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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 | ||
7726942f RB |
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 | /* | |
395cf969 | 42 | * One option can be changed at boot time as follows: |
7726942f RB |
43 | * apm=on/off enable/disable APM |
44 | */ | |
45 | ||
46 | /* | |
47 | * Maximum number of events stored | |
48 | */ | |
49 | #define APM_MAX_EVENTS 16 | |
50 | ||
51 | struct apm_queue { | |
52 | unsigned int event_head; | |
53 | unsigned int event_tail; | |
54 | apm_event_t events[APM_MAX_EVENTS]; | |
55 | }; | |
56 | ||
d20a4dca JB |
57 | /* |
58 | * thread states (for threads using a writable /dev/apm_bios fd): | |
59 | * | |
60 | * SUSPEND_NONE: nothing happening | |
61 | * SUSPEND_PENDING: suspend event queued for thread and pending to be read | |
62 | * SUSPEND_READ: suspend event read, pending acknowledgement | |
63 | * SUSPEND_ACKED: acknowledgement received from thread (via ioctl), | |
64 | * waiting for resume | |
65 | * SUSPEND_ACKTO: acknowledgement timeout | |
66 | * SUSPEND_DONE: thread had acked suspend and is now notified of | |
67 | * resume | |
68 | * | |
69 | * SUSPEND_WAIT: this thread invoked suspend and is waiting for resume | |
70 | * | |
71 | * A thread migrates in one of three paths: | |
72 | * NONE -1-> PENDING -2-> READ -3-> ACKED -4-> DONE -5-> NONE | |
73 | * -6-> ACKTO -7-> NONE | |
74 | * NONE -8-> WAIT -9-> NONE | |
75 | * | |
76 | * While in PENDING or READ, the thread is accounted for in the | |
77 | * suspend_acks_pending counter. | |
78 | * | |
79 | * The transitions are invoked as follows: | |
80 | * 1: suspend event is signalled from the core PM code | |
81 | * 2: the suspend event is read from the fd by the userspace thread | |
82 | * 3: userspace thread issues the APM_IOC_SUSPEND ioctl (as ack) | |
83 | * 4: core PM code signals that we have resumed | |
84 | * 5: APM_IOC_SUSPEND ioctl returns | |
85 | * | |
86 | * 6: the notifier invoked from the core PM code timed out waiting | |
87 | * for all relevant threds to enter ACKED state and puts those | |
88 | * that haven't into ACKTO | |
89 | * 7: those threads issue APM_IOC_SUSPEND ioctl too late, | |
90 | * get an error | |
91 | * | |
92 | * 8: userspace thread issues the APM_IOC_SUSPEND ioctl (to suspend), | |
93 | * ioctl code invokes pm_suspend() | |
94 | * 9: pm_suspend() returns indicating resume | |
95 | */ | |
96 | enum apm_suspend_state { | |
97 | SUSPEND_NONE, | |
98 | SUSPEND_PENDING, | |
99 | SUSPEND_READ, | |
100 | SUSPEND_ACKED, | |
101 | SUSPEND_ACKTO, | |
102 | SUSPEND_WAIT, | |
103 | SUSPEND_DONE, | |
104 | }; | |
105 | ||
7726942f RB |
106 | /* |
107 | * The per-file APM data | |
108 | */ | |
109 | struct apm_user { | |
110 | struct list_head list; | |
111 | ||
112 | unsigned int suser: 1; | |
113 | unsigned int writer: 1; | |
114 | unsigned int reader: 1; | |
115 | ||
116 | int suspend_result; | |
d20a4dca | 117 | enum apm_suspend_state suspend_state; |
7726942f RB |
118 | |
119 | struct apm_queue queue; | |
120 | }; | |
121 | ||
122 | /* | |
123 | * Local variables | |
124 | */ | |
d20a4dca JB |
125 | static atomic_t suspend_acks_pending = ATOMIC_INIT(0); |
126 | static atomic_t userspace_notification_inhibit = ATOMIC_INIT(0); | |
7726942f RB |
127 | static int apm_disabled; |
128 | static struct task_struct *kapmd_tsk; | |
129 | ||
130 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); | |
131 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); | |
132 | ||
133 | /* | |
134 | * This is a list of everyone who has opened /dev/apm_bios | |
135 | */ | |
136 | static DECLARE_RWSEM(user_list_lock); | |
137 | static LIST_HEAD(apm_user_list); | |
138 | ||
139 | /* | |
140 | * kapmd info. kapmd provides us a process context to handle | |
141 | * "APM" events within - specifically necessary if we're going | |
142 | * to be suspending the system. | |
143 | */ | |
144 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); | |
145 | static DEFINE_SPINLOCK(kapmd_queue_lock); | |
146 | static struct apm_queue kapmd_queue; | |
147 | ||
148 | static DEFINE_MUTEX(state_lock); | |
149 | ||
150 | static const char driver_version[] = "1.13"; /* no spaces */ | |
151 | ||
152 | ||
153 | ||
154 | /* | |
155 | * Compatibility cruft until the IPAQ people move over to the new | |
156 | * interface. | |
157 | */ | |
158 | static void __apm_get_power_status(struct apm_power_info *info) | |
159 | { | |
160 | } | |
161 | ||
162 | /* | |
163 | * This allows machines to provide their own "apm get power status" function. | |
164 | */ | |
165 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; | |
166 | EXPORT_SYMBOL(apm_get_power_status); | |
167 | ||
168 | ||
169 | /* | |
170 | * APM event queue management. | |
171 | */ | |
172 | static inline int queue_empty(struct apm_queue *q) | |
173 | { | |
174 | return q->event_head == q->event_tail; | |
175 | } | |
176 | ||
177 | static inline apm_event_t queue_get_event(struct apm_queue *q) | |
178 | { | |
179 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
180 | return q->events[q->event_tail]; | |
181 | } | |
182 | ||
183 | static void queue_add_event(struct apm_queue *q, apm_event_t event) | |
184 | { | |
185 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; | |
186 | if (q->event_head == q->event_tail) { | |
187 | static int notified; | |
188 | ||
189 | if (notified++ == 0) | |
190 | printk(KERN_ERR "apm: an event queue overflowed\n"); | |
191 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
192 | } | |
193 | q->events[q->event_head] = event; | |
194 | } | |
195 | ||
196 | static void queue_event(apm_event_t event) | |
197 | { | |
198 | struct apm_user *as; | |
199 | ||
200 | down_read(&user_list_lock); | |
201 | list_for_each_entry(as, &apm_user_list, list) { | |
202 | if (as->reader) | |
203 | queue_add_event(&as->queue, event); | |
204 | } | |
205 | up_read(&user_list_lock); | |
206 | wake_up_interruptible(&apm_waitqueue); | |
207 | } | |
208 | ||
7726942f RB |
209 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) |
210 | { | |
211 | struct apm_user *as = fp->private_data; | |
212 | apm_event_t event; | |
213 | int i = count, ret = 0; | |
214 | ||
215 | if (count < sizeof(apm_event_t)) | |
216 | return -EINVAL; | |
217 | ||
218 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) | |
219 | return -EAGAIN; | |
220 | ||
221 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); | |
222 | ||
223 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { | |
224 | event = queue_get_event(&as->queue); | |
225 | ||
226 | ret = -EFAULT; | |
227 | if (copy_to_user(buf, &event, sizeof(event))) | |
228 | break; | |
229 | ||
230 | mutex_lock(&state_lock); | |
231 | if (as->suspend_state == SUSPEND_PENDING && | |
232 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) | |
233 | as->suspend_state = SUSPEND_READ; | |
234 | mutex_unlock(&state_lock); | |
235 | ||
236 | buf += sizeof(event); | |
237 | i -= sizeof(event); | |
238 | } | |
239 | ||
240 | if (i < count) | |
241 | ret = count - i; | |
242 | ||
243 | return ret; | |
244 | } | |
245 | ||
246 | static unsigned int apm_poll(struct file *fp, poll_table * wait) | |
247 | { | |
248 | struct apm_user *as = fp->private_data; | |
249 | ||
250 | poll_wait(fp, &apm_waitqueue, wait); | |
251 | return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM; | |
252 | } | |
253 | ||
254 | /* | |
255 | * apm_ioctl - handle APM ioctl | |
256 | * | |
257 | * APM_IOC_SUSPEND | |
258 | * This IOCTL is overloaded, and performs two functions. It is used to: | |
259 | * - initiate a suspend | |
260 | * - acknowledge a suspend read from /dev/apm_bios. | |
261 | * Only when everyone who has opened /dev/apm_bios with write permission | |
262 | * has acknowledge does the actual suspend happen. | |
263 | */ | |
55929332 AB |
264 | static long |
265 | apm_ioctl(struct file *filp, u_int cmd, u_long arg) | |
7726942f RB |
266 | { |
267 | struct apm_user *as = filp->private_data; | |
7726942f RB |
268 | int err = -EINVAL; |
269 | ||
270 | if (!as->suser || !as->writer) | |
271 | return -EPERM; | |
272 | ||
273 | switch (cmd) { | |
274 | case APM_IOC_SUSPEND: | |
275 | mutex_lock(&state_lock); | |
276 | ||
277 | as->suspend_result = -EINTR; | |
278 | ||
d20a4dca JB |
279 | switch (as->suspend_state) { |
280 | case SUSPEND_READ: | |
7726942f RB |
281 | /* |
282 | * If we read a suspend command from /dev/apm_bios, | |
283 | * then the corresponding APM_IOC_SUSPEND ioctl is | |
284 | * interpreted as an acknowledge. | |
285 | */ | |
286 | as->suspend_state = SUSPEND_ACKED; | |
d20a4dca | 287 | atomic_dec(&suspend_acks_pending); |
7726942f RB |
288 | mutex_unlock(&state_lock); |
289 | ||
290 | /* | |
d20a4dca JB |
291 | * suspend_acks_pending changed, the notifier needs to |
292 | * be woken up for this | |
7726942f | 293 | */ |
d20a4dca | 294 | wake_up(&apm_suspend_waitqueue); |
7726942f RB |
295 | |
296 | /* | |
297 | * Wait for the suspend/resume to complete. If there | |
298 | * are pending acknowledges, we wait here for them. | |
1d927c3b TH |
299 | * wait_event_freezable() is interruptible and pending |
300 | * signal can cause busy looping. We aren't doing | |
301 | * anything critical, chill a bit on each iteration. | |
7726942f | 302 | */ |
1d927c3b | 303 | while (wait_event_freezable(apm_suspend_waitqueue, |
f283d227 | 304 | as->suspend_state != SUSPEND_ACKED)) |
1d927c3b | 305 | msleep(10); |
d20a4dca JB |
306 | break; |
307 | case SUSPEND_ACKTO: | |
308 | as->suspend_result = -ETIMEDOUT; | |
309 | mutex_unlock(&state_lock); | |
310 | break; | |
311 | default: | |
7726942f RB |
312 | as->suspend_state = SUSPEND_WAIT; |
313 | mutex_unlock(&state_lock); | |
314 | ||
315 | /* | |
316 | * Otherwise it is a request to suspend the system. | |
d20a4dca JB |
317 | * Just invoke pm_suspend(), we'll handle it from |
318 | * there via the notifier. | |
7726942f | 319 | */ |
d20a4dca | 320 | as->suspend_result = pm_suspend(PM_SUSPEND_MEM); |
7726942f RB |
321 | } |
322 | ||
7726942f RB |
323 | mutex_lock(&state_lock); |
324 | err = as->suspend_result; | |
325 | as->suspend_state = SUSPEND_NONE; | |
326 | mutex_unlock(&state_lock); | |
327 | break; | |
328 | } | |
329 | ||
330 | return err; | |
331 | } | |
332 | ||
333 | static int apm_release(struct inode * inode, struct file * filp) | |
334 | { | |
335 | struct apm_user *as = filp->private_data; | |
7726942f RB |
336 | |
337 | filp->private_data = NULL; | |
338 | ||
339 | down_write(&user_list_lock); | |
340 | list_del(&as->list); | |
341 | up_write(&user_list_lock); | |
342 | ||
343 | /* | |
344 | * We are now unhooked from the chain. As far as new | |
d20a4dca | 345 | * events are concerned, we no longer exist. |
7726942f RB |
346 | */ |
347 | mutex_lock(&state_lock); | |
d20a4dca JB |
348 | if (as->suspend_state == SUSPEND_PENDING || |
349 | as->suspend_state == SUSPEND_READ) | |
350 | atomic_dec(&suspend_acks_pending); | |
7726942f | 351 | mutex_unlock(&state_lock); |
d20a4dca JB |
352 | |
353 | wake_up(&apm_suspend_waitqueue); | |
7726942f RB |
354 | |
355 | kfree(as); | |
356 | return 0; | |
357 | } | |
358 | ||
359 | static int apm_open(struct inode * inode, struct file * filp) | |
360 | { | |
361 | struct apm_user *as; | |
362 | ||
363 | as = kzalloc(sizeof(*as), GFP_KERNEL); | |
364 | if (as) { | |
365 | /* | |
366 | * XXX - this is a tiny bit broken, when we consider BSD | |
367 | * process accounting. If the device is opened by root, we | |
368 | * instantly flag that we used superuser privs. Who knows, | |
369 | * we might close the device immediately without doing a | |
370 | * privileged operation -- cevans | |
371 | */ | |
372 | as->suser = capable(CAP_SYS_ADMIN); | |
373 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
374 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
375 | ||
376 | down_write(&user_list_lock); | |
377 | list_add(&as->list, &apm_user_list); | |
378 | up_write(&user_list_lock); | |
379 | ||
380 | filp->private_data = as; | |
381 | } | |
382 | ||
383 | return as ? 0 : -ENOMEM; | |
384 | } | |
385 | ||
828c0950 | 386 | static const struct file_operations apm_bios_fops = { |
7726942f RB |
387 | .owner = THIS_MODULE, |
388 | .read = apm_read, | |
389 | .poll = apm_poll, | |
55929332 | 390 | .unlocked_ioctl = apm_ioctl, |
7726942f RB |
391 | .open = apm_open, |
392 | .release = apm_release, | |
6038f373 | 393 | .llseek = noop_llseek, |
7726942f RB |
394 | }; |
395 | ||
396 | static struct miscdevice apm_device = { | |
397 | .minor = APM_MINOR_DEV, | |
398 | .name = "apm_bios", | |
399 | .fops = &apm_bios_fops | |
400 | }; | |
401 | ||
402 | ||
403 | #ifdef CONFIG_PROC_FS | |
404 | /* | |
405 | * Arguments, with symbols from linux/apm_bios.h. | |
406 | * | |
407 | * 0) Linux driver version (this will change if format changes) | |
408 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
409 | * 2) APM flags from APM Installation Check (0x00): | |
410 | * bit 0: APM_16_BIT_SUPPORT | |
411 | * bit 1: APM_32_BIT_SUPPORT | |
412 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
413 | * bit 3: APM_BIOS_DISABLED | |
414 | * bit 4: APM_BIOS_DISENGAGED | |
415 | * 3) AC line status | |
416 | * 0x00: Off-line | |
417 | * 0x01: On-line | |
418 | * 0x02: On backup power (BIOS >= 1.1 only) | |
419 | * 0xff: Unknown | |
420 | * 4) Battery status | |
421 | * 0x00: High | |
422 | * 0x01: Low | |
423 | * 0x02: Critical | |
424 | * 0x03: Charging | |
425 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
426 | * 0xff: Unknown | |
427 | * 5) Battery flag | |
428 | * bit 0: High | |
429 | * bit 1: Low | |
430 | * bit 2: Critical | |
431 | * bit 3: Charging | |
432 | * bit 7: No system battery | |
433 | * 0xff: Unknown | |
434 | * 6) Remaining battery life (percentage of charge): | |
435 | * 0-100: valid | |
436 | * -1: Unknown | |
437 | * 7) Remaining battery life (time units): | |
438 | * Number of remaining minutes or seconds | |
439 | * -1: Unknown | |
440 | * 8) min = minutes; sec = seconds | |
441 | */ | |
647634df | 442 | static int proc_apm_show(struct seq_file *m, void *v) |
7726942f RB |
443 | { |
444 | struct apm_power_info info; | |
445 | char *units; | |
7726942f RB |
446 | |
447 | info.ac_line_status = 0xff; | |
448 | info.battery_status = 0xff; | |
449 | info.battery_flag = 0xff; | |
450 | info.battery_life = -1; | |
451 | info.time = -1; | |
452 | info.units = -1; | |
453 | ||
454 | if (apm_get_power_status) | |
455 | apm_get_power_status(&info); | |
456 | ||
457 | switch (info.units) { | |
458 | default: units = "?"; break; | |
459 | case 0: units = "min"; break; | |
460 | case 1: units = "sec"; break; | |
461 | } | |
462 | ||
647634df | 463 | seq_printf(m, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", |
7726942f RB |
464 | driver_version, APM_32_BIT_SUPPORT, |
465 | info.ac_line_status, info.battery_status, | |
466 | info.battery_flag, info.battery_life, | |
467 | info.time, units); | |
468 | ||
647634df | 469 | return 0; |
7726942f | 470 | } |
647634df AD |
471 | |
472 | static int proc_apm_open(struct inode *inode, struct file *file) | |
473 | { | |
474 | return single_open(file, proc_apm_show, NULL); | |
475 | } | |
476 | ||
477 | static const struct file_operations apm_proc_fops = { | |
478 | .owner = THIS_MODULE, | |
479 | .open = proc_apm_open, | |
480 | .read = seq_read, | |
481 | .llseek = seq_lseek, | |
482 | .release = single_release, | |
483 | }; | |
7726942f RB |
484 | #endif |
485 | ||
486 | static int kapmd(void *arg) | |
487 | { | |
488 | do { | |
489 | apm_event_t event; | |
7726942f RB |
490 | |
491 | wait_event_interruptible(kapmd_wait, | |
492 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
493 | ||
494 | if (kthread_should_stop()) | |
495 | break; | |
496 | ||
497 | spin_lock_irq(&kapmd_queue_lock); | |
498 | event = 0; | |
499 | if (!queue_empty(&kapmd_queue)) | |
500 | event = queue_get_event(&kapmd_queue); | |
501 | spin_unlock_irq(&kapmd_queue_lock); | |
502 | ||
503 | switch (event) { | |
504 | case 0: | |
505 | break; | |
506 | ||
507 | case APM_LOW_BATTERY: | |
508 | case APM_POWER_STATUS_CHANGE: | |
509 | queue_event(event); | |
510 | break; | |
511 | ||
512 | case APM_USER_SUSPEND: | |
513 | case APM_SYS_SUSPEND: | |
d20a4dca | 514 | pm_suspend(PM_SUSPEND_MEM); |
7726942f RB |
515 | break; |
516 | ||
517 | case APM_CRITICAL_SUSPEND: | |
d20a4dca JB |
518 | atomic_inc(&userspace_notification_inhibit); |
519 | pm_suspend(PM_SUSPEND_MEM); | |
520 | atomic_dec(&userspace_notification_inhibit); | |
7726942f RB |
521 | break; |
522 | } | |
523 | } while (1); | |
524 | ||
525 | return 0; | |
526 | } | |
527 | ||
d20a4dca JB |
528 | static int apm_suspend_notifier(struct notifier_block *nb, |
529 | unsigned long event, | |
530 | void *dummy) | |
531 | { | |
532 | struct apm_user *as; | |
533 | int err; | |
534 | ||
535 | /* short-cut emergency suspends */ | |
536 | if (atomic_read(&userspace_notification_inhibit)) | |
537 | return NOTIFY_DONE; | |
538 | ||
539 | switch (event) { | |
540 | case PM_SUSPEND_PREPARE: | |
541 | /* | |
542 | * Queue an event to all "writer" users that we want | |
543 | * to suspend and need their ack. | |
544 | */ | |
545 | mutex_lock(&state_lock); | |
546 | down_read(&user_list_lock); | |
547 | ||
548 | list_for_each_entry(as, &apm_user_list, list) { | |
549 | if (as->suspend_state != SUSPEND_WAIT && as->reader && | |
550 | as->writer && as->suser) { | |
551 | as->suspend_state = SUSPEND_PENDING; | |
552 | atomic_inc(&suspend_acks_pending); | |
553 | queue_add_event(&as->queue, APM_USER_SUSPEND); | |
554 | } | |
555 | } | |
556 | ||
557 | up_read(&user_list_lock); | |
558 | mutex_unlock(&state_lock); | |
559 | wake_up_interruptible(&apm_waitqueue); | |
560 | ||
561 | /* | |
562 | * Wait for the the suspend_acks_pending variable to drop to | |
563 | * zero, meaning everybody acked the suspend event (or the | |
564 | * process was killed.) | |
565 | * | |
566 | * If the app won't answer within a short while we assume it | |
567 | * locked up and ignore it. | |
568 | */ | |
569 | err = wait_event_interruptible_timeout( | |
570 | apm_suspend_waitqueue, | |
571 | atomic_read(&suspend_acks_pending) == 0, | |
572 | 5*HZ); | |
573 | ||
574 | /* timed out */ | |
575 | if (err == 0) { | |
576 | /* | |
577 | * Move anybody who timed out to "ack timeout" state. | |
578 | * | |
579 | * We could time out and the userspace does the ACK | |
580 | * right after we time out but before we enter the | |
581 | * locked section here, but that's fine. | |
582 | */ | |
583 | mutex_lock(&state_lock); | |
584 | down_read(&user_list_lock); | |
585 | list_for_each_entry(as, &apm_user_list, list) { | |
586 | if (as->suspend_state == SUSPEND_PENDING || | |
587 | as->suspend_state == SUSPEND_READ) { | |
588 | as->suspend_state = SUSPEND_ACKTO; | |
589 | atomic_dec(&suspend_acks_pending); | |
590 | } | |
591 | } | |
592 | up_read(&user_list_lock); | |
593 | mutex_unlock(&state_lock); | |
594 | } | |
595 | ||
596 | /* let suspend proceed */ | |
597 | if (err >= 0) | |
598 | return NOTIFY_OK; | |
599 | ||
600 | /* interrupted by signal */ | |
f0c077a8 | 601 | return notifier_from_errno(err); |
d20a4dca JB |
602 | |
603 | case PM_POST_SUSPEND: | |
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_NORMAL_RESUME); | |
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 | ||
7726942f RB |
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; | |
d20a4dca | 655 | goto out; |
7726942f | 656 | } |
7726942f RB |
657 | wake_up_process(kapmd_tsk); |
658 | ||
659 | #ifdef CONFIG_PROC_FS | |
647634df | 660 | proc_create("apm", 0, NULL, &apm_proc_fops); |
7726942f RB |
661 | #endif |
662 | ||
663 | ret = misc_register(&apm_device); | |
d20a4dca JB |
664 | if (ret) |
665 | goto out_stop; | |
7726942f | 666 | |
d20a4dca JB |
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: | |
7726942f RB |
679 | return ret; |
680 | } | |
681 | ||
682 | static void __exit apm_exit(void) | |
683 | { | |
d20a4dca | 684 | unregister_pm_notifier(&apm_notif_block); |
7726942f RB |
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); |