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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 <rafael.j.wysocki@intel.com>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11 */
12
13#include <linux/acpi.h>
14#include <linux/export.h>
15#include <linux/mutex.h>
16#include <linux/pm_qos.h>
17#include <linux/pm_domain.h>
18#include <linux/pm_runtime.h>
19#include <linux/suspend.h>
20
21#include "internal.h"
22
23#define _COMPONENT ACPI_POWER_COMPONENT
24ACPI_MODULE_NAME("device_pm");
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 int error;
79
80 if (!device || !state)
81 return -EINVAL;
82
83 if (!device->flags.power_manageable) {
84 /* TBD: Non-recursive algorithm for walking up hierarchy. */
85 *state = device->parent ?
86 device->parent->power.state : ACPI_STATE_D0;
87 goto out;
88 }
89
90 /*
91 * Get the device's power state from power resources settings and _PSC,
92 * if available.
93 */
94 if (device->power.flags.power_resources) {
95 error = acpi_power_get_inferred_state(device, &result);
96 if (error)
97 return error;
98 }
99 if (device->power.flags.explicit_get) {
100 int psc;
101
102 error = acpi_dev_pm_explicit_get(device, &psc);
103 if (error)
104 return error;
105
106 /*
107 * The power resources settings may indicate a power state
108 * shallower than the actual power state of the device, because
109 * the same power resources may be referenced by other devices.
110 *
111 * For systems predating ACPI 4.0 we assume that D3hot is the
112 * deepest state that can be supported.
113 */
114 if (psc > result && psc < ACPI_STATE_D3_COLD)
115 result = psc;
116 else if (result == ACPI_STATE_UNKNOWN)
117 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
118 }
119
120 /*
121 * If we were unsure about the device parent's power state up to this
122 * point, the fact that the device is in D0 implies that the parent has
123 * to be in D0 too, except if ignore_parent is set.
124 */
125 if (!device->power.flags.ignore_parent && device->parent
126 && device->parent->power.state == ACPI_STATE_UNKNOWN
127 && result == ACPI_STATE_D0)
128 device->parent->power.state = ACPI_STATE_D0;
129
130 *state = result;
131
132 out:
133 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
134 device->pnp.bus_id, acpi_power_state_string(*state)));
135
136 return 0;
137}
138
139static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
140{
141 if (adev->power.states[state].flags.explicit_set) {
142 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
143 acpi_status status;
144
145 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
146 if (ACPI_FAILURE(status))
147 return -ENODEV;
148 }
149 return 0;
150}
151
152/**
153 * acpi_device_set_power - Set power state of an ACPI device.
154 * @device: Device to set the power state of.
155 * @state: New power state to set.
156 *
157 * Callers must ensure that the device is power manageable before using this
158 * function.
159 */
160int acpi_device_set_power(struct acpi_device *device, int state)
161{
162 int target_state = state;
163 int result = 0;
164
165 if (!device || !device->flags.power_manageable
166 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
167 return -EINVAL;
168
169 acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",
170 acpi_power_state_string(device->power.state),
171 acpi_power_state_string(state));
172
173 /* Make sure this is a valid target state */
174
175 /* There is a special case for D0 addressed below. */
176 if (state > ACPI_STATE_D0 && state == device->power.state) {
177 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
178 device->pnp.bus_id,
179 acpi_power_state_string(state)));
180 return 0;
181 }
182
183 if (state == ACPI_STATE_D3_COLD) {
184 /*
185 * For transitions to D3cold we need to execute _PS3 and then
186 * possibly drop references to the power resources in use.
187 */
188 state = ACPI_STATE_D3_HOT;
189 /* If D3cold is not supported, use D3hot as the target state. */
190 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
191 target_state = state;
192 } else if (!device->power.states[state].flags.valid) {
193 dev_warn(&device->dev, "Power state %s not supported\n",
194 acpi_power_state_string(state));
195 return -ENODEV;
196 }
197
198 if (!device->power.flags.ignore_parent &&
199 device->parent && (state < device->parent->power.state)) {
200 dev_warn(&device->dev,
201 "Cannot transition to power state %s for parent in %s\n",
202 acpi_power_state_string(state),
203 acpi_power_state_string(device->parent->power.state));
204 return -ENODEV;
205 }
206
207 /*
208 * Transition Power
209 * ----------------
210 * In accordance with ACPI 6, _PSx is executed before manipulating power
211 * resources, unless the target state is D0, in which case _PS0 is
212 * supposed to be executed after turning the power resources on.
213 */
214 if (state > ACPI_STATE_D0) {
215 /*
216 * According to ACPI 6, devices cannot go from lower-power
217 * (deeper) states to higher-power (shallower) states.
218 */
219 if (state < device->power.state) {
220 dev_warn(&device->dev, "Cannot transition from %s to %s\n",
221 acpi_power_state_string(device->power.state),
222 acpi_power_state_string(state));
223 return -ENODEV;
224 }
225
226 /*
227 * If the device goes from D3hot to D3cold, _PS3 has been
228 * evaluated for it already, so skip it in that case.
229 */
230 if (device->power.state < ACPI_STATE_D3_HOT) {
231 result = acpi_dev_pm_explicit_set(device, state);
232 if (result)
233 goto end;
234 }
235
236 if (device->power.flags.power_resources)
237 result = acpi_power_transition(device, target_state);
238 } else {
239 int cur_state = device->power.state;
240
241 if (device->power.flags.power_resources) {
242 result = acpi_power_transition(device, ACPI_STATE_D0);
243 if (result)
244 goto end;
245 }
246
247 if (cur_state == ACPI_STATE_D0) {
248 int psc;
249
250 /* Nothing to do here if _PSC is not present. */
251 if (!device->power.flags.explicit_get)
252 return 0;
253
254 /*
255 * The power state of the device was set to D0 last
256 * time, but that might have happened before a
257 * system-wide transition involving the platform
258 * firmware, so it may be necessary to evaluate _PS0
259 * for the device here. However, use extra care here
260 * and evaluate _PSC to check the device's current power
261 * state, and only invoke _PS0 if the evaluation of _PSC
262 * is successful and it returns a power state different
263 * from D0.
264 */
265 result = acpi_dev_pm_explicit_get(device, &psc);
266 if (result || psc == ACPI_STATE_D0)
267 return 0;
268 }
269
270 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
271 }
272
273 end:
274 if (result) {
275 dev_warn(&device->dev, "Failed to change power state to %s\n",
276 acpi_power_state_string(target_state));
277 } else {
278 device->power.state = target_state;
279 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
280 "Device [%s] transitioned to %s\n",
281 device->pnp.bus_id,
282 acpi_power_state_string(target_state)));
283 }
284
285 return result;
286}
287EXPORT_SYMBOL(acpi_device_set_power);
288
289int acpi_bus_set_power(acpi_handle handle, int state)
290{
291 struct acpi_device *device;
292 int result;
293
294 result = acpi_bus_get_device(handle, &device);
295 if (result)
296 return result;
297
298 return acpi_device_set_power(device, state);
299}
300EXPORT_SYMBOL(acpi_bus_set_power);
301
302int acpi_bus_init_power(struct acpi_device *device)
303{
304 int state;
305 int result;
306
307 if (!device)
308 return -EINVAL;
309
310 device->power.state = ACPI_STATE_UNKNOWN;
311 if (!acpi_device_is_present(device)) {
312 device->flags.initialized = false;
313 return -ENXIO;
314 }
315
316 result = acpi_device_get_power(device, &state);
317 if (result)
318 return result;
319
320 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
321 /* Reference count the power resources. */
322 result = acpi_power_on_resources(device, state);
323 if (result)
324 return result;
325
326 if (state == ACPI_STATE_D0) {
327 /*
328 * If _PSC is not present and the state inferred from
329 * power resources appears to be D0, it still may be
330 * necessary to execute _PS0 at this point, because
331 * another device using the same power resources may
332 * have been put into D0 previously and that's why we
333 * see D0 here.
334 */
335 result = acpi_dev_pm_explicit_set(device, state);
336 if (result)
337 return result;
338 }
339 } else if (state == ACPI_STATE_UNKNOWN) {
340 /*
341 * No power resources and missing _PSC? Cross fingers and make
342 * it D0 in hope that this is what the BIOS put the device into.
343 * [We tried to force D0 here by executing _PS0, but that broke
344 * Toshiba P870-303 in a nasty way.]
345 */
346 state = ACPI_STATE_D0;
347 }
348 device->power.state = state;
349 return 0;
350}
351
352/**
353 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
354 * @device: Device object whose power state is to be fixed up.
355 *
356 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
357 * are assumed to be put into D0 by the BIOS. However, in some cases that may
358 * not be the case and this function should be used then.
359 */
360int acpi_device_fix_up_power(struct acpi_device *device)
361{
362 int ret = 0;
363
364 if (!device->power.flags.power_resources
365 && !device->power.flags.explicit_get
366 && device->power.state == ACPI_STATE_D0)
367 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
368
369 return ret;
370}
371EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
372
373int acpi_device_update_power(struct acpi_device *device, int *state_p)
374{
375 int state;
376 int result;
377
378 if (device->power.state == ACPI_STATE_UNKNOWN) {
379 result = acpi_bus_init_power(device);
380 if (!result && state_p)
381 *state_p = device->power.state;
382
383 return result;
384 }
385
386 result = acpi_device_get_power(device, &state);
387 if (result)
388 return result;
389
390 if (state == ACPI_STATE_UNKNOWN) {
391 state = ACPI_STATE_D0;
392 result = acpi_device_set_power(device, state);
393 if (result)
394 return result;
395 } else {
396 if (device->power.flags.power_resources) {
397 /*
398 * We don't need to really switch the state, bu we need
399 * to update the power resources' reference counters.
400 */
401 result = acpi_power_transition(device, state);
402 if (result)
403 return result;
404 }
405 device->power.state = state;
406 }
407 if (state_p)
408 *state_p = state;
409
410 return 0;
411}
412EXPORT_SYMBOL_GPL(acpi_device_update_power);
413
414int acpi_bus_update_power(acpi_handle handle, int *state_p)
415{
416 struct acpi_device *device;
417 int result;
418
419 result = acpi_bus_get_device(handle, &device);
420 return result ? result : acpi_device_update_power(device, state_p);
421}
422EXPORT_SYMBOL_GPL(acpi_bus_update_power);
423
424bool acpi_bus_power_manageable(acpi_handle handle)
425{
426 struct acpi_device *device;
427 int result;
428
429 result = acpi_bus_get_device(handle, &device);
430 return result ? false : device->flags.power_manageable;
431}
432EXPORT_SYMBOL(acpi_bus_power_manageable);
433
434#ifdef CONFIG_PM
435static DEFINE_MUTEX(acpi_pm_notifier_lock);
436static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
437
438void acpi_pm_wakeup_event(struct device *dev)
439{
440 pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
441}
442EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
443
444static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
445{
446 struct acpi_device *adev;
447
448 if (val != ACPI_NOTIFY_DEVICE_WAKE)
449 return;
450
451 acpi_handle_debug(handle, "Wake notify\n");
452
453 adev = acpi_bus_get_acpi_device(handle);
454 if (!adev)
455 return;
456
457 mutex_lock(&acpi_pm_notifier_lock);
458
459 if (adev->wakeup.flags.notifier_present) {
460 pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
461 if (adev->wakeup.context.func) {
462 acpi_handle_debug(handle, "Running %pS for %s\n",
463 adev->wakeup.context.func,
464 dev_name(adev->wakeup.context.dev));
465 adev->wakeup.context.func(&adev->wakeup.context);
466 }
467 }
468
469 mutex_unlock(&acpi_pm_notifier_lock);
470
471 acpi_bus_put_acpi_device(adev);
472}
473
474/**
475 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
476 * @adev: ACPI device to add the notify handler for.
477 * @dev: Device to generate a wakeup event for while handling the notification.
478 * @func: Work function to execute when handling the notification.
479 *
480 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
481 * PM wakeup events. For example, wakeup events may be generated for bridges
482 * if one of the devices below the bridge is signaling wakeup, even if the
483 * bridge itself doesn't have a wakeup GPE associated with it.
484 */
485acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
486 void (*func)(struct acpi_device_wakeup_context *context))
487{
488 acpi_status status = AE_ALREADY_EXISTS;
489
490 if (!dev && !func)
491 return AE_BAD_PARAMETER;
492
493 mutex_lock(&acpi_pm_notifier_install_lock);
494
495 if (adev->wakeup.flags.notifier_present)
496 goto out;
497
498 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
499 acpi_pm_notify_handler, NULL);
500 if (ACPI_FAILURE(status))
501 goto out;
502
503 mutex_lock(&acpi_pm_notifier_lock);
504 adev->wakeup.ws = wakeup_source_register(&adev->dev,
505 dev_name(&adev->dev));
506 adev->wakeup.context.dev = dev;
507 adev->wakeup.context.func = func;
508 adev->wakeup.flags.notifier_present = true;
509 mutex_unlock(&acpi_pm_notifier_lock);
510
511 out:
512 mutex_unlock(&acpi_pm_notifier_install_lock);
513 return status;
514}
515
516/**
517 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
518 * @adev: ACPI device to remove the notifier from.
519 */
520acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
521{
522 acpi_status status = AE_BAD_PARAMETER;
523
524 mutex_lock(&acpi_pm_notifier_install_lock);
525
526 if (!adev->wakeup.flags.notifier_present)
527 goto out;
528
529 status = acpi_remove_notify_handler(adev->handle,
530 ACPI_SYSTEM_NOTIFY,
531 acpi_pm_notify_handler);
532 if (ACPI_FAILURE(status))
533 goto out;
534
535 mutex_lock(&acpi_pm_notifier_lock);
536 adev->wakeup.context.func = NULL;
537 adev->wakeup.context.dev = NULL;
538 wakeup_source_unregister(adev->wakeup.ws);
539 adev->wakeup.flags.notifier_present = false;
540 mutex_unlock(&acpi_pm_notifier_lock);
541
542 out:
543 mutex_unlock(&acpi_pm_notifier_install_lock);
544 return status;
545}
546
547bool acpi_bus_can_wakeup(acpi_handle handle)
548{
549 struct acpi_device *device;
550 int result;
551
552 result = acpi_bus_get_device(handle, &device);
553 return result ? false : device->wakeup.flags.valid;
554}
555EXPORT_SYMBOL(acpi_bus_can_wakeup);
556
557bool acpi_pm_device_can_wakeup(struct device *dev)
558{
559 struct acpi_device *adev = ACPI_COMPANION(dev);
560
561 return adev ? acpi_device_can_wakeup(adev) : false;
562}
563
564/**
565 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
566 * @dev: Device whose preferred target power state to return.
567 * @adev: ACPI device node corresponding to @dev.
568 * @target_state: System state to match the resultant device state.
569 * @d_min_p: Location to store the highest power state available to the device.
570 * @d_max_p: Location to store the lowest power state available to the device.
571 *
572 * Find the lowest power (highest number) and highest power (lowest number) ACPI
573 * device power states that the device can be in while the system is in the
574 * state represented by @target_state. Store the integer numbers representing
575 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
576 * respectively.
577 *
578 * Callers must ensure that @dev and @adev are valid pointers and that @adev
579 * actually corresponds to @dev before using this function.
580 *
581 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
582 * returns a value that doesn't make sense. The memory locations pointed to by
583 * @d_max_p and @d_min_p are only modified on success.
584 */
585static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
586 u32 target_state, int *d_min_p, int *d_max_p)
587{
588 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
589 acpi_handle handle = adev->handle;
590 unsigned long long ret;
591 int d_min, d_max;
592 bool wakeup = false;
593 bool has_sxd = false;
594 acpi_status status;
595
596 /*
597 * If the system state is S0, the lowest power state the device can be
598 * in is D3cold, unless the device has _S0W and is supposed to signal
599 * wakeup, in which case the return value of _S0W has to be used as the
600 * lowest power state available to the device.
601 */
602 d_min = ACPI_STATE_D0;
603 d_max = ACPI_STATE_D3_COLD;
604
605 /*
606 * If present, _SxD methods return the minimum D-state (highest power
607 * state) we can use for the corresponding S-states. Otherwise, the
608 * minimum D-state is D0 (ACPI 3.x).
609 */
610 if (target_state > ACPI_STATE_S0) {
611 /*
612 * We rely on acpi_evaluate_integer() not clobbering the integer
613 * provided if AE_NOT_FOUND is returned.
614 */
615 ret = d_min;
616 status = acpi_evaluate_integer(handle, method, NULL, &ret);
617 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
618 || ret > ACPI_STATE_D3_COLD)
619 return -ENODATA;
620
621 /*
622 * We need to handle legacy systems where D3hot and D3cold are
623 * the same and 3 is returned in both cases, so fall back to
624 * D3cold if D3hot is not a valid state.
625 */
626 if (!adev->power.states[ret].flags.valid) {
627 if (ret == ACPI_STATE_D3_HOT)
628 ret = ACPI_STATE_D3_COLD;
629 else
630 return -ENODATA;
631 }
632
633 if (status == AE_OK)
634 has_sxd = true;
635
636 d_min = ret;
637 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
638 && adev->wakeup.sleep_state >= target_state;
639 } else {
640 wakeup = adev->wakeup.flags.valid;
641 }
642
643 /*
644 * If _PRW says we can wake up the system from the target sleep state,
645 * the D-state returned by _SxD is sufficient for that (we assume a
646 * wakeup-aware driver if wake is set). Still, if _SxW exists
647 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
648 * can wake the system. _S0W may be valid, too.
649 */
650 if (wakeup) {
651 method[3] = 'W';
652 status = acpi_evaluate_integer(handle, method, NULL, &ret);
653 if (status == AE_NOT_FOUND) {
654 /* No _SxW. In this case, the ACPI spec says that we
655 * must not go into any power state deeper than the
656 * value returned from _SxD.
657 */
658 if (has_sxd && target_state > ACPI_STATE_S0)
659 d_max = d_min;
660 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
661 /* Fall back to D3cold if ret is not a valid state. */
662 if (!adev->power.states[ret].flags.valid)
663 ret = ACPI_STATE_D3_COLD;
664
665 d_max = ret > d_min ? ret : d_min;
666 } else {
667 return -ENODATA;
668 }
669 }
670
671 if (d_min_p)
672 *d_min_p = d_min;
673
674 if (d_max_p)
675 *d_max_p = d_max;
676
677 return 0;
678}
679
680/**
681 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
682 * @dev: Device whose preferred target power state to return.
683 * @d_min_p: Location to store the upper limit of the allowed states range.
684 * @d_max_in: Deepest low-power state to take into consideration.
685 * Return value: Preferred power state of the device on success, -ENODEV
686 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
687 * incorrect, or -ENODATA on ACPI method failure.
688 *
689 * The caller must ensure that @dev is valid before using this function.
690 */
691int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
692{
693 struct acpi_device *adev;
694 int ret, d_min, d_max;
695
696 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
697 return -EINVAL;
698
699 if (d_max_in > ACPI_STATE_D2) {
700 enum pm_qos_flags_status stat;
701
702 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
703 if (stat == PM_QOS_FLAGS_ALL)
704 d_max_in = ACPI_STATE_D2;
705 }
706
707 adev = ACPI_COMPANION(dev);
708 if (!adev) {
709 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
710 return -ENODEV;
711 }
712
713 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
714 &d_min, &d_max);
715 if (ret)
716 return ret;
717
718 if (d_max_in < d_min)
719 return -EINVAL;
720
721 if (d_max > d_max_in) {
722 for (d_max = d_max_in; d_max > d_min; d_max--) {
723 if (adev->power.states[d_max].flags.valid)
724 break;
725 }
726 }
727
728 if (d_min_p)
729 *d_min_p = d_min;
730
731 return d_max;
732}
733EXPORT_SYMBOL(acpi_pm_device_sleep_state);
734
735/**
736 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
737 * @context: Device wakeup context.
738 */
739static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
740{
741 struct device *dev = context->dev;
742
743 if (dev) {
744 pm_wakeup_event(dev, 0);
745 pm_request_resume(dev);
746 }
747}
748
749static DEFINE_MUTEX(acpi_wakeup_lock);
750
751static int __acpi_device_wakeup_enable(struct acpi_device *adev,
752 u32 target_state, int max_count)
753{
754 struct acpi_device_wakeup *wakeup = &adev->wakeup;
755 acpi_status status;
756 int error = 0;
757
758 mutex_lock(&acpi_wakeup_lock);
759
760 if (wakeup->enable_count >= max_count)
761 goto out;
762
763 if (wakeup->enable_count > 0)
764 goto inc;
765
766 error = acpi_enable_wakeup_device_power(adev, target_state);
767 if (error)
768 goto out;
769
770 status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
771 if (ACPI_FAILURE(status)) {
772 acpi_disable_wakeup_device_power(adev);
773 error = -EIO;
774 goto out;
775 }
776
777 acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
778 (unsigned int)wakeup->gpe_number);
779
780inc:
781 wakeup->enable_count++;
782
783out:
784 mutex_unlock(&acpi_wakeup_lock);
785 return error;
786}
787
788/**
789 * acpi_device_wakeup_enable - Enable wakeup functionality for device.
790 * @adev: ACPI device to enable wakeup functionality for.
791 * @target_state: State the system is transitioning into.
792 *
793 * Enable the GPE associated with @adev so that it can generate wakeup signals
794 * for the device in response to external (remote) events and enable wakeup
795 * power for it.
796 *
797 * Callers must ensure that @adev is a valid ACPI device node before executing
798 * this function.
799 */
800static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
801{
802 return __acpi_device_wakeup_enable(adev, target_state, 1);
803}
804
805/**
806 * acpi_device_wakeup_disable - Disable wakeup functionality for device.
807 * @adev: ACPI device to disable wakeup functionality for.
808 *
809 * Disable the GPE associated with @adev and disable wakeup power for it.
810 *
811 * Callers must ensure that @adev is a valid ACPI device node before executing
812 * this function.
813 */
814static void acpi_device_wakeup_disable(struct acpi_device *adev)
815{
816 struct acpi_device_wakeup *wakeup = &adev->wakeup;
817
818 mutex_lock(&acpi_wakeup_lock);
819
820 if (!wakeup->enable_count)
821 goto out;
822
823 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
824 acpi_disable_wakeup_device_power(adev);
825
826 wakeup->enable_count--;
827
828out:
829 mutex_unlock(&acpi_wakeup_lock);
830}
831
832static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable,
833 int max_count)
834{
835 struct acpi_device *adev;
836 int error;
837
838 adev = ACPI_COMPANION(dev);
839 if (!adev) {
840 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
841 return -ENODEV;
842 }
843
844 if (!acpi_device_can_wakeup(adev))
845 return -EINVAL;
846
847 if (!enable) {
848 acpi_device_wakeup_disable(adev);
849 dev_dbg(dev, "Wakeup disabled by ACPI\n");
850 return 0;
851 }
852
853 error = __acpi_device_wakeup_enable(adev, acpi_target_system_state(),
854 max_count);
855 if (!error)
856 dev_dbg(dev, "Wakeup enabled by ACPI\n");
857
858 return error;
859}
860
861/**
862 * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
863 * @dev: Device to enable/disable to generate wakeup events.
864 * @enable: Whether to enable or disable the wakeup functionality.
865 */
866int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
867{
868 return __acpi_pm_set_device_wakeup(dev, enable, 1);
869}
870EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
871
872/**
873 * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge.
874 * @dev: Bridge device to enable/disable to generate wakeup events.
875 * @enable: Whether to enable or disable the wakeup functionality.
876 */
877int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable)
878{
879 return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX);
880}
881EXPORT_SYMBOL_GPL(acpi_pm_set_bridge_wakeup);
882
883/**
884 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
885 * @dev: Device to put into a low-power state.
886 * @adev: ACPI device node corresponding to @dev.
887 * @system_state: System state to choose the device state for.
888 */
889static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
890 u32 system_state)
891{
892 int ret, state;
893
894 if (!acpi_device_power_manageable(adev))
895 return 0;
896
897 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
898 return ret ? ret : acpi_device_set_power(adev, state);
899}
900
901/**
902 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
903 * @adev: ACPI device node to put into the full-power state.
904 */
905static int acpi_dev_pm_full_power(struct acpi_device *adev)
906{
907 return acpi_device_power_manageable(adev) ?
908 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
909}
910
911/**
912 * acpi_dev_suspend - Put device into a low-power state using ACPI.
913 * @dev: Device to put into a low-power state.
914 * @wakeup: Whether or not to enable wakeup for the device.
915 *
916 * Put the given device into a low-power state using the standard ACPI
917 * mechanism. Set up remote wakeup if desired, choose the state to put the
918 * device into (this checks if remote wakeup is expected to work too), and set
919 * the power state of the device.
920 */
921int acpi_dev_suspend(struct device *dev, bool wakeup)
922{
923 struct acpi_device *adev = ACPI_COMPANION(dev);
924 u32 target_state = acpi_target_system_state();
925 int error;
926
927 if (!adev)
928 return 0;
929
930 if (wakeup && acpi_device_can_wakeup(adev)) {
931 error = acpi_device_wakeup_enable(adev, target_state);
932 if (error)
933 return -EAGAIN;
934 } else {
935 wakeup = false;
936 }
937
938 error = acpi_dev_pm_low_power(dev, adev, target_state);
939 if (error && wakeup)
940 acpi_device_wakeup_disable(adev);
941
942 return error;
943}
944EXPORT_SYMBOL_GPL(acpi_dev_suspend);
945
946/**
947 * acpi_dev_resume - Put device into the full-power state using ACPI.
948 * @dev: Device to put into the full-power state.
949 *
950 * Put the given device into the full-power state using the standard ACPI
951 * mechanism. Set the power state of the device to ACPI D0 and disable wakeup.
952 */
953int acpi_dev_resume(struct device *dev)
954{
955 struct acpi_device *adev = ACPI_COMPANION(dev);
956 int error;
957
958 if (!adev)
959 return 0;
960
961 error = acpi_dev_pm_full_power(adev);
962 acpi_device_wakeup_disable(adev);
963 return error;
964}
965EXPORT_SYMBOL_GPL(acpi_dev_resume);
966
967/**
968 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
969 * @dev: Device to suspend.
970 *
971 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
972 * it into a runtime low-power state.
973 */
974int acpi_subsys_runtime_suspend(struct device *dev)
975{
976 int ret = pm_generic_runtime_suspend(dev);
977 return ret ? ret : acpi_dev_suspend(dev, true);
978}
979EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
980
981/**
982 * acpi_subsys_runtime_resume - Resume device using ACPI.
983 * @dev: Device to Resume.
984 *
985 * Use ACPI to put the given device into the full-power state and carry out the
986 * generic runtime resume procedure for it.
987 */
988int acpi_subsys_runtime_resume(struct device *dev)
989{
990 int ret = acpi_dev_resume(dev);
991 return ret ? ret : pm_generic_runtime_resume(dev);
992}
993EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
994
995#ifdef CONFIG_PM_SLEEP
996static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
997{
998 u32 sys_target = acpi_target_system_state();
999 int ret, state;
1000
1001 if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
1002 device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
1003 return true;
1004
1005 if (sys_target == ACPI_STATE_S0)
1006 return false;
1007
1008 if (adev->power.flags.dsw_present)
1009 return true;
1010
1011 ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
1012 if (ret)
1013 return true;
1014
1015 return state != adev->power.state;
1016}
1017
1018/**
1019 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1020 * @dev: Device to prepare.
1021 */
1022int acpi_subsys_prepare(struct device *dev)
1023{
1024 struct acpi_device *adev = ACPI_COMPANION(dev);
1025
1026 if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
1027 int ret = dev->driver->pm->prepare(dev);
1028
1029 if (ret < 0)
1030 return ret;
1031
1032 if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
1033 return 0;
1034 }
1035
1036 return !acpi_dev_needs_resume(dev, adev);
1037}
1038EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
1039
1040/**
1041 * acpi_subsys_complete - Finalize device's resume during system resume.
1042 * @dev: Device to handle.
1043 */
1044void acpi_subsys_complete(struct device *dev)
1045{
1046 pm_generic_complete(dev);
1047 /*
1048 * If the device had been runtime-suspended before the system went into
1049 * the sleep state it is going out of and it has never been resumed till
1050 * now, resume it in case the firmware powered it up.
1051 */
1052 if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1053 pm_request_resume(dev);
1054}
1055EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1056
1057/**
1058 * acpi_subsys_suspend - Run the device driver's suspend callback.
1059 * @dev: Device to handle.
1060 *
1061 * Follow PCI and resume devices from runtime suspend before running their
1062 * system suspend callbacks, unless the driver can cope with runtime-suspended
1063 * devices during system suspend and there are no ACPI-specific reasons for
1064 * resuming them.
1065 */
1066int acpi_subsys_suspend(struct device *dev)
1067{
1068 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1069 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1070 pm_runtime_resume(dev);
1071
1072 return pm_generic_suspend(dev);
1073}
1074EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1075
1076/**
1077 * acpi_subsys_suspend_late - Suspend device using ACPI.
1078 * @dev: Device to suspend.
1079 *
1080 * Carry out the generic late suspend procedure for @dev and use ACPI to put
1081 * it into a low-power state during system transition into a sleep state.
1082 */
1083int acpi_subsys_suspend_late(struct device *dev)
1084{
1085 int ret;
1086
1087 if (dev_pm_skip_suspend(dev))
1088 return 0;
1089
1090 ret = pm_generic_suspend_late(dev);
1091 return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1092}
1093EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1094
1095/**
1096 * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1097 * @dev: Device to suspend.
1098 */
1099int acpi_subsys_suspend_noirq(struct device *dev)
1100{
1101 int ret;
1102
1103 if (dev_pm_skip_suspend(dev))
1104 return 0;
1105
1106 ret = pm_generic_suspend_noirq(dev);
1107 if (ret)
1108 return ret;
1109
1110 /*
1111 * If the target system sleep state is suspend-to-idle, it is sufficient
1112 * to check whether or not the device's wakeup settings are good for
1113 * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause
1114 * acpi_subsys_complete() to take care of fixing up the device's state
1115 * anyway, if need be.
1116 */
1117 if (device_can_wakeup(dev) && !device_may_wakeup(dev))
1118 dev->power.may_skip_resume = false;
1119
1120 return 0;
1121}
1122EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1123
1124/**
1125 * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1126 * @dev: Device to handle.
1127 */
1128static int acpi_subsys_resume_noirq(struct device *dev)
1129{
1130 if (dev_pm_skip_resume(dev))
1131 return 0;
1132
1133 return pm_generic_resume_noirq(dev);
1134}
1135
1136/**
1137 * acpi_subsys_resume_early - Resume device using ACPI.
1138 * @dev: Device to Resume.
1139 *
1140 * Use ACPI to put the given device into the full-power state and carry out the
1141 * generic early resume procedure for it during system transition into the
1142 * working state.
1143 */
1144static int acpi_subsys_resume_early(struct device *dev)
1145{
1146 int ret;
1147
1148 if (dev_pm_skip_resume(dev))
1149 return 0;
1150
1151 ret = acpi_dev_resume(dev);
1152 return ret ? ret : pm_generic_resume_early(dev);
1153}
1154
1155/**
1156 * acpi_subsys_freeze - Run the device driver's freeze callback.
1157 * @dev: Device to handle.
1158 */
1159int acpi_subsys_freeze(struct device *dev)
1160{
1161 /*
1162 * Resume all runtime-suspended devices before creating a snapshot
1163 * image of system memory, because the restore kernel generally cannot
1164 * be expected to always handle them consistently and they need to be
1165 * put into the runtime-active metastate during system resume anyway,
1166 * so it is better to ensure that the state saved in the image will be
1167 * always consistent with that.
1168 */
1169 pm_runtime_resume(dev);
1170
1171 return pm_generic_freeze(dev);
1172}
1173EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1174
1175/**
1176 * acpi_subsys_restore_early - Restore device using ACPI.
1177 * @dev: Device to restore.
1178 */
1179int acpi_subsys_restore_early(struct device *dev)
1180{
1181 int ret = acpi_dev_resume(dev);
1182 return ret ? ret : pm_generic_restore_early(dev);
1183}
1184EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1185
1186/**
1187 * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1188 * @dev: Device to handle.
1189 *
1190 * Follow PCI and resume devices from runtime suspend before running their
1191 * system poweroff callbacks, unless the driver can cope with runtime-suspended
1192 * devices during system suspend and there are no ACPI-specific reasons for
1193 * resuming them.
1194 */
1195int acpi_subsys_poweroff(struct device *dev)
1196{
1197 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1198 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1199 pm_runtime_resume(dev);
1200
1201 return pm_generic_poweroff(dev);
1202}
1203EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1204
1205/**
1206 * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1207 * @dev: Device to handle.
1208 *
1209 * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1210 * it into a low-power state during system transition into a sleep state.
1211 */
1212static int acpi_subsys_poweroff_late(struct device *dev)
1213{
1214 int ret;
1215
1216 if (dev_pm_skip_suspend(dev))
1217 return 0;
1218
1219 ret = pm_generic_poweroff_late(dev);
1220 if (ret)
1221 return ret;
1222
1223 return acpi_dev_suspend(dev, device_may_wakeup(dev));
1224}
1225
1226/**
1227 * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1228 * @dev: Device to suspend.
1229 */
1230static int acpi_subsys_poweroff_noirq(struct device *dev)
1231{
1232 if (dev_pm_skip_suspend(dev))
1233 return 0;
1234
1235 return pm_generic_poweroff_noirq(dev);
1236}
1237#endif /* CONFIG_PM_SLEEP */
1238
1239static struct dev_pm_domain acpi_general_pm_domain = {
1240 .ops = {
1241 .runtime_suspend = acpi_subsys_runtime_suspend,
1242 .runtime_resume = acpi_subsys_runtime_resume,
1243#ifdef CONFIG_PM_SLEEP
1244 .prepare = acpi_subsys_prepare,
1245 .complete = acpi_subsys_complete,
1246 .suspend = acpi_subsys_suspend,
1247 .suspend_late = acpi_subsys_suspend_late,
1248 .suspend_noirq = acpi_subsys_suspend_noirq,
1249 .resume_noirq = acpi_subsys_resume_noirq,
1250 .resume_early = acpi_subsys_resume_early,
1251 .freeze = acpi_subsys_freeze,
1252 .poweroff = acpi_subsys_poweroff,
1253 .poweroff_late = acpi_subsys_poweroff_late,
1254 .poweroff_noirq = acpi_subsys_poweroff_noirq,
1255 .restore_early = acpi_subsys_restore_early,
1256#endif
1257 },
1258};
1259
1260/**
1261 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1262 * @dev: Device to take care of.
1263 * @power_off: Whether or not to try to remove power from the device.
1264 *
1265 * Remove the device from the general ACPI PM domain and remove its wakeup
1266 * notifier. If @power_off is set, additionally remove power from the device if
1267 * possible.
1268 *
1269 * Callers must ensure proper synchronization of this function with power
1270 * management callbacks.
1271 */
1272static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1273{
1274 struct acpi_device *adev = ACPI_COMPANION(dev);
1275
1276 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1277 dev_pm_domain_set(dev, NULL);
1278 acpi_remove_pm_notifier(adev);
1279 if (power_off) {
1280 /*
1281 * If the device's PM QoS resume latency limit or flags
1282 * have been exposed to user space, they have to be
1283 * hidden at this point, so that they don't affect the
1284 * choice of the low-power state to put the device into.
1285 */
1286 dev_pm_qos_hide_latency_limit(dev);
1287 dev_pm_qos_hide_flags(dev);
1288 acpi_device_wakeup_disable(adev);
1289 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1290 }
1291 }
1292}
1293
1294/**
1295 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1296 * @dev: Device to prepare.
1297 * @power_on: Whether or not to power on the device.
1298 *
1299 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1300 * attached to it, install a wakeup notification handler for the device and
1301 * add it to the general ACPI PM domain. If @power_on is set, the device will
1302 * be put into the ACPI D0 state before the function returns.
1303 *
1304 * This assumes that the @dev's bus type uses generic power management callbacks
1305 * (or doesn't use any power management callbacks at all).
1306 *
1307 * Callers must ensure proper synchronization of this function with power
1308 * management callbacks.
1309 */
1310int acpi_dev_pm_attach(struct device *dev, bool power_on)
1311{
1312 /*
1313 * Skip devices whose ACPI companions match the device IDs below,
1314 * because they require special power management handling incompatible
1315 * with the generic ACPI PM domain.
1316 */
1317 static const struct acpi_device_id special_pm_ids[] = {
1318 {"PNP0C0B", }, /* Generic ACPI fan */
1319 {"INT3404", }, /* Fan */
1320 {"INTC1044", }, /* Fan for Tiger Lake generation */
1321 {}
1322 };
1323 struct acpi_device *adev = ACPI_COMPANION(dev);
1324
1325 if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
1326 return 0;
1327
1328 /*
1329 * Only attach the power domain to the first device if the
1330 * companion is shared by multiple. This is to prevent doing power
1331 * management twice.
1332 */
1333 if (!acpi_device_is_first_physical_node(adev, dev))
1334 return 0;
1335
1336 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1337 dev_pm_domain_set(dev, &acpi_general_pm_domain);
1338 if (power_on) {
1339 acpi_dev_pm_full_power(adev);
1340 acpi_device_wakeup_disable(adev);
1341 }
1342
1343 dev->pm_domain->detach = acpi_dev_pm_detach;
1344 return 1;
1345}
1346EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1347#endif /* CONFIG_PM */
1/*
2 * drivers/acpi/device_pm.c - ACPI device power management routines.
3 *
4 * Copyright (C) 2012, Intel Corp.
5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as published
11 * by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21 *
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23 */
24
25#include <linux/acpi.h>
26#include <linux/export.h>
27#include <linux/mutex.h>
28#include <linux/pm_qos.h>
29#include <linux/pm_runtime.h>
30
31#include "internal.h"
32
33#define _COMPONENT ACPI_POWER_COMPONENT
34ACPI_MODULE_NAME("device_pm");
35
36/**
37 * acpi_power_state_string - String representation of ACPI device power state.
38 * @state: ACPI device power state to return the string representation of.
39 */
40const char *acpi_power_state_string(int state)
41{
42 switch (state) {
43 case ACPI_STATE_D0:
44 return "D0";
45 case ACPI_STATE_D1:
46 return "D1";
47 case ACPI_STATE_D2:
48 return "D2";
49 case ACPI_STATE_D3_HOT:
50 return "D3hot";
51 case ACPI_STATE_D3_COLD:
52 return "D3cold";
53 default:
54 return "(unknown)";
55 }
56}
57
58/**
59 * acpi_device_get_power - Get power state of an ACPI device.
60 * @device: Device to get the power state of.
61 * @state: Place to store the power state of the device.
62 *
63 * This function does not update the device's power.state field, but it may
64 * update its parent's power.state field (when the parent's power state is
65 * unknown and the device's power state turns out to be D0).
66 */
67int acpi_device_get_power(struct acpi_device *device, int *state)
68{
69 int result = ACPI_STATE_UNKNOWN;
70
71 if (!device || !state)
72 return -EINVAL;
73
74 if (!device->flags.power_manageable) {
75 /* TBD: Non-recursive algorithm for walking up hierarchy. */
76 *state = device->parent ?
77 device->parent->power.state : ACPI_STATE_D0;
78 goto out;
79 }
80
81 /*
82 * Get the device's power state from power resources settings and _PSC,
83 * if available.
84 */
85 if (device->power.flags.power_resources) {
86 int error = acpi_power_get_inferred_state(device, &result);
87 if (error)
88 return error;
89 }
90 if (device->power.flags.explicit_get) {
91 acpi_handle handle = device->handle;
92 unsigned long long psc;
93 acpi_status status;
94
95 status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
96 if (ACPI_FAILURE(status))
97 return -ENODEV;
98
99 /*
100 * The power resources settings may indicate a power state
101 * shallower than the actual power state of the device.
102 *
103 * Moreover, on systems predating ACPI 4.0, if the device
104 * doesn't depend on any power resources and _PSC returns 3,
105 * that means "power off". We need to maintain compatibility
106 * with those systems.
107 */
108 if (psc > result && psc < ACPI_STATE_D3_COLD)
109 result = psc;
110 else if (result == ACPI_STATE_UNKNOWN)
111 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc;
112 }
113
114 /*
115 * If we were unsure about the device parent's power state up to this
116 * point, the fact that the device is in D0 implies that the parent has
117 * to be in D0 too, except if ignore_parent is set.
118 */
119 if (!device->power.flags.ignore_parent && device->parent
120 && device->parent->power.state == ACPI_STATE_UNKNOWN
121 && result == ACPI_STATE_D0)
122 device->parent->power.state = ACPI_STATE_D0;
123
124 *state = result;
125
126 out:
127 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
128 device->pnp.bus_id, acpi_power_state_string(*state)));
129
130 return 0;
131}
132
133static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
134{
135 if (adev->power.states[state].flags.explicit_set) {
136 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
137 acpi_status status;
138
139 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
140 if (ACPI_FAILURE(status))
141 return -ENODEV;
142 }
143 return 0;
144}
145
146/**
147 * acpi_device_set_power - Set power state of an ACPI device.
148 * @device: Device to set the power state of.
149 * @state: New power state to set.
150 *
151 * Callers must ensure that the device is power manageable before using this
152 * function.
153 */
154int acpi_device_set_power(struct acpi_device *device, int state)
155{
156 int result = 0;
157 bool cut_power = false;
158
159 if (!device || !device->flags.power_manageable
160 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
161 return -EINVAL;
162
163 /* Make sure this is a valid target state */
164
165 if (state == device->power.state) {
166 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
167 device->pnp.bus_id,
168 acpi_power_state_string(state)));
169 return 0;
170 }
171
172 if (!device->power.states[state].flags.valid) {
173 dev_warn(&device->dev, "Power state %s not supported\n",
174 acpi_power_state_string(state));
175 return -ENODEV;
176 }
177 if (!device->power.flags.ignore_parent &&
178 device->parent && (state < device->parent->power.state)) {
179 dev_warn(&device->dev,
180 "Cannot transition to power state %s for parent in %s\n",
181 acpi_power_state_string(state),
182 acpi_power_state_string(device->parent->power.state));
183 return -ENODEV;
184 }
185
186 /* For D3cold we should first transition into D3hot. */
187 if (state == ACPI_STATE_D3_COLD
188 && device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) {
189 state = ACPI_STATE_D3_HOT;
190 cut_power = true;
191 }
192
193 if (state < device->power.state && state != ACPI_STATE_D0
194 && device->power.state >= ACPI_STATE_D3_HOT) {
195 dev_warn(&device->dev,
196 "Cannot transition to non-D0 state from D3\n");
197 return -ENODEV;
198 }
199
200 /*
201 * Transition Power
202 * ----------------
203 * In accordance with the ACPI specification first apply power (via
204 * power resources) and then evalute _PSx.
205 */
206 if (device->power.flags.power_resources) {
207 result = acpi_power_transition(device, state);
208 if (result)
209 goto end;
210 }
211 result = acpi_dev_pm_explicit_set(device, state);
212 if (result)
213 goto end;
214
215 if (cut_power) {
216 device->power.state = state;
217 state = ACPI_STATE_D3_COLD;
218 result = acpi_power_transition(device, state);
219 }
220
221 end:
222 if (result) {
223 dev_warn(&device->dev, "Failed to change power state to %s\n",
224 acpi_power_state_string(state));
225 } else {
226 device->power.state = state;
227 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
228 "Device [%s] transitioned to %s\n",
229 device->pnp.bus_id,
230 acpi_power_state_string(state)));
231 }
232
233 return result;
234}
235EXPORT_SYMBOL(acpi_device_set_power);
236
237int acpi_bus_set_power(acpi_handle handle, int state)
238{
239 struct acpi_device *device;
240 int result;
241
242 result = acpi_bus_get_device(handle, &device);
243 if (result)
244 return result;
245
246 return acpi_device_set_power(device, state);
247}
248EXPORT_SYMBOL(acpi_bus_set_power);
249
250int acpi_bus_init_power(struct acpi_device *device)
251{
252 int state;
253 int result;
254
255 if (!device)
256 return -EINVAL;
257
258 device->power.state = ACPI_STATE_UNKNOWN;
259 if (!acpi_device_is_present(device))
260 return 0;
261
262 result = acpi_device_get_power(device, &state);
263 if (result)
264 return result;
265
266 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
267 result = acpi_power_on_resources(device, state);
268 if (result)
269 return result;
270
271 result = acpi_dev_pm_explicit_set(device, state);
272 if (result)
273 return result;
274 } else if (state == ACPI_STATE_UNKNOWN) {
275 /*
276 * No power resources and missing _PSC? Cross fingers and make
277 * it D0 in hope that this is what the BIOS put the device into.
278 * [We tried to force D0 here by executing _PS0, but that broke
279 * Toshiba P870-303 in a nasty way.]
280 */
281 state = ACPI_STATE_D0;
282 }
283 device->power.state = state;
284 return 0;
285}
286
287/**
288 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
289 * @device: Device object whose power state is to be fixed up.
290 *
291 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
292 * are assumed to be put into D0 by the BIOS. However, in some cases that may
293 * not be the case and this function should be used then.
294 */
295int acpi_device_fix_up_power(struct acpi_device *device)
296{
297 int ret = 0;
298
299 if (!device->power.flags.power_resources
300 && !device->power.flags.explicit_get
301 && device->power.state == ACPI_STATE_D0)
302 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
303
304 return ret;
305}
306
307int acpi_device_update_power(struct acpi_device *device, int *state_p)
308{
309 int state;
310 int result;
311
312 if (device->power.state == ACPI_STATE_UNKNOWN) {
313 result = acpi_bus_init_power(device);
314 if (!result && state_p)
315 *state_p = device->power.state;
316
317 return result;
318 }
319
320 result = acpi_device_get_power(device, &state);
321 if (result)
322 return result;
323
324 if (state == ACPI_STATE_UNKNOWN) {
325 state = ACPI_STATE_D0;
326 result = acpi_device_set_power(device, state);
327 if (result)
328 return result;
329 } else {
330 if (device->power.flags.power_resources) {
331 /*
332 * We don't need to really switch the state, bu we need
333 * to update the power resources' reference counters.
334 */
335 result = acpi_power_transition(device, state);
336 if (result)
337 return result;
338 }
339 device->power.state = state;
340 }
341 if (state_p)
342 *state_p = state;
343
344 return 0;
345}
346
347int acpi_bus_update_power(acpi_handle handle, int *state_p)
348{
349 struct acpi_device *device;
350 int result;
351
352 result = acpi_bus_get_device(handle, &device);
353 return result ? result : acpi_device_update_power(device, state_p);
354}
355EXPORT_SYMBOL_GPL(acpi_bus_update_power);
356
357bool acpi_bus_power_manageable(acpi_handle handle)
358{
359 struct acpi_device *device;
360 int result;
361
362 result = acpi_bus_get_device(handle, &device);
363 return result ? false : device->flags.power_manageable;
364}
365EXPORT_SYMBOL(acpi_bus_power_manageable);
366
367#ifdef CONFIG_PM
368static DEFINE_MUTEX(acpi_pm_notifier_lock);
369
370/**
371 * acpi_add_pm_notifier - Register PM notifier for given ACPI device.
372 * @adev: ACPI device to add the notifier for.
373 * @context: Context information to pass to the notifier routine.
374 *
375 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
376 * PM wakeup events. For example, wakeup events may be generated for bridges
377 * if one of the devices below the bridge is signaling wakeup, even if the
378 * bridge itself doesn't have a wakeup GPE associated with it.
379 */
380acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
381 acpi_notify_handler handler, void *context)
382{
383 acpi_status status = AE_ALREADY_EXISTS;
384
385 mutex_lock(&acpi_pm_notifier_lock);
386
387 if (adev->wakeup.flags.notifier_present)
388 goto out;
389
390 status = acpi_install_notify_handler(adev->handle,
391 ACPI_SYSTEM_NOTIFY,
392 handler, context);
393 if (ACPI_FAILURE(status))
394 goto out;
395
396 adev->wakeup.flags.notifier_present = true;
397
398 out:
399 mutex_unlock(&acpi_pm_notifier_lock);
400 return status;
401}
402
403/**
404 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
405 * @adev: ACPI device to remove the notifier from.
406 */
407acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
408 acpi_notify_handler handler)
409{
410 acpi_status status = AE_BAD_PARAMETER;
411
412 mutex_lock(&acpi_pm_notifier_lock);
413
414 if (!adev->wakeup.flags.notifier_present)
415 goto out;
416
417 status = acpi_remove_notify_handler(adev->handle,
418 ACPI_SYSTEM_NOTIFY,
419 handler);
420 if (ACPI_FAILURE(status))
421 goto out;
422
423 adev->wakeup.flags.notifier_present = false;
424
425 out:
426 mutex_unlock(&acpi_pm_notifier_lock);
427 return status;
428}
429
430bool acpi_bus_can_wakeup(acpi_handle handle)
431{
432 struct acpi_device *device;
433 int result;
434
435 result = acpi_bus_get_device(handle, &device);
436 return result ? false : device->wakeup.flags.valid;
437}
438EXPORT_SYMBOL(acpi_bus_can_wakeup);
439
440/**
441 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
442 * @dev: Device whose preferred target power state to return.
443 * @adev: ACPI device node corresponding to @dev.
444 * @target_state: System state to match the resultant device state.
445 * @d_min_p: Location to store the highest power state available to the device.
446 * @d_max_p: Location to store the lowest power state available to the device.
447 *
448 * Find the lowest power (highest number) and highest power (lowest number) ACPI
449 * device power states that the device can be in while the system is in the
450 * state represented by @target_state. Store the integer numbers representing
451 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
452 * respectively.
453 *
454 * Callers must ensure that @dev and @adev are valid pointers and that @adev
455 * actually corresponds to @dev before using this function.
456 *
457 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
458 * returns a value that doesn't make sense. The memory locations pointed to by
459 * @d_max_p and @d_min_p are only modified on success.
460 */
461static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
462 u32 target_state, int *d_min_p, int *d_max_p)
463{
464 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
465 acpi_handle handle = adev->handle;
466 unsigned long long ret;
467 int d_min, d_max;
468 bool wakeup = false;
469 acpi_status status;
470
471 /*
472 * If the system state is S0, the lowest power state the device can be
473 * in is D3cold, unless the device has _S0W and is supposed to signal
474 * wakeup, in which case the return value of _S0W has to be used as the
475 * lowest power state available to the device.
476 */
477 d_min = ACPI_STATE_D0;
478 d_max = ACPI_STATE_D3_COLD;
479
480 /*
481 * If present, _SxD methods return the minimum D-state (highest power
482 * state) we can use for the corresponding S-states. Otherwise, the
483 * minimum D-state is D0 (ACPI 3.x).
484 */
485 if (target_state > ACPI_STATE_S0) {
486 /*
487 * We rely on acpi_evaluate_integer() not clobbering the integer
488 * provided if AE_NOT_FOUND is returned.
489 */
490 ret = d_min;
491 status = acpi_evaluate_integer(handle, method, NULL, &ret);
492 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
493 || ret > ACPI_STATE_D3_COLD)
494 return -ENODATA;
495
496 /*
497 * We need to handle legacy systems where D3hot and D3cold are
498 * the same and 3 is returned in both cases, so fall back to
499 * D3cold if D3hot is not a valid state.
500 */
501 if (!adev->power.states[ret].flags.valid) {
502 if (ret == ACPI_STATE_D3_HOT)
503 ret = ACPI_STATE_D3_COLD;
504 else
505 return -ENODATA;
506 }
507 d_min = ret;
508 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
509 && adev->wakeup.sleep_state >= target_state;
510 } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
511 PM_QOS_FLAGS_NONE) {
512 wakeup = adev->wakeup.flags.valid;
513 }
514
515 /*
516 * If _PRW says we can wake up the system from the target sleep state,
517 * the D-state returned by _SxD is sufficient for that (we assume a
518 * wakeup-aware driver if wake is set). Still, if _SxW exists
519 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
520 * can wake the system. _S0W may be valid, too.
521 */
522 if (wakeup) {
523 method[3] = 'W';
524 status = acpi_evaluate_integer(handle, method, NULL, &ret);
525 if (status == AE_NOT_FOUND) {
526 if (target_state > ACPI_STATE_S0)
527 d_max = d_min;
528 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
529 /* Fall back to D3cold if ret is not a valid state. */
530 if (!adev->power.states[ret].flags.valid)
531 ret = ACPI_STATE_D3_COLD;
532
533 d_max = ret > d_min ? ret : d_min;
534 } else {
535 return -ENODATA;
536 }
537 }
538
539 if (d_min_p)
540 *d_min_p = d_min;
541
542 if (d_max_p)
543 *d_max_p = d_max;
544
545 return 0;
546}
547
548/**
549 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
550 * @dev: Device whose preferred target power state to return.
551 * @d_min_p: Location to store the upper limit of the allowed states range.
552 * @d_max_in: Deepest low-power state to take into consideration.
553 * Return value: Preferred power state of the device on success, -ENODEV
554 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
555 * incorrect, or -ENODATA on ACPI method failure.
556 *
557 * The caller must ensure that @dev is valid before using this function.
558 */
559int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
560{
561 acpi_handle handle = ACPI_HANDLE(dev);
562 struct acpi_device *adev;
563 int ret, d_min, d_max;
564
565 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
566 return -EINVAL;
567
568 if (d_max_in > ACPI_STATE_D3_HOT) {
569 enum pm_qos_flags_status stat;
570
571 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
572 if (stat == PM_QOS_FLAGS_ALL)
573 d_max_in = ACPI_STATE_D3_HOT;
574 }
575
576 if (!handle || acpi_bus_get_device(handle, &adev)) {
577 dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
578 return -ENODEV;
579 }
580
581 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
582 &d_min, &d_max);
583 if (ret)
584 return ret;
585
586 if (d_max_in < d_min)
587 return -EINVAL;
588
589 if (d_max > d_max_in) {
590 for (d_max = d_max_in; d_max > d_min; d_max--) {
591 if (adev->power.states[d_max].flags.valid)
592 break;
593 }
594 }
595
596 if (d_min_p)
597 *d_min_p = d_min;
598
599 return d_max;
600}
601EXPORT_SYMBOL(acpi_pm_device_sleep_state);
602
603#ifdef CONFIG_PM_RUNTIME
604/**
605 * acpi_wakeup_device - Wakeup notification handler for ACPI devices.
606 * @handle: ACPI handle of the device the notification is for.
607 * @event: Type of the signaled event.
608 * @context: Device corresponding to @handle.
609 */
610static void acpi_wakeup_device(acpi_handle handle, u32 event, void *context)
611{
612 struct device *dev = context;
613
614 if (event == ACPI_NOTIFY_DEVICE_WAKE && dev) {
615 pm_wakeup_event(dev, 0);
616 pm_runtime_resume(dev);
617 }
618}
619
620/**
621 * __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
622 * @adev: ACPI device to enable/disable the remote wakeup for.
623 * @enable: Whether to enable or disable the wakeup functionality.
624 *
625 * Enable/disable the GPE associated with @adev so that it can generate
626 * wakeup signals for the device in response to external (remote) events and
627 * enable/disable device wakeup power.
628 *
629 * Callers must ensure that @adev is a valid ACPI device node before executing
630 * this function.
631 */
632int __acpi_device_run_wake(struct acpi_device *adev, bool enable)
633{
634 struct acpi_device_wakeup *wakeup = &adev->wakeup;
635
636 if (enable) {
637 acpi_status res;
638 int error;
639
640 error = acpi_enable_wakeup_device_power(adev, ACPI_STATE_S0);
641 if (error)
642 return error;
643
644 res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
645 if (ACPI_FAILURE(res)) {
646 acpi_disable_wakeup_device_power(adev);
647 return -EIO;
648 }
649 } else {
650 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
651 acpi_disable_wakeup_device_power(adev);
652 }
653 return 0;
654}
655
656/**
657 * acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
658 * @dev: Device to enable/disable the platform to wake up.
659 * @enable: Whether to enable or disable the wakeup functionality.
660 */
661int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
662{
663 struct acpi_device *adev;
664 acpi_handle handle;
665
666 if (!device_run_wake(phys_dev))
667 return -EINVAL;
668
669 handle = ACPI_HANDLE(phys_dev);
670 if (!handle || acpi_bus_get_device(handle, &adev)) {
671 dev_dbg(phys_dev, "ACPI handle without context in %s!\n",
672 __func__);
673 return -ENODEV;
674 }
675
676 return __acpi_device_run_wake(adev, enable);
677}
678EXPORT_SYMBOL(acpi_pm_device_run_wake);
679#else
680static inline void acpi_wakeup_device(acpi_handle handle, u32 event,
681 void *context) {}
682#endif /* CONFIG_PM_RUNTIME */
683
684#ifdef CONFIG_PM_SLEEP
685/**
686 * __acpi_device_sleep_wake - Enable or disable device to wake up the system.
687 * @dev: Device to enable/desible to wake up the system.
688 * @target_state: System state the device is supposed to wake up from.
689 * @enable: Whether to enable or disable @dev to wake up the system.
690 */
691int __acpi_device_sleep_wake(struct acpi_device *adev, u32 target_state,
692 bool enable)
693{
694 return enable ?
695 acpi_enable_wakeup_device_power(adev, target_state) :
696 acpi_disable_wakeup_device_power(adev);
697}
698
699/**
700 * acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
701 * @dev: Device to enable/desible to wake up the system from sleep states.
702 * @enable: Whether to enable or disable @dev to wake up the system.
703 */
704int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
705{
706 acpi_handle handle;
707 struct acpi_device *adev;
708 int error;
709
710 if (!device_can_wakeup(dev))
711 return -EINVAL;
712
713 handle = ACPI_HANDLE(dev);
714 if (!handle || acpi_bus_get_device(handle, &adev)) {
715 dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
716 return -ENODEV;
717 }
718
719 error = __acpi_device_sleep_wake(adev, acpi_target_system_state(),
720 enable);
721 if (!error)
722 dev_info(dev, "System wakeup %s by ACPI\n",
723 enable ? "enabled" : "disabled");
724
725 return error;
726}
727#endif /* CONFIG_PM_SLEEP */
728
729/**
730 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
731 * @dev: Device to put into a low-power state.
732 * @adev: ACPI device node corresponding to @dev.
733 * @system_state: System state to choose the device state for.
734 */
735static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
736 u32 system_state)
737{
738 int ret, state;
739
740 if (!acpi_device_power_manageable(adev))
741 return 0;
742
743 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
744 return ret ? ret : acpi_device_set_power(adev, state);
745}
746
747/**
748 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
749 * @adev: ACPI device node to put into the full-power state.
750 */
751static int acpi_dev_pm_full_power(struct acpi_device *adev)
752{
753 return acpi_device_power_manageable(adev) ?
754 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
755}
756
757#ifdef CONFIG_PM_RUNTIME
758/**
759 * acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
760 * @dev: Device to put into a low-power state.
761 *
762 * Put the given device into a runtime low-power state using the standard ACPI
763 * mechanism. Set up remote wakeup if desired, choose the state to put the
764 * device into (this checks if remote wakeup is expected to work too), and set
765 * the power state of the device.
766 */
767int acpi_dev_runtime_suspend(struct device *dev)
768{
769 struct acpi_device *adev = ACPI_COMPANION(dev);
770 bool remote_wakeup;
771 int error;
772
773 if (!adev)
774 return 0;
775
776 remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
777 PM_QOS_FLAGS_NONE;
778 error = __acpi_device_run_wake(adev, remote_wakeup);
779 if (remote_wakeup && error)
780 return -EAGAIN;
781
782 error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
783 if (error)
784 __acpi_device_run_wake(adev, false);
785
786 return error;
787}
788EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
789
790/**
791 * acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
792 * @dev: Device to put into the full-power state.
793 *
794 * Put the given device into the full-power state using the standard ACPI
795 * mechanism at run time. Set the power state of the device to ACPI D0 and
796 * disable remote wakeup.
797 */
798int acpi_dev_runtime_resume(struct device *dev)
799{
800 struct acpi_device *adev = ACPI_COMPANION(dev);
801 int error;
802
803 if (!adev)
804 return 0;
805
806 error = acpi_dev_pm_full_power(adev);
807 __acpi_device_run_wake(adev, false);
808 return error;
809}
810EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
811
812/**
813 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
814 * @dev: Device to suspend.
815 *
816 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
817 * it into a runtime low-power state.
818 */
819int acpi_subsys_runtime_suspend(struct device *dev)
820{
821 int ret = pm_generic_runtime_suspend(dev);
822 return ret ? ret : acpi_dev_runtime_suspend(dev);
823}
824EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
825
826/**
827 * acpi_subsys_runtime_resume - Resume device using ACPI.
828 * @dev: Device to Resume.
829 *
830 * Use ACPI to put the given device into the full-power state and carry out the
831 * generic runtime resume procedure for it.
832 */
833int acpi_subsys_runtime_resume(struct device *dev)
834{
835 int ret = acpi_dev_runtime_resume(dev);
836 return ret ? ret : pm_generic_runtime_resume(dev);
837}
838EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
839#endif /* CONFIG_PM_RUNTIME */
840
841#ifdef CONFIG_PM_SLEEP
842/**
843 * acpi_dev_suspend_late - Put device into a low-power state using ACPI.
844 * @dev: Device to put into a low-power state.
845 *
846 * Put the given device into a low-power state during system transition to a
847 * sleep state using the standard ACPI mechanism. Set up system wakeup if
848 * desired, choose the state to put the device into (this checks if system
849 * wakeup is expected to work too), and set the power state of the device.
850 */
851int acpi_dev_suspend_late(struct device *dev)
852{
853 struct acpi_device *adev = ACPI_COMPANION(dev);
854 u32 target_state;
855 bool wakeup;
856 int error;
857
858 if (!adev)
859 return 0;
860
861 target_state = acpi_target_system_state();
862 wakeup = device_may_wakeup(dev);
863 error = __acpi_device_sleep_wake(adev, target_state, wakeup);
864 if (wakeup && error)
865 return error;
866
867 error = acpi_dev_pm_low_power(dev, adev, target_state);
868 if (error)
869 __acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false);
870
871 return error;
872}
873EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
874
875/**
876 * acpi_dev_resume_early - Put device into the full-power state using ACPI.
877 * @dev: Device to put into the full-power state.
878 *
879 * Put the given device into the full-power state using the standard ACPI
880 * mechanism during system transition to the working state. Set the power
881 * state of the device to ACPI D0 and disable remote wakeup.
882 */
883int acpi_dev_resume_early(struct device *dev)
884{
885 struct acpi_device *adev = ACPI_COMPANION(dev);
886 int error;
887
888 if (!adev)
889 return 0;
890
891 error = acpi_dev_pm_full_power(adev);
892 __acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false);
893 return error;
894}
895EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
896
897/**
898 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
899 * @dev: Device to prepare.
900 */
901int acpi_subsys_prepare(struct device *dev)
902{
903 /*
904 * Devices having power.ignore_children set may still be necessary for
905 * suspending their children in the next phase of device suspend.
906 */
907 if (dev->power.ignore_children)
908 pm_runtime_resume(dev);
909
910 return pm_generic_prepare(dev);
911}
912EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
913
914/**
915 * acpi_subsys_suspend - Run the device driver's suspend callback.
916 * @dev: Device to handle.
917 *
918 * Follow PCI and resume devices suspended at run time before running their
919 * system suspend callbacks.
920 */
921int acpi_subsys_suspend(struct device *dev)
922{
923 pm_runtime_resume(dev);
924 return pm_generic_suspend(dev);
925}
926
927/**
928 * acpi_subsys_suspend_late - Suspend device using ACPI.
929 * @dev: Device to suspend.
930 *
931 * Carry out the generic late suspend procedure for @dev and use ACPI to put
932 * it into a low-power state during system transition into a sleep state.
933 */
934int acpi_subsys_suspend_late(struct device *dev)
935{
936 int ret = pm_generic_suspend_late(dev);
937 return ret ? ret : acpi_dev_suspend_late(dev);
938}
939EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
940
941/**
942 * acpi_subsys_resume_early - Resume device using ACPI.
943 * @dev: Device to Resume.
944 *
945 * Use ACPI to put the given device into the full-power state and carry out the
946 * generic early resume procedure for it during system transition into the
947 * working state.
948 */
949int acpi_subsys_resume_early(struct device *dev)
950{
951 int ret = acpi_dev_resume_early(dev);
952 return ret ? ret : pm_generic_resume_early(dev);
953}
954EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
955
956/**
957 * acpi_subsys_freeze - Run the device driver's freeze callback.
958 * @dev: Device to handle.
959 */
960int acpi_subsys_freeze(struct device *dev)
961{
962 /*
963 * This used to be done in acpi_subsys_prepare() for all devices and
964 * some drivers may depend on it, so do it here. Ideally, however,
965 * runtime-suspended devices should not be touched during freeze/thaw
966 * transitions.
967 */
968 pm_runtime_resume(dev);
969 return pm_generic_freeze(dev);
970}
971
972#endif /* CONFIG_PM_SLEEP */
973
974static struct dev_pm_domain acpi_general_pm_domain = {
975 .ops = {
976#ifdef CONFIG_PM_RUNTIME
977 .runtime_suspend = acpi_subsys_runtime_suspend,
978 .runtime_resume = acpi_subsys_runtime_resume,
979#endif
980#ifdef CONFIG_PM_SLEEP
981 .prepare = acpi_subsys_prepare,
982 .suspend = acpi_subsys_suspend,
983 .suspend_late = acpi_subsys_suspend_late,
984 .resume_early = acpi_subsys_resume_early,
985 .freeze = acpi_subsys_freeze,
986 .poweroff = acpi_subsys_suspend,
987 .poweroff_late = acpi_subsys_suspend_late,
988 .restore_early = acpi_subsys_resume_early,
989#endif
990 },
991};
992
993/**
994 * acpi_dev_pm_attach - Prepare device for ACPI power management.
995 * @dev: Device to prepare.
996 * @power_on: Whether or not to power on the device.
997 *
998 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
999 * attached to it, install a wakeup notification handler for the device and
1000 * add it to the general ACPI PM domain. If @power_on is set, the device will
1001 * be put into the ACPI D0 state before the function returns.
1002 *
1003 * This assumes that the @dev's bus type uses generic power management callbacks
1004 * (or doesn't use any power management callbacks at all).
1005 *
1006 * Callers must ensure proper synchronization of this function with power
1007 * management callbacks.
1008 */
1009int acpi_dev_pm_attach(struct device *dev, bool power_on)
1010{
1011 struct acpi_device *adev = ACPI_COMPANION(dev);
1012
1013 if (!adev)
1014 return -ENODEV;
1015
1016 if (dev->pm_domain)
1017 return -EEXIST;
1018
1019 acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
1020 dev->pm_domain = &acpi_general_pm_domain;
1021 if (power_on) {
1022 acpi_dev_pm_full_power(adev);
1023 __acpi_device_run_wake(adev, false);
1024 }
1025 return 0;
1026}
1027EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1028
1029/**
1030 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1031 * @dev: Device to take care of.
1032 * @power_off: Whether or not to try to remove power from the device.
1033 *
1034 * Remove the device from the general ACPI PM domain and remove its wakeup
1035 * notifier. If @power_off is set, additionally remove power from the device if
1036 * possible.
1037 *
1038 * Callers must ensure proper synchronization of this function with power
1039 * management callbacks.
1040 */
1041void acpi_dev_pm_detach(struct device *dev, bool power_off)
1042{
1043 struct acpi_device *adev = ACPI_COMPANION(dev);
1044
1045 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1046 dev->pm_domain = NULL;
1047 acpi_remove_pm_notifier(adev, acpi_wakeup_device);
1048 if (power_off) {
1049 /*
1050 * If the device's PM QoS resume latency limit or flags
1051 * have been exposed to user space, they have to be
1052 * hidden at this point, so that they don't affect the
1053 * choice of the low-power state to put the device into.
1054 */
1055 dev_pm_qos_hide_latency_limit(dev);
1056 dev_pm_qos_hide_flags(dev);
1057 __acpi_device_run_wake(adev, false);
1058 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1059 }
1060 }
1061}
1062EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
1063#endif /* CONFIG_PM */