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5e928f77 RW |
1 | /* |
2 | * drivers/base/power/runtime.c - Helper functions for device run-time PM | |
3 | * | |
4 | * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. | |
5 | * | |
6 | * This file is released under the GPLv2. | |
7 | */ | |
8 | ||
9 | #include <linux/sched.h> | |
10 | #include <linux/pm_runtime.h> | |
11 | #include <linux/jiffies.h> | |
12 | ||
13 | static int __pm_runtime_resume(struct device *dev, bool from_wq); | |
14 | static int __pm_request_idle(struct device *dev); | |
15 | static int __pm_request_resume(struct device *dev); | |
16 | ||
17 | /** | |
18 | * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. | |
19 | * @dev: Device to handle. | |
20 | */ | |
21 | static void pm_runtime_deactivate_timer(struct device *dev) | |
22 | { | |
23 | if (dev->power.timer_expires > 0) { | |
24 | del_timer(&dev->power.suspend_timer); | |
25 | dev->power.timer_expires = 0; | |
26 | } | |
27 | } | |
28 | ||
29 | /** | |
30 | * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests. | |
31 | * @dev: Device to handle. | |
32 | */ | |
33 | static void pm_runtime_cancel_pending(struct device *dev) | |
34 | { | |
35 | pm_runtime_deactivate_timer(dev); | |
36 | /* | |
37 | * In case there's a request pending, make sure its work function will | |
38 | * return without doing anything. | |
39 | */ | |
40 | dev->power.request = RPM_REQ_NONE; | |
41 | } | |
42 | ||
43 | /** | |
44 | * __pm_runtime_idle - Notify device bus type if the device can be suspended. | |
45 | * @dev: Device to notify the bus type about. | |
46 | * | |
47 | * This function must be called under dev->power.lock with interrupts disabled. | |
48 | */ | |
49 | static int __pm_runtime_idle(struct device *dev) | |
50 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
51 | { | |
52 | int retval = 0; | |
53 | ||
5e928f77 RW |
54 | if (dev->power.runtime_error) |
55 | retval = -EINVAL; | |
56 | else if (dev->power.idle_notification) | |
57 | retval = -EINPROGRESS; | |
58 | else if (atomic_read(&dev->power.usage_count) > 0 | |
59 | || dev->power.disable_depth > 0 | |
60 | || dev->power.runtime_status != RPM_ACTIVE) | |
61 | retval = -EAGAIN; | |
62 | else if (!pm_children_suspended(dev)) | |
63 | retval = -EBUSY; | |
64 | if (retval) | |
65 | goto out; | |
66 | ||
67 | if (dev->power.request_pending) { | |
68 | /* | |
69 | * If an idle notification request is pending, cancel it. Any | |
70 | * other pending request takes precedence over us. | |
71 | */ | |
72 | if (dev->power.request == RPM_REQ_IDLE) { | |
73 | dev->power.request = RPM_REQ_NONE; | |
74 | } else if (dev->power.request != RPM_REQ_NONE) { | |
75 | retval = -EAGAIN; | |
76 | goto out; | |
77 | } | |
78 | } | |
79 | ||
80 | dev->power.idle_notification = true; | |
81 | ||
82 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) { | |
83 | spin_unlock_irq(&dev->power.lock); | |
84 | ||
85 | dev->bus->pm->runtime_idle(dev); | |
86 | ||
a6ab7aa9 RW |
87 | spin_lock_irq(&dev->power.lock); |
88 | } else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle) { | |
89 | spin_unlock_irq(&dev->power.lock); | |
90 | ||
91 | dev->type->pm->runtime_idle(dev); | |
92 | ||
93 | spin_lock_irq(&dev->power.lock); | |
94 | } else if (dev->class && dev->class->pm | |
95 | && dev->class->pm->runtime_idle) { | |
96 | spin_unlock_irq(&dev->power.lock); | |
97 | ||
98 | dev->class->pm->runtime_idle(dev); | |
99 | ||
5e928f77 RW |
100 | spin_lock_irq(&dev->power.lock); |
101 | } | |
102 | ||
103 | dev->power.idle_notification = false; | |
104 | wake_up_all(&dev->power.wait_queue); | |
105 | ||
106 | out: | |
5e928f77 RW |
107 | return retval; |
108 | } | |
109 | ||
110 | /** | |
111 | * pm_runtime_idle - Notify device bus type if the device can be suspended. | |
112 | * @dev: Device to notify the bus type about. | |
113 | */ | |
114 | int pm_runtime_idle(struct device *dev) | |
115 | { | |
116 | int retval; | |
117 | ||
118 | spin_lock_irq(&dev->power.lock); | |
119 | retval = __pm_runtime_idle(dev); | |
120 | spin_unlock_irq(&dev->power.lock); | |
121 | ||
122 | return retval; | |
123 | } | |
124 | EXPORT_SYMBOL_GPL(pm_runtime_idle); | |
125 | ||
126 | /** | |
127 | * __pm_runtime_suspend - Carry out run-time suspend of given device. | |
128 | * @dev: Device to suspend. | |
129 | * @from_wq: If set, the function has been called via pm_wq. | |
130 | * | |
131 | * Check if the device can be suspended and run the ->runtime_suspend() callback | |
132 | * provided by its bus type. If another suspend has been started earlier, wait | |
133 | * for it to finish. If an idle notification or suspend request is pending or | |
134 | * scheduled, cancel it. | |
135 | * | |
136 | * This function must be called under dev->power.lock with interrupts disabled. | |
137 | */ | |
138 | int __pm_runtime_suspend(struct device *dev, bool from_wq) | |
139 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
140 | { | |
141 | struct device *parent = NULL; | |
142 | bool notify = false; | |
143 | int retval = 0; | |
144 | ||
145 | dev_dbg(dev, "__pm_runtime_suspend()%s!\n", | |
146 | from_wq ? " from workqueue" : ""); | |
147 | ||
148 | repeat: | |
149 | if (dev->power.runtime_error) { | |
150 | retval = -EINVAL; | |
151 | goto out; | |
152 | } | |
153 | ||
154 | /* Pending resume requests take precedence over us. */ | |
155 | if (dev->power.request_pending | |
156 | && dev->power.request == RPM_REQ_RESUME) { | |
157 | retval = -EAGAIN; | |
158 | goto out; | |
159 | } | |
160 | ||
161 | /* Other scheduled or pending requests need to be canceled. */ | |
162 | pm_runtime_cancel_pending(dev); | |
163 | ||
164 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
165 | retval = 1; | |
166 | else if (dev->power.runtime_status == RPM_RESUMING | |
167 | || dev->power.disable_depth > 0 | |
168 | || atomic_read(&dev->power.usage_count) > 0) | |
169 | retval = -EAGAIN; | |
170 | else if (!pm_children_suspended(dev)) | |
171 | retval = -EBUSY; | |
172 | if (retval) | |
173 | goto out; | |
174 | ||
175 | if (dev->power.runtime_status == RPM_SUSPENDING) { | |
176 | DEFINE_WAIT(wait); | |
177 | ||
178 | if (from_wq) { | |
179 | retval = -EINPROGRESS; | |
180 | goto out; | |
181 | } | |
182 | ||
183 | /* Wait for the other suspend running in parallel with us. */ | |
184 | for (;;) { | |
185 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
186 | TASK_UNINTERRUPTIBLE); | |
187 | if (dev->power.runtime_status != RPM_SUSPENDING) | |
188 | break; | |
189 | ||
190 | spin_unlock_irq(&dev->power.lock); | |
191 | ||
192 | schedule(); | |
193 | ||
194 | spin_lock_irq(&dev->power.lock); | |
195 | } | |
196 | finish_wait(&dev->power.wait_queue, &wait); | |
197 | goto repeat; | |
198 | } | |
199 | ||
200 | dev->power.runtime_status = RPM_SUSPENDING; | |
63c94801 | 201 | dev->power.deferred_resume = false; |
5e928f77 RW |
202 | |
203 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) { | |
204 | spin_unlock_irq(&dev->power.lock); | |
205 | ||
206 | retval = dev->bus->pm->runtime_suspend(dev); | |
207 | ||
a6ab7aa9 RW |
208 | spin_lock_irq(&dev->power.lock); |
209 | dev->power.runtime_error = retval; | |
210 | } else if (dev->type && dev->type->pm | |
211 | && dev->type->pm->runtime_suspend) { | |
212 | spin_unlock_irq(&dev->power.lock); | |
213 | ||
214 | retval = dev->type->pm->runtime_suspend(dev); | |
215 | ||
216 | spin_lock_irq(&dev->power.lock); | |
217 | dev->power.runtime_error = retval; | |
218 | } else if (dev->class && dev->class->pm | |
219 | && dev->class->pm->runtime_suspend) { | |
220 | spin_unlock_irq(&dev->power.lock); | |
221 | ||
222 | retval = dev->class->pm->runtime_suspend(dev); | |
223 | ||
5e928f77 RW |
224 | spin_lock_irq(&dev->power.lock); |
225 | dev->power.runtime_error = retval; | |
226 | } else { | |
227 | retval = -ENOSYS; | |
228 | } | |
229 | ||
230 | if (retval) { | |
231 | dev->power.runtime_status = RPM_ACTIVE; | |
5e928f77 | 232 | if (retval == -EAGAIN || retval == -EBUSY) { |
240c7337 AS |
233 | if (dev->power.timer_expires == 0) |
234 | notify = true; | |
5e928f77 | 235 | dev->power.runtime_error = 0; |
240c7337 AS |
236 | } else { |
237 | pm_runtime_cancel_pending(dev); | |
5e928f77 RW |
238 | } |
239 | } else { | |
240 | dev->power.runtime_status = RPM_SUSPENDED; | |
240c7337 | 241 | pm_runtime_deactivate_timer(dev); |
5e928f77 RW |
242 | |
243 | if (dev->parent) { | |
244 | parent = dev->parent; | |
245 | atomic_add_unless(&parent->power.child_count, -1, 0); | |
246 | } | |
247 | } | |
248 | wake_up_all(&dev->power.wait_queue); | |
249 | ||
250 | if (dev->power.deferred_resume) { | |
5e928f77 RW |
251 | __pm_runtime_resume(dev, false); |
252 | retval = -EAGAIN; | |
253 | goto out; | |
254 | } | |
255 | ||
256 | if (notify) | |
257 | __pm_runtime_idle(dev); | |
258 | ||
259 | if (parent && !parent->power.ignore_children) { | |
260 | spin_unlock_irq(&dev->power.lock); | |
261 | ||
262 | pm_request_idle(parent); | |
263 | ||
264 | spin_lock_irq(&dev->power.lock); | |
265 | } | |
266 | ||
267 | out: | |
268 | dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval); | |
269 | ||
270 | return retval; | |
271 | } | |
272 | ||
273 | /** | |
274 | * pm_runtime_suspend - Carry out run-time suspend of given device. | |
275 | * @dev: Device to suspend. | |
276 | */ | |
277 | int pm_runtime_suspend(struct device *dev) | |
278 | { | |
279 | int retval; | |
280 | ||
281 | spin_lock_irq(&dev->power.lock); | |
282 | retval = __pm_runtime_suspend(dev, false); | |
283 | spin_unlock_irq(&dev->power.lock); | |
284 | ||
285 | return retval; | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(pm_runtime_suspend); | |
288 | ||
289 | /** | |
290 | * __pm_runtime_resume - Carry out run-time resume of given device. | |
291 | * @dev: Device to resume. | |
292 | * @from_wq: If set, the function has been called via pm_wq. | |
293 | * | |
294 | * Check if the device can be woken up and run the ->runtime_resume() callback | |
295 | * provided by its bus type. If another resume has been started earlier, wait | |
296 | * for it to finish. If there's a suspend running in parallel with this | |
297 | * function, wait for it to finish and resume the device. Cancel any scheduled | |
298 | * or pending requests. | |
299 | * | |
300 | * This function must be called under dev->power.lock with interrupts disabled. | |
301 | */ | |
302 | int __pm_runtime_resume(struct device *dev, bool from_wq) | |
303 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
304 | { | |
305 | struct device *parent = NULL; | |
306 | int retval = 0; | |
307 | ||
308 | dev_dbg(dev, "__pm_runtime_resume()%s!\n", | |
309 | from_wq ? " from workqueue" : ""); | |
310 | ||
311 | repeat: | |
312 | if (dev->power.runtime_error) { | |
313 | retval = -EINVAL; | |
314 | goto out; | |
315 | } | |
316 | ||
317 | pm_runtime_cancel_pending(dev); | |
318 | ||
319 | if (dev->power.runtime_status == RPM_ACTIVE) | |
320 | retval = 1; | |
321 | else if (dev->power.disable_depth > 0) | |
322 | retval = -EAGAIN; | |
323 | if (retval) | |
324 | goto out; | |
325 | ||
326 | if (dev->power.runtime_status == RPM_RESUMING | |
327 | || dev->power.runtime_status == RPM_SUSPENDING) { | |
328 | DEFINE_WAIT(wait); | |
329 | ||
330 | if (from_wq) { | |
331 | if (dev->power.runtime_status == RPM_SUSPENDING) | |
332 | dev->power.deferred_resume = true; | |
333 | retval = -EINPROGRESS; | |
334 | goto out; | |
335 | } | |
336 | ||
337 | /* Wait for the operation carried out in parallel with us. */ | |
338 | for (;;) { | |
339 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
340 | TASK_UNINTERRUPTIBLE); | |
341 | if (dev->power.runtime_status != RPM_RESUMING | |
342 | && dev->power.runtime_status != RPM_SUSPENDING) | |
343 | break; | |
344 | ||
345 | spin_unlock_irq(&dev->power.lock); | |
346 | ||
347 | schedule(); | |
348 | ||
349 | spin_lock_irq(&dev->power.lock); | |
350 | } | |
351 | finish_wait(&dev->power.wait_queue, &wait); | |
352 | goto repeat; | |
353 | } | |
354 | ||
355 | if (!parent && dev->parent) { | |
356 | /* | |
357 | * Increment the parent's resume counter and resume it if | |
358 | * necessary. | |
359 | */ | |
360 | parent = dev->parent; | |
862f89b3 | 361 | spin_unlock(&dev->power.lock); |
5e928f77 RW |
362 | |
363 | pm_runtime_get_noresume(parent); | |
364 | ||
862f89b3 | 365 | spin_lock(&parent->power.lock); |
5e928f77 RW |
366 | /* |
367 | * We can resume if the parent's run-time PM is disabled or it | |
368 | * is set to ignore children. | |
369 | */ | |
370 | if (!parent->power.disable_depth | |
371 | && !parent->power.ignore_children) { | |
372 | __pm_runtime_resume(parent, false); | |
373 | if (parent->power.runtime_status != RPM_ACTIVE) | |
374 | retval = -EBUSY; | |
375 | } | |
862f89b3 | 376 | spin_unlock(&parent->power.lock); |
5e928f77 | 377 | |
862f89b3 | 378 | spin_lock(&dev->power.lock); |
5e928f77 RW |
379 | if (retval) |
380 | goto out; | |
381 | goto repeat; | |
382 | } | |
383 | ||
384 | dev->power.runtime_status = RPM_RESUMING; | |
385 | ||
386 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) { | |
387 | spin_unlock_irq(&dev->power.lock); | |
388 | ||
389 | retval = dev->bus->pm->runtime_resume(dev); | |
390 | ||
a6ab7aa9 RW |
391 | spin_lock_irq(&dev->power.lock); |
392 | dev->power.runtime_error = retval; | |
393 | } else if (dev->type && dev->type->pm | |
394 | && dev->type->pm->runtime_resume) { | |
395 | spin_unlock_irq(&dev->power.lock); | |
396 | ||
397 | retval = dev->type->pm->runtime_resume(dev); | |
398 | ||
399 | spin_lock_irq(&dev->power.lock); | |
400 | dev->power.runtime_error = retval; | |
401 | } else if (dev->class && dev->class->pm | |
402 | && dev->class->pm->runtime_resume) { | |
403 | spin_unlock_irq(&dev->power.lock); | |
404 | ||
405 | retval = dev->class->pm->runtime_resume(dev); | |
406 | ||
5e928f77 RW |
407 | spin_lock_irq(&dev->power.lock); |
408 | dev->power.runtime_error = retval; | |
409 | } else { | |
410 | retval = -ENOSYS; | |
411 | } | |
412 | ||
413 | if (retval) { | |
414 | dev->power.runtime_status = RPM_SUSPENDED; | |
415 | pm_runtime_cancel_pending(dev); | |
416 | } else { | |
417 | dev->power.runtime_status = RPM_ACTIVE; | |
418 | if (parent) | |
419 | atomic_inc(&parent->power.child_count); | |
420 | } | |
421 | wake_up_all(&dev->power.wait_queue); | |
422 | ||
423 | if (!retval) | |
424 | __pm_request_idle(dev); | |
425 | ||
426 | out: | |
427 | if (parent) { | |
428 | spin_unlock_irq(&dev->power.lock); | |
429 | ||
430 | pm_runtime_put(parent); | |
431 | ||
432 | spin_lock_irq(&dev->power.lock); | |
433 | } | |
434 | ||
435 | dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval); | |
436 | ||
437 | return retval; | |
438 | } | |
439 | ||
440 | /** | |
441 | * pm_runtime_resume - Carry out run-time resume of given device. | |
442 | * @dev: Device to suspend. | |
443 | */ | |
444 | int pm_runtime_resume(struct device *dev) | |
445 | { | |
446 | int retval; | |
447 | ||
448 | spin_lock_irq(&dev->power.lock); | |
449 | retval = __pm_runtime_resume(dev, false); | |
450 | spin_unlock_irq(&dev->power.lock); | |
451 | ||
452 | return retval; | |
453 | } | |
454 | EXPORT_SYMBOL_GPL(pm_runtime_resume); | |
455 | ||
456 | /** | |
457 | * pm_runtime_work - Universal run-time PM work function. | |
458 | * @work: Work structure used for scheduling the execution of this function. | |
459 | * | |
460 | * Use @work to get the device object the work is to be done for, determine what | |
461 | * is to be done and execute the appropriate run-time PM function. | |
462 | */ | |
463 | static void pm_runtime_work(struct work_struct *work) | |
464 | { | |
465 | struct device *dev = container_of(work, struct device, power.work); | |
466 | enum rpm_request req; | |
467 | ||
468 | spin_lock_irq(&dev->power.lock); | |
469 | ||
470 | if (!dev->power.request_pending) | |
471 | goto out; | |
472 | ||
473 | req = dev->power.request; | |
474 | dev->power.request = RPM_REQ_NONE; | |
475 | dev->power.request_pending = false; | |
476 | ||
477 | switch (req) { | |
478 | case RPM_REQ_NONE: | |
479 | break; | |
480 | case RPM_REQ_IDLE: | |
481 | __pm_runtime_idle(dev); | |
482 | break; | |
483 | case RPM_REQ_SUSPEND: | |
484 | __pm_runtime_suspend(dev, true); | |
485 | break; | |
486 | case RPM_REQ_RESUME: | |
487 | __pm_runtime_resume(dev, true); | |
488 | break; | |
489 | } | |
490 | ||
491 | out: | |
492 | spin_unlock_irq(&dev->power.lock); | |
493 | } | |
494 | ||
495 | /** | |
496 | * __pm_request_idle - Submit an idle notification request for given device. | |
497 | * @dev: Device to handle. | |
498 | * | |
499 | * Check if the device's run-time PM status is correct for suspending the device | |
500 | * and queue up a request to run __pm_runtime_idle() for it. | |
501 | * | |
502 | * This function must be called under dev->power.lock with interrupts disabled. | |
503 | */ | |
504 | static int __pm_request_idle(struct device *dev) | |
505 | { | |
506 | int retval = 0; | |
507 | ||
508 | if (dev->power.runtime_error) | |
509 | retval = -EINVAL; | |
510 | else if (atomic_read(&dev->power.usage_count) > 0 | |
511 | || dev->power.disable_depth > 0 | |
512 | || dev->power.runtime_status == RPM_SUSPENDED | |
513 | || dev->power.runtime_status == RPM_SUSPENDING) | |
514 | retval = -EAGAIN; | |
515 | else if (!pm_children_suspended(dev)) | |
516 | retval = -EBUSY; | |
517 | if (retval) | |
518 | return retval; | |
519 | ||
520 | if (dev->power.request_pending) { | |
521 | /* Any requests other then RPM_REQ_IDLE take precedence. */ | |
522 | if (dev->power.request == RPM_REQ_NONE) | |
523 | dev->power.request = RPM_REQ_IDLE; | |
524 | else if (dev->power.request != RPM_REQ_IDLE) | |
525 | retval = -EAGAIN; | |
526 | return retval; | |
527 | } | |
528 | ||
529 | dev->power.request = RPM_REQ_IDLE; | |
530 | dev->power.request_pending = true; | |
531 | queue_work(pm_wq, &dev->power.work); | |
532 | ||
533 | return retval; | |
534 | } | |
535 | ||
536 | /** | |
537 | * pm_request_idle - Submit an idle notification request for given device. | |
538 | * @dev: Device to handle. | |
539 | */ | |
540 | int pm_request_idle(struct device *dev) | |
541 | { | |
542 | unsigned long flags; | |
543 | int retval; | |
544 | ||
545 | spin_lock_irqsave(&dev->power.lock, flags); | |
546 | retval = __pm_request_idle(dev); | |
547 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
548 | ||
549 | return retval; | |
550 | } | |
551 | EXPORT_SYMBOL_GPL(pm_request_idle); | |
552 | ||
553 | /** | |
554 | * __pm_request_suspend - Submit a suspend request for given device. | |
555 | * @dev: Device to suspend. | |
556 | * | |
557 | * This function must be called under dev->power.lock with interrupts disabled. | |
558 | */ | |
559 | static int __pm_request_suspend(struct device *dev) | |
560 | { | |
561 | int retval = 0; | |
562 | ||
563 | if (dev->power.runtime_error) | |
564 | return -EINVAL; | |
565 | ||
566 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
567 | retval = 1; | |
568 | else if (atomic_read(&dev->power.usage_count) > 0 | |
569 | || dev->power.disable_depth > 0) | |
570 | retval = -EAGAIN; | |
571 | else if (dev->power.runtime_status == RPM_SUSPENDING) | |
572 | retval = -EINPROGRESS; | |
573 | else if (!pm_children_suspended(dev)) | |
574 | retval = -EBUSY; | |
575 | if (retval < 0) | |
576 | return retval; | |
577 | ||
578 | pm_runtime_deactivate_timer(dev); | |
579 | ||
580 | if (dev->power.request_pending) { | |
581 | /* | |
582 | * Pending resume requests take precedence over us, but we can | |
583 | * overtake any other pending request. | |
584 | */ | |
585 | if (dev->power.request == RPM_REQ_RESUME) | |
586 | retval = -EAGAIN; | |
587 | else if (dev->power.request != RPM_REQ_SUSPEND) | |
588 | dev->power.request = retval ? | |
589 | RPM_REQ_NONE : RPM_REQ_SUSPEND; | |
590 | return retval; | |
591 | } else if (retval) { | |
592 | return retval; | |
593 | } | |
594 | ||
595 | dev->power.request = RPM_REQ_SUSPEND; | |
596 | dev->power.request_pending = true; | |
597 | queue_work(pm_wq, &dev->power.work); | |
598 | ||
599 | return 0; | |
600 | } | |
601 | ||
602 | /** | |
603 | * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). | |
604 | * @data: Device pointer passed by pm_schedule_suspend(). | |
605 | * | |
606 | * Check if the time is right and execute __pm_request_suspend() in that case. | |
607 | */ | |
608 | static void pm_suspend_timer_fn(unsigned long data) | |
609 | { | |
610 | struct device *dev = (struct device *)data; | |
611 | unsigned long flags; | |
612 | unsigned long expires; | |
613 | ||
614 | spin_lock_irqsave(&dev->power.lock, flags); | |
615 | ||
616 | expires = dev->power.timer_expires; | |
617 | /* If 'expire' is after 'jiffies' we've been called too early. */ | |
618 | if (expires > 0 && !time_after(expires, jiffies)) { | |
619 | dev->power.timer_expires = 0; | |
620 | __pm_request_suspend(dev); | |
621 | } | |
622 | ||
623 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
624 | } | |
625 | ||
626 | /** | |
627 | * pm_schedule_suspend - Set up a timer to submit a suspend request in future. | |
628 | * @dev: Device to suspend. | |
629 | * @delay: Time to wait before submitting a suspend request, in milliseconds. | |
630 | */ | |
631 | int pm_schedule_suspend(struct device *dev, unsigned int delay) | |
632 | { | |
633 | unsigned long flags; | |
634 | int retval = 0; | |
635 | ||
636 | spin_lock_irqsave(&dev->power.lock, flags); | |
637 | ||
638 | if (dev->power.runtime_error) { | |
639 | retval = -EINVAL; | |
640 | goto out; | |
641 | } | |
642 | ||
643 | if (!delay) { | |
644 | retval = __pm_request_suspend(dev); | |
645 | goto out; | |
646 | } | |
647 | ||
648 | pm_runtime_deactivate_timer(dev); | |
649 | ||
650 | if (dev->power.request_pending) { | |
651 | /* | |
652 | * Pending resume requests take precedence over us, but any | |
653 | * other pending requests have to be canceled. | |
654 | */ | |
655 | if (dev->power.request == RPM_REQ_RESUME) { | |
656 | retval = -EAGAIN; | |
657 | goto out; | |
658 | } | |
659 | dev->power.request = RPM_REQ_NONE; | |
660 | } | |
661 | ||
662 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
663 | retval = 1; | |
5e928f77 RW |
664 | else if (atomic_read(&dev->power.usage_count) > 0 |
665 | || dev->power.disable_depth > 0) | |
666 | retval = -EAGAIN; | |
667 | else if (!pm_children_suspended(dev)) | |
668 | retval = -EBUSY; | |
669 | if (retval) | |
670 | goto out; | |
671 | ||
672 | dev->power.timer_expires = jiffies + msecs_to_jiffies(delay); | |
0ddf0ed1 RW |
673 | if (!dev->power.timer_expires) |
674 | dev->power.timer_expires = 1; | |
5e928f77 RW |
675 | mod_timer(&dev->power.suspend_timer, dev->power.timer_expires); |
676 | ||
677 | out: | |
678 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
679 | ||
680 | return retval; | |
681 | } | |
682 | EXPORT_SYMBOL_GPL(pm_schedule_suspend); | |
683 | ||
684 | /** | |
685 | * pm_request_resume - Submit a resume request for given device. | |
686 | * @dev: Device to resume. | |
687 | * | |
688 | * This function must be called under dev->power.lock with interrupts disabled. | |
689 | */ | |
690 | static int __pm_request_resume(struct device *dev) | |
691 | { | |
692 | int retval = 0; | |
693 | ||
694 | if (dev->power.runtime_error) | |
695 | return -EINVAL; | |
696 | ||
697 | if (dev->power.runtime_status == RPM_ACTIVE) | |
698 | retval = 1; | |
699 | else if (dev->power.runtime_status == RPM_RESUMING) | |
700 | retval = -EINPROGRESS; | |
701 | else if (dev->power.disable_depth > 0) | |
702 | retval = -EAGAIN; | |
703 | if (retval < 0) | |
704 | return retval; | |
705 | ||
706 | pm_runtime_deactivate_timer(dev); | |
707 | ||
63c94801 AS |
708 | if (dev->power.runtime_status == RPM_SUSPENDING) { |
709 | dev->power.deferred_resume = true; | |
710 | return retval; | |
711 | } | |
5e928f77 RW |
712 | if (dev->power.request_pending) { |
713 | /* If non-resume request is pending, we can overtake it. */ | |
714 | dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME; | |
715 | return retval; | |
5e928f77 | 716 | } |
63c94801 AS |
717 | if (retval) |
718 | return retval; | |
5e928f77 RW |
719 | |
720 | dev->power.request = RPM_REQ_RESUME; | |
721 | dev->power.request_pending = true; | |
722 | queue_work(pm_wq, &dev->power.work); | |
723 | ||
724 | return retval; | |
725 | } | |
726 | ||
727 | /** | |
728 | * pm_request_resume - Submit a resume request for given device. | |
729 | * @dev: Device to resume. | |
730 | */ | |
731 | int pm_request_resume(struct device *dev) | |
732 | { | |
733 | unsigned long flags; | |
734 | int retval; | |
735 | ||
736 | spin_lock_irqsave(&dev->power.lock, flags); | |
737 | retval = __pm_request_resume(dev); | |
738 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
739 | ||
740 | return retval; | |
741 | } | |
742 | EXPORT_SYMBOL_GPL(pm_request_resume); | |
743 | ||
744 | /** | |
745 | * __pm_runtime_get - Reference count a device and wake it up, if necessary. | |
746 | * @dev: Device to handle. | |
747 | * @sync: If set and the device is suspended, resume it synchronously. | |
748 | * | |
1d531c14 AS |
749 | * Increment the usage count of the device and resume it or submit a resume |
750 | * request for it, depending on the value of @sync. | |
5e928f77 RW |
751 | */ |
752 | int __pm_runtime_get(struct device *dev, bool sync) | |
753 | { | |
1d531c14 | 754 | int retval; |
5e928f77 | 755 | |
1d531c14 AS |
756 | atomic_inc(&dev->power.usage_count); |
757 | retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev); | |
5e928f77 RW |
758 | |
759 | return retval; | |
760 | } | |
761 | EXPORT_SYMBOL_GPL(__pm_runtime_get); | |
762 | ||
763 | /** | |
764 | * __pm_runtime_put - Decrement the device's usage counter and notify its bus. | |
765 | * @dev: Device to handle. | |
766 | * @sync: If the device's bus type is to be notified, do that synchronously. | |
767 | * | |
768 | * Decrement the usage count of the device and if it reaches zero, carry out a | |
769 | * synchronous idle notification or submit an idle notification request for it, | |
770 | * depending on the value of @sync. | |
771 | */ | |
772 | int __pm_runtime_put(struct device *dev, bool sync) | |
773 | { | |
774 | int retval = 0; | |
775 | ||
776 | if (atomic_dec_and_test(&dev->power.usage_count)) | |
777 | retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev); | |
778 | ||
779 | return retval; | |
780 | } | |
781 | EXPORT_SYMBOL_GPL(__pm_runtime_put); | |
782 | ||
783 | /** | |
784 | * __pm_runtime_set_status - Set run-time PM status of a device. | |
785 | * @dev: Device to handle. | |
786 | * @status: New run-time PM status of the device. | |
787 | * | |
788 | * If run-time PM of the device is disabled or its power.runtime_error field is | |
789 | * different from zero, the status may be changed either to RPM_ACTIVE, or to | |
790 | * RPM_SUSPENDED, as long as that reflects the actual state of the device. | |
791 | * However, if the device has a parent and the parent is not active, and the | |
792 | * parent's power.ignore_children flag is unset, the device's status cannot be | |
793 | * set to RPM_ACTIVE, so -EBUSY is returned in that case. | |
794 | * | |
795 | * If successful, __pm_runtime_set_status() clears the power.runtime_error field | |
796 | * and the device parent's counter of unsuspended children is modified to | |
797 | * reflect the new status. If the new status is RPM_SUSPENDED, an idle | |
798 | * notification request for the parent is submitted. | |
799 | */ | |
800 | int __pm_runtime_set_status(struct device *dev, unsigned int status) | |
801 | { | |
802 | struct device *parent = dev->parent; | |
803 | unsigned long flags; | |
804 | bool notify_parent = false; | |
805 | int error = 0; | |
806 | ||
807 | if (status != RPM_ACTIVE && status != RPM_SUSPENDED) | |
808 | return -EINVAL; | |
809 | ||
810 | spin_lock_irqsave(&dev->power.lock, flags); | |
811 | ||
812 | if (!dev->power.runtime_error && !dev->power.disable_depth) { | |
813 | error = -EAGAIN; | |
814 | goto out; | |
815 | } | |
816 | ||
817 | if (dev->power.runtime_status == status) | |
818 | goto out_set; | |
819 | ||
820 | if (status == RPM_SUSPENDED) { | |
821 | /* It always is possible to set the status to 'suspended'. */ | |
822 | if (parent) { | |
823 | atomic_add_unless(&parent->power.child_count, -1, 0); | |
824 | notify_parent = !parent->power.ignore_children; | |
825 | } | |
826 | goto out_set; | |
827 | } | |
828 | ||
829 | if (parent) { | |
bab636b9 | 830 | spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING); |
5e928f77 RW |
831 | |
832 | /* | |
833 | * It is invalid to put an active child under a parent that is | |
834 | * not active, has run-time PM enabled and the | |
835 | * 'power.ignore_children' flag unset. | |
836 | */ | |
837 | if (!parent->power.disable_depth | |
838 | && !parent->power.ignore_children | |
965c4ac0 | 839 | && parent->power.runtime_status != RPM_ACTIVE) |
5e928f77 | 840 | error = -EBUSY; |
965c4ac0 RW |
841 | else if (dev->power.runtime_status == RPM_SUSPENDED) |
842 | atomic_inc(&parent->power.child_count); | |
5e928f77 | 843 | |
862f89b3 | 844 | spin_unlock(&parent->power.lock); |
5e928f77 RW |
845 | |
846 | if (error) | |
847 | goto out; | |
848 | } | |
849 | ||
850 | out_set: | |
851 | dev->power.runtime_status = status; | |
852 | dev->power.runtime_error = 0; | |
853 | out: | |
854 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
855 | ||
856 | if (notify_parent) | |
857 | pm_request_idle(parent); | |
858 | ||
859 | return error; | |
860 | } | |
861 | EXPORT_SYMBOL_GPL(__pm_runtime_set_status); | |
862 | ||
863 | /** | |
864 | * __pm_runtime_barrier - Cancel pending requests and wait for completions. | |
865 | * @dev: Device to handle. | |
866 | * | |
867 | * Flush all pending requests for the device from pm_wq and wait for all | |
868 | * run-time PM operations involving the device in progress to complete. | |
869 | * | |
870 | * Should be called under dev->power.lock with interrupts disabled. | |
871 | */ | |
872 | static void __pm_runtime_barrier(struct device *dev) | |
873 | { | |
874 | pm_runtime_deactivate_timer(dev); | |
875 | ||
876 | if (dev->power.request_pending) { | |
877 | dev->power.request = RPM_REQ_NONE; | |
878 | spin_unlock_irq(&dev->power.lock); | |
879 | ||
880 | cancel_work_sync(&dev->power.work); | |
881 | ||
882 | spin_lock_irq(&dev->power.lock); | |
883 | dev->power.request_pending = false; | |
884 | } | |
885 | ||
886 | if (dev->power.runtime_status == RPM_SUSPENDING | |
887 | || dev->power.runtime_status == RPM_RESUMING | |
888 | || dev->power.idle_notification) { | |
889 | DEFINE_WAIT(wait); | |
890 | ||
891 | /* Suspend, wake-up or idle notification in progress. */ | |
892 | for (;;) { | |
893 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
894 | TASK_UNINTERRUPTIBLE); | |
895 | if (dev->power.runtime_status != RPM_SUSPENDING | |
896 | && dev->power.runtime_status != RPM_RESUMING | |
897 | && !dev->power.idle_notification) | |
898 | break; | |
899 | spin_unlock_irq(&dev->power.lock); | |
900 | ||
901 | schedule(); | |
902 | ||
903 | spin_lock_irq(&dev->power.lock); | |
904 | } | |
905 | finish_wait(&dev->power.wait_queue, &wait); | |
906 | } | |
907 | } | |
908 | ||
909 | /** | |
910 | * pm_runtime_barrier - Flush pending requests and wait for completions. | |
911 | * @dev: Device to handle. | |
912 | * | |
913 | * Prevent the device from being suspended by incrementing its usage counter and | |
914 | * if there's a pending resume request for the device, wake the device up. | |
915 | * Next, make sure that all pending requests for the device have been flushed | |
916 | * from pm_wq and wait for all run-time PM operations involving the device in | |
917 | * progress to complete. | |
918 | * | |
919 | * Return value: | |
920 | * 1, if there was a resume request pending and the device had to be woken up, | |
921 | * 0, otherwise | |
922 | */ | |
923 | int pm_runtime_barrier(struct device *dev) | |
924 | { | |
925 | int retval = 0; | |
926 | ||
927 | pm_runtime_get_noresume(dev); | |
928 | spin_lock_irq(&dev->power.lock); | |
929 | ||
930 | if (dev->power.request_pending | |
931 | && dev->power.request == RPM_REQ_RESUME) { | |
932 | __pm_runtime_resume(dev, false); | |
933 | retval = 1; | |
934 | } | |
935 | ||
936 | __pm_runtime_barrier(dev); | |
937 | ||
938 | spin_unlock_irq(&dev->power.lock); | |
939 | pm_runtime_put_noidle(dev); | |
940 | ||
941 | return retval; | |
942 | } | |
943 | EXPORT_SYMBOL_GPL(pm_runtime_barrier); | |
944 | ||
945 | /** | |
946 | * __pm_runtime_disable - Disable run-time PM of a device. | |
947 | * @dev: Device to handle. | |
948 | * @check_resume: If set, check if there's a resume request for the device. | |
949 | * | |
950 | * Increment power.disable_depth for the device and if was zero previously, | |
951 | * cancel all pending run-time PM requests for the device and wait for all | |
952 | * operations in progress to complete. The device can be either active or | |
953 | * suspended after its run-time PM has been disabled. | |
954 | * | |
955 | * If @check_resume is set and there's a resume request pending when | |
956 | * __pm_runtime_disable() is called and power.disable_depth is zero, the | |
957 | * function will wake up the device before disabling its run-time PM. | |
958 | */ | |
959 | void __pm_runtime_disable(struct device *dev, bool check_resume) | |
960 | { | |
961 | spin_lock_irq(&dev->power.lock); | |
962 | ||
963 | if (dev->power.disable_depth > 0) { | |
964 | dev->power.disable_depth++; | |
965 | goto out; | |
966 | } | |
967 | ||
968 | /* | |
969 | * Wake up the device if there's a resume request pending, because that | |
970 | * means there probably is some I/O to process and disabling run-time PM | |
971 | * shouldn't prevent the device from processing the I/O. | |
972 | */ | |
973 | if (check_resume && dev->power.request_pending | |
974 | && dev->power.request == RPM_REQ_RESUME) { | |
975 | /* | |
976 | * Prevent suspends and idle notifications from being carried | |
977 | * out after we have woken up the device. | |
978 | */ | |
979 | pm_runtime_get_noresume(dev); | |
980 | ||
981 | __pm_runtime_resume(dev, false); | |
982 | ||
983 | pm_runtime_put_noidle(dev); | |
984 | } | |
985 | ||
986 | if (!dev->power.disable_depth++) | |
987 | __pm_runtime_barrier(dev); | |
988 | ||
989 | out: | |
990 | spin_unlock_irq(&dev->power.lock); | |
991 | } | |
992 | EXPORT_SYMBOL_GPL(__pm_runtime_disable); | |
993 | ||
994 | /** | |
995 | * pm_runtime_enable - Enable run-time PM of a device. | |
996 | * @dev: Device to handle. | |
997 | */ | |
998 | void pm_runtime_enable(struct device *dev) | |
999 | { | |
1000 | unsigned long flags; | |
1001 | ||
1002 | spin_lock_irqsave(&dev->power.lock, flags); | |
1003 | ||
1004 | if (dev->power.disable_depth > 0) | |
1005 | dev->power.disable_depth--; | |
1006 | else | |
1007 | dev_warn(dev, "Unbalanced %s!\n", __func__); | |
1008 | ||
1009 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
1010 | } | |
1011 | EXPORT_SYMBOL_GPL(pm_runtime_enable); | |
1012 | ||
53823639 RW |
1013 | /** |
1014 | * pm_runtime_forbid - Block run-time PM of a device. | |
1015 | * @dev: Device to handle. | |
1016 | * | |
1017 | * Increase the device's usage count and clear its power.runtime_auto flag, | |
1018 | * so that it cannot be suspended at run time until pm_runtime_allow() is called | |
1019 | * for it. | |
1020 | */ | |
1021 | void pm_runtime_forbid(struct device *dev) | |
1022 | { | |
1023 | spin_lock_irq(&dev->power.lock); | |
1024 | if (!dev->power.runtime_auto) | |
1025 | goto out; | |
1026 | ||
1027 | dev->power.runtime_auto = false; | |
1028 | atomic_inc(&dev->power.usage_count); | |
1029 | __pm_runtime_resume(dev, false); | |
1030 | ||
1031 | out: | |
1032 | spin_unlock_irq(&dev->power.lock); | |
1033 | } | |
1034 | EXPORT_SYMBOL_GPL(pm_runtime_forbid); | |
1035 | ||
1036 | /** | |
1037 | * pm_runtime_allow - Unblock run-time PM of a device. | |
1038 | * @dev: Device to handle. | |
1039 | * | |
1040 | * Decrease the device's usage count and set its power.runtime_auto flag. | |
1041 | */ | |
1042 | void pm_runtime_allow(struct device *dev) | |
1043 | { | |
1044 | spin_lock_irq(&dev->power.lock); | |
1045 | if (dev->power.runtime_auto) | |
1046 | goto out; | |
1047 | ||
1048 | dev->power.runtime_auto = true; | |
1049 | if (atomic_dec_and_test(&dev->power.usage_count)) | |
1050 | __pm_runtime_idle(dev); | |
1051 | ||
1052 | out: | |
1053 | spin_unlock_irq(&dev->power.lock); | |
1054 | } | |
1055 | EXPORT_SYMBOL_GPL(pm_runtime_allow); | |
1056 | ||
5e928f77 RW |
1057 | /** |
1058 | * pm_runtime_init - Initialize run-time PM fields in given device object. | |
1059 | * @dev: Device object to initialize. | |
1060 | */ | |
1061 | void pm_runtime_init(struct device *dev) | |
1062 | { | |
1063 | spin_lock_init(&dev->power.lock); | |
1064 | ||
1065 | dev->power.runtime_status = RPM_SUSPENDED; | |
1066 | dev->power.idle_notification = false; | |
1067 | ||
1068 | dev->power.disable_depth = 1; | |
1069 | atomic_set(&dev->power.usage_count, 0); | |
1070 | ||
1071 | dev->power.runtime_error = 0; | |
1072 | ||
1073 | atomic_set(&dev->power.child_count, 0); | |
1074 | pm_suspend_ignore_children(dev, false); | |
53823639 | 1075 | dev->power.runtime_auto = true; |
5e928f77 RW |
1076 | |
1077 | dev->power.request_pending = false; | |
1078 | dev->power.request = RPM_REQ_NONE; | |
1079 | dev->power.deferred_resume = false; | |
1080 | INIT_WORK(&dev->power.work, pm_runtime_work); | |
1081 | ||
1082 | dev->power.timer_expires = 0; | |
1083 | setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn, | |
1084 | (unsigned long)dev); | |
1085 | ||
1086 | init_waitqueue_head(&dev->power.wait_queue); | |
1087 | } | |
1088 | ||
1089 | /** | |
1090 | * pm_runtime_remove - Prepare for removing a device from device hierarchy. | |
1091 | * @dev: Device object being removed from device hierarchy. | |
1092 | */ | |
1093 | void pm_runtime_remove(struct device *dev) | |
1094 | { | |
1095 | __pm_runtime_disable(dev, false); | |
1096 | ||
1097 | /* Change the status back to 'suspended' to match the initial status. */ | |
1098 | if (dev->power.runtime_status == RPM_ACTIVE) | |
1099 | pm_runtime_set_suspended(dev); | |
1100 | } |