Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
7726942f RB |
2 | /* |
3 | * bios-less APM driver for ARM Linux | |
4 | * Jamey Hicks <jamey@crl.dec.com> | |
5 | * adapted from the APM BIOS driver for Linux by Stephen Rothwell (sfr@linuxcare.com) | |
6 | * | |
7 | * APM 1.2 Reference: | |
8 | * Intel Corporation, Microsoft Corporation. Advanced Power Management | |
9 | * (APM) BIOS Interface Specification, Revision 1.2, February 1996. | |
10 | * | |
631dd1a8 JM |
11 | * This document is available from Microsoft at: |
12 | * http://www.microsoft.com/whdc/archive/amp_12.mspx | |
7726942f RB |
13 | */ |
14 | #include <linux/module.h> | |
15 | #include <linux/poll.h> | |
16 | #include <linux/slab.h> | |
613655fa | 17 | #include <linux/mutex.h> |
7726942f | 18 | #include <linux/proc_fs.h> |
647634df | 19 | #include <linux/seq_file.h> |
7726942f RB |
20 | #include <linux/miscdevice.h> |
21 | #include <linux/apm_bios.h> | |
22 | #include <linux/capability.h> | |
23 | #include <linux/sched.h> | |
95d9ffbe | 24 | #include <linux/suspend.h> |
7726942f | 25 | #include <linux/apm-emulation.h> |
83144186 | 26 | #include <linux/freezer.h> |
7726942f RB |
27 | #include <linux/device.h> |
28 | #include <linux/kernel.h> | |
29 | #include <linux/list.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/completion.h> | |
32 | #include <linux/kthread.h> | |
33 | #include <linux/delay.h> | |
34 | ||
7726942f | 35 | /* |
395cf969 | 36 | * One option can be changed at boot time as follows: |
7726942f RB |
37 | * apm=on/off enable/disable APM |
38 | */ | |
39 | ||
40 | /* | |
41 | * Maximum number of events stored | |
42 | */ | |
43 | #define APM_MAX_EVENTS 16 | |
44 | ||
45 | struct apm_queue { | |
46 | unsigned int event_head; | |
47 | unsigned int event_tail; | |
48 | apm_event_t events[APM_MAX_EVENTS]; | |
49 | }; | |
50 | ||
d20a4dca JB |
51 | /* |
52 | * thread states (for threads using a writable /dev/apm_bios fd): | |
53 | * | |
54 | * SUSPEND_NONE: nothing happening | |
55 | * SUSPEND_PENDING: suspend event queued for thread and pending to be read | |
56 | * SUSPEND_READ: suspend event read, pending acknowledgement | |
57 | * SUSPEND_ACKED: acknowledgement received from thread (via ioctl), | |
58 | * waiting for resume | |
59 | * SUSPEND_ACKTO: acknowledgement timeout | |
60 | * SUSPEND_DONE: thread had acked suspend and is now notified of | |
61 | * resume | |
62 | * | |
63 | * SUSPEND_WAIT: this thread invoked suspend and is waiting for resume | |
64 | * | |
65 | * A thread migrates in one of three paths: | |
66 | * NONE -1-> PENDING -2-> READ -3-> ACKED -4-> DONE -5-> NONE | |
67 | * -6-> ACKTO -7-> NONE | |
68 | * NONE -8-> WAIT -9-> NONE | |
69 | * | |
70 | * While in PENDING or READ, the thread is accounted for in the | |
71 | * suspend_acks_pending counter. | |
72 | * | |
73 | * The transitions are invoked as follows: | |
74 | * 1: suspend event is signalled from the core PM code | |
75 | * 2: the suspend event is read from the fd by the userspace thread | |
76 | * 3: userspace thread issues the APM_IOC_SUSPEND ioctl (as ack) | |
77 | * 4: core PM code signals that we have resumed | |
78 | * 5: APM_IOC_SUSPEND ioctl returns | |
79 | * | |
80 | * 6: the notifier invoked from the core PM code timed out waiting | |
81 | * for all relevant threds to enter ACKED state and puts those | |
82 | * that haven't into ACKTO | |
83 | * 7: those threads issue APM_IOC_SUSPEND ioctl too late, | |
84 | * get an error | |
85 | * | |
86 | * 8: userspace thread issues the APM_IOC_SUSPEND ioctl (to suspend), | |
87 | * ioctl code invokes pm_suspend() | |
88 | * 9: pm_suspend() returns indicating resume | |
89 | */ | |
90 | enum apm_suspend_state { | |
91 | SUSPEND_NONE, | |
92 | SUSPEND_PENDING, | |
93 | SUSPEND_READ, | |
94 | SUSPEND_ACKED, | |
95 | SUSPEND_ACKTO, | |
96 | SUSPEND_WAIT, | |
97 | SUSPEND_DONE, | |
98 | }; | |
99 | ||
7726942f RB |
100 | /* |
101 | * The per-file APM data | |
102 | */ | |
103 | struct apm_user { | |
104 | struct list_head list; | |
105 | ||
106 | unsigned int suser: 1; | |
107 | unsigned int writer: 1; | |
108 | unsigned int reader: 1; | |
109 | ||
110 | int suspend_result; | |
d20a4dca | 111 | enum apm_suspend_state suspend_state; |
7726942f RB |
112 | |
113 | struct apm_queue queue; | |
114 | }; | |
115 | ||
116 | /* | |
117 | * Local variables | |
118 | */ | |
d20a4dca JB |
119 | static atomic_t suspend_acks_pending = ATOMIC_INIT(0); |
120 | static atomic_t userspace_notification_inhibit = ATOMIC_INIT(0); | |
7726942f RB |
121 | static int apm_disabled; |
122 | static struct task_struct *kapmd_tsk; | |
123 | ||
124 | static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue); | |
125 | static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue); | |
126 | ||
127 | /* | |
128 | * This is a list of everyone who has opened /dev/apm_bios | |
129 | */ | |
130 | static DECLARE_RWSEM(user_list_lock); | |
131 | static LIST_HEAD(apm_user_list); | |
132 | ||
133 | /* | |
134 | * kapmd info. kapmd provides us a process context to handle | |
135 | * "APM" events within - specifically necessary if we're going | |
136 | * to be suspending the system. | |
137 | */ | |
138 | static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait); | |
139 | static DEFINE_SPINLOCK(kapmd_queue_lock); | |
140 | static struct apm_queue kapmd_queue; | |
141 | ||
142 | static DEFINE_MUTEX(state_lock); | |
143 | ||
144 | static const char driver_version[] = "1.13"; /* no spaces */ | |
145 | ||
146 | ||
147 | ||
148 | /* | |
149 | * Compatibility cruft until the IPAQ people move over to the new | |
150 | * interface. | |
151 | */ | |
152 | static void __apm_get_power_status(struct apm_power_info *info) | |
153 | { | |
154 | } | |
155 | ||
156 | /* | |
157 | * This allows machines to provide their own "apm get power status" function. | |
158 | */ | |
159 | void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status; | |
160 | EXPORT_SYMBOL(apm_get_power_status); | |
161 | ||
162 | ||
163 | /* | |
164 | * APM event queue management. | |
165 | */ | |
166 | static inline int queue_empty(struct apm_queue *q) | |
167 | { | |
168 | return q->event_head == q->event_tail; | |
169 | } | |
170 | ||
171 | static inline apm_event_t queue_get_event(struct apm_queue *q) | |
172 | { | |
173 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
174 | return q->events[q->event_tail]; | |
175 | } | |
176 | ||
177 | static void queue_add_event(struct apm_queue *q, apm_event_t event) | |
178 | { | |
179 | q->event_head = (q->event_head + 1) % APM_MAX_EVENTS; | |
180 | if (q->event_head == q->event_tail) { | |
181 | static int notified; | |
182 | ||
183 | if (notified++ == 0) | |
184 | printk(KERN_ERR "apm: an event queue overflowed\n"); | |
185 | q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS; | |
186 | } | |
187 | q->events[q->event_head] = event; | |
188 | } | |
189 | ||
190 | static void queue_event(apm_event_t event) | |
191 | { | |
192 | struct apm_user *as; | |
193 | ||
194 | down_read(&user_list_lock); | |
195 | list_for_each_entry(as, &apm_user_list, list) { | |
196 | if (as->reader) | |
197 | queue_add_event(&as->queue, event); | |
198 | } | |
199 | up_read(&user_list_lock); | |
200 | wake_up_interruptible(&apm_waitqueue); | |
201 | } | |
202 | ||
7726942f RB |
203 | static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos) |
204 | { | |
205 | struct apm_user *as = fp->private_data; | |
206 | apm_event_t event; | |
207 | int i = count, ret = 0; | |
208 | ||
209 | if (count < sizeof(apm_event_t)) | |
210 | return -EINVAL; | |
211 | ||
212 | if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK) | |
213 | return -EAGAIN; | |
214 | ||
215 | wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue)); | |
216 | ||
217 | while ((i >= sizeof(event)) && !queue_empty(&as->queue)) { | |
218 | event = queue_get_event(&as->queue); | |
219 | ||
220 | ret = -EFAULT; | |
221 | if (copy_to_user(buf, &event, sizeof(event))) | |
222 | break; | |
223 | ||
224 | mutex_lock(&state_lock); | |
225 | if (as->suspend_state == SUSPEND_PENDING && | |
226 | (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)) | |
227 | as->suspend_state = SUSPEND_READ; | |
228 | mutex_unlock(&state_lock); | |
229 | ||
230 | buf += sizeof(event); | |
231 | i -= sizeof(event); | |
232 | } | |
233 | ||
234 | if (i < count) | |
235 | ret = count - i; | |
236 | ||
237 | return ret; | |
238 | } | |
239 | ||
afc9a42b | 240 | static __poll_t apm_poll(struct file *fp, poll_table * wait) |
7726942f RB |
241 | { |
242 | struct apm_user *as = fp->private_data; | |
243 | ||
244 | poll_wait(fp, &apm_waitqueue, wait); | |
a9a08845 | 245 | return queue_empty(&as->queue) ? 0 : EPOLLIN | EPOLLRDNORM; |
7726942f RB |
246 | } |
247 | ||
248 | /* | |
249 | * apm_ioctl - handle APM ioctl | |
250 | * | |
251 | * APM_IOC_SUSPEND | |
252 | * This IOCTL is overloaded, and performs two functions. It is used to: | |
253 | * - initiate a suspend | |
254 | * - acknowledge a suspend read from /dev/apm_bios. | |
255 | * Only when everyone who has opened /dev/apm_bios with write permission | |
256 | * has acknowledge does the actual suspend happen. | |
257 | */ | |
55929332 AB |
258 | static long |
259 | apm_ioctl(struct file *filp, u_int cmd, u_long arg) | |
7726942f RB |
260 | { |
261 | struct apm_user *as = filp->private_data; | |
7726942f RB |
262 | int err = -EINVAL; |
263 | ||
264 | if (!as->suser || !as->writer) | |
265 | return -EPERM; | |
266 | ||
267 | switch (cmd) { | |
268 | case APM_IOC_SUSPEND: | |
269 | mutex_lock(&state_lock); | |
270 | ||
271 | as->suspend_result = -EINTR; | |
272 | ||
d20a4dca JB |
273 | switch (as->suspend_state) { |
274 | case SUSPEND_READ: | |
7726942f RB |
275 | /* |
276 | * If we read a suspend command from /dev/apm_bios, | |
277 | * then the corresponding APM_IOC_SUSPEND ioctl is | |
278 | * interpreted as an acknowledge. | |
279 | */ | |
280 | as->suspend_state = SUSPEND_ACKED; | |
d20a4dca | 281 | atomic_dec(&suspend_acks_pending); |
7726942f RB |
282 | mutex_unlock(&state_lock); |
283 | ||
284 | /* | |
d20a4dca JB |
285 | * suspend_acks_pending changed, the notifier needs to |
286 | * be woken up for this | |
7726942f | 287 | */ |
d20a4dca | 288 | wake_up(&apm_suspend_waitqueue); |
7726942f RB |
289 | |
290 | /* | |
291 | * Wait for the suspend/resume to complete. If there | |
292 | * are pending acknowledges, we wait here for them. | |
1d927c3b TH |
293 | * wait_event_freezable() is interruptible and pending |
294 | * signal can cause busy looping. We aren't doing | |
295 | * anything critical, chill a bit on each iteration. | |
7726942f | 296 | */ |
1d927c3b | 297 | while (wait_event_freezable(apm_suspend_waitqueue, |
f283d227 | 298 | as->suspend_state != SUSPEND_ACKED)) |
1d927c3b | 299 | msleep(10); |
d20a4dca JB |
300 | break; |
301 | case SUSPEND_ACKTO: | |
302 | as->suspend_result = -ETIMEDOUT; | |
303 | mutex_unlock(&state_lock); | |
304 | break; | |
305 | default: | |
7726942f RB |
306 | as->suspend_state = SUSPEND_WAIT; |
307 | mutex_unlock(&state_lock); | |
308 | ||
309 | /* | |
310 | * Otherwise it is a request to suspend the system. | |
d20a4dca JB |
311 | * Just invoke pm_suspend(), we'll handle it from |
312 | * there via the notifier. | |
7726942f | 313 | */ |
d20a4dca | 314 | as->suspend_result = pm_suspend(PM_SUSPEND_MEM); |
7726942f RB |
315 | } |
316 | ||
7726942f RB |
317 | mutex_lock(&state_lock); |
318 | err = as->suspend_result; | |
319 | as->suspend_state = SUSPEND_NONE; | |
320 | mutex_unlock(&state_lock); | |
321 | break; | |
322 | } | |
323 | ||
324 | return err; | |
325 | } | |
326 | ||
327 | static int apm_release(struct inode * inode, struct file * filp) | |
328 | { | |
329 | struct apm_user *as = filp->private_data; | |
7726942f RB |
330 | |
331 | filp->private_data = NULL; | |
332 | ||
333 | down_write(&user_list_lock); | |
334 | list_del(&as->list); | |
335 | up_write(&user_list_lock); | |
336 | ||
337 | /* | |
338 | * We are now unhooked from the chain. As far as new | |
d20a4dca | 339 | * events are concerned, we no longer exist. |
7726942f RB |
340 | */ |
341 | mutex_lock(&state_lock); | |
d20a4dca JB |
342 | if (as->suspend_state == SUSPEND_PENDING || |
343 | as->suspend_state == SUSPEND_READ) | |
344 | atomic_dec(&suspend_acks_pending); | |
7726942f | 345 | mutex_unlock(&state_lock); |
d20a4dca JB |
346 | |
347 | wake_up(&apm_suspend_waitqueue); | |
7726942f RB |
348 | |
349 | kfree(as); | |
350 | return 0; | |
351 | } | |
352 | ||
353 | static int apm_open(struct inode * inode, struct file * filp) | |
354 | { | |
355 | struct apm_user *as; | |
356 | ||
357 | as = kzalloc(sizeof(*as), GFP_KERNEL); | |
358 | if (as) { | |
359 | /* | |
360 | * XXX - this is a tiny bit broken, when we consider BSD | |
361 | * process accounting. If the device is opened by root, we | |
362 | * instantly flag that we used superuser privs. Who knows, | |
363 | * we might close the device immediately without doing a | |
364 | * privileged operation -- cevans | |
365 | */ | |
366 | as->suser = capable(CAP_SYS_ADMIN); | |
367 | as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE; | |
368 | as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ; | |
369 | ||
370 | down_write(&user_list_lock); | |
371 | list_add(&as->list, &apm_user_list); | |
372 | up_write(&user_list_lock); | |
373 | ||
374 | filp->private_data = as; | |
375 | } | |
376 | ||
377 | return as ? 0 : -ENOMEM; | |
378 | } | |
379 | ||
828c0950 | 380 | static const struct file_operations apm_bios_fops = { |
7726942f RB |
381 | .owner = THIS_MODULE, |
382 | .read = apm_read, | |
383 | .poll = apm_poll, | |
55929332 | 384 | .unlocked_ioctl = apm_ioctl, |
7726942f RB |
385 | .open = apm_open, |
386 | .release = apm_release, | |
6038f373 | 387 | .llseek = noop_llseek, |
7726942f RB |
388 | }; |
389 | ||
390 | static struct miscdevice apm_device = { | |
391 | .minor = APM_MINOR_DEV, | |
392 | .name = "apm_bios", | |
393 | .fops = &apm_bios_fops | |
394 | }; | |
395 | ||
396 | ||
397 | #ifdef CONFIG_PROC_FS | |
398 | /* | |
399 | * Arguments, with symbols from linux/apm_bios.h. | |
400 | * | |
401 | * 0) Linux driver version (this will change if format changes) | |
402 | * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2. | |
403 | * 2) APM flags from APM Installation Check (0x00): | |
404 | * bit 0: APM_16_BIT_SUPPORT | |
405 | * bit 1: APM_32_BIT_SUPPORT | |
406 | * bit 2: APM_IDLE_SLOWS_CLOCK | |
407 | * bit 3: APM_BIOS_DISABLED | |
408 | * bit 4: APM_BIOS_DISENGAGED | |
409 | * 3) AC line status | |
410 | * 0x00: Off-line | |
411 | * 0x01: On-line | |
412 | * 0x02: On backup power (BIOS >= 1.1 only) | |
413 | * 0xff: Unknown | |
414 | * 4) Battery status | |
415 | * 0x00: High | |
416 | * 0x01: Low | |
417 | * 0x02: Critical | |
418 | * 0x03: Charging | |
419 | * 0x04: Selected battery not present (BIOS >= 1.2 only) | |
420 | * 0xff: Unknown | |
421 | * 5) Battery flag | |
422 | * bit 0: High | |
423 | * bit 1: Low | |
424 | * bit 2: Critical | |
425 | * bit 3: Charging | |
426 | * bit 7: No system battery | |
427 | * 0xff: Unknown | |
428 | * 6) Remaining battery life (percentage of charge): | |
429 | * 0-100: valid | |
430 | * -1: Unknown | |
431 | * 7) Remaining battery life (time units): | |
432 | * Number of remaining minutes or seconds | |
433 | * -1: Unknown | |
434 | * 8) min = minutes; sec = seconds | |
435 | */ | |
647634df | 436 | static int proc_apm_show(struct seq_file *m, void *v) |
7726942f RB |
437 | { |
438 | struct apm_power_info info; | |
439 | char *units; | |
7726942f RB |
440 | |
441 | info.ac_line_status = 0xff; | |
442 | info.battery_status = 0xff; | |
443 | info.battery_flag = 0xff; | |
444 | info.battery_life = -1; | |
445 | info.time = -1; | |
446 | info.units = -1; | |
447 | ||
448 | if (apm_get_power_status) | |
449 | apm_get_power_status(&info); | |
450 | ||
451 | switch (info.units) { | |
452 | default: units = "?"; break; | |
453 | case 0: units = "min"; break; | |
454 | case 1: units = "sec"; break; | |
455 | } | |
456 | ||
647634df | 457 | seq_printf(m, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n", |
7726942f RB |
458 | driver_version, APM_32_BIT_SUPPORT, |
459 | info.ac_line_status, info.battery_status, | |
460 | info.battery_flag, info.battery_life, | |
461 | info.time, units); | |
462 | ||
647634df | 463 | return 0; |
7726942f RB |
464 | } |
465 | #endif | |
466 | ||
467 | static int kapmd(void *arg) | |
468 | { | |
469 | do { | |
470 | apm_event_t event; | |
7726942f RB |
471 | |
472 | wait_event_interruptible(kapmd_wait, | |
473 | !queue_empty(&kapmd_queue) || kthread_should_stop()); | |
474 | ||
475 | if (kthread_should_stop()) | |
476 | break; | |
477 | ||
478 | spin_lock_irq(&kapmd_queue_lock); | |
479 | event = 0; | |
480 | if (!queue_empty(&kapmd_queue)) | |
481 | event = queue_get_event(&kapmd_queue); | |
482 | spin_unlock_irq(&kapmd_queue_lock); | |
483 | ||
484 | switch (event) { | |
485 | case 0: | |
486 | break; | |
487 | ||
488 | case APM_LOW_BATTERY: | |
489 | case APM_POWER_STATUS_CHANGE: | |
490 | queue_event(event); | |
491 | break; | |
492 | ||
493 | case APM_USER_SUSPEND: | |
494 | case APM_SYS_SUSPEND: | |
d20a4dca | 495 | pm_suspend(PM_SUSPEND_MEM); |
7726942f RB |
496 | break; |
497 | ||
498 | case APM_CRITICAL_SUSPEND: | |
d20a4dca JB |
499 | atomic_inc(&userspace_notification_inhibit); |
500 | pm_suspend(PM_SUSPEND_MEM); | |
501 | atomic_dec(&userspace_notification_inhibit); | |
7726942f RB |
502 | break; |
503 | } | |
504 | } while (1); | |
505 | ||
506 | return 0; | |
507 | } | |
508 | ||
d20a4dca JB |
509 | static int apm_suspend_notifier(struct notifier_block *nb, |
510 | unsigned long event, | |
511 | void *dummy) | |
512 | { | |
513 | struct apm_user *as; | |
514 | int err; | |
15820439 | 515 | unsigned long apm_event; |
d20a4dca JB |
516 | |
517 | /* short-cut emergency suspends */ | |
518 | if (atomic_read(&userspace_notification_inhibit)) | |
519 | return NOTIFY_DONE; | |
520 | ||
521 | switch (event) { | |
522 | case PM_SUSPEND_PREPARE: | |
15820439 BS |
523 | case PM_HIBERNATION_PREPARE: |
524 | apm_event = (event == PM_SUSPEND_PREPARE) ? | |
525 | APM_USER_SUSPEND : APM_USER_HIBERNATION; | |
d20a4dca JB |
526 | /* |
527 | * Queue an event to all "writer" users that we want | |
528 | * to suspend and need their ack. | |
529 | */ | |
530 | mutex_lock(&state_lock); | |
531 | down_read(&user_list_lock); | |
532 | ||
533 | list_for_each_entry(as, &apm_user_list, list) { | |
534 | if (as->suspend_state != SUSPEND_WAIT && as->reader && | |
535 | as->writer && as->suser) { | |
536 | as->suspend_state = SUSPEND_PENDING; | |
537 | atomic_inc(&suspend_acks_pending); | |
15820439 | 538 | queue_add_event(&as->queue, apm_event); |
d20a4dca JB |
539 | } |
540 | } | |
541 | ||
542 | up_read(&user_list_lock); | |
543 | mutex_unlock(&state_lock); | |
544 | wake_up_interruptible(&apm_waitqueue); | |
545 | ||
546 | /* | |
1cb53f04 | 547 | * Wait for the suspend_acks_pending variable to drop to |
d20a4dca JB |
548 | * zero, meaning everybody acked the suspend event (or the |
549 | * process was killed.) | |
550 | * | |
551 | * If the app won't answer within a short while we assume it | |
552 | * locked up and ignore it. | |
553 | */ | |
554 | err = wait_event_interruptible_timeout( | |
555 | apm_suspend_waitqueue, | |
556 | atomic_read(&suspend_acks_pending) == 0, | |
557 | 5*HZ); | |
558 | ||
559 | /* timed out */ | |
560 | if (err == 0) { | |
561 | /* | |
562 | * Move anybody who timed out to "ack timeout" state. | |
563 | * | |
564 | * We could time out and the userspace does the ACK | |
565 | * right after we time out but before we enter the | |
566 | * locked section here, but that's fine. | |
567 | */ | |
568 | mutex_lock(&state_lock); | |
569 | down_read(&user_list_lock); | |
570 | list_for_each_entry(as, &apm_user_list, list) { | |
571 | if (as->suspend_state == SUSPEND_PENDING || | |
572 | as->suspend_state == SUSPEND_READ) { | |
573 | as->suspend_state = SUSPEND_ACKTO; | |
574 | atomic_dec(&suspend_acks_pending); | |
575 | } | |
576 | } | |
577 | up_read(&user_list_lock); | |
578 | mutex_unlock(&state_lock); | |
579 | } | |
580 | ||
581 | /* let suspend proceed */ | |
582 | if (err >= 0) | |
583 | return NOTIFY_OK; | |
584 | ||
585 | /* interrupted by signal */ | |
f0c077a8 | 586 | return notifier_from_errno(err); |
d20a4dca JB |
587 | |
588 | case PM_POST_SUSPEND: | |
15820439 BS |
589 | case PM_POST_HIBERNATION: |
590 | apm_event = (event == PM_POST_SUSPEND) ? | |
591 | APM_NORMAL_RESUME : APM_HIBERNATION_RESUME; | |
d20a4dca JB |
592 | /* |
593 | * Anyone on the APM queues will think we're still suspended. | |
594 | * Send a message so everyone knows we're now awake again. | |
595 | */ | |
15820439 | 596 | queue_event(apm_event); |
d20a4dca JB |
597 | |
598 | /* | |
599 | * Finally, wake up anyone who is sleeping on the suspend. | |
600 | */ | |
601 | mutex_lock(&state_lock); | |
602 | down_read(&user_list_lock); | |
603 | list_for_each_entry(as, &apm_user_list, list) { | |
604 | if (as->suspend_state == SUSPEND_ACKED) { | |
605 | /* | |
606 | * TODO: maybe grab error code, needs core | |
607 | * changes to push the error to the notifier | |
608 | * chain (could use the second parameter if | |
609 | * implemented) | |
610 | */ | |
611 | as->suspend_result = 0; | |
612 | as->suspend_state = SUSPEND_DONE; | |
613 | } | |
614 | } | |
615 | up_read(&user_list_lock); | |
616 | mutex_unlock(&state_lock); | |
617 | ||
618 | wake_up(&apm_suspend_waitqueue); | |
619 | return NOTIFY_OK; | |
620 | ||
621 | default: | |
622 | return NOTIFY_DONE; | |
623 | } | |
624 | } | |
625 | ||
626 | static struct notifier_block apm_notif_block = { | |
627 | .notifier_call = apm_suspend_notifier, | |
628 | }; | |
629 | ||
7726942f RB |
630 | static int __init apm_init(void) |
631 | { | |
632 | int ret; | |
633 | ||
634 | if (apm_disabled) { | |
635 | printk(KERN_NOTICE "apm: disabled on user request.\n"); | |
636 | return -ENODEV; | |
637 | } | |
638 | ||
639 | kapmd_tsk = kthread_create(kapmd, NULL, "kapmd"); | |
640 | if (IS_ERR(kapmd_tsk)) { | |
641 | ret = PTR_ERR(kapmd_tsk); | |
642 | kapmd_tsk = NULL; | |
d20a4dca | 643 | goto out; |
7726942f | 644 | } |
7726942f RB |
645 | wake_up_process(kapmd_tsk); |
646 | ||
647 | #ifdef CONFIG_PROC_FS | |
3f3942ac | 648 | proc_create_single("apm", 0, NULL, proc_apm_show); |
7726942f RB |
649 | #endif |
650 | ||
651 | ret = misc_register(&apm_device); | |
d20a4dca JB |
652 | if (ret) |
653 | goto out_stop; | |
7726942f | 654 | |
d20a4dca JB |
655 | ret = register_pm_notifier(&apm_notif_block); |
656 | if (ret) | |
657 | goto out_unregister; | |
658 | ||
659 | return 0; | |
660 | ||
661 | out_unregister: | |
662 | misc_deregister(&apm_device); | |
663 | out_stop: | |
664 | remove_proc_entry("apm", NULL); | |
665 | kthread_stop(kapmd_tsk); | |
666 | out: | |
7726942f RB |
667 | return ret; |
668 | } | |
669 | ||
670 | static void __exit apm_exit(void) | |
671 | { | |
d20a4dca | 672 | unregister_pm_notifier(&apm_notif_block); |
7726942f RB |
673 | misc_deregister(&apm_device); |
674 | remove_proc_entry("apm", NULL); | |
675 | ||
676 | kthread_stop(kapmd_tsk); | |
677 | } | |
678 | ||
679 | module_init(apm_init); | |
680 | module_exit(apm_exit); | |
681 | ||
682 | MODULE_AUTHOR("Stephen Rothwell"); | |
683 | MODULE_DESCRIPTION("Advanced Power Management"); | |
684 | MODULE_LICENSE("GPL"); | |
685 | ||
686 | #ifndef MODULE | |
687 | static int __init apm_setup(char *str) | |
688 | { | |
689 | while ((str != NULL) && (*str != '\0')) { | |
690 | if (strncmp(str, "off", 3) == 0) | |
691 | apm_disabled = 1; | |
692 | if (strncmp(str, "on", 2) == 0) | |
693 | apm_disabled = 0; | |
694 | str = strchr(str, ','); | |
695 | if (str != NULL) | |
696 | str += strspn(str, ", \t"); | |
697 | } | |
698 | return 1; | |
699 | } | |
700 | ||
701 | __setup("apm=", apm_setup); | |
702 | #endif | |
703 | ||
704 | /** | |
705 | * apm_queue_event - queue an APM event for kapmd | |
706 | * @event: APM event | |
707 | * | |
708 | * Queue an APM event for kapmd to process and ultimately take the | |
709 | * appropriate action. Only a subset of events are handled: | |
710 | * %APM_LOW_BATTERY | |
711 | * %APM_POWER_STATUS_CHANGE | |
712 | * %APM_USER_SUSPEND | |
713 | * %APM_SYS_SUSPEND | |
714 | * %APM_CRITICAL_SUSPEND | |
715 | */ | |
716 | void apm_queue_event(apm_event_t event) | |
717 | { | |
718 | unsigned long flags; | |
719 | ||
720 | spin_lock_irqsave(&kapmd_queue_lock, flags); | |
721 | queue_add_event(&kapmd_queue, event); | |
722 | spin_unlock_irqrestore(&kapmd_queue_lock, flags); | |
723 | ||
724 | wake_up_interruptible(&kapmd_wait); | |
725 | } | |
726 | EXPORT_SYMBOL(apm_queue_event); |