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1/*
2 * drivers/acpi/device_pm.c - ACPI device power management routines.
3 *
4 * Copyright (C) 2012, Intel Corp.
5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as published
11 * by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19 */
20
21#include <linux/acpi.h>
22#include <linux/export.h>
23#include <linux/mutex.h>
24#include <linux/pm_qos.h>
25#include <linux/pm_domain.h>
26#include <linux/pm_runtime.h>
27
28#include "internal.h"
29
30#define _COMPONENT ACPI_POWER_COMPONENT
31ACPI_MODULE_NAME("device_pm");
32
33/**
34 * acpi_power_state_string - String representation of ACPI device power state.
35 * @state: ACPI device power state to return the string representation of.
36 */
37const char *acpi_power_state_string(int state)
38{
39 switch (state) {
40 case ACPI_STATE_D0:
41 return "D0";
42 case ACPI_STATE_D1:
43 return "D1";
44 case ACPI_STATE_D2:
45 return "D2";
46 case ACPI_STATE_D3_HOT:
47 return "D3hot";
48 case ACPI_STATE_D3_COLD:
49 return "D3cold";
50 default:
51 return "(unknown)";
52 }
53}
54
55/**
56 * acpi_device_get_power - Get power state of an ACPI device.
57 * @device: Device to get the power state of.
58 * @state: Place to store the power state of the device.
59 *
60 * This function does not update the device's power.state field, but it may
61 * update its parent's power.state field (when the parent's power state is
62 * unknown and the device's power state turns out to be D0).
63 */
64int acpi_device_get_power(struct acpi_device *device, int *state)
65{
66 int result = ACPI_STATE_UNKNOWN;
67
68 if (!device || !state)
69 return -EINVAL;
70
71 if (!device->flags.power_manageable) {
72 /* TBD: Non-recursive algorithm for walking up hierarchy. */
73 *state = device->parent ?
74 device->parent->power.state : ACPI_STATE_D0;
75 goto out;
76 }
77
78 /*
79 * Get the device's power state from power resources settings and _PSC,
80 * if available.
81 */
82 if (device->power.flags.power_resources) {
83 int error = acpi_power_get_inferred_state(device, &result);
84 if (error)
85 return error;
86 }
87 if (device->power.flags.explicit_get) {
88 acpi_handle handle = device->handle;
89 unsigned long long psc;
90 acpi_status status;
91
92 status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
93 if (ACPI_FAILURE(status))
94 return -ENODEV;
95
96 /*
97 * The power resources settings may indicate a power state
98 * shallower than the actual power state of the device, because
99 * the same power resources may be referenced by other devices.
100 *
101 * For systems predating ACPI 4.0 we assume that D3hot is the
102 * deepest state that can be supported.
103 */
104 if (psc > result && psc < ACPI_STATE_D3_COLD)
105 result = psc;
106 else if (result == ACPI_STATE_UNKNOWN)
107 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
108 }
109
110 /*
111 * If we were unsure about the device parent's power state up to this
112 * point, the fact that the device is in D0 implies that the parent has
113 * to be in D0 too, except if ignore_parent is set.
114 */
115 if (!device->power.flags.ignore_parent && device->parent
116 && device->parent->power.state == ACPI_STATE_UNKNOWN
117 && result == ACPI_STATE_D0)
118 device->parent->power.state = ACPI_STATE_D0;
119
120 *state = result;
121
122 out:
123 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
124 device->pnp.bus_id, acpi_power_state_string(*state)));
125
126 return 0;
127}
128
129static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
130{
131 if (adev->power.states[state].flags.explicit_set) {
132 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
133 acpi_status status;
134
135 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
136 if (ACPI_FAILURE(status))
137 return -ENODEV;
138 }
139 return 0;
140}
141
142/**
143 * acpi_device_set_power - Set power state of an ACPI device.
144 * @device: Device to set the power state of.
145 * @state: New power state to set.
146 *
147 * Callers must ensure that the device is power manageable before using this
148 * function.
149 */
150int acpi_device_set_power(struct acpi_device *device, int state)
151{
152 int target_state = state;
153 int result = 0;
154
155 if (!device || !device->flags.power_manageable
156 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
157 return -EINVAL;
158
159 /* Make sure this is a valid target state */
160
161 if (state == device->power.state) {
162 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
163 device->pnp.bus_id,
164 acpi_power_state_string(state)));
165 return 0;
166 }
167
168 if (state == ACPI_STATE_D3_COLD) {
169 /*
170 * For transitions to D3cold we need to execute _PS3 and then
171 * possibly drop references to the power resources in use.
172 */
173 state = ACPI_STATE_D3_HOT;
174 /* If _PR3 is not available, use D3hot as the target state. */
175 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
176 target_state = state;
177 } else if (!device->power.states[state].flags.valid) {
178 dev_warn(&device->dev, "Power state %s not supported\n",
179 acpi_power_state_string(state));
180 return -ENODEV;
181 }
182
183 if (!device->power.flags.ignore_parent &&
184 device->parent && (state < device->parent->power.state)) {
185 dev_warn(&device->dev,
186 "Cannot transition to power state %s for parent in %s\n",
187 acpi_power_state_string(state),
188 acpi_power_state_string(device->parent->power.state));
189 return -ENODEV;
190 }
191
192 /*
193 * Transition Power
194 * ----------------
195 * In accordance with ACPI 6, _PSx is executed before manipulating power
196 * resources, unless the target state is D0, in which case _PS0 is
197 * supposed to be executed after turning the power resources on.
198 */
199 if (state > ACPI_STATE_D0) {
200 /*
201 * According to ACPI 6, devices cannot go from lower-power
202 * (deeper) states to higher-power (shallower) states.
203 */
204 if (state < device->power.state) {
205 dev_warn(&device->dev, "Cannot transition from %s to %s\n",
206 acpi_power_state_string(device->power.state),
207 acpi_power_state_string(state));
208 return -ENODEV;
209 }
210
211 result = acpi_dev_pm_explicit_set(device, state);
212 if (result)
213 goto end;
214
215 if (device->power.flags.power_resources)
216 result = acpi_power_transition(device, target_state);
217 } else {
218 if (device->power.flags.power_resources) {
219 result = acpi_power_transition(device, ACPI_STATE_D0);
220 if (result)
221 goto end;
222 }
223 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
224 }
225
226 end:
227 if (result) {
228 dev_warn(&device->dev, "Failed to change power state to %s\n",
229 acpi_power_state_string(state));
230 } else {
231 device->power.state = target_state;
232 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
233 "Device [%s] transitioned to %s\n",
234 device->pnp.bus_id,
235 acpi_power_state_string(state)));
236 }
237
238 return result;
239}
240EXPORT_SYMBOL(acpi_device_set_power);
241
242int acpi_bus_set_power(acpi_handle handle, int state)
243{
244 struct acpi_device *device;
245 int result;
246
247 result = acpi_bus_get_device(handle, &device);
248 if (result)
249 return result;
250
251 return acpi_device_set_power(device, state);
252}
253EXPORT_SYMBOL(acpi_bus_set_power);
254
255int acpi_bus_init_power(struct acpi_device *device)
256{
257 int state;
258 int result;
259
260 if (!device)
261 return -EINVAL;
262
263 device->power.state = ACPI_STATE_UNKNOWN;
264 if (!acpi_device_is_present(device))
265 return -ENXIO;
266
267 result = acpi_device_get_power(device, &state);
268 if (result)
269 return result;
270
271 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
272 /* Reference count the power resources. */
273 result = acpi_power_on_resources(device, state);
274 if (result)
275 return result;
276
277 if (state == ACPI_STATE_D0) {
278 /*
279 * If _PSC is not present and the state inferred from
280 * power resources appears to be D0, it still may be
281 * necessary to execute _PS0 at this point, because
282 * another device using the same power resources may
283 * have been put into D0 previously and that's why we
284 * see D0 here.
285 */
286 result = acpi_dev_pm_explicit_set(device, state);
287 if (result)
288 return result;
289 }
290 } else if (state == ACPI_STATE_UNKNOWN) {
291 /*
292 * No power resources and missing _PSC? Cross fingers and make
293 * it D0 in hope that this is what the BIOS put the device into.
294 * [We tried to force D0 here by executing _PS0, but that broke
295 * Toshiba P870-303 in a nasty way.]
296 */
297 state = ACPI_STATE_D0;
298 }
299 device->power.state = state;
300 return 0;
301}
302
303/**
304 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
305 * @device: Device object whose power state is to be fixed up.
306 *
307 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
308 * are assumed to be put into D0 by the BIOS. However, in some cases that may
309 * not be the case and this function should be used then.
310 */
311int acpi_device_fix_up_power(struct acpi_device *device)
312{
313 int ret = 0;
314
315 if (!device->power.flags.power_resources
316 && !device->power.flags.explicit_get
317 && device->power.state == ACPI_STATE_D0)
318 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
319
320 return ret;
321}
322EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
323
324int acpi_device_update_power(struct acpi_device *device, int *state_p)
325{
326 int state;
327 int result;
328
329 if (device->power.state == ACPI_STATE_UNKNOWN) {
330 result = acpi_bus_init_power(device);
331 if (!result && state_p)
332 *state_p = device->power.state;
333
334 return result;
335 }
336
337 result = acpi_device_get_power(device, &state);
338 if (result)
339 return result;
340
341 if (state == ACPI_STATE_UNKNOWN) {
342 state = ACPI_STATE_D0;
343 result = acpi_device_set_power(device, state);
344 if (result)
345 return result;
346 } else {
347 if (device->power.flags.power_resources) {
348 /*
349 * We don't need to really switch the state, bu we need
350 * to update the power resources' reference counters.
351 */
352 result = acpi_power_transition(device, state);
353 if (result)
354 return result;
355 }
356 device->power.state = state;
357 }
358 if (state_p)
359 *state_p = state;
360
361 return 0;
362}
363EXPORT_SYMBOL_GPL(acpi_device_update_power);
364
365int acpi_bus_update_power(acpi_handle handle, int *state_p)
366{
367 struct acpi_device *device;
368 int result;
369
370 result = acpi_bus_get_device(handle, &device);
371 return result ? result : acpi_device_update_power(device, state_p);
372}
373EXPORT_SYMBOL_GPL(acpi_bus_update_power);
374
375bool acpi_bus_power_manageable(acpi_handle handle)
376{
377 struct acpi_device *device;
378 int result;
379
380 result = acpi_bus_get_device(handle, &device);
381 return result ? false : device->flags.power_manageable;
382}
383EXPORT_SYMBOL(acpi_bus_power_manageable);
384
385#ifdef CONFIG_PM
386static DEFINE_MUTEX(acpi_pm_notifier_lock);
387
388static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
389{
390 struct acpi_device *adev;
391
392 if (val != ACPI_NOTIFY_DEVICE_WAKE)
393 return;
394
395 adev = acpi_bus_get_acpi_device(handle);
396 if (!adev)
397 return;
398
399 mutex_lock(&acpi_pm_notifier_lock);
400
401 if (adev->wakeup.flags.notifier_present) {
402 __pm_wakeup_event(adev->wakeup.ws, 0);
403 if (adev->wakeup.context.work.func)
404 queue_pm_work(&adev->wakeup.context.work);
405 }
406
407 mutex_unlock(&acpi_pm_notifier_lock);
408
409 acpi_bus_put_acpi_device(adev);
410}
411
412/**
413 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
414 * @adev: ACPI device to add the notify handler for.
415 * @dev: Device to generate a wakeup event for while handling the notification.
416 * @work_func: Work function to execute when handling the notification.
417 *
418 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
419 * PM wakeup events. For example, wakeup events may be generated for bridges
420 * if one of the devices below the bridge is signaling wakeup, even if the
421 * bridge itself doesn't have a wakeup GPE associated with it.
422 */
423acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
424 void (*work_func)(struct work_struct *work))
425{
426 acpi_status status = AE_ALREADY_EXISTS;
427
428 if (!dev && !work_func)
429 return AE_BAD_PARAMETER;
430
431 mutex_lock(&acpi_pm_notifier_lock);
432
433 if (adev->wakeup.flags.notifier_present)
434 goto out;
435
436 adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev));
437 adev->wakeup.context.dev = dev;
438 if (work_func)
439 INIT_WORK(&adev->wakeup.context.work, work_func);
440
441 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
442 acpi_pm_notify_handler, NULL);
443 if (ACPI_FAILURE(status))
444 goto out;
445
446 adev->wakeup.flags.notifier_present = true;
447
448 out:
449 mutex_unlock(&acpi_pm_notifier_lock);
450 return status;
451}
452
453/**
454 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
455 * @adev: ACPI device to remove the notifier from.
456 */
457acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
458{
459 acpi_status status = AE_BAD_PARAMETER;
460
461 mutex_lock(&acpi_pm_notifier_lock);
462
463 if (!adev->wakeup.flags.notifier_present)
464 goto out;
465
466 status = acpi_remove_notify_handler(adev->handle,
467 ACPI_SYSTEM_NOTIFY,
468 acpi_pm_notify_handler);
469 if (ACPI_FAILURE(status))
470 goto out;
471
472 if (adev->wakeup.context.work.func) {
473 cancel_work_sync(&adev->wakeup.context.work);
474 adev->wakeup.context.work.func = NULL;
475 }
476 adev->wakeup.context.dev = NULL;
477 wakeup_source_unregister(adev->wakeup.ws);
478
479 adev->wakeup.flags.notifier_present = false;
480
481 out:
482 mutex_unlock(&acpi_pm_notifier_lock);
483 return status;
484}
485
486bool acpi_bus_can_wakeup(acpi_handle handle)
487{
488 struct acpi_device *device;
489 int result;
490
491 result = acpi_bus_get_device(handle, &device);
492 return result ? false : device->wakeup.flags.valid;
493}
494EXPORT_SYMBOL(acpi_bus_can_wakeup);
495
496/**
497 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
498 * @dev: Device whose preferred target power state to return.
499 * @adev: ACPI device node corresponding to @dev.
500 * @target_state: System state to match the resultant device state.
501 * @d_min_p: Location to store the highest power state available to the device.
502 * @d_max_p: Location to store the lowest power state available to the device.
503 *
504 * Find the lowest power (highest number) and highest power (lowest number) ACPI
505 * device power states that the device can be in while the system is in the
506 * state represented by @target_state. Store the integer numbers representing
507 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
508 * respectively.
509 *
510 * Callers must ensure that @dev and @adev are valid pointers and that @adev
511 * actually corresponds to @dev before using this function.
512 *
513 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
514 * returns a value that doesn't make sense. The memory locations pointed to by
515 * @d_max_p and @d_min_p are only modified on success.
516 */
517static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
518 u32 target_state, int *d_min_p, int *d_max_p)
519{
520 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
521 acpi_handle handle = adev->handle;
522 unsigned long long ret;
523 int d_min, d_max;
524 bool wakeup = false;
525 acpi_status status;
526
527 /*
528 * If the system state is S0, the lowest power state the device can be
529 * in is D3cold, unless the device has _S0W and is supposed to signal
530 * wakeup, in which case the return value of _S0W has to be used as the
531 * lowest power state available to the device.
532 */
533 d_min = ACPI_STATE_D0;
534 d_max = ACPI_STATE_D3_COLD;
535
536 /*
537 * If present, _SxD methods return the minimum D-state (highest power
538 * state) we can use for the corresponding S-states. Otherwise, the
539 * minimum D-state is D0 (ACPI 3.x).
540 */
541 if (target_state > ACPI_STATE_S0) {
542 /*
543 * We rely on acpi_evaluate_integer() not clobbering the integer
544 * provided if AE_NOT_FOUND is returned.
545 */
546 ret = d_min;
547 status = acpi_evaluate_integer(handle, method, NULL, &ret);
548 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
549 || ret > ACPI_STATE_D3_COLD)
550 return -ENODATA;
551
552 /*
553 * We need to handle legacy systems where D3hot and D3cold are
554 * the same and 3 is returned in both cases, so fall back to
555 * D3cold if D3hot is not a valid state.
556 */
557 if (!adev->power.states[ret].flags.valid) {
558 if (ret == ACPI_STATE_D3_HOT)
559 ret = ACPI_STATE_D3_COLD;
560 else
561 return -ENODATA;
562 }
563 d_min = ret;
564 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
565 && adev->wakeup.sleep_state >= target_state;
566 } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
567 PM_QOS_FLAGS_NONE) {
568 wakeup = adev->wakeup.flags.valid;
569 }
570
571 /*
572 * If _PRW says we can wake up the system from the target sleep state,
573 * the D-state returned by _SxD is sufficient for that (we assume a
574 * wakeup-aware driver if wake is set). Still, if _SxW exists
575 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
576 * can wake the system. _S0W may be valid, too.
577 */
578 if (wakeup) {
579 method[3] = 'W';
580 status = acpi_evaluate_integer(handle, method, NULL, &ret);
581 if (status == AE_NOT_FOUND) {
582 if (target_state > ACPI_STATE_S0)
583 d_max = d_min;
584 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
585 /* Fall back to D3cold if ret is not a valid state. */
586 if (!adev->power.states[ret].flags.valid)
587 ret = ACPI_STATE_D3_COLD;
588
589 d_max = ret > d_min ? ret : d_min;
590 } else {
591 return -ENODATA;
592 }
593 }
594
595 if (d_min_p)
596 *d_min_p = d_min;
597
598 if (d_max_p)
599 *d_max_p = d_max;
600
601 return 0;
602}
603
604/**
605 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
606 * @dev: Device whose preferred target power state to return.
607 * @d_min_p: Location to store the upper limit of the allowed states range.
608 * @d_max_in: Deepest low-power state to take into consideration.
609 * Return value: Preferred power state of the device on success, -ENODEV
610 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
611 * incorrect, or -ENODATA on ACPI method failure.
612 *
613 * The caller must ensure that @dev is valid before using this function.
614 */
615int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
616{
617 struct acpi_device *adev;
618 int ret, d_min, d_max;
619
620 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
621 return -EINVAL;
622
623 if (d_max_in > ACPI_STATE_D2) {
624 enum pm_qos_flags_status stat;
625
626 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
627 if (stat == PM_QOS_FLAGS_ALL)
628 d_max_in = ACPI_STATE_D2;
629 }
630
631 adev = ACPI_COMPANION(dev);
632 if (!adev) {
633 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
634 return -ENODEV;
635 }
636
637 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
638 &d_min, &d_max);
639 if (ret)
640 return ret;
641
642 if (d_max_in < d_min)
643 return -EINVAL;
644
645 if (d_max > d_max_in) {
646 for (d_max = d_max_in; d_max > d_min; d_max--) {
647 if (adev->power.states[d_max].flags.valid)
648 break;
649 }
650 }
651
652 if (d_min_p)
653 *d_min_p = d_min;
654
655 return d_max;
656}
657EXPORT_SYMBOL(acpi_pm_device_sleep_state);
658
659/**
660 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
661 * @work: Work item to handle.
662 */
663static void acpi_pm_notify_work_func(struct work_struct *work)
664{
665 struct device *dev;
666
667 dev = container_of(work, struct acpi_device_wakeup_context, work)->dev;
668 if (dev) {
669 pm_wakeup_event(dev, 0);
670 pm_runtime_resume(dev);
671 }
672}
673
674/**
675 * acpi_device_wakeup - Enable/disable wakeup functionality for device.
676 * @adev: ACPI device to enable/disable wakeup functionality for.
677 * @target_state: State the system is transitioning into.
678 * @enable: Whether to enable or disable the wakeup functionality.
679 *
680 * Enable/disable the GPE associated with @adev so that it can generate
681 * wakeup signals for the device in response to external (remote) events and
682 * enable/disable device wakeup power.
683 *
684 * Callers must ensure that @adev is a valid ACPI device node before executing
685 * this function.
686 */
687static int acpi_device_wakeup(struct acpi_device *adev, u32 target_state,
688 bool enable)
689{
690 struct acpi_device_wakeup *wakeup = &adev->wakeup;
691
692 if (enable) {
693 acpi_status res;
694 int error;
695
696 error = acpi_enable_wakeup_device_power(adev, target_state);
697 if (error)
698 return error;
699
700 if (adev->wakeup.flags.enabled)
701 return 0;
702
703 res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
704 if (ACPI_SUCCESS(res)) {
705 adev->wakeup.flags.enabled = 1;
706 } else {
707 acpi_disable_wakeup_device_power(adev);
708 return -EIO;
709 }
710 } else {
711 if (adev->wakeup.flags.enabled) {
712 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
713 adev->wakeup.flags.enabled = 0;
714 }
715 acpi_disable_wakeup_device_power(adev);
716 }
717 return 0;
718}
719
720/**
721 * acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
722 * @dev: Device to enable/disable the platform to wake up.
723 * @enable: Whether to enable or disable the wakeup functionality.
724 */
725int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
726{
727 struct acpi_device *adev;
728
729 if (!device_run_wake(phys_dev))
730 return -EINVAL;
731
732 adev = ACPI_COMPANION(phys_dev);
733 if (!adev) {
734 dev_dbg(phys_dev, "ACPI companion missing in %s!\n", __func__);
735 return -ENODEV;
736 }
737
738 return acpi_device_wakeup(adev, ACPI_STATE_S0, enable);
739}
740EXPORT_SYMBOL(acpi_pm_device_run_wake);
741
742#ifdef CONFIG_PM_SLEEP
743/**
744 * acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
745 * @dev: Device to enable/desible to wake up the system from sleep states.
746 * @enable: Whether to enable or disable @dev to wake up the system.
747 */
748int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
749{
750 struct acpi_device *adev;
751 int error;
752
753 if (!device_can_wakeup(dev))
754 return -EINVAL;
755
756 adev = ACPI_COMPANION(dev);
757 if (!adev) {
758 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
759 return -ENODEV;
760 }
761
762 error = acpi_device_wakeup(adev, acpi_target_system_state(), enable);
763 if (!error)
764 dev_info(dev, "System wakeup %s by ACPI\n",
765 enable ? "enabled" : "disabled");
766
767 return error;
768}
769#endif /* CONFIG_PM_SLEEP */
770
771/**
772 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
773 * @dev: Device to put into a low-power state.
774 * @adev: ACPI device node corresponding to @dev.
775 * @system_state: System state to choose the device state for.
776 */
777static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
778 u32 system_state)
779{
780 int ret, state;
781
782 if (!acpi_device_power_manageable(adev))
783 return 0;
784
785 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
786 return ret ? ret : acpi_device_set_power(adev, state);
787}
788
789/**
790 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
791 * @adev: ACPI device node to put into the full-power state.
792 */
793static int acpi_dev_pm_full_power(struct acpi_device *adev)
794{
795 return acpi_device_power_manageable(adev) ?
796 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
797}
798
799/**
800 * acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
801 * @dev: Device to put into a low-power state.
802 *
803 * Put the given device into a runtime low-power state using the standard ACPI
804 * mechanism. Set up remote wakeup if desired, choose the state to put the
805 * device into (this checks if remote wakeup is expected to work too), and set
806 * the power state of the device.
807 */
808int acpi_dev_runtime_suspend(struct device *dev)
809{
810 struct acpi_device *adev = ACPI_COMPANION(dev);
811 bool remote_wakeup;
812 int error;
813
814 if (!adev)
815 return 0;
816
817 remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
818 PM_QOS_FLAGS_NONE;
819 error = acpi_device_wakeup(adev, ACPI_STATE_S0, remote_wakeup);
820 if (remote_wakeup && error)
821 return -EAGAIN;
822
823 error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
824 if (error)
825 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
826
827 return error;
828}
829EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
830
831/**
832 * acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
833 * @dev: Device to put into the full-power state.
834 *
835 * Put the given device into the full-power state using the standard ACPI
836 * mechanism at run time. Set the power state of the device to ACPI D0 and
837 * disable remote wakeup.
838 */
839int acpi_dev_runtime_resume(struct device *dev)
840{
841 struct acpi_device *adev = ACPI_COMPANION(dev);
842 int error;
843
844 if (!adev)
845 return 0;
846
847 error = acpi_dev_pm_full_power(adev);
848 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
849 return error;
850}
851EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
852
853/**
854 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
855 * @dev: Device to suspend.
856 *
857 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
858 * it into a runtime low-power state.
859 */
860int acpi_subsys_runtime_suspend(struct device *dev)
861{
862 int ret = pm_generic_runtime_suspend(dev);
863 return ret ? ret : acpi_dev_runtime_suspend(dev);
864}
865EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
866
867/**
868 * acpi_subsys_runtime_resume - Resume device using ACPI.
869 * @dev: Device to Resume.
870 *
871 * Use ACPI to put the given device into the full-power state and carry out the
872 * generic runtime resume procedure for it.
873 */
874int acpi_subsys_runtime_resume(struct device *dev)
875{
876 int ret = acpi_dev_runtime_resume(dev);
877 return ret ? ret : pm_generic_runtime_resume(dev);
878}
879EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
880
881#ifdef CONFIG_PM_SLEEP
882/**
883 * acpi_dev_suspend_late - Put device into a low-power state using ACPI.
884 * @dev: Device to put into a low-power state.
885 *
886 * Put the given device into a low-power state during system transition to a
887 * sleep state using the standard ACPI mechanism. Set up system wakeup if
888 * desired, choose the state to put the device into (this checks if system
889 * wakeup is expected to work too), and set the power state of the device.
890 */
891int acpi_dev_suspend_late(struct device *dev)
892{
893 struct acpi_device *adev = ACPI_COMPANION(dev);
894 u32 target_state;
895 bool wakeup;
896 int error;
897
898 if (!adev)
899 return 0;
900
901 target_state = acpi_target_system_state();
902 wakeup = device_may_wakeup(dev) && acpi_device_can_wakeup(adev);
903 error = acpi_device_wakeup(adev, target_state, wakeup);
904 if (wakeup && error)
905 return error;
906
907 error = acpi_dev_pm_low_power(dev, adev, target_state);
908 if (error)
909 acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
910
911 return error;
912}
913EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
914
915/**
916 * acpi_dev_resume_early - Put device into the full-power state using ACPI.
917 * @dev: Device to put into the full-power state.
918 *
919 * Put the given device into the full-power state using the standard ACPI
920 * mechanism during system transition to the working state. Set the power
921 * state of the device to ACPI D0 and disable remote wakeup.
922 */
923int acpi_dev_resume_early(struct device *dev)
924{
925 struct acpi_device *adev = ACPI_COMPANION(dev);
926 int error;
927
928 if (!adev)
929 return 0;
930
931 error = acpi_dev_pm_full_power(adev);
932 acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
933 return error;
934}
935EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
936
937/**
938 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
939 * @dev: Device to prepare.
940 */
941int acpi_subsys_prepare(struct device *dev)
942{
943 struct acpi_device *adev = ACPI_COMPANION(dev);
944 u32 sys_target;
945 int ret, state;
946
947 ret = pm_generic_prepare(dev);
948 if (ret < 0)
949 return ret;
950
951 if (!adev || !pm_runtime_suspended(dev)
952 || device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
953 return 0;
954
955 sys_target = acpi_target_system_state();
956 if (sys_target == ACPI_STATE_S0)
957 return 1;
958
959 if (adev->power.flags.dsw_present)
960 return 0;
961
962 ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
963 return !ret && state == adev->power.state;
964}
965EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
966
967/**
968 * acpi_subsys_suspend - Run the device driver's suspend callback.
969 * @dev: Device to handle.
970 *
971 * Follow PCI and resume devices suspended at run time before running their
972 * system suspend callbacks.
973 */
974int acpi_subsys_suspend(struct device *dev)
975{
976 pm_runtime_resume(dev);
977 return pm_generic_suspend(dev);
978}
979EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
980
981/**
982 * acpi_subsys_suspend_late - Suspend device using ACPI.
983 * @dev: Device to suspend.
984 *
985 * Carry out the generic late suspend procedure for @dev and use ACPI to put
986 * it into a low-power state during system transition into a sleep state.
987 */
988int acpi_subsys_suspend_late(struct device *dev)
989{
990 int ret = pm_generic_suspend_late(dev);
991 return ret ? ret : acpi_dev_suspend_late(dev);
992}
993EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
994
995/**
996 * acpi_subsys_resume_early - Resume device using ACPI.
997 * @dev: Device to Resume.
998 *
999 * Use ACPI to put the given device into the full-power state and carry out the
1000 * generic early resume procedure for it during system transition into the
1001 * working state.
1002 */
1003int acpi_subsys_resume_early(struct device *dev)
1004{
1005 int ret = acpi_dev_resume_early(dev);
1006 return ret ? ret : pm_generic_resume_early(dev);
1007}
1008EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
1009
1010/**
1011 * acpi_subsys_freeze - Run the device driver's freeze callback.
1012 * @dev: Device to handle.
1013 */
1014int acpi_subsys_freeze(struct device *dev)
1015{
1016 /*
1017 * This used to be done in acpi_subsys_prepare() for all devices and
1018 * some drivers may depend on it, so do it here. Ideally, however,
1019 * runtime-suspended devices should not be touched during freeze/thaw
1020 * transitions.
1021 */
1022 pm_runtime_resume(dev);
1023 return pm_generic_freeze(dev);
1024}
1025EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1026
1027#endif /* CONFIG_PM_SLEEP */
1028
1029static struct dev_pm_domain acpi_general_pm_domain = {
1030 .ops = {
1031 .runtime_suspend = acpi_subsys_runtime_suspend,
1032 .runtime_resume = acpi_subsys_runtime_resume,
1033#ifdef CONFIG_PM_SLEEP
1034 .prepare = acpi_subsys_prepare,
1035 .complete = pm_complete_with_resume_check,
1036 .suspend = acpi_subsys_suspend,
1037 .suspend_late = acpi_subsys_suspend_late,
1038 .resume_early = acpi_subsys_resume_early,
1039 .freeze = acpi_subsys_freeze,
1040 .poweroff = acpi_subsys_suspend,
1041 .poweroff_late = acpi_subsys_suspend_late,
1042 .restore_early = acpi_subsys_resume_early,
1043#endif
1044 },
1045};
1046
1047/**
1048 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1049 * @dev: Device to take care of.
1050 * @power_off: Whether or not to try to remove power from the device.
1051 *
1052 * Remove the device from the general ACPI PM domain and remove its wakeup
1053 * notifier. If @power_off is set, additionally remove power from the device if
1054 * possible.
1055 *
1056 * Callers must ensure proper synchronization of this function with power
1057 * management callbacks.
1058 */
1059static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1060{
1061 struct acpi_device *adev = ACPI_COMPANION(dev);
1062
1063 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1064 dev_pm_domain_set(dev, NULL);
1065 acpi_remove_pm_notifier(adev);
1066 if (power_off) {
1067 /*
1068 * If the device's PM QoS resume latency limit or flags
1069 * have been exposed to user space, they have to be
1070 * hidden at this point, so that they don't affect the
1071 * choice of the low-power state to put the device into.
1072 */
1073 dev_pm_qos_hide_latency_limit(dev);
1074 dev_pm_qos_hide_flags(dev);
1075 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
1076 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1077 }
1078 }
1079}
1080
1081/**
1082 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1083 * @dev: Device to prepare.
1084 * @power_on: Whether or not to power on the device.
1085 *
1086 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1087 * attached to it, install a wakeup notification handler for the device and
1088 * add it to the general ACPI PM domain. If @power_on is set, the device will
1089 * be put into the ACPI D0 state before the function returns.
1090 *
1091 * This assumes that the @dev's bus type uses generic power management callbacks
1092 * (or doesn't use any power management callbacks at all).
1093 *
1094 * Callers must ensure proper synchronization of this function with power
1095 * management callbacks.
1096 */
1097int acpi_dev_pm_attach(struct device *dev, bool power_on)
1098{
1099 struct acpi_device *adev = ACPI_COMPANION(dev);
1100
1101 if (!adev)
1102 return -ENODEV;
1103
1104 if (dev->pm_domain)
1105 return -EEXIST;
1106
1107 /*
1108 * Only attach the power domain to the first device if the
1109 * companion is shared by multiple. This is to prevent doing power
1110 * management twice.
1111 */
1112 if (!acpi_device_is_first_physical_node(adev, dev))
1113 return -EBUSY;
1114
1115 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1116 dev_pm_domain_set(dev, &acpi_general_pm_domain);
1117 if (power_on) {
1118 acpi_dev_pm_full_power(adev);
1119 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
1120 }
1121
1122 dev->pm_domain->detach = acpi_dev_pm_detach;
1123 return 0;
1124}
1125EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1126#endif /* CONFIG_PM */