |
493 | .read = seq_read, | |
494 | .llseek = seq_lseek, | |
495 | .release = single_release, | |
496 | }; | |
7726942f RB |
497 | #endif |
498 | ||
499 | static int kapmd(void *arg) | |
500 | { | |
501 | do { | |
502 | apm_event_t event; | |
7726942f RB |
503 | |
504 | wait_event_interruptible(kapmd_wait, | |
505 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
506 | ||
507 | if (kthread_should_stop()) | |
508 | break; | |
509 | ||
510 | spin_lock_irq(&kapmd_queue_lock); | |
511 | event = 0; | |
512 | if (!queue_empty(&kapmd_queue)) | |
513 | event = queue_get_event(&kapmd_queue); | |
514 | spin_unlock_irq(&kapmd_queue_lock); | |
515 | ||
516 | switch (event) { | |
517 | case 0: | |
518 | break; | |
519 | ||
520 | case APM_LOW_BATTERY: | |
521 | case APM_POWER_STATUS_CHANGE: | |
522 | queue_event(event); | |
523 | break; | |
524 | ||
525 | case APM_USER_SUSPEND: | |
526 | case APM_SYS_SUSPEND: | |
d20a4dca | 527 | pm_suspend(PM_SUSPEND_MEM); |
7726942f RB |
528 | break; |
529 | ||
530 | case APM_CRITICAL_SUSPEND: | |
d20a4dca JB |
531 | atomic_inc(&userspace_notification_inhibit); |
532 | pm_suspend(PM_SUSPEND_MEM); | |
533 | atomic_dec(&userspace_notification_inhibit); | |
7726942f RB |
534 | break; |
535 | } | |
536 | } while (1); | |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
d20a4dca JB |
541 | static int apm_suspend_notifier(struct notifier_block *nb, |
542 | unsigned long event, | |
543 | void *dummy) | |
544 | { | |
545 | struct apm_user *as; | |
546 | int err; | |
547 | ||
548 | /* short-cut emergency suspends */ | |
549 | if (atomic_read(&userspace_notification_inhibit)) | |
550 | return NOTIFY_DONE; | |
551 | ||
552 | switch (event) { | |
553 | case PM_SUSPEND_PREPARE: | |
554 | /* | |
555 | * Queue an event to all "writer" users that we want | |
556 | * to suspend and need their ack. | |
557 | */ | |
558 | mutex_lock(&state_lock); | |
559 | down_read(&user_list_lock); | |
560 | ||
561 | list_for_each_entry(as, &apm_user_list, list) { | |
562 | if (as->suspend_state != SUSPEND_WAIT && as->reader && | |
563 | as->writer && as->suser) { | |
564 | as->suspend_state = SUSPEND_PENDING; | |
565 | atomic_inc(&suspend_acks_pending); | |
566 | queue_add_event(&as->queue, APM_USER_SUSPEND); | |
567 | } | |
568 | } | |
569 | ||
570 | up_read(&user_list_lock); | |
571 | mutex_unlock(&state_lock); | |
572 | wake_up_interruptible(&apm_waitqueue); | |
573 | ||
574 | /* | |
575 | * Wait for the the suspend_acks_pending variable to drop to | |
576 | * zero, meaning everybody acked the suspend event (or the | |
577 | * process was killed.) | |
578 | * | |
579 | * If the app won't answer within a short while we assume it | |
580 | * locked up and ignore it. | |
581 | */ | |
582 | err = wait_event_interruptible_timeout( | |
583 | apm_suspend_waitqueue, | |
584 | atomic_read(&suspend_acks_pending) == 0, | |
585 | 5*HZ); | |
586 | ||
587 | /* timed out */ | |
588 | if (err == 0) { | |
589 | /* | |
590 | * Move anybody who timed out to "ack timeout" state. | |
591 | * | |
592 | * We could time out and the userspace does the ACK | |
593 | * right after we time out but before we enter the | |
594 | * locked section here, but that's fine. | |
595 | */ | |
596 | mutex_lock(&state_lock); | |
597 | down_read(&user_list_lock); | |
598 | list_for_each_entry(as, &apm_user_list, list) { | |
599 | if (as->suspend_state == SUSPEND_PENDING || | |
600 | as->suspend_state == SUSPEND_READ) { | |
601 | as->suspend_state = SUSPEND_ACKTO; | |
602 | atomic_dec(&suspend_acks_pending); | |
603 | } | |
604 | } | |
605 | up_read(&user_list_lock); | |
606 | mutex_unlock(&state_lock); | |
607 | } | |
608 | ||
609 | /* let suspend proceed */ | |
610 | if (err >= 0) | |
611 | return NOTIFY_OK; | |
612 | ||
613 | /* interrupted by signal */ | |
614 | return NOTIFY_BAD; | |
615 | ||
616 | case PM_POST_SUSPEND: | |
617 | /* | |
618 | * Anyone on the APM queues will think we're still suspended. | |
619 | * Send a message so everyone knows we're now awake again. | |
620 | */ | |
621 | queue_event(APM_NORMAL_RESUME); | |
622 | ||
623 | /* | |
624 | * Finally, wake up anyone who is sleeping on the suspend. | |
625 | */ | |
626 | mutex_lock(&state_lock); | |
627 | down_read(&user_list_lock); | |
628 | list_for_each_entry(as, &apm_user_list, list) { | |
629 | if (as->suspend_state == SUSPEND_ACKED) { | |
630 | /* | |
631 | * TODO: maybe grab error code, needs core | |
632 | * changes to push the error to the notifier | |
633 | * chain (could use the second parameter if | |
634 | * implemented) | |
635 | */ | |
636 | as->suspend_result = 0; | |
637 | as->suspend_state = SUSPEND_DONE; | |
638 | } | |
639 | } | |
640 | up_read(&user_list_lock); | |
641 | mutex_unlock(&state_lock); | |
642 | ||
643 | wake_up(&apm_suspend_waitqueue); | |
644 | return NOTIFY_OK; | |
645 | ||
646 | default: | |
647 | return NOTIFY_DONE; | |
648 | } | |
649 | } | |
650 | ||
651 | static struct notifier_block apm_notif_block = { | |
652 | .notifier_call = apm_suspend_notifier, | |
653 | }; | |
654 | ||
7726942f RB |
655 | static int __init apm_init(void) |
656 | { | |
657 | int ret; | |
658 | ||
659 | if (apm_disabled) { | |
660 | printk(KERN_NOTICE "apm: disabled on user request.\n"); | |
661 | return -ENODEV; | |
662 | } | |
663 | ||
664 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); | |
665 | if (IS_ERR(kapmd_tsk)) { | |
666 | ret = PTR_ERR(kapmd_tsk); | |
667 | kapmd_tsk = NULL; | |
d20a4dca | 668 | goto out; |
7726942f | 669 | } |
7726942f RB |
670 | wake_up_process(kapmd_tsk); |
671 | ||
672 | #ifdef CONFIG_PROC_FS | |
647634df | 673 | proc_create("apm", 0, NULL, &apm_proc_fops); |
7726942f RB |
674 | #endif |
675 | ||
676 | ret = misc_register(&apm_device); | |
d20a4dca JB |
677 | if (ret) |
678 | goto out_stop; | |
7726942f | 679 | |
d20a4dca JB |
680 | ret = register_pm_notifier(&apm_notif_block); |
681 | if (ret) | |
682 | goto out_unregister; | |
683 | ||
684 | return 0; | |
685 | ||
686 | out_unregister: | |
687 | misc_deregister(&apm_device); | |
688 | out_stop: | |
689 | remove_proc_entry("apm", NULL); | |
690 | kthread_stop(kapmd_tsk); | |
691 | out: | |
7726942f RB |
692 | return ret; |
693 | } | |
694 | ||
695 | static void __exit apm_exit(void) | |
696 | { | |
d20a4dca | 697 | unregister_pm_notifier(&apm_notif_block); |
7726942f RB |
698 | misc_deregister(&apm_device); |
699 | remove_proc_entry("apm", NULL); | |
700 | ||
701 | kthread_stop(kapmd_tsk); | |
702 | } | |
703 | ||
704 | module_init(apm_init); | |
705 | module_exit(apm_exit); | |
706 | ||
707 | MODULE_AUTHOR("Stephen Rothwell"); | |
708 | MODULE_DESCRIPTION("Advanced Power Management"); | |
709 | MODULE_LICENSE("GPL"); | |
710 | ||
711 | #ifndef MODULE | |
712 | static int __init apm_setup(char *str) | |
713 | { | |
714 | while ((str != NULL) && (*str != '\0')) { | |
715 | if (strncmp(str, "off", 3) == 0) | |
716 | apm_disabled = 1; | |
717 | if (strncmp(str, "on", 2) == 0) | |
718 | apm_disabled = 0; | |
719 | str = strchr(str, ','); | |
720 | if (str != NULL) | |
721 | str += strspn(str, ", \t"); | |
722 | } | |
723 | return 1; | |
724 | } | |
725 | ||
726 | __setup("apm=", apm_setup); | |
727 | #endif | |
728 | ||
729 | /** | |
730 | * apm_queue_event - queue an APM event for kapmd | |
731 | * @event: APM event | |
732 | * | |
733 | * Queue an APM event for kapmd to process and ultimately take the | |
734 | * appropriate action. Only a subset of events are handled: | |
735 | * %APM_LOW_BATTERY | |
736 | * %APM_POWER_STATUS_CHANGE | |
737 | * %APM_USER_SUSPEND | |
738 | * %APM_SYS_SUSPEND | |
739 | * %APM_CRITICAL_SUSPEND | |
740 | */ | |
741 | void apm_queue_event(apm_event_t event) | |
742 | { | |
743 | unsigned long flags; | |
744 | ||
745 | spin_lock_irqsave(&kapmd_queue_lock, flags); | |
746 | queue_add_event(&kapmd_queue, event); | |
747 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); | |
748 | ||
749 | wake_up_interruptible(&kapmd_wait); | |
750 | } | |
751 | EXPORT_SYMBOL(apm_queue_event); |