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 <rafael.j.wysocki@intel.com>
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(handle: device->handle, pathname: "_PSC", NULL, data: &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(adev: 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, state: &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, state: &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(object: adev->handle, pathname: 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(adev: 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(adev: device, state);
235 if (result)
236 goto end;
237 }
238
239 if (device->power.flags.power_resources)
240 result = acpi_power_transition(device, state: 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, state: &psc);
269 if (result || psc == ACPI_STATE_D0)
270 goto no_change;
271 }
272
273 result = acpi_dev_pm_explicit_set(adev: 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(adev: device)) {
317 device->flags.initialized = false;
318 return -ENXIO;
319 }
320
321 result = acpi_device_get_power(device, state: &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(adev: 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(adev: 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, fn: fix_up_power_if_applicable, NULL);
397}
398EXPORT_SYMBOL_GPL(acpi_device_fix_up_power_extended);
399
400int acpi_device_update_power(struct acpi_device *device, int *state_p)
401{
402 int state;
403 int result;
404
405 if (device->power.state == ACPI_STATE_UNKNOWN) {
406 result = acpi_bus_init_power(device);
407 if (!result && state_p)
408 *state_p = device->power.state;
409
410 return result;
411 }
412
413 result = acpi_device_get_power(device, state: &state);
414 if (result)
415 return result;
416
417 if (state == ACPI_STATE_UNKNOWN) {
418 state = ACPI_STATE_D0;
419 result = acpi_device_set_power(device, state);
420 if (result)
421 return result;
422 } else {
423 if (device->power.flags.power_resources) {
424 /*
425 * We don't need to really switch the state, bu we need
426 * to update the power resources' reference counters.
427 */
428 result = acpi_power_transition(device, state);
429 if (result)
430 return result;
431 }
432 device->power.state = state;
433 }
434 if (state_p)
435 *state_p = state;
436
437 return 0;
438}
439EXPORT_SYMBOL_GPL(acpi_device_update_power);
440
441int acpi_bus_update_power(acpi_handle handle, int *state_p)
442{
443 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
444
445 if (device)
446 return acpi_device_update_power(device, state_p);
447
448 return -ENODEV;
449}
450EXPORT_SYMBOL_GPL(acpi_bus_update_power);
451
452bool acpi_bus_power_manageable(acpi_handle handle)
453{
454 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
455
456 return device && device->flags.power_manageable;
457}
458EXPORT_SYMBOL(acpi_bus_power_manageable);
459
460static int acpi_power_up_if_adr_present(struct acpi_device *adev, void *not_used)
461{
462 if (!(adev->flags.power_manageable && adev->pnp.type.bus_address))
463 return 0;
464
465 acpi_handle_debug(adev->handle, "Power state: %s\n",
466 acpi_power_state_string(adev->power.state));
467
468 if (adev->power.state == ACPI_STATE_D3_COLD)
469 return acpi_device_set_power(adev, ACPI_STATE_D0);
470
471 return 0;
472}
473
474/**
475 * acpi_dev_power_up_children_with_adr - Power up childres with valid _ADR
476 * @adev: Parent ACPI device object.
477 *
478 * Change the power states of the direct children of @adev that are in D3cold
479 * and hold valid _ADR objects to D0 in order to allow bus (e.g. PCI)
480 * enumeration code to access them.
481 */
482void acpi_dev_power_up_children_with_adr(struct acpi_device *adev)
483{
484 acpi_dev_for_each_child(adev, fn: acpi_power_up_if_adr_present, NULL);
485}
486
487/**
488 * acpi_dev_power_state_for_wake - Deepest power state for wakeup signaling
489 * @adev: ACPI companion of the target device.
490 *
491 * Evaluate _S0W for @adev and return the value produced by it or return
492 * ACPI_STATE_UNKNOWN on errors (including _S0W not present).
493 */
494u8 acpi_dev_power_state_for_wake(struct acpi_device *adev)
495{
496 unsigned long long state;
497 acpi_status status;
498
499 status = acpi_evaluate_integer(handle: adev->handle, pathname: "_S0W", NULL, data: &state);
500 if (ACPI_FAILURE(status))
501 return ACPI_STATE_UNKNOWN;
502
503 return state;
504}
505
506#ifdef CONFIG_PM
507static DEFINE_MUTEX(acpi_pm_notifier_lock);
508static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
509
510void acpi_pm_wakeup_event(struct device *dev)
511{
512 pm_wakeup_dev_event(dev, msec: 0, hard: acpi_s2idle_wakeup());
513}
514EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
515
516static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
517{
518 struct acpi_device *adev;
519
520 if (val != ACPI_NOTIFY_DEVICE_WAKE)
521 return;
522
523 acpi_handle_debug(handle, "Wake notify\n");
524
525 adev = acpi_get_acpi_dev(handle);
526 if (!adev)
527 return;
528
529 mutex_lock(&acpi_pm_notifier_lock);
530
531 if (adev->wakeup.flags.notifier_present) {
532 pm_wakeup_ws_event(ws: adev->wakeup.ws, msec: 0, hard: acpi_s2idle_wakeup());
533 if (adev->wakeup.context.func) {
534 acpi_handle_debug(handle, "Running %pS for %s\n",
535 adev->wakeup.context.func,
536 dev_name(adev->wakeup.context.dev));
537 adev->wakeup.context.func(&adev->wakeup.context);
538 }
539 }
540
541 mutex_unlock(lock: &acpi_pm_notifier_lock);
542
543 acpi_put_acpi_dev(adev);
544}
545
546/**
547 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
548 * @adev: ACPI device to add the notify handler for.
549 * @dev: Device to generate a wakeup event for while handling the notification.
550 * @func: Work function to execute when handling the notification.
551 *
552 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
553 * PM wakeup events. For example, wakeup events may be generated for bridges
554 * if one of the devices below the bridge is signaling wakeup, even if the
555 * bridge itself doesn't have a wakeup GPE associated with it.
556 */
557acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
558 void (*func)(struct acpi_device_wakeup_context *context))
559{
560 acpi_status status = AE_ALREADY_EXISTS;
561
562 if (!dev && !func)
563 return AE_BAD_PARAMETER;
564
565 mutex_lock(&acpi_pm_notifier_install_lock);
566
567 if (adev->wakeup.flags.notifier_present)
568 goto out;
569
570 status = acpi_install_notify_handler(device: adev->handle, ACPI_SYSTEM_NOTIFY,
571 handler: acpi_pm_notify_handler, NULL);
572 if (ACPI_FAILURE(status))
573 goto out;
574
575 mutex_lock(&acpi_pm_notifier_lock);
576 adev->wakeup.ws = wakeup_source_register(dev: &adev->dev,
577 name: dev_name(dev: &adev->dev));
578 adev->wakeup.context.dev = dev;
579 adev->wakeup.context.func = func;
580 adev->wakeup.flags.notifier_present = true;
581 mutex_unlock(lock: &acpi_pm_notifier_lock);
582
583 out:
584 mutex_unlock(lock: &acpi_pm_notifier_install_lock);
585 return status;
586}
587
588/**
589 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
590 * @adev: ACPI device to remove the notifier from.
591 */
592acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
593{
594 acpi_status status = AE_BAD_PARAMETER;
595
596 mutex_lock(&acpi_pm_notifier_install_lock);
597
598 if (!adev->wakeup.flags.notifier_present)
599 goto out;
600
601 status = acpi_remove_notify_handler(device: adev->handle,
602 ACPI_SYSTEM_NOTIFY,
603 handler: acpi_pm_notify_handler);
604 if (ACPI_FAILURE(status))
605 goto out;
606
607 mutex_lock(&acpi_pm_notifier_lock);
608 adev->wakeup.context.func = NULL;
609 adev->wakeup.context.dev = NULL;
610 wakeup_source_unregister(ws: adev->wakeup.ws);
611 adev->wakeup.flags.notifier_present = false;
612 mutex_unlock(lock: &acpi_pm_notifier_lock);
613
614 out:
615 mutex_unlock(lock: &acpi_pm_notifier_install_lock);
616 return status;
617}
618
619bool acpi_bus_can_wakeup(acpi_handle handle)
620{
621 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
622
623 return device && device->wakeup.flags.valid;
624}
625EXPORT_SYMBOL(acpi_bus_can_wakeup);
626
627bool acpi_pm_device_can_wakeup(struct device *dev)
628{
629 struct acpi_device *adev = ACPI_COMPANION(dev);
630
631 return adev ? acpi_device_can_wakeup(adev) : false;
632}
633
634/**
635 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
636 * @dev: Device whose preferred target power state to return.
637 * @adev: ACPI device node corresponding to @dev.
638 * @target_state: System state to match the resultant device state.
639 * @d_min_p: Location to store the highest power state available to the device.
640 * @d_max_p: Location to store the lowest power state available to the device.
641 *
642 * Find the lowest power (highest number) and highest power (lowest number) ACPI
643 * device power states that the device can be in while the system is in the
644 * state represented by @target_state. Store the integer numbers representing
645 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
646 * respectively.
647 *
648 * Callers must ensure that @dev and @adev are valid pointers and that @adev
649 * actually corresponds to @dev before using this function.
650 *
651 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
652 * returns a value that doesn't make sense. The memory locations pointed to by
653 * @d_max_p and @d_min_p are only modified on success.
654 */
655static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
656 u32 target_state, int *d_min_p, int *d_max_p)
657{
658 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
659 acpi_handle handle = adev->handle;
660 unsigned long long ret;
661 int d_min, d_max;
662 bool wakeup = false;
663 bool has_sxd = false;
664 acpi_status status;
665
666 /*
667 * If the system state is S0, the lowest power state the device can be
668 * in is D3cold, unless the device has _S0W and is supposed to signal
669 * wakeup, in which case the return value of _S0W has to be used as the
670 * lowest power state available to the device.
671 */
672 d_min = ACPI_STATE_D0;
673 d_max = ACPI_STATE_D3_COLD;
674
675 /*
676 * If present, _SxD methods return the minimum D-state (highest power
677 * state) we can use for the corresponding S-states. Otherwise, the
678 * minimum D-state is D0 (ACPI 3.x).
679 */
680 if (target_state > ACPI_STATE_S0) {
681 /*
682 * We rely on acpi_evaluate_integer() not clobbering the integer
683 * provided if AE_NOT_FOUND is returned.
684 */
685 ret = d_min;
686 status = acpi_evaluate_integer(handle, pathname: method, NULL, data: &ret);
687 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
688 || ret > ACPI_STATE_D3_COLD)
689 return -ENODATA;
690
691 /*
692 * We need to handle legacy systems where D3hot and D3cold are
693 * the same and 3 is returned in both cases, so fall back to
694 * D3cold if D3hot is not a valid state.
695 */
696 if (!adev->power.states[ret].flags.valid) {
697 if (ret == ACPI_STATE_D3_HOT)
698 ret = ACPI_STATE_D3_COLD;
699 else
700 return -ENODATA;
701 }
702
703 if (status == AE_OK)
704 has_sxd = true;
705
706 d_min = ret;
707 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
708 && adev->wakeup.sleep_state >= target_state;
709 } else if (device_may_wakeup(dev) && dev->power.wakeirq) {
710 /*
711 * The ACPI subsystem doesn't manage the wake bit for IRQs
712 * defined with ExclusiveAndWake and SharedAndWake. Instead we
713 * expect them to be managed via the PM subsystem. Drivers
714 * should call dev_pm_set_wake_irq to register an IRQ as a wake
715 * source.
716 *
717 * If a device has a wake IRQ attached we need to check the
718 * _S0W method to get the correct wake D-state. Otherwise we
719 * end up putting the device into D3Cold which will more than
720 * likely disable wake functionality.
721 */
722 wakeup = true;
723 } else {
724 /* ACPI GPE is specified in _PRW. */
725 wakeup = adev->wakeup.flags.valid;
726 }
727
728 /*
729 * If _PRW says we can wake up the system from the target sleep state,
730 * the D-state returned by _SxD is sufficient for that (we assume a
731 * wakeup-aware driver if wake is set). Still, if _SxW exists
732 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
733 * can wake the system. _S0W may be valid, too.
734 */
735 if (wakeup) {
736 method[3] = 'W';
737 status = acpi_evaluate_integer(handle, pathname: method, NULL, data: &ret);
738 if (status == AE_NOT_FOUND) {
739 /* No _SxW. In this case, the ACPI spec says that we
740 * must not go into any power state deeper than the
741 * value returned from _SxD.
742 */
743 if (has_sxd && target_state > ACPI_STATE_S0)
744 d_max = d_min;
745 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
746 /* Fall back to D3cold if ret is not a valid state. */
747 if (!adev->power.states[ret].flags.valid)
748 ret = ACPI_STATE_D3_COLD;
749
750 d_max = ret > d_min ? ret : d_min;
751 } else {
752 return -ENODATA;
753 }
754 }
755
756 if (d_min_p)
757 *d_min_p = d_min;
758
759 if (d_max_p)
760 *d_max_p = d_max;
761
762 return 0;
763}
764
765/**
766 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
767 * @dev: Device whose preferred target power state to return.
768 * @d_min_p: Location to store the upper limit of the allowed states range.
769 * @d_max_in: Deepest low-power state to take into consideration.
770 * Return value: Preferred power state of the device on success, -ENODEV
771 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
772 * incorrect, or -ENODATA on ACPI method failure.
773 *
774 * The caller must ensure that @dev is valid before using this function.
775 */
776int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
777{
778 struct acpi_device *adev;
779 int ret, d_min, d_max;
780
781 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
782 return -EINVAL;
783
784 if (d_max_in > ACPI_STATE_D2) {
785 enum pm_qos_flags_status stat;
786
787 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
788 if (stat == PM_QOS_FLAGS_ALL)
789 d_max_in = ACPI_STATE_D2;
790 }
791
792 adev = ACPI_COMPANION(dev);
793 if (!adev) {
794 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
795 return -ENODEV;
796 }
797
798 ret = acpi_dev_pm_get_state(dev, adev, target_state: acpi_target_system_state(),
799 d_min_p: &d_min, d_max_p: &d_max);
800 if (ret)
801 return ret;
802
803 if (d_max_in < d_min)
804 return -EINVAL;
805
806 if (d_max > d_max_in) {
807 for (d_max = d_max_in; d_max > d_min; d_max--) {
808 if (adev->power.states[d_max].flags.valid)
809 break;
810 }
811 }
812
813 if (d_min_p)
814 *d_min_p = d_min;
815
816 return d_max;
817}
818EXPORT_SYMBOL(acpi_pm_device_sleep_state);
819
820/**
821 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
822 * @context: Device wakeup context.
823 */
824static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
825{
826 struct device *dev = context->dev;
827
828 if (dev) {
829 pm_wakeup_event(dev, msec: 0);
830 pm_request_resume(dev);
831 }
832}
833
834static DEFINE_MUTEX(acpi_wakeup_lock);
835
836static int __acpi_device_wakeup_enable(struct acpi_device *adev,
837 u32 target_state)
838{
839 struct acpi_device_wakeup *wakeup = &adev->wakeup;
840 acpi_status status;
841 int error = 0;
842
843 mutex_lock(&acpi_wakeup_lock);
844
845 /*
846 * If the device wakeup power is already enabled, disable it and enable
847 * it again in case it depends on the configuration of subordinate
848 * devices and the conditions have changed since it was enabled last
849 * time.
850 */
851 if (wakeup->enable_count > 0)
852 acpi_disable_wakeup_device_power(dev: adev);
853
854 error = acpi_enable_wakeup_device_power(dev: adev, state: target_state);
855 if (error) {
856 if (wakeup->enable_count > 0) {
857 acpi_disable_gpe(gpe_device: wakeup->gpe_device, gpe_number: wakeup->gpe_number);
858 wakeup->enable_count = 0;
859 }
860 goto out;
861 }
862
863 if (wakeup->enable_count > 0)
864 goto inc;
865
866 status = acpi_enable_gpe(gpe_device: wakeup->gpe_device, gpe_number: wakeup->gpe_number);
867 if (ACPI_FAILURE(status)) {
868 acpi_disable_wakeup_device_power(dev: adev);
869 error = -EIO;
870 goto out;
871 }
872
873 acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
874 (unsigned int)wakeup->gpe_number);
875
876inc:
877 if (wakeup->enable_count < INT_MAX)
878 wakeup->enable_count++;
879 else
880 acpi_handle_info(adev->handle, "Wakeup enable count out of bounds!\n");
881
882out:
883 mutex_unlock(lock: &acpi_wakeup_lock);
884 return error;
885}
886
887/**
888 * acpi_device_wakeup_enable - Enable wakeup functionality for device.
889 * @adev: ACPI device to enable wakeup functionality for.
890 * @target_state: State the system is transitioning into.
891 *
892 * Enable the GPE associated with @adev so that it can generate wakeup signals
893 * for the device in response to external (remote) events and enable wakeup
894 * power for it.
895 *
896 * Callers must ensure that @adev is a valid ACPI device node before executing
897 * this function.
898 */
899static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
900{
901 return __acpi_device_wakeup_enable(adev, target_state);
902}
903
904/**
905 * acpi_device_wakeup_disable - Disable wakeup functionality for device.
906 * @adev: ACPI device to disable wakeup functionality for.
907 *
908 * Disable the GPE associated with @adev and disable wakeup power for it.
909 *
910 * Callers must ensure that @adev is a valid ACPI device node before executing
911 * this function.
912 */
913static void acpi_device_wakeup_disable(struct acpi_device *adev)
914{
915 struct acpi_device_wakeup *wakeup = &adev->wakeup;
916
917 mutex_lock(&acpi_wakeup_lock);
918
919 if (!wakeup->enable_count)
920 goto out;
921
922 acpi_disable_gpe(gpe_device: wakeup->gpe_device, gpe_number: wakeup->gpe_number);
923 acpi_disable_wakeup_device_power(dev: adev);
924
925 wakeup->enable_count--;
926
927out:
928 mutex_unlock(lock: &acpi_wakeup_lock);
929}
930
931/**
932 * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
933 * @dev: Device to enable/disable to generate wakeup events.
934 * @enable: Whether to enable or disable the wakeup functionality.
935 */
936int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
937{
938 struct acpi_device *adev;
939 int error;
940
941 adev = ACPI_COMPANION(dev);
942 if (!adev) {
943 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
944 return -ENODEV;
945 }
946
947 if (!acpi_device_can_wakeup(adev))
948 return -EINVAL;
949
950 if (!enable) {
951 acpi_device_wakeup_disable(adev);
952 dev_dbg(dev, "Wakeup disabled by ACPI\n");
953 return 0;
954 }
955
956 error = __acpi_device_wakeup_enable(adev, target_state: acpi_target_system_state());
957 if (!error)
958 dev_dbg(dev, "Wakeup enabled by ACPI\n");
959
960 return error;
961}
962EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
963
964/**
965 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
966 * @dev: Device to put into a low-power state.
967 * @adev: ACPI device node corresponding to @dev.
968 * @system_state: System state to choose the device state for.
969 */
970static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
971 u32 system_state)
972{
973 int ret, state;
974
975 if (!acpi_device_power_manageable(adev))
976 return 0;
977
978 ret = acpi_dev_pm_get_state(dev, adev, target_state: system_state, NULL, d_max_p: &state);
979 return ret ? ret : acpi_device_set_power(adev, state);
980}
981
982/**
983 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
984 * @adev: ACPI device node to put into the full-power state.
985 */
986static int acpi_dev_pm_full_power(struct acpi_device *adev)
987{
988 return acpi_device_power_manageable(adev) ?
989 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
990}
991
992/**
993 * acpi_dev_suspend - Put device into a low-power state using ACPI.
994 * @dev: Device to put into a low-power state.
995 * @wakeup: Whether or not to enable wakeup for the device.
996 *
997 * Put the given device into a low-power state using the standard ACPI
998 * mechanism. Set up remote wakeup if desired, choose the state to put the
999 * device into (this checks if remote wakeup is expected to work too), and set
1000 * the power state of the device.
1001 */
1002int acpi_dev_suspend(struct device *dev, bool wakeup)
1003{
1004 struct acpi_device *adev = ACPI_COMPANION(dev);
1005 u32 target_state = acpi_target_system_state();
1006 int error;
1007
1008 if (!adev)
1009 return 0;
1010
1011 if (wakeup && acpi_device_can_wakeup(adev)) {
1012 error = acpi_device_wakeup_enable(adev, target_state);
1013 if (error)
1014 return -EAGAIN;
1015 } else {
1016 wakeup = false;
1017 }
1018
1019 error = acpi_dev_pm_low_power(dev, adev, system_state: target_state);
1020 if (error && wakeup)
1021 acpi_device_wakeup_disable(adev);
1022
1023 return error;
1024}
1025EXPORT_SYMBOL_GPL(acpi_dev_suspend);
1026
1027/**
1028 * acpi_dev_resume - Put device into the full-power state using ACPI.
1029 * @dev: Device to put into the full-power state.
1030 *
1031 * Put the given device into the full-power state using the standard ACPI
1032 * mechanism. Set the power state of the device to ACPI D0 and disable wakeup.
1033 */
1034int acpi_dev_resume(struct device *dev)
1035{
1036 struct acpi_device *adev = ACPI_COMPANION(dev);
1037 int error;
1038
1039 if (!adev)
1040 return 0;
1041
1042 error = acpi_dev_pm_full_power(adev);
1043 acpi_device_wakeup_disable(adev);
1044 return error;
1045}
1046EXPORT_SYMBOL_GPL(acpi_dev_resume);
1047
1048/**
1049 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
1050 * @dev: Device to suspend.
1051 *
1052 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
1053 * it into a runtime low-power state.
1054 */
1055int acpi_subsys_runtime_suspend(struct device *dev)
1056{
1057 int ret = pm_generic_runtime_suspend(dev);
1058
1059 return ret ? ret : acpi_dev_suspend(dev, true);
1060}
1061EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
1062
1063/**
1064 * acpi_subsys_runtime_resume - Resume device using ACPI.
1065 * @dev: Device to Resume.
1066 *
1067 * Use ACPI to put the given device into the full-power state and carry out the
1068 * generic runtime resume procedure for it.
1069 */
1070int acpi_subsys_runtime_resume(struct device *dev)
1071{
1072 int ret = acpi_dev_resume(dev);
1073
1074 return ret ? ret : pm_generic_runtime_resume(dev);
1075}
1076EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
1077
1078#ifdef CONFIG_PM_SLEEP
1079static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
1080{
1081 u32 sys_target = acpi_target_system_state();
1082 int ret, state;
1083
1084 if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
1085 device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
1086 return true;
1087
1088 if (sys_target == ACPI_STATE_S0)
1089 return false;
1090
1091 if (adev->power.flags.dsw_present)
1092 return true;
1093
1094 ret = acpi_dev_pm_get_state(dev, adev, target_state: sys_target, NULL, d_max_p: &state);
1095 if (ret)
1096 return true;
1097
1098 return state != adev->power.state;
1099}
1100
1101/**
1102 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1103 * @dev: Device to prepare.
1104 */
1105int acpi_subsys_prepare(struct device *dev)
1106{
1107 struct acpi_device *adev = ACPI_COMPANION(dev);
1108
1109 if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
1110 int ret = dev->driver->pm->prepare(dev);
1111
1112 if (ret < 0)
1113 return ret;
1114
1115 if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
1116 return 0;
1117 }
1118
1119 return !acpi_dev_needs_resume(dev, adev);
1120}
1121EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
1122
1123/**
1124 * acpi_subsys_complete - Finalize device's resume during system resume.
1125 * @dev: Device to handle.
1126 */
1127void acpi_subsys_complete(struct device *dev)
1128{
1129 pm_generic_complete(dev);
1130 /*
1131 * If the device had been runtime-suspended before the system went into
1132 * the sleep state it is going out of and it has never been resumed till
1133 * now, resume it in case the firmware powered it up.
1134 */
1135 if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1136 pm_request_resume(dev);
1137}
1138EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1139
1140/**
1141 * acpi_subsys_suspend - Run the device driver's suspend callback.
1142 * @dev: Device to handle.
1143 *
1144 * Follow PCI and resume devices from runtime suspend before running their
1145 * system suspend callbacks, unless the driver can cope with runtime-suspended
1146 * devices during system suspend and there are no ACPI-specific reasons for
1147 * resuming them.
1148 */
1149int acpi_subsys_suspend(struct device *dev)
1150{
1151 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1152 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1153 pm_runtime_resume(dev);
1154
1155 return pm_generic_suspend(dev);
1156}
1157EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1158
1159/**
1160 * acpi_subsys_suspend_late - Suspend device using ACPI.
1161 * @dev: Device to suspend.
1162 *
1163 * Carry out the generic late suspend procedure for @dev and use ACPI to put
1164 * it into a low-power state during system transition into a sleep state.
1165 */
1166int acpi_subsys_suspend_late(struct device *dev)
1167{
1168 int ret;
1169
1170 if (dev_pm_skip_suspend(dev))
1171 return 0;
1172
1173 ret = pm_generic_suspend_late(dev);
1174 return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1175}
1176EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1177
1178/**
1179 * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1180 * @dev: Device to suspend.
1181 */
1182int acpi_subsys_suspend_noirq(struct device *dev)
1183{
1184 int ret;
1185
1186 if (dev_pm_skip_suspend(dev))
1187 return 0;
1188
1189 ret = pm_generic_suspend_noirq(dev);
1190 if (ret)
1191 return ret;
1192
1193 /*
1194 * If the target system sleep state is suspend-to-idle, it is sufficient
1195 * to check whether or not the device's wakeup settings are good for
1196 * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause
1197 * acpi_subsys_complete() to take care of fixing up the device's state
1198 * anyway, if need be.
1199 */
1200 if (device_can_wakeup(dev) && !device_may_wakeup(dev))
1201 dev->power.may_skip_resume = false;
1202
1203 return 0;
1204}
1205EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1206
1207/**
1208 * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1209 * @dev: Device to handle.
1210 */
1211static int acpi_subsys_resume_noirq(struct device *dev)
1212{
1213 if (dev_pm_skip_resume(dev))
1214 return 0;
1215
1216 return pm_generic_resume_noirq(dev);
1217}
1218
1219/**
1220 * acpi_subsys_resume_early - Resume device using ACPI.
1221 * @dev: Device to Resume.
1222 *
1223 * Use ACPI to put the given device into the full-power state and carry out the
1224 * generic early resume procedure for it during system transition into the
1225 * working state, but only do that if device either defines early resume
1226 * handler, or does not define power operations at all. Otherwise powering up
1227 * of the device is postponed to the normal resume phase.
1228 */
1229static int acpi_subsys_resume_early(struct device *dev)
1230{
1231 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1232 int ret;
1233
1234 if (dev_pm_skip_resume(dev))
1235 return 0;
1236
1237 if (pm && !pm->resume_early) {
1238 dev_dbg(dev, "postponing D0 transition to normal resume stage\n");
1239 return 0;
1240 }
1241
1242 ret = acpi_dev_resume(dev);
1243 return ret ? ret : pm_generic_resume_early(dev);
1244}
1245
1246/**
1247 * acpi_subsys_resume - Resume device using ACPI.
1248 * @dev: Device to Resume.
1249 *
1250 * Use ACPI to put the given device into the full-power state if it has not been
1251 * powered up during early resume phase, and carry out the generic resume
1252 * procedure for it during system transition into the working state.
1253 */
1254static int acpi_subsys_resume(struct device *dev)
1255{
1256 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1257 int ret = 0;
1258
1259 if (!dev_pm_skip_resume(dev) && pm && !pm->resume_early) {
1260 dev_dbg(dev, "executing postponed D0 transition\n");
1261 ret = acpi_dev_resume(dev);
1262 }
1263
1264 return ret ? ret : pm_generic_resume(dev);
1265}
1266
1267/**
1268 * acpi_subsys_freeze - Run the device driver's freeze callback.
1269 * @dev: Device to handle.
1270 */
1271int acpi_subsys_freeze(struct device *dev)
1272{
1273 /*
1274 * Resume all runtime-suspended devices before creating a snapshot
1275 * image of system memory, because the restore kernel generally cannot
1276 * be expected to always handle them consistently and they need to be
1277 * put into the runtime-active metastate during system resume anyway,
1278 * so it is better to ensure that the state saved in the image will be
1279 * always consistent with that.
1280 */
1281 pm_runtime_resume(dev);
1282
1283 return pm_generic_freeze(dev);
1284}
1285EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1286
1287/**
1288 * acpi_subsys_restore_early - Restore device using ACPI.
1289 * @dev: Device to restore.
1290 */
1291int acpi_subsys_restore_early(struct device *dev)
1292{
1293 int ret = acpi_dev_resume(dev);
1294
1295 return ret ? ret : pm_generic_restore_early(dev);
1296}
1297EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1298
1299/**
1300 * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1301 * @dev: Device to handle.
1302 *
1303 * Follow PCI and resume devices from runtime suspend before running their
1304 * system poweroff callbacks, unless the driver can cope with runtime-suspended
1305 * devices during system suspend and there are no ACPI-specific reasons for
1306 * resuming them.
1307 */
1308int acpi_subsys_poweroff(struct device *dev)
1309{
1310 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1311 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1312 pm_runtime_resume(dev);
1313
1314 return pm_generic_poweroff(dev);
1315}
1316EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1317
1318/**
1319 * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1320 * @dev: Device to handle.
1321 *
1322 * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1323 * it into a low-power state during system transition into a sleep state.
1324 */
1325static int acpi_subsys_poweroff_late(struct device *dev)
1326{
1327 int ret;
1328
1329 if (dev_pm_skip_suspend(dev))
1330 return 0;
1331
1332 ret = pm_generic_poweroff_late(dev);
1333 if (ret)
1334 return ret;
1335
1336 return acpi_dev_suspend(dev, device_may_wakeup(dev));
1337}
1338
1339/**
1340 * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1341 * @dev: Device to suspend.
1342 */
1343static int acpi_subsys_poweroff_noirq(struct device *dev)
1344{
1345 if (dev_pm_skip_suspend(dev))
1346 return 0;
1347
1348 return pm_generic_poweroff_noirq(dev);
1349}
1350#endif /* CONFIG_PM_SLEEP */
1351
1352static struct dev_pm_domain acpi_general_pm_domain = {
1353 .ops = {
1354 .runtime_suspend = acpi_subsys_runtime_suspend,
1355 .runtime_resume = acpi_subsys_runtime_resume,
1356#ifdef CONFIG_PM_SLEEP
1357 .prepare = acpi_subsys_prepare,
1358 .complete = acpi_subsys_complete,
1359 .suspend = acpi_subsys_suspend,
1360 .resume = acpi_subsys_resume,
1361 .suspend_late = acpi_subsys_suspend_late,
1362 .suspend_noirq = acpi_subsys_suspend_noirq,
1363 .resume_noirq = acpi_subsys_resume_noirq,
1364 .resume_early = acpi_subsys_resume_early,
1365 .freeze = acpi_subsys_freeze,
1366 .poweroff = acpi_subsys_poweroff,
1367 .poweroff_late = acpi_subsys_poweroff_late,
1368 .poweroff_noirq = acpi_subsys_poweroff_noirq,
1369 .restore_early = acpi_subsys_restore_early,
1370#endif
1371 },
1372};
1373
1374/**
1375 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1376 * @dev: Device to take care of.
1377 * @power_off: Whether or not to try to remove power from the device.
1378 *
1379 * Remove the device from the general ACPI PM domain and remove its wakeup
1380 * notifier. If @power_off is set, additionally remove power from the device if
1381 * possible.
1382 *
1383 * Callers must ensure proper synchronization of this function with power
1384 * management callbacks.
1385 */
1386static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1387{
1388 struct acpi_device *adev = ACPI_COMPANION(dev);
1389
1390 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1391 dev_pm_domain_set(dev, NULL);
1392 acpi_remove_pm_notifier(adev);
1393 if (power_off) {
1394 /*
1395 * If the device's PM QoS resume latency limit or flags
1396 * have been exposed to user space, they have to be
1397 * hidden at this point, so that they don't affect the
1398 * choice of the low-power state to put the device into.
1399 */
1400 dev_pm_qos_hide_latency_limit(dev);
1401 dev_pm_qos_hide_flags(dev);
1402 acpi_device_wakeup_disable(adev);
1403 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1404 }
1405 }
1406}
1407
1408/**
1409 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1410 * @dev: Device to prepare.
1411 * @power_on: Whether or not to power on the device.
1412 *
1413 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1414 * attached to it, install a wakeup notification handler for the device and
1415 * add it to the general ACPI PM domain. If @power_on is set, the device will
1416 * be put into the ACPI D0 state before the function returns.
1417 *
1418 * This assumes that the @dev's bus type uses generic power management callbacks
1419 * (or doesn't use any power management callbacks at all).
1420 *
1421 * Callers must ensure proper synchronization of this function with power
1422 * management callbacks.
1423 */
1424int acpi_dev_pm_attach(struct device *dev, bool power_on)
1425{
1426 /*
1427 * Skip devices whose ACPI companions match the device IDs below,
1428 * because they require special power management handling incompatible
1429 * with the generic ACPI PM domain.
1430 */
1431 static const struct acpi_device_id special_pm_ids[] = {
1432 ACPI_FAN_DEVICE_IDS,
1433 {}
1434 };
1435 struct acpi_device *adev = ACPI_COMPANION(dev);
1436
1437 if (!adev || !acpi_match_device_ids(device: adev, ids: special_pm_ids))
1438 return 0;
1439
1440 /*
1441 * Only attach the power domain to the first device if the
1442 * companion is shared by multiple. This is to prevent doing power
1443 * management twice.
1444 */
1445 if (!acpi_device_is_first_physical_node(adev, dev))
1446 return 0;
1447
1448 acpi_add_pm_notifier(adev, dev, func: acpi_pm_notify_work_func);
1449 dev_pm_domain_set(dev, pd: &acpi_general_pm_domain);
1450 if (power_on) {
1451 acpi_dev_pm_full_power(adev);
1452 acpi_device_wakeup_disable(adev);
1453 }
1454
1455 dev->pm_domain->detach = acpi_dev_pm_detach;
1456 return 1;
1457}
1458EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1459
1460/**
1461 * acpi_storage_d3 - Check if D3 should be used in the suspend path
1462 * @dev: Device to check
1463 *
1464 * Return %true if the platform firmware wants @dev to be programmed
1465 * into D3hot or D3cold (if supported) in the suspend path, or %false
1466 * when there is no specific preference. On some platforms, if this
1467 * hint is ignored, @dev may remain unresponsive after suspending the
1468 * platform as a whole.
1469 *
1470 * Although the property has storage in the name it actually is
1471 * applied to the PCIe slot and plugging in a non-storage device the
1472 * same platform restrictions will likely apply.
1473 */
1474bool acpi_storage_d3(struct device *dev)
1475{
1476 struct acpi_device *adev = ACPI_COMPANION(dev);
1477 u8 val;
1478
1479 if (force_storage_d3())
1480 return true;
1481
1482 if (!adev)
1483 return false;
1484 if (fwnode_property_read_u8(fwnode: acpi_fwnode_handle(adev), propname: "StorageD3Enable",
1485 val: &val))
1486 return false;
1487 return val == 1;
1488}
1489EXPORT_SYMBOL_GPL(acpi_storage_d3);
1490
1491/**
1492 * acpi_dev_state_d0 - Tell if the device is in D0 power state
1493 * @dev: Physical device the ACPI power state of which to check
1494 *
1495 * On a system without ACPI, return true. On a system with ACPI, return true if
1496 * the current ACPI power state of the device is D0, or false otherwise.
1497 *
1498 * Note that the power state of a device is not well-defined after it has been
1499 * passed to acpi_device_set_power() and before that function returns, so it is
1500 * not valid to ask for the ACPI power state of the device in that time frame.
1501 *
1502 * This function is intended to be used in a driver's probe or remove
1503 * function. See Documentation/firmware-guide/acpi/non-d0-probe.rst for
1504 * more information.
1505 */
1506bool acpi_dev_state_d0(struct device *dev)
1507{
1508 struct acpi_device *adev = ACPI_COMPANION(dev);
1509
1510 if (!adev)
1511 return true;
1512
1513 return adev->power.state == ACPI_STATE_D0;
1514}
1515EXPORT_SYMBOL_GPL(acpi_dev_state_d0);
1516
1517#endif /* CONFIG_PM */
1518

source code of linux/drivers/acpi/device_pm.c