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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 _PR3 is not available, 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(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(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_smart_suspend_and_suspended(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_smart_suspend_and_suspended(dev)) {
1104 dev->power.may_skip_resume = true;
1105 return 0;
1106 }
1107
1108 ret = pm_generic_suspend_noirq(dev);
1109 if (ret)
1110 return ret;
1111
1112 /*
1113 * If the target system sleep state is suspend-to-idle, it is sufficient
1114 * to check whether or not the device's wakeup settings are good for
1115 * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause
1116 * acpi_subsys_complete() to take care of fixing up the device's state
1117 * anyway, if need be.
1118 */
1119 dev->power.may_skip_resume = device_may_wakeup(dev) ||
1120 !device_can_wakeup(dev);
1121
1122 return 0;
1123}
1124EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1125
1126/**
1127 * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1128 * @dev: Device to handle.
1129 */
1130static int acpi_subsys_resume_noirq(struct device *dev)
1131{
1132 if (dev_pm_may_skip_resume(dev))
1133 return 0;
1134
1135 /*
1136 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
1137 * during system suspend, so update their runtime PM status to "active"
1138 * as they will be put into D0 going forward.
1139 */
1140 if (dev_pm_smart_suspend_and_suspended(dev))
1141 pm_runtime_set_active(dev);
1142
1143 return pm_generic_resume_noirq(dev);
1144}
1145
1146/**
1147 * acpi_subsys_resume_early - Resume device using ACPI.
1148 * @dev: Device to Resume.
1149 *
1150 * Use ACPI to put the given device into the full-power state and carry out the
1151 * generic early resume procedure for it during system transition into the
1152 * working state.
1153 */
1154static int acpi_subsys_resume_early(struct device *dev)
1155{
1156 int ret = acpi_dev_resume(dev);
1157 return ret ? ret : pm_generic_resume_early(dev);
1158}
1159
1160/**
1161 * acpi_subsys_freeze - Run the device driver's freeze callback.
1162 * @dev: Device to handle.
1163 */
1164int acpi_subsys_freeze(struct device *dev)
1165{
1166 /*
1167 * Resume all runtime-suspended devices before creating a snapshot
1168 * image of system memory, because the restore kernel generally cannot
1169 * be expected to always handle them consistently and they need to be
1170 * put into the runtime-active metastate during system resume anyway,
1171 * so it is better to ensure that the state saved in the image will be
1172 * always consistent with that.
1173 */
1174 pm_runtime_resume(dev);
1175
1176 return pm_generic_freeze(dev);
1177}
1178EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1179
1180/**
1181 * acpi_subsys_restore_early - Restore device using ACPI.
1182 * @dev: Device to restore.
1183 */
1184int acpi_subsys_restore_early(struct device *dev)
1185{
1186 int ret = acpi_dev_resume(dev);
1187 return ret ? ret : pm_generic_restore_early(dev);
1188}
1189EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1190
1191/**
1192 * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1193 * @dev: Device to handle.
1194 *
1195 * Follow PCI and resume devices from runtime suspend before running their
1196 * system poweroff callbacks, unless the driver can cope with runtime-suspended
1197 * devices during system suspend and there are no ACPI-specific reasons for
1198 * resuming them.
1199 */
1200int acpi_subsys_poweroff(struct device *dev)
1201{
1202 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1203 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1204 pm_runtime_resume(dev);
1205
1206 return pm_generic_poweroff(dev);
1207}
1208EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1209
1210/**
1211 * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1212 * @dev: Device to handle.
1213 *
1214 * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1215 * it into a low-power state during system transition into a sleep state.
1216 */
1217static int acpi_subsys_poweroff_late(struct device *dev)
1218{
1219 int ret;
1220
1221 if (dev_pm_smart_suspend_and_suspended(dev))
1222 return 0;
1223
1224 ret = pm_generic_poweroff_late(dev);
1225 if (ret)
1226 return ret;
1227
1228 return acpi_dev_suspend(dev, device_may_wakeup(dev));
1229}
1230
1231/**
1232 * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1233 * @dev: Device to suspend.
1234 */
1235static int acpi_subsys_poweroff_noirq(struct device *dev)
1236{
1237 if (dev_pm_smart_suspend_and_suspended(dev))
1238 return 0;
1239
1240 return pm_generic_poweroff_noirq(dev);
1241}
1242#endif /* CONFIG_PM_SLEEP */
1243
1244static struct dev_pm_domain acpi_general_pm_domain = {
1245 .ops = {
1246 .runtime_suspend = acpi_subsys_runtime_suspend,
1247 .runtime_resume = acpi_subsys_runtime_resume,
1248#ifdef CONFIG_PM_SLEEP
1249 .prepare = acpi_subsys_prepare,
1250 .complete = acpi_subsys_complete,
1251 .suspend = acpi_subsys_suspend,
1252 .suspend_late = acpi_subsys_suspend_late,
1253 .suspend_noirq = acpi_subsys_suspend_noirq,
1254 .resume_noirq = acpi_subsys_resume_noirq,
1255 .resume_early = acpi_subsys_resume_early,
1256 .freeze = acpi_subsys_freeze,
1257 .poweroff = acpi_subsys_poweroff,
1258 .poweroff_late = acpi_subsys_poweroff_late,
1259 .poweroff_noirq = acpi_subsys_poweroff_noirq,
1260 .restore_early = acpi_subsys_restore_early,
1261#endif
1262 },
1263};
1264
1265/**
1266 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1267 * @dev: Device to take care of.
1268 * @power_off: Whether or not to try to remove power from the device.
1269 *
1270 * Remove the device from the general ACPI PM domain and remove its wakeup
1271 * notifier. If @power_off is set, additionally remove power from the device if
1272 * possible.
1273 *
1274 * Callers must ensure proper synchronization of this function with power
1275 * management callbacks.
1276 */
1277static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1278{
1279 struct acpi_device *adev = ACPI_COMPANION(dev);
1280
1281 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1282 dev_pm_domain_set(dev, NULL);
1283 acpi_remove_pm_notifier(adev);
1284 if (power_off) {
1285 /*
1286 * If the device's PM QoS resume latency limit or flags
1287 * have been exposed to user space, they have to be
1288 * hidden at this point, so that they don't affect the
1289 * choice of the low-power state to put the device into.
1290 */
1291 dev_pm_qos_hide_latency_limit(dev);
1292 dev_pm_qos_hide_flags(dev);
1293 acpi_device_wakeup_disable(adev);
1294 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1295 }
1296 }
1297}
1298
1299/**
1300 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1301 * @dev: Device to prepare.
1302 * @power_on: Whether or not to power on the device.
1303 *
1304 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1305 * attached to it, install a wakeup notification handler for the device and
1306 * add it to the general ACPI PM domain. If @power_on is set, the device will
1307 * be put into the ACPI D0 state before the function returns.
1308 *
1309 * This assumes that the @dev's bus type uses generic power management callbacks
1310 * (or doesn't use any power management callbacks at all).
1311 *
1312 * Callers must ensure proper synchronization of this function with power
1313 * management callbacks.
1314 */
1315int acpi_dev_pm_attach(struct device *dev, bool power_on)
1316{
1317 struct acpi_device *adev = ACPI_COMPANION(dev);
1318
1319 if (!adev)
1320 return 0;
1321
1322 /*
1323 * Only attach the power domain to the first device if the
1324 * companion is shared by multiple. This is to prevent doing power
1325 * management twice.
1326 */
1327 if (!acpi_device_is_first_physical_node(adev, dev))
1328 return 0;
1329
1330 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1331 dev_pm_domain_set(dev, &acpi_general_pm_domain);
1332 if (power_on) {
1333 acpi_dev_pm_full_power(adev);
1334 acpi_device_wakeup_disable(adev);
1335 }
1336
1337 dev->pm_domain->detach = acpi_dev_pm_detach;
1338 return 1;
1339}
1340EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1341#endif /* CONFIG_PM */