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