blob: e957c496a1b19b25f0b8ab95c6daea78aa06a1cb [file] [log] [blame]
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +02001/*
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.
Alan Stern1bfee5b2010-09-25 23:35:00 +02005 * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +02006 *
7 * This file is released under the GPLv2.
8 */
9
10#include <linux/sched.h>
11#include <linux/pm_runtime.h>
Alan Stern7490e442010-09-25 23:35:15 +020012#include "power.h"
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +020013
Alan Stern140a6c92010-09-25 23:35:07 +020014static int rpm_resume(struct device *dev, int rpmflags);
Alan Stern7490e442010-09-25 23:35:15 +020015static int rpm_suspend(struct device *dev, int rpmflags);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +020016
17/**
Alan Stern47693732010-09-25 23:34:46 +020018 * update_pm_runtime_accounting - Update the time accounting of power states
19 * @dev: Device to update the accounting for
20 *
21 * In order to be able to have time accounting of the various power states
22 * (as used by programs such as PowerTOP to show the effectiveness of runtime
23 * PM), we need to track the time spent in each state.
24 * update_pm_runtime_accounting must be called each time before the
25 * runtime_status field is updated, to account the time in the old state
26 * correctly.
27 */
28void update_pm_runtime_accounting(struct device *dev)
29{
30 unsigned long now = jiffies;
31 int delta;
32
33 delta = now - dev->power.accounting_timestamp;
34
35 if (delta < 0)
36 delta = 0;
37
38 dev->power.accounting_timestamp = now;
39
40 if (dev->power.disable_depth > 0)
41 return;
42
43 if (dev->power.runtime_status == RPM_SUSPENDED)
44 dev->power.suspended_jiffies += delta;
45 else
46 dev->power.active_jiffies += delta;
47}
48
49static void __update_runtime_status(struct device *dev, enum rpm_status status)
50{
51 update_pm_runtime_accounting(dev);
52 dev->power.runtime_status = status;
53}
54
55/**
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +020056 * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
57 * @dev: Device to handle.
58 */
59static void pm_runtime_deactivate_timer(struct device *dev)
60{
61 if (dev->power.timer_expires > 0) {
62 del_timer(&dev->power.suspend_timer);
63 dev->power.timer_expires = 0;
64 }
65}
66
67/**
68 * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
69 * @dev: Device to handle.
70 */
71static void pm_runtime_cancel_pending(struct device *dev)
72{
73 pm_runtime_deactivate_timer(dev);
74 /*
75 * In case there's a request pending, make sure its work function will
76 * return without doing anything.
77 */
78 dev->power.request = RPM_REQ_NONE;
79}
80
Alan Stern15bcb912010-09-25 23:35:21 +020081/*
82 * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
83 * @dev: Device to handle.
84 *
85 * Compute the autosuspend-delay expiration time based on the device's
86 * power.last_busy time. If the delay has already expired or is disabled
87 * (negative) or the power.use_autosuspend flag isn't set, return 0.
88 * Otherwise return the expiration time in jiffies (adjusted to be nonzero).
89 *
90 * This function may be called either with or without dev->power.lock held.
91 * Either way it can be racy, since power.last_busy may be updated at any time.
92 */
93unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
94{
95 int autosuspend_delay;
96 long elapsed;
97 unsigned long last_busy;
98 unsigned long expires = 0;
99
100 if (!dev->power.use_autosuspend)
101 goto out;
102
103 autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
104 if (autosuspend_delay < 0)
105 goto out;
106
107 last_busy = ACCESS_ONCE(dev->power.last_busy);
108 elapsed = jiffies - last_busy;
109 if (elapsed < 0)
110 goto out; /* jiffies has wrapped around. */
111
112 /*
113 * If the autosuspend_delay is >= 1 second, align the timer by rounding
114 * up to the nearest second.
115 */
116 expires = last_busy + msecs_to_jiffies(autosuspend_delay);
117 if (autosuspend_delay >= 1000)
118 expires = round_jiffies(expires);
119 expires += !expires;
120 if (elapsed >= expires - last_busy)
121 expires = 0; /* Already expired. */
122
123 out:
124 return expires;
125}
126EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
127
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200128/**
Alan Stern1bfee5b2010-09-25 23:35:00 +0200129 * rpm_check_suspend_allowed - Test whether a device may be suspended.
130 * @dev: Device to test.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200131 */
Alan Stern1bfee5b2010-09-25 23:35:00 +0200132static int rpm_check_suspend_allowed(struct device *dev)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200133{
134 int retval = 0;
135
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200136 if (dev->power.runtime_error)
137 retval = -EINVAL;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200138 else if (atomic_read(&dev->power.usage_count) > 0
Alan Stern1bfee5b2010-09-25 23:35:00 +0200139 || dev->power.disable_depth > 0)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200140 retval = -EAGAIN;
141 else if (!pm_children_suspended(dev))
142 retval = -EBUSY;
Alan Stern1bfee5b2010-09-25 23:35:00 +0200143
144 /* Pending resume requests take precedence over suspends. */
145 else if ((dev->power.deferred_resume
146 && dev->power.status == RPM_SUSPENDING)
147 || (dev->power.request_pending
148 && dev->power.request == RPM_REQ_RESUME))
149 retval = -EAGAIN;
150 else if (dev->power.runtime_status == RPM_SUSPENDED)
151 retval = 1;
152
153 return retval;
154}
155
Alan Stern1bfee5b2010-09-25 23:35:00 +0200156/**
Alan Stern140a6c92010-09-25 23:35:07 +0200157 * rpm_idle - Notify device bus type if the device can be suspended.
Alan Stern1bfee5b2010-09-25 23:35:00 +0200158 * @dev: Device to notify the bus type about.
159 * @rpmflags: Flag bits.
160 *
161 * Check if the device's run-time PM status allows it to be suspended. If
162 * another idle notification has been started earlier, return immediately. If
163 * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
164 * run the ->runtime_idle() callback directly.
165 *
166 * This function must be called under dev->power.lock with interrupts disabled.
167 */
Alan Stern140a6c92010-09-25 23:35:07 +0200168static int rpm_idle(struct device *dev, int rpmflags)
Alan Stern1bfee5b2010-09-25 23:35:00 +0200169{
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200170 int (*callback)(struct device *);
Alan Stern1bfee5b2010-09-25 23:35:00 +0200171 int retval;
172
173 retval = rpm_check_suspend_allowed(dev);
174 if (retval < 0)
175 ; /* Conditions are wrong. */
176
177 /* Idle notifications are allowed only in the RPM_ACTIVE state. */
178 else if (dev->power.runtime_status != RPM_ACTIVE)
179 retval = -EAGAIN;
180
181 /*
182 * Any pending request other than an idle notification takes
183 * precedence over us, except that the timer may be running.
184 */
185 else if (dev->power.request_pending &&
186 dev->power.request > RPM_REQ_IDLE)
187 retval = -EAGAIN;
188
189 /* Act as though RPM_NOWAIT is always set. */
190 else if (dev->power.idle_notification)
191 retval = -EINPROGRESS;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200192 if (retval)
193 goto out;
194
Alan Stern1bfee5b2010-09-25 23:35:00 +0200195 /* Pending requests need to be canceled. */
196 dev->power.request = RPM_REQ_NONE;
197
Alan Stern7490e442010-09-25 23:35:15 +0200198 if (dev->power.no_callbacks) {
199 /* Assume ->runtime_idle() callback would have suspended. */
200 retval = rpm_suspend(dev, rpmflags);
201 goto out;
202 }
203
Alan Stern1bfee5b2010-09-25 23:35:00 +0200204 /* Carry out an asynchronous or a synchronous idle notification. */
205 if (rpmflags & RPM_ASYNC) {
206 dev->power.request = RPM_REQ_IDLE;
207 if (!dev->power.request_pending) {
208 dev->power.request_pending = true;
209 queue_work(pm_wq, &dev->power.work);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200210 }
Alan Stern1bfee5b2010-09-25 23:35:00 +0200211 goto out;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200212 }
213
214 dev->power.idle_notification = true;
215
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200216 if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle)
217 callback = dev->bus->pm->runtime_idle;
218 else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle)
219 callback = dev->type->pm->runtime_idle;
220 else if (dev->class && dev->class->pm)
221 callback = dev->class->pm->runtime_idle;
222 else
223 callback = NULL;
224
225 if (callback) {
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200226 spin_unlock_irq(&dev->power.lock);
227
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200228 callback(dev);
Rafael J. Wysockia6ab7aa2009-12-22 20:43:17 +0100229
230 spin_lock_irq(&dev->power.lock);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200231 }
232
233 dev->power.idle_notification = false;
234 wake_up_all(&dev->power.wait_queue);
235
236 out:
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200237 return retval;
238}
239
240/**
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200241 * rpm_callback - Run a given runtime PM callback for a given device.
242 * @cb: Runtime PM callback to run.
243 * @dev: Device to run the callback for.
244 */
245static int rpm_callback(int (*cb)(struct device *), struct device *dev)
246 __releases(&dev->power.lock) __acquires(&dev->power.lock)
247{
248 int retval;
249
250 if (!cb)
251 return -ENOSYS;
252
253 spin_unlock_irq(&dev->power.lock);
254
255 retval = cb(dev);
256
257 spin_lock_irq(&dev->power.lock);
258 dev->power.runtime_error = retval;
259
260 return retval;
261}
262
263/**
Alan Stern140a6c92010-09-25 23:35:07 +0200264 * rpm_suspend - Carry out run-time suspend of given device.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200265 * @dev: Device to suspend.
Alan Stern3f9af052010-09-25 23:34:54 +0200266 * @rpmflags: Flag bits.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200267 *
Alan Stern1bfee5b2010-09-25 23:35:00 +0200268 * Check if the device's run-time PM status allows it to be suspended. If
269 * another suspend has been started earlier, either return immediately or wait
270 * for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags. Cancel a
271 * pending idle notification. If the RPM_ASYNC flag is set then queue a
272 * suspend request; otherwise run the ->runtime_suspend() callback directly.
273 * If a deferred resume was requested while the callback was running then carry
274 * it out; otherwise send an idle notification for the device (if the suspend
275 * failed) or for its parent (if the suspend succeeded).
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200276 *
277 * This function must be called under dev->power.lock with interrupts disabled.
278 */
Alan Stern140a6c92010-09-25 23:35:07 +0200279static int rpm_suspend(struct device *dev, int rpmflags)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200280 __releases(&dev->power.lock) __acquires(&dev->power.lock)
281{
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200282 int (*callback)(struct device *);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200283 struct device *parent = NULL;
284 bool notify = false;
Alan Stern1bfee5b2010-09-25 23:35:00 +0200285 int retval;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200286
Alan Stern3f9af052010-09-25 23:34:54 +0200287 dev_dbg(dev, "%s flags 0x%x\n", __func__, rpmflags);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200288
289 repeat:
Alan Stern1bfee5b2010-09-25 23:35:00 +0200290 retval = rpm_check_suspend_allowed(dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200291
Alan Stern1bfee5b2010-09-25 23:35:00 +0200292 if (retval < 0)
293 ; /* Conditions are wrong. */
294
295 /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
296 else if (dev->power.runtime_status == RPM_RESUMING &&
297 !(rpmflags & RPM_ASYNC))
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200298 retval = -EAGAIN;
Alan Stern1bfee5b2010-09-25 23:35:00 +0200299 if (retval)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200300 goto out;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200301
Alan Stern15bcb912010-09-25 23:35:21 +0200302 /* If the autosuspend_delay time hasn't expired yet, reschedule. */
303 if ((rpmflags & RPM_AUTO)
304 && dev->power.runtime_status != RPM_SUSPENDING) {
305 unsigned long expires = pm_runtime_autosuspend_expiration(dev);
306
307 if (expires != 0) {
308 /* Pending requests need to be canceled. */
309 dev->power.request = RPM_REQ_NONE;
310
311 /*
312 * Optimization: If the timer is already running and is
313 * set to expire at or before the autosuspend delay,
314 * avoid the overhead of resetting it. Just let it
315 * expire; pm_suspend_timer_fn() will take care of the
316 * rest.
317 */
318 if (!(dev->power.timer_expires && time_before_eq(
319 dev->power.timer_expires, expires))) {
320 dev->power.timer_expires = expires;
321 mod_timer(&dev->power.suspend_timer, expires);
322 }
323 dev->power.timer_autosuspends = 1;
324 goto out;
325 }
326 }
327
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200328 /* Other scheduled or pending requests need to be canceled. */
329 pm_runtime_cancel_pending(dev);
330
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200331 if (dev->power.runtime_status == RPM_SUSPENDING) {
332 DEFINE_WAIT(wait);
333
Alan Stern1bfee5b2010-09-25 23:35:00 +0200334 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200335 retval = -EINPROGRESS;
336 goto out;
337 }
338
339 /* Wait for the other suspend running in parallel with us. */
340 for (;;) {
341 prepare_to_wait(&dev->power.wait_queue, &wait,
342 TASK_UNINTERRUPTIBLE);
343 if (dev->power.runtime_status != RPM_SUSPENDING)
344 break;
345
346 spin_unlock_irq(&dev->power.lock);
347
348 schedule();
349
350 spin_lock_irq(&dev->power.lock);
351 }
352 finish_wait(&dev->power.wait_queue, &wait);
353 goto repeat;
354 }
355
Alan Stern7490e442010-09-25 23:35:15 +0200356 dev->power.deferred_resume = false;
357 if (dev->power.no_callbacks)
358 goto no_callback; /* Assume success. */
359
Alan Stern1bfee5b2010-09-25 23:35:00 +0200360 /* Carry out an asynchronous or a synchronous suspend. */
361 if (rpmflags & RPM_ASYNC) {
Alan Stern15bcb912010-09-25 23:35:21 +0200362 dev->power.request = (rpmflags & RPM_AUTO) ?
363 RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
Alan Stern1bfee5b2010-09-25 23:35:00 +0200364 if (!dev->power.request_pending) {
365 dev->power.request_pending = true;
366 queue_work(pm_wq, &dev->power.work);
367 }
368 goto out;
369 }
370
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200371 __update_runtime_status(dev, RPM_SUSPENDING);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200372
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200373 if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
374 callback = dev->bus->pm->runtime_suspend;
375 else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
376 callback = dev->type->pm->runtime_suspend;
377 else if (dev->class && dev->class->pm)
378 callback = dev->class->pm->runtime_suspend;
379 else
380 callback = NULL;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200381
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200382 retval = rpm_callback(callback, dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200383 if (retval) {
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200384 __update_runtime_status(dev, RPM_ACTIVE);
Alan Stern1bfee5b2010-09-25 23:35:00 +0200385 dev->power.deferred_resume = 0;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200386 if (retval == -EAGAIN || retval == -EBUSY) {
Alan Stern240c7332010-03-23 00:50:07 +0100387 if (dev->power.timer_expires == 0)
388 notify = true;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200389 dev->power.runtime_error = 0;
Alan Stern240c7332010-03-23 00:50:07 +0100390 } else {
391 pm_runtime_cancel_pending(dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200392 }
393 } else {
Alan Stern7490e442010-09-25 23:35:15 +0200394 no_callback:
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200395 __update_runtime_status(dev, RPM_SUSPENDED);
Alan Stern240c7332010-03-23 00:50:07 +0100396 pm_runtime_deactivate_timer(dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200397
398 if (dev->parent) {
399 parent = dev->parent;
400 atomic_add_unless(&parent->power.child_count, -1, 0);
401 }
402 }
403 wake_up_all(&dev->power.wait_queue);
404
405 if (dev->power.deferred_resume) {
Alan Stern140a6c92010-09-25 23:35:07 +0200406 rpm_resume(dev, 0);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200407 retval = -EAGAIN;
408 goto out;
409 }
410
411 if (notify)
Alan Stern140a6c92010-09-25 23:35:07 +0200412 rpm_idle(dev, 0);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200413
414 if (parent && !parent->power.ignore_children) {
415 spin_unlock_irq(&dev->power.lock);
416
417 pm_request_idle(parent);
418
419 spin_lock_irq(&dev->power.lock);
420 }
421
422 out:
Alan Stern3f9af052010-09-25 23:34:54 +0200423 dev_dbg(dev, "%s returns %d\n", __func__, retval);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200424
425 return retval;
426}
427
428/**
Alan Stern140a6c92010-09-25 23:35:07 +0200429 * rpm_resume - Carry out run-time resume of given device.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200430 * @dev: Device to resume.
Alan Stern3f9af052010-09-25 23:34:54 +0200431 * @rpmflags: Flag bits.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200432 *
Alan Stern1bfee5b2010-09-25 23:35:00 +0200433 * Check if the device's run-time PM status allows it to be resumed. Cancel
434 * any scheduled or pending requests. If another resume has been started
435 * earlier, either return imediately or wait for it to finish, depending on the
436 * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
437 * parallel with this function, either tell the other process to resume after
438 * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
439 * flag is set then queue a resume request; otherwise run the
440 * ->runtime_resume() callback directly. Queue an idle notification for the
441 * device if the resume succeeded.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200442 *
443 * This function must be called under dev->power.lock with interrupts disabled.
444 */
Alan Stern140a6c92010-09-25 23:35:07 +0200445static int rpm_resume(struct device *dev, int rpmflags)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200446 __releases(&dev->power.lock) __acquires(&dev->power.lock)
447{
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200448 int (*callback)(struct device *);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200449 struct device *parent = NULL;
450 int retval = 0;
451
Alan Stern3f9af052010-09-25 23:34:54 +0200452 dev_dbg(dev, "%s flags 0x%x\n", __func__, rpmflags);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200453
454 repeat:
Alan Stern1bfee5b2010-09-25 23:35:00 +0200455 if (dev->power.runtime_error)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200456 retval = -EINVAL;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200457 else if (dev->power.disable_depth > 0)
458 retval = -EAGAIN;
459 if (retval)
460 goto out;
461
Alan Stern15bcb912010-09-25 23:35:21 +0200462 /*
463 * Other scheduled or pending requests need to be canceled. Small
464 * optimization: If an autosuspend timer is running, leave it running
465 * rather than cancelling it now only to restart it again in the near
466 * future.
467 */
468 dev->power.request = RPM_REQ_NONE;
469 if (!dev->power.timer_autosuspends)
470 pm_runtime_deactivate_timer(dev);
Alan Stern1bfee5b2010-09-25 23:35:00 +0200471
472 if (dev->power.runtime_status == RPM_ACTIVE) {
473 retval = 1;
474 goto out;
475 }
476
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200477 if (dev->power.runtime_status == RPM_RESUMING
478 || dev->power.runtime_status == RPM_SUSPENDING) {
479 DEFINE_WAIT(wait);
480
Alan Stern1bfee5b2010-09-25 23:35:00 +0200481 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200482 if (dev->power.runtime_status == RPM_SUSPENDING)
483 dev->power.deferred_resume = true;
Alan Stern1bfee5b2010-09-25 23:35:00 +0200484 else
485 retval = -EINPROGRESS;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200486 goto out;
487 }
488
489 /* Wait for the operation carried out in parallel with us. */
490 for (;;) {
491 prepare_to_wait(&dev->power.wait_queue, &wait,
492 TASK_UNINTERRUPTIBLE);
493 if (dev->power.runtime_status != RPM_RESUMING
494 && dev->power.runtime_status != RPM_SUSPENDING)
495 break;
496
497 spin_unlock_irq(&dev->power.lock);
498
499 schedule();
500
501 spin_lock_irq(&dev->power.lock);
502 }
503 finish_wait(&dev->power.wait_queue, &wait);
504 goto repeat;
505 }
506
Alan Stern7490e442010-09-25 23:35:15 +0200507 /*
508 * See if we can skip waking up the parent. This is safe only if
509 * power.no_callbacks is set, because otherwise we don't know whether
510 * the resume will actually succeed.
511 */
512 if (dev->power.no_callbacks && !parent && dev->parent) {
513 spin_lock(&dev->parent->power.lock);
514 if (dev->parent->power.disable_depth > 0
515 || dev->parent->power.ignore_children
516 || dev->parent->power.runtime_status == RPM_ACTIVE) {
517 atomic_inc(&dev->parent->power.child_count);
518 spin_unlock(&dev->parent->power.lock);
519 goto no_callback; /* Assume success. */
520 }
521 spin_unlock(&dev->parent->power.lock);
522 }
523
Alan Stern1bfee5b2010-09-25 23:35:00 +0200524 /* Carry out an asynchronous or a synchronous resume. */
525 if (rpmflags & RPM_ASYNC) {
526 dev->power.request = RPM_REQ_RESUME;
527 if (!dev->power.request_pending) {
528 dev->power.request_pending = true;
529 queue_work(pm_wq, &dev->power.work);
530 }
531 retval = 0;
532 goto out;
533 }
534
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200535 if (!parent && dev->parent) {
536 /*
537 * Increment the parent's resume counter and resume it if
538 * necessary.
539 */
540 parent = dev->parent;
Alan Stern862f89b2009-11-25 01:06:37 +0100541 spin_unlock(&dev->power.lock);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200542
543 pm_runtime_get_noresume(parent);
544
Alan Stern862f89b2009-11-25 01:06:37 +0100545 spin_lock(&parent->power.lock);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200546 /*
547 * We can resume if the parent's run-time PM is disabled or it
548 * is set to ignore children.
549 */
550 if (!parent->power.disable_depth
551 && !parent->power.ignore_children) {
Alan Stern140a6c92010-09-25 23:35:07 +0200552 rpm_resume(parent, 0);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200553 if (parent->power.runtime_status != RPM_ACTIVE)
554 retval = -EBUSY;
555 }
Alan Stern862f89b2009-11-25 01:06:37 +0100556 spin_unlock(&parent->power.lock);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200557
Alan Stern862f89b2009-11-25 01:06:37 +0100558 spin_lock(&dev->power.lock);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200559 if (retval)
560 goto out;
561 goto repeat;
562 }
563
Alan Stern7490e442010-09-25 23:35:15 +0200564 if (dev->power.no_callbacks)
565 goto no_callback; /* Assume success. */
566
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200567 __update_runtime_status(dev, RPM_RESUMING);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200568
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200569 if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
570 callback = dev->bus->pm->runtime_resume;
571 else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume)
572 callback = dev->type->pm->runtime_resume;
573 else if (dev->class && dev->class->pm)
574 callback = dev->class->pm->runtime_resume;
575 else
576 callback = NULL;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200577
Rafael J. Wysocki71c63122010-10-04 22:08:01 +0200578 retval = rpm_callback(callback, dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200579 if (retval) {
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200580 __update_runtime_status(dev, RPM_SUSPENDED);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200581 pm_runtime_cancel_pending(dev);
582 } else {
Alan Stern7490e442010-09-25 23:35:15 +0200583 no_callback:
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200584 __update_runtime_status(dev, RPM_ACTIVE);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200585 if (parent)
586 atomic_inc(&parent->power.child_count);
587 }
588 wake_up_all(&dev->power.wait_queue);
589
590 if (!retval)
Alan Stern140a6c92010-09-25 23:35:07 +0200591 rpm_idle(dev, RPM_ASYNC);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200592
593 out:
594 if (parent) {
595 spin_unlock_irq(&dev->power.lock);
596
597 pm_runtime_put(parent);
598
599 spin_lock_irq(&dev->power.lock);
600 }
601
Alan Stern3f9af052010-09-25 23:34:54 +0200602 dev_dbg(dev, "%s returns %d\n", __func__, retval);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200603
604 return retval;
605}
606
607/**
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200608 * pm_runtime_work - Universal run-time PM work function.
609 * @work: Work structure used for scheduling the execution of this function.
610 *
611 * Use @work to get the device object the work is to be done for, determine what
612 * is to be done and execute the appropriate run-time PM function.
613 */
614static void pm_runtime_work(struct work_struct *work)
615{
616 struct device *dev = container_of(work, struct device, power.work);
617 enum rpm_request req;
618
619 spin_lock_irq(&dev->power.lock);
620
621 if (!dev->power.request_pending)
622 goto out;
623
624 req = dev->power.request;
625 dev->power.request = RPM_REQ_NONE;
626 dev->power.request_pending = false;
627
628 switch (req) {
629 case RPM_REQ_NONE:
630 break;
631 case RPM_REQ_IDLE:
Alan Stern140a6c92010-09-25 23:35:07 +0200632 rpm_idle(dev, RPM_NOWAIT);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200633 break;
634 case RPM_REQ_SUSPEND:
Alan Stern140a6c92010-09-25 23:35:07 +0200635 rpm_suspend(dev, RPM_NOWAIT);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200636 break;
Alan Stern15bcb912010-09-25 23:35:21 +0200637 case RPM_REQ_AUTOSUSPEND:
638 rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
639 break;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200640 case RPM_REQ_RESUME:
Alan Stern140a6c92010-09-25 23:35:07 +0200641 rpm_resume(dev, RPM_NOWAIT);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200642 break;
643 }
644
645 out:
646 spin_unlock_irq(&dev->power.lock);
647}
648
649/**
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200650 * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
651 * @data: Device pointer passed by pm_schedule_suspend().
652 *
Alan Stern1bfee5b2010-09-25 23:35:00 +0200653 * Check if the time is right and queue a suspend request.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200654 */
655static void pm_suspend_timer_fn(unsigned long data)
656{
657 struct device *dev = (struct device *)data;
658 unsigned long flags;
659 unsigned long expires;
660
661 spin_lock_irqsave(&dev->power.lock, flags);
662
663 expires = dev->power.timer_expires;
664 /* If 'expire' is after 'jiffies' we've been called too early. */
665 if (expires > 0 && !time_after(expires, jiffies)) {
666 dev->power.timer_expires = 0;
Alan Stern15bcb912010-09-25 23:35:21 +0200667 rpm_suspend(dev, dev->power.timer_autosuspends ?
668 (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200669 }
670
671 spin_unlock_irqrestore(&dev->power.lock, flags);
672}
673
674/**
675 * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
676 * @dev: Device to suspend.
677 * @delay: Time to wait before submitting a suspend request, in milliseconds.
678 */
679int pm_schedule_suspend(struct device *dev, unsigned int delay)
680{
681 unsigned long flags;
Alan Stern1bfee5b2010-09-25 23:35:00 +0200682 int retval;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200683
684 spin_lock_irqsave(&dev->power.lock, flags);
685
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200686 if (!delay) {
Alan Stern140a6c92010-09-25 23:35:07 +0200687 retval = rpm_suspend(dev, RPM_ASYNC);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200688 goto out;
689 }
690
Alan Stern1bfee5b2010-09-25 23:35:00 +0200691 retval = rpm_check_suspend_allowed(dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200692 if (retval)
693 goto out;
694
Alan Stern1bfee5b2010-09-25 23:35:00 +0200695 /* Other scheduled or pending requests need to be canceled. */
696 pm_runtime_cancel_pending(dev);
697
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200698 dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
Alan Stern1bfee5b2010-09-25 23:35:00 +0200699 dev->power.timer_expires += !dev->power.timer_expires;
Alan Stern15bcb912010-09-25 23:35:21 +0200700 dev->power.timer_autosuspends = 0;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200701 mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
702
703 out:
704 spin_unlock_irqrestore(&dev->power.lock, flags);
705
706 return retval;
707}
708EXPORT_SYMBOL_GPL(pm_schedule_suspend);
709
710/**
Alan Stern140a6c92010-09-25 23:35:07 +0200711 * __pm_runtime_idle - Entry point for run-time idle operations.
712 * @dev: Device to send idle notification for.
713 * @rpmflags: Flag bits.
714 *
715 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
716 * return immediately if it is larger than zero. Then carry out an idle
717 * notification, either synchronous or asynchronous.
718 *
719 * This routine may be called in atomic context if the RPM_ASYNC flag is set.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200720 */
Alan Stern140a6c92010-09-25 23:35:07 +0200721int __pm_runtime_idle(struct device *dev, int rpmflags)
722{
723 unsigned long flags;
724 int retval;
725
726 if (rpmflags & RPM_GET_PUT) {
727 if (!atomic_dec_and_test(&dev->power.usage_count))
728 return 0;
729 }
730
731 spin_lock_irqsave(&dev->power.lock, flags);
732 retval = rpm_idle(dev, rpmflags);
733 spin_unlock_irqrestore(&dev->power.lock, flags);
734
735 return retval;
736}
737EXPORT_SYMBOL_GPL(__pm_runtime_idle);
738
739/**
740 * __pm_runtime_suspend - Entry point for run-time put/suspend operations.
741 * @dev: Device to suspend.
742 * @rpmflags: Flag bits.
743 *
Alan Stern15bcb912010-09-25 23:35:21 +0200744 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
745 * return immediately if it is larger than zero. Then carry out a suspend,
746 * either synchronous or asynchronous.
Alan Stern140a6c92010-09-25 23:35:07 +0200747 *
748 * This routine may be called in atomic context if the RPM_ASYNC flag is set.
749 */
750int __pm_runtime_suspend(struct device *dev, int rpmflags)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200751{
752 unsigned long flags;
753 int retval;
754
Alan Stern15bcb912010-09-25 23:35:21 +0200755 if (rpmflags & RPM_GET_PUT) {
756 if (!atomic_dec_and_test(&dev->power.usage_count))
757 return 0;
758 }
759
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200760 spin_lock_irqsave(&dev->power.lock, flags);
Alan Stern140a6c92010-09-25 23:35:07 +0200761 retval = rpm_suspend(dev, rpmflags);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200762 spin_unlock_irqrestore(&dev->power.lock, flags);
763
764 return retval;
765}
Alan Stern140a6c92010-09-25 23:35:07 +0200766EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200767
768/**
Alan Stern140a6c92010-09-25 23:35:07 +0200769 * __pm_runtime_resume - Entry point for run-time resume operations.
770 * @dev: Device to resume.
Alan Stern3f9af052010-09-25 23:34:54 +0200771 * @rpmflags: Flag bits.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200772 *
Alan Stern140a6c92010-09-25 23:35:07 +0200773 * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
774 * carry out a resume, either synchronous or asynchronous.
775 *
776 * This routine may be called in atomic context if the RPM_ASYNC flag is set.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200777 */
Alan Stern140a6c92010-09-25 23:35:07 +0200778int __pm_runtime_resume(struct device *dev, int rpmflags)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200779{
Alan Stern140a6c92010-09-25 23:35:07 +0200780 unsigned long flags;
Alan Stern1d531c12009-12-13 20:28:30 +0100781 int retval;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200782
Alan Stern140a6c92010-09-25 23:35:07 +0200783 if (rpmflags & RPM_GET_PUT)
784 atomic_inc(&dev->power.usage_count);
785
786 spin_lock_irqsave(&dev->power.lock, flags);
787 retval = rpm_resume(dev, rpmflags);
788 spin_unlock_irqrestore(&dev->power.lock, flags);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200789
790 return retval;
791}
Alan Stern140a6c92010-09-25 23:35:07 +0200792EXPORT_SYMBOL_GPL(__pm_runtime_resume);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200793
794/**
795 * __pm_runtime_set_status - Set run-time PM status of a device.
796 * @dev: Device to handle.
797 * @status: New run-time PM status of the device.
798 *
799 * If run-time PM of the device is disabled or its power.runtime_error field is
800 * different from zero, the status may be changed either to RPM_ACTIVE, or to
801 * RPM_SUSPENDED, as long as that reflects the actual state of the device.
802 * However, if the device has a parent and the parent is not active, and the
803 * parent's power.ignore_children flag is unset, the device's status cannot be
804 * set to RPM_ACTIVE, so -EBUSY is returned in that case.
805 *
806 * If successful, __pm_runtime_set_status() clears the power.runtime_error field
807 * and the device parent's counter of unsuspended children is modified to
808 * reflect the new status. If the new status is RPM_SUSPENDED, an idle
809 * notification request for the parent is submitted.
810 */
811int __pm_runtime_set_status(struct device *dev, unsigned int status)
812{
813 struct device *parent = dev->parent;
814 unsigned long flags;
815 bool notify_parent = false;
816 int error = 0;
817
818 if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
819 return -EINVAL;
820
821 spin_lock_irqsave(&dev->power.lock, flags);
822
823 if (!dev->power.runtime_error && !dev->power.disable_depth) {
824 error = -EAGAIN;
825 goto out;
826 }
827
828 if (dev->power.runtime_status == status)
829 goto out_set;
830
831 if (status == RPM_SUSPENDED) {
832 /* It always is possible to set the status to 'suspended'. */
833 if (parent) {
834 atomic_add_unless(&parent->power.child_count, -1, 0);
835 notify_parent = !parent->power.ignore_children;
836 }
837 goto out_set;
838 }
839
840 if (parent) {
Rafael J. Wysockibab636b2009-12-03 20:21:21 +0100841 spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200842
843 /*
844 * It is invalid to put an active child under a parent that is
845 * not active, has run-time PM enabled and the
846 * 'power.ignore_children' flag unset.
847 */
848 if (!parent->power.disable_depth
849 && !parent->power.ignore_children
Rafael J. Wysocki965c4ac2009-12-03 21:04:41 +0100850 && parent->power.runtime_status != RPM_ACTIVE)
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200851 error = -EBUSY;
Rafael J. Wysocki965c4ac2009-12-03 21:04:41 +0100852 else if (dev->power.runtime_status == RPM_SUSPENDED)
853 atomic_inc(&parent->power.child_count);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200854
Alan Stern862f89b2009-11-25 01:06:37 +0100855 spin_unlock(&parent->power.lock);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200856
857 if (error)
858 goto out;
859 }
860
861 out_set:
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +0200862 __update_runtime_status(dev, status);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200863 dev->power.runtime_error = 0;
864 out:
865 spin_unlock_irqrestore(&dev->power.lock, flags);
866
867 if (notify_parent)
868 pm_request_idle(parent);
869
870 return error;
871}
872EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
873
874/**
875 * __pm_runtime_barrier - Cancel pending requests and wait for completions.
876 * @dev: Device to handle.
877 *
878 * Flush all pending requests for the device from pm_wq and wait for all
879 * run-time PM operations involving the device in progress to complete.
880 *
881 * Should be called under dev->power.lock with interrupts disabled.
882 */
883static void __pm_runtime_barrier(struct device *dev)
884{
885 pm_runtime_deactivate_timer(dev);
886
887 if (dev->power.request_pending) {
888 dev->power.request = RPM_REQ_NONE;
889 spin_unlock_irq(&dev->power.lock);
890
891 cancel_work_sync(&dev->power.work);
892
893 spin_lock_irq(&dev->power.lock);
894 dev->power.request_pending = false;
895 }
896
897 if (dev->power.runtime_status == RPM_SUSPENDING
898 || dev->power.runtime_status == RPM_RESUMING
899 || dev->power.idle_notification) {
900 DEFINE_WAIT(wait);
901
902 /* Suspend, wake-up or idle notification in progress. */
903 for (;;) {
904 prepare_to_wait(&dev->power.wait_queue, &wait,
905 TASK_UNINTERRUPTIBLE);
906 if (dev->power.runtime_status != RPM_SUSPENDING
907 && dev->power.runtime_status != RPM_RESUMING
908 && !dev->power.idle_notification)
909 break;
910 spin_unlock_irq(&dev->power.lock);
911
912 schedule();
913
914 spin_lock_irq(&dev->power.lock);
915 }
916 finish_wait(&dev->power.wait_queue, &wait);
917 }
918}
919
920/**
921 * pm_runtime_barrier - Flush pending requests and wait for completions.
922 * @dev: Device to handle.
923 *
924 * Prevent the device from being suspended by incrementing its usage counter and
925 * if there's a pending resume request for the device, wake the device up.
926 * Next, make sure that all pending requests for the device have been flushed
927 * from pm_wq and wait for all run-time PM operations involving the device in
928 * progress to complete.
929 *
930 * Return value:
931 * 1, if there was a resume request pending and the device had to be woken up,
932 * 0, otherwise
933 */
934int pm_runtime_barrier(struct device *dev)
935{
936 int retval = 0;
937
938 pm_runtime_get_noresume(dev);
939 spin_lock_irq(&dev->power.lock);
940
941 if (dev->power.request_pending
942 && dev->power.request == RPM_REQ_RESUME) {
Alan Stern140a6c92010-09-25 23:35:07 +0200943 rpm_resume(dev, 0);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200944 retval = 1;
945 }
946
947 __pm_runtime_barrier(dev);
948
949 spin_unlock_irq(&dev->power.lock);
950 pm_runtime_put_noidle(dev);
951
952 return retval;
953}
954EXPORT_SYMBOL_GPL(pm_runtime_barrier);
955
956/**
957 * __pm_runtime_disable - Disable run-time PM of a device.
958 * @dev: Device to handle.
959 * @check_resume: If set, check if there's a resume request for the device.
960 *
961 * Increment power.disable_depth for the device and if was zero previously,
962 * cancel all pending run-time PM requests for the device and wait for all
963 * operations in progress to complete. The device can be either active or
964 * suspended after its run-time PM has been disabled.
965 *
966 * If @check_resume is set and there's a resume request pending when
967 * __pm_runtime_disable() is called and power.disable_depth is zero, the
968 * function will wake up the device before disabling its run-time PM.
969 */
970void __pm_runtime_disable(struct device *dev, bool check_resume)
971{
972 spin_lock_irq(&dev->power.lock);
973
974 if (dev->power.disable_depth > 0) {
975 dev->power.disable_depth++;
976 goto out;
977 }
978
979 /*
980 * Wake up the device if there's a resume request pending, because that
981 * means there probably is some I/O to process and disabling run-time PM
982 * shouldn't prevent the device from processing the I/O.
983 */
984 if (check_resume && dev->power.request_pending
985 && dev->power.request == RPM_REQ_RESUME) {
986 /*
987 * Prevent suspends and idle notifications from being carried
988 * out after we have woken up the device.
989 */
990 pm_runtime_get_noresume(dev);
991
Alan Stern140a6c92010-09-25 23:35:07 +0200992 rpm_resume(dev, 0);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200993
994 pm_runtime_put_noidle(dev);
995 }
996
997 if (!dev->power.disable_depth++)
998 __pm_runtime_barrier(dev);
999
1000 out:
1001 spin_unlock_irq(&dev->power.lock);
1002}
1003EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1004
1005/**
1006 * pm_runtime_enable - Enable run-time PM of a device.
1007 * @dev: Device to handle.
1008 */
1009void pm_runtime_enable(struct device *dev)
1010{
1011 unsigned long flags;
1012
1013 spin_lock_irqsave(&dev->power.lock, flags);
1014
1015 if (dev->power.disable_depth > 0)
1016 dev->power.disable_depth--;
1017 else
1018 dev_warn(dev, "Unbalanced %s!\n", __func__);
1019
1020 spin_unlock_irqrestore(&dev->power.lock, flags);
1021}
1022EXPORT_SYMBOL_GPL(pm_runtime_enable);
1023
1024/**
Rafael J. Wysocki53823632010-01-23 22:02:51 +01001025 * pm_runtime_forbid - Block run-time PM of a device.
1026 * @dev: Device to handle.
1027 *
1028 * Increase the device's usage count and clear its power.runtime_auto flag,
1029 * so that it cannot be suspended at run time until pm_runtime_allow() is called
1030 * for it.
1031 */
1032void pm_runtime_forbid(struct device *dev)
1033{
1034 spin_lock_irq(&dev->power.lock);
1035 if (!dev->power.runtime_auto)
1036 goto out;
1037
1038 dev->power.runtime_auto = false;
1039 atomic_inc(&dev->power.usage_count);
Alan Stern140a6c92010-09-25 23:35:07 +02001040 rpm_resume(dev, 0);
Rafael J. Wysocki53823632010-01-23 22:02:51 +01001041
1042 out:
1043 spin_unlock_irq(&dev->power.lock);
1044}
1045EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1046
1047/**
1048 * pm_runtime_allow - Unblock run-time PM of a device.
1049 * @dev: Device to handle.
1050 *
1051 * Decrease the device's usage count and set its power.runtime_auto flag.
1052 */
1053void pm_runtime_allow(struct device *dev)
1054{
1055 spin_lock_irq(&dev->power.lock);
1056 if (dev->power.runtime_auto)
1057 goto out;
1058
1059 dev->power.runtime_auto = true;
1060 if (atomic_dec_and_test(&dev->power.usage_count))
Alan Stern15bcb912010-09-25 23:35:21 +02001061 rpm_idle(dev, RPM_AUTO);
Rafael J. Wysocki53823632010-01-23 22:02:51 +01001062
1063 out:
1064 spin_unlock_irq(&dev->power.lock);
1065}
1066EXPORT_SYMBOL_GPL(pm_runtime_allow);
1067
1068/**
Alan Stern7490e442010-09-25 23:35:15 +02001069 * pm_runtime_no_callbacks - Ignore run-time PM callbacks for a device.
1070 * @dev: Device to handle.
1071 *
1072 * Set the power.no_callbacks flag, which tells the PM core that this
1073 * device is power-managed through its parent and has no run-time PM
1074 * callbacks of its own. The run-time sysfs attributes will be removed.
1075 *
1076 */
1077void pm_runtime_no_callbacks(struct device *dev)
1078{
1079 spin_lock_irq(&dev->power.lock);
1080 dev->power.no_callbacks = 1;
1081 spin_unlock_irq(&dev->power.lock);
1082 if (device_is_registered(dev))
1083 rpm_sysfs_remove(dev);
1084}
1085EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1086
1087/**
Alan Stern15bcb912010-09-25 23:35:21 +02001088 * update_autosuspend - Handle a change to a device's autosuspend settings.
1089 * @dev: Device to handle.
1090 * @old_delay: The former autosuspend_delay value.
1091 * @old_use: The former use_autosuspend value.
1092 *
1093 * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1094 * set; otherwise allow it. Send an idle notification if suspends are allowed.
1095 *
1096 * This function must be called under dev->power.lock with interrupts disabled.
1097 */
1098static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1099{
1100 int delay = dev->power.autosuspend_delay;
1101
1102 /* Should runtime suspend be prevented now? */
1103 if (dev->power.use_autosuspend && delay < 0) {
1104
1105 /* If it used to be allowed then prevent it. */
1106 if (!old_use || old_delay >= 0) {
1107 atomic_inc(&dev->power.usage_count);
1108 rpm_resume(dev, 0);
1109 }
1110 }
1111
1112 /* Runtime suspend should be allowed now. */
1113 else {
1114
1115 /* If it used to be prevented then allow it. */
1116 if (old_use && old_delay < 0)
1117 atomic_dec(&dev->power.usage_count);
1118
1119 /* Maybe we can autosuspend now. */
1120 rpm_idle(dev, RPM_AUTO);
1121 }
1122}
1123
1124/**
1125 * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1126 * @dev: Device to handle.
1127 * @delay: Value of the new delay in milliseconds.
1128 *
1129 * Set the device's power.autosuspend_delay value. If it changes to negative
1130 * and the power.use_autosuspend flag is set, prevent run-time suspends. If it
1131 * changes the other way, allow run-time suspends.
1132 */
1133void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1134{
1135 int old_delay, old_use;
1136
1137 spin_lock_irq(&dev->power.lock);
1138 old_delay = dev->power.autosuspend_delay;
1139 old_use = dev->power.use_autosuspend;
1140 dev->power.autosuspend_delay = delay;
1141 update_autosuspend(dev, old_delay, old_use);
1142 spin_unlock_irq(&dev->power.lock);
1143}
1144EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1145
1146/**
1147 * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1148 * @dev: Device to handle.
1149 * @use: New value for use_autosuspend.
1150 *
1151 * Set the device's power.use_autosuspend flag, and allow or prevent run-time
1152 * suspends as needed.
1153 */
1154void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1155{
1156 int old_delay, old_use;
1157
1158 spin_lock_irq(&dev->power.lock);
1159 old_delay = dev->power.autosuspend_delay;
1160 old_use = dev->power.use_autosuspend;
1161 dev->power.use_autosuspend = use;
1162 update_autosuspend(dev, old_delay, old_use);
1163 spin_unlock_irq(&dev->power.lock);
1164}
1165EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1166
1167/**
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +02001168 * pm_runtime_init - Initialize run-time PM fields in given device object.
1169 * @dev: Device object to initialize.
1170 */
1171void pm_runtime_init(struct device *dev)
1172{
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +02001173 dev->power.runtime_status = RPM_SUSPENDED;
1174 dev->power.idle_notification = false;
1175
1176 dev->power.disable_depth = 1;
1177 atomic_set(&dev->power.usage_count, 0);
1178
1179 dev->power.runtime_error = 0;
1180
1181 atomic_set(&dev->power.child_count, 0);
1182 pm_suspend_ignore_children(dev, false);
Rafael J. Wysocki53823632010-01-23 22:02:51 +01001183 dev->power.runtime_auto = true;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +02001184
1185 dev->power.request_pending = false;
1186 dev->power.request = RPM_REQ_NONE;
1187 dev->power.deferred_resume = false;
Arjan van de Ven8d4b9d12010-07-19 02:01:06 +02001188 dev->power.accounting_timestamp = jiffies;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +02001189 INIT_WORK(&dev->power.work, pm_runtime_work);
1190
1191 dev->power.timer_expires = 0;
1192 setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
1193 (unsigned long)dev);
1194
1195 init_waitqueue_head(&dev->power.wait_queue);
1196}
1197
1198/**
1199 * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1200 * @dev: Device object being removed from device hierarchy.
1201 */
1202void pm_runtime_remove(struct device *dev)
1203{
1204 __pm_runtime_disable(dev, false);
1205
1206 /* Change the status back to 'suspended' to match the initial status. */
1207 if (dev->power.runtime_status == RPM_ACTIVE)
1208 pm_runtime_set_suspended(dev);
1209}