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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/acpi/device_pm.c - ACPI device power management routines.
4 *
5 * Copyright (C) 2012, Intel Corp.
6 * Author: Rafael J. Wysocki <[email protected]>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11 */
12
13#define pr_fmt(fmt) "PM: " fmt
14
15#include <linux/acpi.h>
16#include <linux/export.h>
17#include <linux/mutex.h>
18#include <linux/pm_qos.h>
19#include <linux/pm_domain.h>
20#include <linux/pm_runtime.h>
21#include <linux/suspend.h>
22
23#include "fan.h"
24#include "internal.h"
25
26/**
27 * acpi_power_state_string - String representation of ACPI device power state.
28 * @state: ACPI device power state to return the string representation of.
29 */
30const char *acpi_power_state_string(int state)
31{
32 switch (state) {
33 case ACPI_STATE_D0:
34 return "D0";
35 case ACPI_STATE_D1:
36 return "D1";
37 case ACPI_STATE_D2:
38 return "D2";
39 case ACPI_STATE_D3_HOT:
40 return "D3hot";
41 case ACPI_STATE_D3_COLD:
42 return "D3cold";
43 default:
44 return "(unknown)";
45 }
46}
47
48static int acpi_dev_pm_explicit_get(struct acpi_device *device, int *state)
49{
50 unsigned long long psc;
51 acpi_status status;
52
53 status = acpi_evaluate_integer(device->handle, "_PSC", NULL, &psc);
54 if (ACPI_FAILURE(status))
55 return -ENODEV;
56
57 *state = psc;
58 return 0;
59}
60
61/**
62 * acpi_device_get_power - Get power state of an ACPI device.
63 * @device: Device to get the power state of.
64 * @state: Place to store the power state of the device.
65 *
66 * This function does not update the device's power.state field, but it may
67 * update its parent's power.state field (when the parent's power state is
68 * unknown and the device's power state turns out to be D0).
69 *
70 * Also, it does not update power resource reference counters to ensure that
71 * the power state returned by it will be persistent and it may return a power
72 * state shallower than previously set by acpi_device_set_power() for @device
73 * (if that power state depends on any power resources).
74 */
75int acpi_device_get_power(struct acpi_device *device, int *state)
76{
77 int result = ACPI_STATE_UNKNOWN;
78 struct acpi_device *parent;
79 int error;
80
81 if (!device || !state)
82 return -EINVAL;
83
84 parent = acpi_dev_parent(device);
85
86 if (!device->flags.power_manageable) {
87 /* TBD: Non-recursive algorithm for walking up hierarchy. */
88 *state = parent ? parent->power.state : ACPI_STATE_D0;
89 goto out;
90 }
91
92 /*
93 * Get the device's power state from power resources settings and _PSC,
94 * if available.
95 */
96 if (device->power.flags.power_resources) {
97 error = acpi_power_get_inferred_state(device, &result);
98 if (error)
99 return error;
100 }
101 if (device->power.flags.explicit_get) {
102 int psc;
103
104 error = acpi_dev_pm_explicit_get(device, &psc);
105 if (error)
106 return error;
107
108 /*
109 * The power resources settings may indicate a power state
110 * shallower than the actual power state of the device, because
111 * the same power resources may be referenced by other devices.
112 *
113 * For systems predating ACPI 4.0 we assume that D3hot is the
114 * deepest state that can be supported.
115 */
116 if (psc > result && psc < ACPI_STATE_D3_COLD)
117 result = psc;
118 else if (result == ACPI_STATE_UNKNOWN)
119 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
120 }
121
122 /*
123 * If we were unsure about the device parent's power state up to this
124 * point, the fact that the device is in D0 implies that the parent has
125 * to be in D0 too, except if ignore_parent is set.
126 */
127 if (!device->power.flags.ignore_parent && parent &&
128 parent->power.state == ACPI_STATE_UNKNOWN &&
129 result == ACPI_STATE_D0)
130 parent->power.state = ACPI_STATE_D0;
131
132 *state = result;
133
134 out:
135 acpi_handle_debug(device->handle, "Power state: %s\n",
136 acpi_power_state_string(*state));
137
138 return 0;
139}
140
141static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
142{
143 if (adev->power.states[state].flags.explicit_set) {
144 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
145 acpi_status status;
146
147 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
148 if (ACPI_FAILURE(status))
149 return -ENODEV;
150 }
151 return 0;
152}
153
154/**
155 * acpi_device_set_power - Set power state of an ACPI device.
156 * @device: Device to set the power state of.
157 * @state: New power state to set.
158 *
159 * Callers must ensure that the device is power manageable before using this
160 * function.
161 */
162int acpi_device_set_power(struct acpi_device *device, int state)
163{
164 int target_state = state;
165 int result = 0;
166
167 if (!device || !device->flags.power_manageable
168 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
169 return -EINVAL;
170
171 acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",
172 acpi_power_state_string(device->power.state),
173 acpi_power_state_string(state));
174
175 /* Make sure this is a valid target state */
176
177 /* There is a special case for D0 addressed below. */
178 if (state > ACPI_STATE_D0 && state == device->power.state)
179 goto no_change;
180
181 if (state == ACPI_STATE_D3_COLD) {
182 /*
183 * For transitions to D3cold we need to execute _PS3 and then
184 * possibly drop references to the power resources in use.
185 */
186 state = ACPI_STATE_D3_HOT;
187 /* If D3cold is not supported, use D3hot as the target state. */
188 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
189 target_state = state;
190 } else if (!device->power.states[state].flags.valid) {
191 acpi_handle_debug(device->handle, "Power state %s not supported\n",
192 acpi_power_state_string(state));
193 return -ENODEV;
194 }
195
196 if (!device->power.flags.ignore_parent) {
197 struct acpi_device *parent;
198
199 parent = acpi_dev_parent(device);
200 if (parent && state < parent->power.state) {
201 acpi_handle_debug(device->handle,
202 "Cannot transition to %s for parent in %s\n",
203 acpi_power_state_string(state),
204 acpi_power_state_string(parent->power.state));
205 return -ENODEV;
206 }
207 }
208
209 /*
210 * Transition Power
211 * ----------------
212 * In accordance with ACPI 6, _PSx is executed before manipulating power
213 * resources, unless the target state is D0, in which case _PS0 is
214 * supposed to be executed after turning the power resources on.
215 */
216 if (state > ACPI_STATE_D0) {
217 /*
218 * According to ACPI 6, devices cannot go from lower-power
219 * (deeper) states to higher-power (shallower) states.
220 */
221 if (state < device->power.state) {
222 acpi_handle_debug(device->handle,
223 "Cannot transition from %s to %s\n",
224 acpi_power_state_string(device->power.state),
225 acpi_power_state_string(state));
226 return -ENODEV;
227 }
228
229 /*
230 * If the device goes from D3hot to D3cold, _PS3 has been
231 * evaluated for it already, so skip it in that case.
232 */
233 if (device->power.state < ACPI_STATE_D3_HOT) {
234 result = acpi_dev_pm_explicit_set(device, state);
235 if (result)
236 goto end;
237 }
238
239 if (device->power.flags.power_resources)
240 result = acpi_power_transition(device, target_state);
241 } else {
242 int cur_state = device->power.state;
243
244 if (device->power.flags.power_resources) {
245 result = acpi_power_transition(device, ACPI_STATE_D0);
246 if (result)
247 goto end;
248 }
249
250 if (cur_state == ACPI_STATE_D0) {
251 int psc;
252
253 /* Nothing to do here if _PSC is not present. */
254 if (!device->power.flags.explicit_get)
255 goto no_change;
256
257 /*
258 * The power state of the device was set to D0 last
259 * time, but that might have happened before a
260 * system-wide transition involving the platform
261 * firmware, so it may be necessary to evaluate _PS0
262 * for the device here. However, use extra care here
263 * and evaluate _PSC to check the device's current power
264 * state, and only invoke _PS0 if the evaluation of _PSC
265 * is successful and it returns a power state different
266 * from D0.
267 */
268 result = acpi_dev_pm_explicit_get(device, &psc);
269 if (result || psc == ACPI_STATE_D0)
270 goto no_change;
271 }
272
273 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
274 }
275
276end:
277 if (result) {
278 acpi_handle_debug(device->handle,
279 "Failed to change power state to %s\n",
280 acpi_power_state_string(target_state));
281 } else {
282 device->power.state = target_state;
283 acpi_handle_debug(device->handle, "Power state changed to %s\n",
284 acpi_power_state_string(target_state));
285 }
286
287 return result;
288
289no_change:
290 acpi_handle_debug(device->handle, "Already in %s\n",
291 acpi_power_state_string(state));
292 return 0;
293}
294EXPORT_SYMBOL(acpi_device_set_power);
295
296int acpi_bus_set_power(acpi_handle handle, int state)
297{
298 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
299
300 if (device)
301 return acpi_device_set_power(device, state);
302
303 return -ENODEV;
304}
305EXPORT_SYMBOL(acpi_bus_set_power);
306
307int acpi_bus_init_power(struct acpi_device *device)
308{
309 int state;
310 int result;
311
312 if (!device)
313 return -EINVAL;
314
315 device->power.state = ACPI_STATE_UNKNOWN;
316 if (!acpi_device_is_present(device)) {
317 device->flags.initialized = false;
318 return -ENXIO;
319 }
320
321 result = acpi_device_get_power(device, &state);
322 if (result)
323 return result;
324
325 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
326 /* Reference count the power resources. */
327 result = acpi_power_on_resources(device, state);
328 if (result)
329 return result;
330
331 if (state == ACPI_STATE_D0) {
332 /*
333 * If _PSC is not present and the state inferred from
334 * power resources appears to be D0, it still may be
335 * necessary to execute _PS0 at this point, because
336 * another device using the same power resources may
337 * have been put into D0 previously and that's why we
338 * see D0 here.
339 */
340 result = acpi_dev_pm_explicit_set(device, state);
341 if (result)
342 return result;
343 }
344 } else if (state == ACPI_STATE_UNKNOWN) {
345 /*
346 * No power resources and missing _PSC? Cross fingers and make
347 * it D0 in hope that this is what the BIOS put the device into.
348 * [We tried to force D0 here by executing _PS0, but that broke
349 * Toshiba P870-303 in a nasty way.]
350 */
351 state = ACPI_STATE_D0;
352 }
353 device->power.state = state;
354 return 0;
355}
356
357/**
358 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
359 * @device: Device object whose power state is to be fixed up.
360 *
361 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
362 * are assumed to be put into D0 by the BIOS. However, in some cases that may
363 * not be the case and this function should be used then.
364 */
365int acpi_device_fix_up_power(struct acpi_device *device)
366{
367 int ret = 0;
368
369 if (!device->power.flags.power_resources
370 && !device->power.flags.explicit_get
371 && device->power.state == ACPI_STATE_D0)
372 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
373
374 return ret;
375}
376EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
377
378static int fix_up_power_if_applicable(struct acpi_device *adev, void *not_used)
379{
380 if (adev->status.present && adev->status.enabled)
381 acpi_device_fix_up_power(adev);
382
383 return 0;
384}
385
386/**
387 * acpi_device_fix_up_power_extended - Force device and its children into D0.
388 * @adev: Parent device object whose power state is to be fixed up.
389 *
390 * Call acpi_device_fix_up_power() for @adev and its children so long as they
391 * are reported as present and enabled.
392 */
393void acpi_device_fix_up_power_extended(struct acpi_device *adev)
394{
395 acpi_device_fix_up_power(adev);
396 acpi_dev_for_each_child(adev, fix_up_power_if_applicable, NULL);
397}
398EXPORT_SYMBOL_GPL(acpi_device_fix_up_power_extended);
399
400/**
401 * acpi_device_fix_up_power_children - Force a device's children into D0.
402 * @adev: Parent device object whose children's power state is to be fixed up.
403 *
404 * Call acpi_device_fix_up_power() for @adev's children so long as they
405 * are reported as present and enabled.
406 */
407void acpi_device_fix_up_power_children(struct acpi_device *adev)
408{
409 acpi_dev_for_each_child(adev, fix_up_power_if_applicable, NULL);
410}
411EXPORT_SYMBOL_GPL(acpi_device_fix_up_power_children);
412
413int acpi_device_update_power(struct acpi_device *device, int *state_p)
414{
415 int state;
416 int result;
417
418 if (device->power.state == ACPI_STATE_UNKNOWN) {
419 result = acpi_bus_init_power(device);
420 if (!result && state_p)
421 *state_p = device->power.state;
422
423 return result;
424 }
425
426 result = acpi_device_get_power(device, &state);
427 if (result)
428 return result;
429
430 if (state == ACPI_STATE_UNKNOWN) {
431 state = ACPI_STATE_D0;
432 result = acpi_device_set_power(device, state);
433 if (result)
434 return result;
435 } else {
436 if (device->power.flags.power_resources) {
437 /*
438 * We don't need to really switch the state, bu we need
439 * to update the power resources' reference counters.
440 */
441 result = acpi_power_transition(device, state);
442 if (result)
443 return result;
444 }
445 device->power.state = state;
446 }
447 if (state_p)
448 *state_p = state;
449
450 return 0;
451}
452EXPORT_SYMBOL_GPL(acpi_device_update_power);
453
454int acpi_bus_update_power(acpi_handle handle, int *state_p)
455{
456 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
457
458 if (device)
459 return acpi_device_update_power(device, state_p);
460
461 return -ENODEV;
462}
463EXPORT_SYMBOL_GPL(acpi_bus_update_power);
464
465bool acpi_bus_power_manageable(acpi_handle handle)
466{
467 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
468
469 return device && device->flags.power_manageable;
470}
471EXPORT_SYMBOL(acpi_bus_power_manageable);
472
473static int acpi_power_up_if_adr_present(struct acpi_device *adev, void *not_used)
474{
475 if (!(adev->flags.power_manageable && adev->pnp.type.bus_address))
476 return 0;
477
478 acpi_handle_debug(adev->handle, "Power state: %s\n",
479 acpi_power_state_string(adev->power.state));
480
481 if (adev->power.state == ACPI_STATE_D3_COLD)
482 return acpi_device_set_power(adev, ACPI_STATE_D0);
483
484 return 0;
485}
486
487/**
488 * acpi_dev_power_up_children_with_adr - Power up childres with valid _ADR
489 * @adev: Parent ACPI device object.
490 *
491 * Change the power states of the direct children of @adev that are in D3cold
492 * and hold valid _ADR objects to D0 in order to allow bus (e.g. PCI)
493 * enumeration code to access them.
494 */
495void acpi_dev_power_up_children_with_adr(struct acpi_device *adev)
496{
497 acpi_dev_for_each_child(adev, acpi_power_up_if_adr_present, NULL);
498}
499
500/**
501 * acpi_dev_power_state_for_wake - Deepest power state for wakeup signaling
502 * @adev: ACPI companion of the target device.
503 *
504 * Evaluate _S0W for @adev and return the value produced by it or return
505 * ACPI_STATE_UNKNOWN on errors (including _S0W not present).
506 */
507u8 acpi_dev_power_state_for_wake(struct acpi_device *adev)
508{
509 unsigned long long state;
510 acpi_status status;
511
512 status = acpi_evaluate_integer(adev->handle, "_S0W", NULL, &state);
513 if (ACPI_FAILURE(status))
514 return ACPI_STATE_UNKNOWN;
515
516 return state;
517}
518
519#ifdef CONFIG_PM
520static DEFINE_MUTEX(acpi_pm_notifier_lock);
521static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
522
523void acpi_pm_wakeup_event(struct device *dev)
524{
525 pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
526}
527EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
528
529static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
530{
531 struct acpi_device *adev;
532
533 if (val != ACPI_NOTIFY_DEVICE_WAKE)
534 return;
535
536 acpi_handle_debug(handle, "Wake notify\n");
537
538 adev = acpi_get_acpi_dev(handle);
539 if (!adev)
540 return;
541
542 mutex_lock(&acpi_pm_notifier_lock);
543
544 if (adev->wakeup.flags.notifier_present) {
545 pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
546 if (adev->wakeup.context.func) {
547 acpi_handle_debug(handle, "Running %pS for %s\n",
548 adev->wakeup.context.func,
549 dev_name(adev->wakeup.context.dev));
550 adev->wakeup.context.func(&adev->wakeup.context);
551 }
552 }
553
554 mutex_unlock(&acpi_pm_notifier_lock);
555
556 acpi_put_acpi_dev(adev);
557}
558
559/**
560 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
561 * @adev: ACPI device to add the notify handler for.
562 * @dev: Device to generate a wakeup event for while handling the notification.
563 * @func: Work function to execute when handling the notification.
564 *
565 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
566 * PM wakeup events. For example, wakeup events may be generated for bridges
567 * if one of the devices below the bridge is signaling wakeup, even if the
568 * bridge itself doesn't have a wakeup GPE associated with it.
569 */
570acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
571 void (*func)(struct acpi_device_wakeup_context *context))
572{
573 acpi_status status = AE_ALREADY_EXISTS;
574
575 if (!dev && !func)
576 return AE_BAD_PARAMETER;
577
578 mutex_lock(&acpi_pm_notifier_install_lock);
579
580 if (adev->wakeup.flags.notifier_present)
581 goto out;
582
583 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
584 acpi_pm_notify_handler, NULL);
585 if (ACPI_FAILURE(status))
586 goto out;
587
588 mutex_lock(&acpi_pm_notifier_lock);
589 adev->wakeup.ws = wakeup_source_register(dev, dev_name(&adev->dev));
590 adev->wakeup.context.dev = dev;
591 adev->wakeup.context.func = func;
592 adev->wakeup.flags.notifier_present = true;
593 mutex_unlock(&acpi_pm_notifier_lock);
594
595 out:
596 mutex_unlock(&acpi_pm_notifier_install_lock);
597 return status;
598}
599
600/**
601 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
602 * @adev: ACPI device to remove the notifier from.
603 */
604acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
605{
606 acpi_status status = AE_BAD_PARAMETER;
607
608 mutex_lock(&acpi_pm_notifier_install_lock);
609
610 if (!adev->wakeup.flags.notifier_present)
611 goto out;
612
613 status = acpi_remove_notify_handler(adev->handle,
614 ACPI_SYSTEM_NOTIFY,
615 acpi_pm_notify_handler);
616 if (ACPI_FAILURE(status))
617 goto out;
618
619 mutex_lock(&acpi_pm_notifier_lock);
620 adev->wakeup.context.func = NULL;
621 adev->wakeup.context.dev = NULL;
622 wakeup_source_unregister(adev->wakeup.ws);
623 adev->wakeup.flags.notifier_present = false;
624 mutex_unlock(&acpi_pm_notifier_lock);
625
626 out:
627 mutex_unlock(&acpi_pm_notifier_install_lock);
628 return status;
629}
630
631bool acpi_bus_can_wakeup(acpi_handle handle)
632{
633 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
634
635 return device && device->wakeup.flags.valid;
636}
637EXPORT_SYMBOL(acpi_bus_can_wakeup);
638
639bool acpi_pm_device_can_wakeup(struct device *dev)
640{
641 struct acpi_device *adev = ACPI_COMPANION(dev);
642
643 return adev ? acpi_device_can_wakeup(adev) : false;
644}
645
646/**
647 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
648 * @dev: Device whose preferred target power state to return.
649 * @adev: ACPI device node corresponding to @dev.
650 * @target_state: System state to match the resultant device state.
651 * @d_min_p: Location to store the highest power state available to the device.
652 * @d_max_p: Location to store the lowest power state available to the device.
653 *
654 * Find the lowest power (highest number) and highest power (lowest number) ACPI
655 * device power states that the device can be in while the system is in the
656 * state represented by @target_state. Store the integer numbers representing
657 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
658 * respectively.
659 *
660 * Callers must ensure that @dev and @adev are valid pointers and that @adev
661 * actually corresponds to @dev before using this function.
662 *
663 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
664 * returns a value that doesn't make sense. The memory locations pointed to by
665 * @d_max_p and @d_min_p are only modified on success.
666 */
667static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
668 u32 target_state, int *d_min_p, int *d_max_p)
669{
670 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
671 acpi_handle handle = adev->handle;
672 unsigned long long ret;
673 int d_min, d_max;
674 bool wakeup = false;
675 bool has_sxd = false;
676 acpi_status status;
677
678 /*
679 * If the system state is S0, the lowest power state the device can be
680 * in is D3cold, unless the device has _S0W and is supposed to signal
681 * wakeup, in which case the return value of _S0W has to be used as the
682 * lowest power state available to the device.
683 */
684 d_min = ACPI_STATE_D0;
685 d_max = ACPI_STATE_D3_COLD;
686
687 /*
688 * If present, _SxD methods return the minimum D-state (highest power
689 * state) we can use for the corresponding S-states. Otherwise, the
690 * minimum D-state is D0 (ACPI 3.x).
691 */
692 if (target_state > ACPI_STATE_S0) {
693 /*
694 * We rely on acpi_evaluate_integer() not clobbering the integer
695 * provided if AE_NOT_FOUND is returned.
696 */
697 ret = d_min;
698 status = acpi_evaluate_integer(handle, method, NULL, &ret);
699 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
700 || ret > ACPI_STATE_D3_COLD)
701 return -ENODATA;
702
703 /*
704 * We need to handle legacy systems where D3hot and D3cold are
705 * the same and 3 is returned in both cases, so fall back to
706 * D3cold if D3hot is not a valid state.
707 */
708 if (!adev->power.states[ret].flags.valid) {
709 if (ret == ACPI_STATE_D3_HOT)
710 ret = ACPI_STATE_D3_COLD;
711 else
712 return -ENODATA;
713 }
714
715 if (status == AE_OK)
716 has_sxd = true;
717
718 d_min = ret;
719 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
720 && adev->wakeup.sleep_state >= target_state;
721 } else if (device_may_wakeup(dev) && dev->power.wakeirq) {
722 /*
723 * The ACPI subsystem doesn't manage the wake bit for IRQs
724 * defined with ExclusiveAndWake and SharedAndWake. Instead we
725 * expect them to be managed via the PM subsystem. Drivers
726 * should call dev_pm_set_wake_irq to register an IRQ as a wake
727 * source.
728 *
729 * If a device has a wake IRQ attached we need to check the
730 * _S0W method to get the correct wake D-state. Otherwise we
731 * end up putting the device into D3Cold which will more than
732 * likely disable wake functionality.
733 */
734 wakeup = true;
735 } else {
736 /* ACPI GPE is specified in _PRW. */
737 wakeup = adev->wakeup.flags.valid;
738 }
739
740 /*
741 * If _PRW says we can wake up the system from the target sleep state,
742 * the D-state returned by _SxD is sufficient for that (we assume a
743 * wakeup-aware driver if wake is set). Still, if _SxW exists
744 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
745 * can wake the system. _S0W may be valid, too.
746 */
747 if (wakeup) {
748 method[3] = 'W';
749 status = acpi_evaluate_integer(handle, method, NULL, &ret);
750 if (status == AE_NOT_FOUND) {
751 /* No _SxW. In this case, the ACPI spec says that we
752 * must not go into any power state deeper than the
753 * value returned from _SxD.
754 */
755 if (has_sxd && target_state > ACPI_STATE_S0)
756 d_max = d_min;
757 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
758 /* Fall back to D3cold if ret is not a valid state. */
759 if (!adev->power.states[ret].flags.valid)
760 ret = ACPI_STATE_D3_COLD;
761
762 d_max = ret > d_min ? ret : d_min;
763 } else {
764 return -ENODATA;
765 }
766 }
767
768 if (d_min_p)
769 *d_min_p = d_min;
770
771 if (d_max_p)
772 *d_max_p = d_max;
773
774 return 0;
775}
776
777/**
778 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
779 * @dev: Device whose preferred target power state to return.
780 * @d_min_p: Location to store the upper limit of the allowed states range.
781 * @d_max_in: Deepest low-power state to take into consideration.
782 * Return value: Preferred power state of the device on success, -ENODEV
783 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
784 * incorrect, or -ENODATA on ACPI method failure.
785 *
786 * The caller must ensure that @dev is valid before using this function.
787 */
788int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
789{
790 struct acpi_device *adev;
791 int ret, d_min, d_max;
792
793 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
794 return -EINVAL;
795
796 if (d_max_in > ACPI_STATE_D2) {
797 enum pm_qos_flags_status stat;
798
799 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
800 if (stat == PM_QOS_FLAGS_ALL)
801 d_max_in = ACPI_STATE_D2;
802 }
803
804 adev = ACPI_COMPANION(dev);
805 if (!adev) {
806 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
807 return -ENODEV;
808 }
809
810 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
811 &d_min, &d_max);
812 if (ret)
813 return ret;
814
815 if (d_max_in < d_min)
816 return -EINVAL;
817
818 if (d_max > d_max_in) {
819 for (d_max = d_max_in; d_max > d_min; d_max--) {
820 if (adev->power.states[d_max].flags.valid)
821 break;
822 }
823 }
824
825 if (d_min_p)
826 *d_min_p = d_min;
827
828 return d_max;
829}
830EXPORT_SYMBOL(acpi_pm_device_sleep_state);
831
832/**
833 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
834 * @context: Device wakeup context.
835 */
836static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
837{
838 struct device *dev = context->dev;
839
840 if (dev) {
841 pm_wakeup_event(dev, 0);
842 pm_request_resume(dev);
843 }
844}
845
846static DEFINE_MUTEX(acpi_wakeup_lock);
847
848static int __acpi_device_wakeup_enable(struct acpi_device *adev,
849 u32 target_state)
850{
851 struct acpi_device_wakeup *wakeup = &adev->wakeup;
852 acpi_status status;
853 int error = 0;
854
855 mutex_lock(&acpi_wakeup_lock);
856
857 /*
858 * If the device wakeup power is already enabled, disable it and enable
859 * it again in case it depends on the configuration of subordinate
860 * devices and the conditions have changed since it was enabled last
861 * time.
862 */
863 if (wakeup->enable_count > 0)
864 acpi_disable_wakeup_device_power(adev);
865
866 error = acpi_enable_wakeup_device_power(adev, target_state);
867 if (error) {
868 if (wakeup->enable_count > 0) {
869 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
870 wakeup->enable_count = 0;
871 }
872 goto out;
873 }
874
875 if (wakeup->enable_count > 0)
876 goto inc;
877
878 status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
879 if (ACPI_FAILURE(status)) {
880 acpi_disable_wakeup_device_power(adev);
881 error = -EIO;
882 goto out;
883 }
884
885 acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
886 (unsigned int)wakeup->gpe_number);
887
888inc:
889 if (wakeup->enable_count < INT_MAX)
890 wakeup->enable_count++;
891 else
892 acpi_handle_info(adev->handle, "Wakeup enable count out of bounds!\n");
893
894out:
895 mutex_unlock(&acpi_wakeup_lock);
896 return error;
897}
898
899/**
900 * acpi_device_wakeup_enable - Enable wakeup functionality for device.
901 * @adev: ACPI device to enable wakeup functionality for.
902 * @target_state: State the system is transitioning into.
903 *
904 * Enable the GPE associated with @adev so that it can generate wakeup signals
905 * for the device in response to external (remote) events and enable wakeup
906 * power for it.
907 *
908 * Callers must ensure that @adev is a valid ACPI device node before executing
909 * this function.
910 */
911static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
912{
913 return __acpi_device_wakeup_enable(adev, target_state);
914}
915
916/**
917 * acpi_device_wakeup_disable - Disable wakeup functionality for device.
918 * @adev: ACPI device to disable wakeup functionality for.
919 *
920 * Disable the GPE associated with @adev and disable wakeup power for it.
921 *
922 * Callers must ensure that @adev is a valid ACPI device node before executing
923 * this function.
924 */
925static void acpi_device_wakeup_disable(struct acpi_device *adev)
926{
927 struct acpi_device_wakeup *wakeup = &adev->wakeup;
928
929 mutex_lock(&acpi_wakeup_lock);
930
931 if (!wakeup->enable_count)
932 goto out;
933
934 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
935 acpi_disable_wakeup_device_power(adev);
936
937 wakeup->enable_count--;
938
939out:
940 mutex_unlock(&acpi_wakeup_lock);
941}
942
943/**
944 * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
945 * @dev: Device to enable/disable to generate wakeup events.
946 * @enable: Whether to enable or disable the wakeup functionality.
947 */
948int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
949{
950 struct acpi_device *adev;
951 int error;
952
953 adev = ACPI_COMPANION(dev);
954 if (!adev) {
955 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
956 return -ENODEV;
957 }
958
959 if (!acpi_device_can_wakeup(adev))
960 return -EINVAL;
961
962 if (!enable) {
963 acpi_device_wakeup_disable(adev);
964 dev_dbg(dev, "Wakeup disabled by ACPI\n");
965 return 0;
966 }
967
968 error = __acpi_device_wakeup_enable(adev, acpi_target_system_state());
969 if (!error)
970 dev_dbg(dev, "Wakeup enabled by ACPI\n");
971
972 return error;
973}
974EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
975
976/**
977 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
978 * @dev: Device to put into a low-power state.
979 * @adev: ACPI device node corresponding to @dev.
980 * @system_state: System state to choose the device state for.
981 */
982static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
983 u32 system_state)
984{
985 int ret, state;
986
987 if (!acpi_device_power_manageable(adev))
988 return 0;
989
990 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
991 return ret ? ret : acpi_device_set_power(adev, state);
992}
993
994/**
995 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
996 * @adev: ACPI device node to put into the full-power state.
997 */
998static int acpi_dev_pm_full_power(struct acpi_device *adev)
999{
1000 return acpi_device_power_manageable(adev) ?
1001 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
1002}
1003
1004/**
1005 * acpi_dev_suspend - Put device into a low-power state using ACPI.
1006 * @dev: Device to put into a low-power state.
1007 * @wakeup: Whether or not to enable wakeup for the device.
1008 *
1009 * Put the given device into a low-power state using the standard ACPI
1010 * mechanism. Set up remote wakeup if desired, choose the state to put the
1011 * device into (this checks if remote wakeup is expected to work too), and set
1012 * the power state of the device.
1013 */
1014int acpi_dev_suspend(struct device *dev, bool wakeup)
1015{
1016 struct acpi_device *adev = ACPI_COMPANION(dev);
1017 u32 target_state = acpi_target_system_state();
1018 int error;
1019
1020 if (!adev)
1021 return 0;
1022
1023 if (wakeup && acpi_device_can_wakeup(adev)) {
1024 error = acpi_device_wakeup_enable(adev, target_state);
1025 if (error)
1026 return -EAGAIN;
1027 } else {
1028 wakeup = false;
1029 }
1030
1031 error = acpi_dev_pm_low_power(dev, adev, target_state);
1032 if (error && wakeup)
1033 acpi_device_wakeup_disable(adev);
1034
1035 return error;
1036}
1037EXPORT_SYMBOL_GPL(acpi_dev_suspend);
1038
1039/**
1040 * acpi_dev_resume - Put device into the full-power state using ACPI.
1041 * @dev: Device to put into the full-power state.
1042 *
1043 * Put the given device into the full-power state using the standard ACPI
1044 * mechanism. Set the power state of the device to ACPI D0 and disable wakeup.
1045 */
1046int acpi_dev_resume(struct device *dev)
1047{
1048 struct acpi_device *adev = ACPI_COMPANION(dev);
1049 int error;
1050
1051 if (!adev)
1052 return 0;
1053
1054 error = acpi_dev_pm_full_power(adev);
1055 acpi_device_wakeup_disable(adev);
1056 return error;
1057}
1058EXPORT_SYMBOL_GPL(acpi_dev_resume);
1059
1060/**
1061 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
1062 * @dev: Device to suspend.
1063 *
1064 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
1065 * it into a runtime low-power state.
1066 */
1067int acpi_subsys_runtime_suspend(struct device *dev)
1068{
1069 int ret = pm_generic_runtime_suspend(dev);
1070
1071 return ret ? ret : acpi_dev_suspend(dev, true);
1072}
1073EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
1074
1075/**
1076 * acpi_subsys_runtime_resume - Resume device using ACPI.
1077 * @dev: Device to Resume.
1078 *
1079 * Use ACPI to put the given device into the full-power state and carry out the
1080 * generic runtime resume procedure for it.
1081 */
1082int acpi_subsys_runtime_resume(struct device *dev)
1083{
1084 int ret = acpi_dev_resume(dev);
1085
1086 return ret ? ret : pm_generic_runtime_resume(dev);
1087}
1088EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
1089
1090#ifdef CONFIG_PM_SLEEP
1091static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
1092{
1093 u32 sys_target = acpi_target_system_state();
1094 int ret, state;
1095
1096 if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
1097 device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
1098 return true;
1099
1100 if (sys_target == ACPI_STATE_S0)
1101 return false;
1102
1103 if (adev->power.flags.dsw_present)
1104 return true;
1105
1106 ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
1107 if (ret)
1108 return true;
1109
1110 return state != adev->power.state;
1111}
1112
1113/**
1114 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1115 * @dev: Device to prepare.
1116 */
1117int acpi_subsys_prepare(struct device *dev)
1118{
1119 struct acpi_device *adev = ACPI_COMPANION(dev);
1120
1121 dev_pm_set_strict_midlayer(dev, true);
1122
1123 if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
1124 int ret = dev->driver->pm->prepare(dev);
1125
1126 if (ret < 0)
1127 return ret;
1128
1129 if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
1130 return 0;
1131 }
1132
1133 return !acpi_dev_needs_resume(dev, adev);
1134}
1135EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
1136
1137/**
1138 * acpi_subsys_complete - Finalize device's resume during system resume.
1139 * @dev: Device to handle.
1140 */
1141void acpi_subsys_complete(struct device *dev)
1142{
1143 pm_generic_complete(dev);
1144 /*
1145 * If the device had been runtime-suspended before the system went into
1146 * the sleep state it is going out of and it has never been resumed till
1147 * now, resume it in case the firmware powered it up.
1148 */
1149 if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1150 pm_request_resume(dev);
1151
1152 dev_pm_set_strict_midlayer(dev, false);
1153}
1154EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1155
1156/**
1157 * acpi_subsys_suspend - Run the device driver's suspend callback.
1158 * @dev: Device to handle.
1159 *
1160 * Follow PCI and resume devices from runtime suspend before running their
1161 * system suspend callbacks, unless the driver can cope with runtime-suspended
1162 * devices during system suspend and there are no ACPI-specific reasons for
1163 * resuming them.
1164 */
1165int acpi_subsys_suspend(struct device *dev)
1166{
1167 if (!dev_pm_smart_suspend(dev) ||
1168 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1169 pm_runtime_resume(dev);
1170
1171 return pm_generic_suspend(dev);
1172}
1173EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1174
1175/**
1176 * acpi_subsys_suspend_late - Suspend device using ACPI.
1177 * @dev: Device to suspend.
1178 *
1179 * Carry out the generic late suspend procedure for @dev and use ACPI to put
1180 * it into a low-power state during system transition into a sleep state.
1181 */
1182int acpi_subsys_suspend_late(struct device *dev)
1183{
1184 int ret;
1185
1186 if (dev_pm_skip_suspend(dev))
1187 return 0;
1188
1189 ret = pm_generic_suspend_late(dev);
1190 return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1191}
1192EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1193
1194/**
1195 * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1196 * @dev: Device to suspend.
1197 */
1198int acpi_subsys_suspend_noirq(struct device *dev)
1199{
1200 int ret;
1201
1202 if (dev_pm_skip_suspend(dev))
1203 return 0;
1204
1205 ret = pm_generic_suspend_noirq(dev);
1206 if (ret)
1207 return ret;
1208
1209 /*
1210 * If the target system sleep state is suspend-to-idle, it is sufficient
1211 * to check whether or not the device's wakeup settings are good for
1212 * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause
1213 * acpi_subsys_complete() to take care of fixing up the device's state
1214 * anyway, if need be.
1215 */
1216 if (device_can_wakeup(dev) && !device_may_wakeup(dev))
1217 dev->power.may_skip_resume = false;
1218
1219 return 0;
1220}
1221EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1222
1223/**
1224 * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1225 * @dev: Device to handle.
1226 */
1227static int acpi_subsys_resume_noirq(struct device *dev)
1228{
1229 if (dev_pm_skip_resume(dev))
1230 return 0;
1231
1232 return pm_generic_resume_noirq(dev);
1233}
1234
1235/**
1236 * acpi_subsys_resume_early - Resume device using ACPI.
1237 * @dev: Device to Resume.
1238 *
1239 * Use ACPI to put the given device into the full-power state and carry out the
1240 * generic early resume procedure for it during system transition into the
1241 * working state, but only do that if device either defines early resume
1242 * handler, or does not define power operations at all. Otherwise powering up
1243 * of the device is postponed to the normal resume phase.
1244 */
1245static int acpi_subsys_resume_early(struct device *dev)
1246{
1247 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1248 int ret;
1249
1250 if (dev_pm_skip_resume(dev))
1251 return 0;
1252
1253 if (pm && !pm->resume_early) {
1254 dev_dbg(dev, "Postponing ACPI PM to normal resume stage\n");
1255 return 0;
1256 }
1257
1258 ret = acpi_dev_resume(dev);
1259 return ret ? ret : pm_generic_resume_early(dev);
1260}
1261
1262/**
1263 * acpi_subsys_resume - Resume device using ACPI.
1264 * @dev: Device to Resume.
1265 *
1266 * Use ACPI to put the given device into the full-power state if it has not been
1267 * powered up during early resume phase, and carry out the generic resume
1268 * procedure for it during system transition into the working state.
1269 */
1270static int acpi_subsys_resume(struct device *dev)
1271{
1272 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1273 int ret = 0;
1274
1275 if (!dev_pm_skip_resume(dev) && pm && !pm->resume_early) {
1276 dev_dbg(dev, "Applying postponed ACPI PM\n");
1277 ret = acpi_dev_resume(dev);
1278 }
1279
1280 return ret ? ret : pm_generic_resume(dev);
1281}
1282
1283/**
1284 * acpi_subsys_freeze - Run the device driver's freeze callback.
1285 * @dev: Device to handle.
1286 */
1287int acpi_subsys_freeze(struct device *dev)
1288{
1289 /*
1290 * Resume all runtime-suspended devices before creating a snapshot
1291 * image of system memory, because the restore kernel generally cannot
1292 * be expected to always handle them consistently and they need to be
1293 * put into the runtime-active metastate during system resume anyway,
1294 * so it is better to ensure that the state saved in the image will be
1295 * always consistent with that.
1296 */
1297 pm_runtime_resume(dev);
1298
1299 return pm_generic_freeze(dev);
1300}
1301EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1302
1303/**
1304 * acpi_subsys_restore_early - Restore device using ACPI.
1305 * @dev: Device to restore.
1306 */
1307int acpi_subsys_restore_early(struct device *dev)
1308{
1309 int ret = acpi_dev_resume(dev);
1310
1311 return ret ? ret : pm_generic_restore_early(dev);
1312}
1313EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1314
1315/**
1316 * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1317 * @dev: Device to handle.
1318 *
1319 * Follow PCI and resume devices from runtime suspend before running their
1320 * system poweroff callbacks, unless the driver can cope with runtime-suspended
1321 * devices during system suspend and there are no ACPI-specific reasons for
1322 * resuming them.
1323 */
1324int acpi_subsys_poweroff(struct device *dev)
1325{
1326 if (!dev_pm_smart_suspend(dev) ||
1327 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1328 pm_runtime_resume(dev);
1329
1330 return pm_generic_poweroff(dev);
1331}
1332EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1333
1334/**
1335 * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1336 * @dev: Device to handle.
1337 *
1338 * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1339 * it into a low-power state during system transition into a sleep state.
1340 */
1341static int acpi_subsys_poweroff_late(struct device *dev)
1342{
1343 int ret;
1344
1345 if (dev_pm_skip_suspend(dev))
1346 return 0;
1347
1348 ret = pm_generic_poweroff_late(dev);
1349 if (ret)
1350 return ret;
1351
1352 return acpi_dev_suspend(dev, device_may_wakeup(dev));
1353}
1354
1355/**
1356 * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1357 * @dev: Device to suspend.
1358 */
1359static int acpi_subsys_poweroff_noirq(struct device *dev)
1360{
1361 if (dev_pm_skip_suspend(dev))
1362 return 0;
1363
1364 return pm_generic_poweroff_noirq(dev);
1365}
1366#endif /* CONFIG_PM_SLEEP */
1367
1368static void acpi_dev_pm_detach(struct device *dev, bool power_off);
1369
1370static struct dev_pm_domain acpi_general_pm_domain = {
1371 .ops = {
1372 .runtime_suspend = acpi_subsys_runtime_suspend,
1373 .runtime_resume = acpi_subsys_runtime_resume,
1374#ifdef CONFIG_PM_SLEEP
1375 .prepare = acpi_subsys_prepare,
1376 .complete = acpi_subsys_complete,
1377 .suspend = acpi_subsys_suspend,
1378 .resume = acpi_subsys_resume,
1379 .suspend_late = acpi_subsys_suspend_late,
1380 .suspend_noirq = acpi_subsys_suspend_noirq,
1381 .resume_noirq = acpi_subsys_resume_noirq,
1382 .resume_early = acpi_subsys_resume_early,
1383 .freeze = acpi_subsys_freeze,
1384 .poweroff = acpi_subsys_poweroff,
1385 .poweroff_late = acpi_subsys_poweroff_late,
1386 .poweroff_noirq = acpi_subsys_poweroff_noirq,
1387 .restore_early = acpi_subsys_restore_early,
1388#endif
1389 },
1390 .detach = acpi_dev_pm_detach,
1391};
1392
1393/**
1394 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1395 * @dev: Device to take care of.
1396 * @power_off: Whether or not to try to remove power from the device.
1397 *
1398 * Remove the device from the general ACPI PM domain and remove its wakeup
1399 * notifier. If @power_off is set, additionally remove power from the device if
1400 * possible.
1401 *
1402 * Callers must ensure proper synchronization of this function with power
1403 * management callbacks.
1404 */
1405static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1406{
1407 struct acpi_device *adev = ACPI_COMPANION(dev);
1408
1409 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1410 dev_pm_domain_set(dev, NULL);
1411 acpi_remove_pm_notifier(adev);
1412 if (power_off) {
1413 /*
1414 * If the device's PM QoS resume latency limit or flags
1415 * have been exposed to user space, they have to be
1416 * hidden at this point, so that they don't affect the
1417 * choice of the low-power state to put the device into.
1418 */
1419 dev_pm_qos_hide_latency_limit(dev);
1420 dev_pm_qos_hide_flags(dev);
1421 acpi_device_wakeup_disable(adev);
1422 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1423 }
1424 }
1425}
1426
1427/**
1428 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1429 * @dev: Device to prepare.
1430 * @power_on: Whether or not to power on the device.
1431 *
1432 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1433 * attached to it, install a wakeup notification handler for the device and
1434 * add it to the general ACPI PM domain. If @power_on is set, the device will
1435 * be put into the ACPI D0 state before the function returns.
1436 *
1437 * This assumes that the @dev's bus type uses generic power management callbacks
1438 * (or doesn't use any power management callbacks at all).
1439 *
1440 * Callers must ensure proper synchronization of this function with power
1441 * management callbacks.
1442 */
1443int acpi_dev_pm_attach(struct device *dev, bool power_on)
1444{
1445 /*
1446 * Skip devices whose ACPI companions match the device IDs below,
1447 * because they require special power management handling incompatible
1448 * with the generic ACPI PM domain.
1449 */
1450 static const struct acpi_device_id special_pm_ids[] = {
1451 ACPI_FAN_DEVICE_IDS,
1452 {}
1453 };
1454 struct acpi_device *adev = ACPI_COMPANION(dev);
1455
1456 if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
1457 return 0;
1458
1459 /*
1460 * Only attach the power domain to the first device if the
1461 * companion is shared by multiple. This is to prevent doing power
1462 * management twice.
1463 */
1464 if (!acpi_device_is_first_physical_node(adev, dev))
1465 return 0;
1466
1467 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1468 dev_pm_domain_set(dev, &acpi_general_pm_domain);
1469 if (power_on) {
1470 acpi_dev_pm_full_power(adev);
1471 acpi_device_wakeup_disable(adev);
1472 }
1473
1474 return 1;
1475}
1476EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1477
1478/**
1479 * acpi_storage_d3 - Check if D3 should be used in the suspend path
1480 * @dev: Device to check
1481 *
1482 * Return %true if the platform firmware wants @dev to be programmed
1483 * into D3hot or D3cold (if supported) in the suspend path, or %false
1484 * when there is no specific preference. On some platforms, if this
1485 * hint is ignored, @dev may remain unresponsive after suspending the
1486 * platform as a whole.
1487 *
1488 * Although the property has storage in the name it actually is
1489 * applied to the PCIe slot and plugging in a non-storage device the
1490 * same platform restrictions will likely apply.
1491 */
1492bool acpi_storage_d3(struct device *dev)
1493{
1494 struct acpi_device *adev = ACPI_COMPANION(dev);
1495 u8 val;
1496
1497 if (force_storage_d3())
1498 return true;
1499
1500 if (!adev)
1501 return false;
1502 if (fwnode_property_read_u8(acpi_fwnode_handle(adev), "StorageD3Enable",
1503 &val))
1504 return false;
1505 return val == 1;
1506}
1507EXPORT_SYMBOL_GPL(acpi_storage_d3);
1508
1509/**
1510 * acpi_dev_state_d0 - Tell if the device is in D0 power state
1511 * @dev: Physical device the ACPI power state of which to check
1512 *
1513 * On a system without ACPI, return true. On a system with ACPI, return true if
1514 * the current ACPI power state of the device is D0, or false otherwise.
1515 *
1516 * Note that the power state of a device is not well-defined after it has been
1517 * passed to acpi_device_set_power() and before that function returns, so it is
1518 * not valid to ask for the ACPI power state of the device in that time frame.
1519 *
1520 * This function is intended to be used in a driver's probe or remove
1521 * function. See Documentation/firmware-guide/acpi/non-d0-probe.rst for
1522 * more information.
1523 */
1524bool acpi_dev_state_d0(struct device *dev)
1525{
1526 struct acpi_device *adev = ACPI_COMPANION(dev);
1527
1528 if (!adev)
1529 return true;
1530
1531 return adev->power.state == ACPI_STATE_D0;
1532}
1533EXPORT_SYMBOL_GPL(acpi_dev_state_d0);
1534
1535#endif /* CONFIG_PM */