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1/*
2 * drivers/acpi/device_pm.c - ACPI device power management routines.
3 *
4 * Copyright (C) 2012, Intel Corp.
5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as published
11 * by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19 */
20
21#include <linux/acpi.h>
22#include <linux/export.h>
23#include <linux/mutex.h>
24#include <linux/pm_qos.h>
25#include <linux/pm_domain.h>
26#include <linux/pm_runtime.h>
27#include <linux/suspend.h>
28
29#include "internal.h"
30
31#define _COMPONENT ACPI_POWER_COMPONENT
32ACPI_MODULE_NAME("device_pm");
33
34/**
35 * acpi_power_state_string - String representation of ACPI device power state.
36 * @state: ACPI device power state to return the string representation of.
37 */
38const char *acpi_power_state_string(int state)
39{
40 switch (state) {
41 case ACPI_STATE_D0:
42 return "D0";
43 case ACPI_STATE_D1:
44 return "D1";
45 case ACPI_STATE_D2:
46 return "D2";
47 case ACPI_STATE_D3_HOT:
48 return "D3hot";
49 case ACPI_STATE_D3_COLD:
50 return "D3cold";
51 default:
52 return "(unknown)";
53 }
54}
55
56/**
57 * acpi_device_get_power - Get power state of an ACPI device.
58 * @device: Device to get the power state of.
59 * @state: Place to store the power state of the device.
60 *
61 * This function does not update the device's power.state field, but it may
62 * update its parent's power.state field (when the parent's power state is
63 * unknown and the device's power state turns out to be D0).
64 */
65int acpi_device_get_power(struct acpi_device *device, int *state)
66{
67 int result = ACPI_STATE_UNKNOWN;
68
69 if (!device || !state)
70 return -EINVAL;
71
72 if (!device->flags.power_manageable) {
73 /* TBD: Non-recursive algorithm for walking up hierarchy. */
74 *state = device->parent ?
75 device->parent->power.state : ACPI_STATE_D0;
76 goto out;
77 }
78
79 /*
80 * Get the device's power state from power resources settings and _PSC,
81 * if available.
82 */
83 if (device->power.flags.power_resources) {
84 int error = acpi_power_get_inferred_state(device, &result);
85 if (error)
86 return error;
87 }
88 if (device->power.flags.explicit_get) {
89 acpi_handle handle = device->handle;
90 unsigned long long psc;
91 acpi_status status;
92
93 status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
94 if (ACPI_FAILURE(status))
95 return -ENODEV;
96
97 /*
98 * The power resources settings may indicate a power state
99 * shallower than the actual power state of the device, because
100 * the same power resources may be referenced by other devices.
101 *
102 * For systems predating ACPI 4.0 we assume that D3hot is the
103 * deepest state that can be supported.
104 */
105 if (psc > result && psc < ACPI_STATE_D3_COLD)
106 result = psc;
107 else if (result == ACPI_STATE_UNKNOWN)
108 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
109 }
110
111 /*
112 * If we were unsure about the device parent's power state up to this
113 * point, the fact that the device is in D0 implies that the parent has
114 * to be in D0 too, except if ignore_parent is set.
115 */
116 if (!device->power.flags.ignore_parent && device->parent
117 && device->parent->power.state == ACPI_STATE_UNKNOWN
118 && result == ACPI_STATE_D0)
119 device->parent->power.state = ACPI_STATE_D0;
120
121 *state = result;
122
123 out:
124 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
125 device->pnp.bus_id, acpi_power_state_string(*state)));
126
127 return 0;
128}
129
130static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
131{
132 if (adev->power.states[state].flags.explicit_set) {
133 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
134 acpi_status status;
135
136 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
137 if (ACPI_FAILURE(status))
138 return -ENODEV;
139 }
140 return 0;
141}
142
143/**
144 * acpi_device_set_power - Set power state of an ACPI device.
145 * @device: Device to set the power state of.
146 * @state: New power state to set.
147 *
148 * Callers must ensure that the device is power manageable before using this
149 * function.
150 */
151int acpi_device_set_power(struct acpi_device *device, int state)
152{
153 int target_state = state;
154 int result = 0;
155
156 if (!device || !device->flags.power_manageable
157 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
158 return -EINVAL;
159
160 /* Make sure this is a valid target state */
161
162 if (state == device->power.state) {
163 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
164 device->pnp.bus_id,
165 acpi_power_state_string(state)));
166 return 0;
167 }
168
169 if (state == ACPI_STATE_D3_COLD) {
170 /*
171 * For transitions to D3cold we need to execute _PS3 and then
172 * possibly drop references to the power resources in use.
173 */
174 state = ACPI_STATE_D3_HOT;
175 /* If _PR3 is not available, use D3hot as the target state. */
176 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
177 target_state = state;
178 } else if (!device->power.states[state].flags.valid) {
179 dev_warn(&device->dev, "Power state %s not supported\n",
180 acpi_power_state_string(state));
181 return -ENODEV;
182 }
183
184 if (!device->power.flags.ignore_parent &&
185 device->parent && (state < device->parent->power.state)) {
186 dev_warn(&device->dev,
187 "Cannot transition to power state %s for parent in %s\n",
188 acpi_power_state_string(state),
189 acpi_power_state_string(device->parent->power.state));
190 return -ENODEV;
191 }
192
193 /*
194 * Transition Power
195 * ----------------
196 * In accordance with ACPI 6, _PSx is executed before manipulating power
197 * resources, unless the target state is D0, in which case _PS0 is
198 * supposed to be executed after turning the power resources on.
199 */
200 if (state > ACPI_STATE_D0) {
201 /*
202 * According to ACPI 6, devices cannot go from lower-power
203 * (deeper) states to higher-power (shallower) states.
204 */
205 if (state < device->power.state) {
206 dev_warn(&device->dev, "Cannot transition from %s to %s\n",
207 acpi_power_state_string(device->power.state),
208 acpi_power_state_string(state));
209 return -ENODEV;
210 }
211
212 result = acpi_dev_pm_explicit_set(device, state);
213 if (result)
214 goto end;
215
216 if (device->power.flags.power_resources)
217 result = acpi_power_transition(device, target_state);
218 } else {
219 if (device->power.flags.power_resources) {
220 result = acpi_power_transition(device, ACPI_STATE_D0);
221 if (result)
222 goto end;
223 }
224 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
225 }
226
227 end:
228 if (result) {
229 dev_warn(&device->dev, "Failed to change power state to %s\n",
230 acpi_power_state_string(state));
231 } else {
232 device->power.state = target_state;
233 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
234 "Device [%s] transitioned to %s\n",
235 device->pnp.bus_id,
236 acpi_power_state_string(state)));
237 }
238
239 return result;
240}
241EXPORT_SYMBOL(acpi_device_set_power);
242
243int acpi_bus_set_power(acpi_handle handle, int state)
244{
245 struct acpi_device *device;
246 int result;
247
248 result = acpi_bus_get_device(handle, &device);
249 if (result)
250 return result;
251
252 return acpi_device_set_power(device, state);
253}
254EXPORT_SYMBOL(acpi_bus_set_power);
255
256int acpi_bus_init_power(struct acpi_device *device)
257{
258 int state;
259 int result;
260
261 if (!device)
262 return -EINVAL;
263
264 device->power.state = ACPI_STATE_UNKNOWN;
265 if (!acpi_device_is_present(device)) {
266 device->flags.initialized = false;
267 return -ENXIO;
268 }
269
270 result = acpi_device_get_power(device, &state);
271 if (result)
272 return result;
273
274 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
275 /* Reference count the power resources. */
276 result = acpi_power_on_resources(device, state);
277 if (result)
278 return result;
279
280 if (state == ACPI_STATE_D0) {
281 /*
282 * If _PSC is not present and the state inferred from
283 * power resources appears to be D0, it still may be
284 * necessary to execute _PS0 at this point, because
285 * another device using the same power resources may
286 * have been put into D0 previously and that's why we
287 * see D0 here.
288 */
289 result = acpi_dev_pm_explicit_set(device, state);
290 if (result)
291 return result;
292 }
293 } else if (state == ACPI_STATE_UNKNOWN) {
294 /*
295 * No power resources and missing _PSC? Cross fingers and make
296 * it D0 in hope that this is what the BIOS put the device into.
297 * [We tried to force D0 here by executing _PS0, but that broke
298 * Toshiba P870-303 in a nasty way.]
299 */
300 state = ACPI_STATE_D0;
301 }
302 device->power.state = state;
303 return 0;
304}
305
306/**
307 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
308 * @device: Device object whose power state is to be fixed up.
309 *
310 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
311 * are assumed to be put into D0 by the BIOS. However, in some cases that may
312 * not be the case and this function should be used then.
313 */
314int acpi_device_fix_up_power(struct acpi_device *device)
315{
316 int ret = 0;
317
318 if (!device->power.flags.power_resources
319 && !device->power.flags.explicit_get
320 && device->power.state == ACPI_STATE_D0)
321 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
322
323 return ret;
324}
325EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
326
327int acpi_device_update_power(struct acpi_device *device, int *state_p)
328{
329 int state;
330 int result;
331
332 if (device->power.state == ACPI_STATE_UNKNOWN) {
333 result = acpi_bus_init_power(device);
334 if (!result && state_p)
335 *state_p = device->power.state;
336
337 return result;
338 }
339
340 result = acpi_device_get_power(device, &state);
341 if (result)
342 return result;
343
344 if (state == ACPI_STATE_UNKNOWN) {
345 state = ACPI_STATE_D0;
346 result = acpi_device_set_power(device, state);
347 if (result)
348 return result;
349 } else {
350 if (device->power.flags.power_resources) {
351 /*
352 * We don't need to really switch the state, bu we need
353 * to update the power resources' reference counters.
354 */
355 result = acpi_power_transition(device, state);
356 if (result)
357 return result;
358 }
359 device->power.state = state;
360 }
361 if (state_p)
362 *state_p = state;
363
364 return 0;
365}
366EXPORT_SYMBOL_GPL(acpi_device_update_power);
367
368int acpi_bus_update_power(acpi_handle handle, int *state_p)
369{
370 struct acpi_device *device;
371 int result;
372
373 result = acpi_bus_get_device(handle, &device);
374 return result ? result : acpi_device_update_power(device, state_p);
375}
376EXPORT_SYMBOL_GPL(acpi_bus_update_power);
377
378bool acpi_bus_power_manageable(acpi_handle handle)
379{
380 struct acpi_device *device;
381 int result;
382
383 result = acpi_bus_get_device(handle, &device);
384 return result ? false : device->flags.power_manageable;
385}
386EXPORT_SYMBOL(acpi_bus_power_manageable);
387
388#ifdef CONFIG_PM
389static DEFINE_MUTEX(acpi_pm_notifier_lock);
390static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
391
392void acpi_pm_wakeup_event(struct device *dev)
393{
394 pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
395}
396EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
397
398static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
399{
400 struct acpi_device *adev;
401
402 if (val != ACPI_NOTIFY_DEVICE_WAKE)
403 return;
404
405 acpi_handle_debug(handle, "Wake notify\n");
406
407 adev = acpi_bus_get_acpi_device(handle);
408 if (!adev)
409 return;
410
411 mutex_lock(&acpi_pm_notifier_lock);
412
413 if (adev->wakeup.flags.notifier_present) {
414 pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
415 if (adev->wakeup.context.func) {
416 acpi_handle_debug(handle, "Running %pF for %s\n",
417 adev->wakeup.context.func,
418 dev_name(adev->wakeup.context.dev));
419 adev->wakeup.context.func(&adev->wakeup.context);
420 }
421 }
422
423 mutex_unlock(&acpi_pm_notifier_lock);
424
425 acpi_bus_put_acpi_device(adev);
426}
427
428/**
429 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
430 * @adev: ACPI device to add the notify handler for.
431 * @dev: Device to generate a wakeup event for while handling the notification.
432 * @func: Work function to execute when handling the notification.
433 *
434 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
435 * PM wakeup events. For example, wakeup events may be generated for bridges
436 * if one of the devices below the bridge is signaling wakeup, even if the
437 * bridge itself doesn't have a wakeup GPE associated with it.
438 */
439acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
440 void (*func)(struct acpi_device_wakeup_context *context))
441{
442 acpi_status status = AE_ALREADY_EXISTS;
443
444 if (!dev && !func)
445 return AE_BAD_PARAMETER;
446
447 mutex_lock(&acpi_pm_notifier_install_lock);
448
449 if (adev->wakeup.flags.notifier_present)
450 goto out;
451
452 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
453 acpi_pm_notify_handler, NULL);
454 if (ACPI_FAILURE(status))
455 goto out;
456
457 mutex_lock(&acpi_pm_notifier_lock);
458 adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev));
459 adev->wakeup.context.dev = dev;
460 adev->wakeup.context.func = func;
461 adev->wakeup.flags.notifier_present = true;
462 mutex_unlock(&acpi_pm_notifier_lock);
463
464 out:
465 mutex_unlock(&acpi_pm_notifier_install_lock);
466 return status;
467}
468
469/**
470 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
471 * @adev: ACPI device to remove the notifier from.
472 */
473acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
474{
475 acpi_status status = AE_BAD_PARAMETER;
476
477 mutex_lock(&acpi_pm_notifier_install_lock);
478
479 if (!adev->wakeup.flags.notifier_present)
480 goto out;
481
482 status = acpi_remove_notify_handler(adev->handle,
483 ACPI_SYSTEM_NOTIFY,
484 acpi_pm_notify_handler);
485 if (ACPI_FAILURE(status))
486 goto out;
487
488 mutex_lock(&acpi_pm_notifier_lock);
489 adev->wakeup.context.func = NULL;
490 adev->wakeup.context.dev = NULL;
491 wakeup_source_unregister(adev->wakeup.ws);
492 adev->wakeup.flags.notifier_present = false;
493 mutex_unlock(&acpi_pm_notifier_lock);
494
495 out:
496 mutex_unlock(&acpi_pm_notifier_install_lock);
497 return status;
498}
499
500bool acpi_bus_can_wakeup(acpi_handle handle)
501{
502 struct acpi_device *device;
503 int result;
504
505 result = acpi_bus_get_device(handle, &device);
506 return result ? false : device->wakeup.flags.valid;
507}
508EXPORT_SYMBOL(acpi_bus_can_wakeup);
509
510bool acpi_pm_device_can_wakeup(struct device *dev)
511{
512 struct acpi_device *adev = ACPI_COMPANION(dev);
513
514 return adev ? acpi_device_can_wakeup(adev) : false;
515}
516
517/**
518 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
519 * @dev: Device whose preferred target power state to return.
520 * @adev: ACPI device node corresponding to @dev.
521 * @target_state: System state to match the resultant device state.
522 * @d_min_p: Location to store the highest power state available to the device.
523 * @d_max_p: Location to store the lowest power state available to the device.
524 *
525 * Find the lowest power (highest number) and highest power (lowest number) ACPI
526 * device power states that the device can be in while the system is in the
527 * state represented by @target_state. Store the integer numbers representing
528 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
529 * respectively.
530 *
531 * Callers must ensure that @dev and @adev are valid pointers and that @adev
532 * actually corresponds to @dev before using this function.
533 *
534 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
535 * returns a value that doesn't make sense. The memory locations pointed to by
536 * @d_max_p and @d_min_p are only modified on success.
537 */
538static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
539 u32 target_state, int *d_min_p, int *d_max_p)
540{
541 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
542 acpi_handle handle = adev->handle;
543 unsigned long long ret;
544 int d_min, d_max;
545 bool wakeup = false;
546 bool has_sxd = false;
547 acpi_status status;
548
549 /*
550 * If the system state is S0, the lowest power state the device can be
551 * in is D3cold, unless the device has _S0W and is supposed to signal
552 * wakeup, in which case the return value of _S0W has to be used as the
553 * lowest power state available to the device.
554 */
555 d_min = ACPI_STATE_D0;
556 d_max = ACPI_STATE_D3_COLD;
557
558 /*
559 * If present, _SxD methods return the minimum D-state (highest power
560 * state) we can use for the corresponding S-states. Otherwise, the
561 * minimum D-state is D0 (ACPI 3.x).
562 */
563 if (target_state > ACPI_STATE_S0) {
564 /*
565 * We rely on acpi_evaluate_integer() not clobbering the integer
566 * provided if AE_NOT_FOUND is returned.
567 */
568 ret = d_min;
569 status = acpi_evaluate_integer(handle, method, NULL, &ret);
570 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
571 || ret > ACPI_STATE_D3_COLD)
572 return -ENODATA;
573
574 /*
575 * We need to handle legacy systems where D3hot and D3cold are
576 * the same and 3 is returned in both cases, so fall back to
577 * D3cold if D3hot is not a valid state.
578 */
579 if (!adev->power.states[ret].flags.valid) {
580 if (ret == ACPI_STATE_D3_HOT)
581 ret = ACPI_STATE_D3_COLD;
582 else
583 return -ENODATA;
584 }
585
586 if (status == AE_OK)
587 has_sxd = true;
588
589 d_min = ret;
590 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
591 && adev->wakeup.sleep_state >= target_state;
592 } else {
593 wakeup = adev->wakeup.flags.valid;
594 }
595
596 /*
597 * If _PRW says we can wake up the system from the target sleep state,
598 * the D-state returned by _SxD is sufficient for that (we assume a
599 * wakeup-aware driver if wake is set). Still, if _SxW exists
600 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
601 * can wake the system. _S0W may be valid, too.
602 */
603 if (wakeup) {
604 method[3] = 'W';
605 status = acpi_evaluate_integer(handle, method, NULL, &ret);
606 if (status == AE_NOT_FOUND) {
607 /* No _SxW. In this case, the ACPI spec says that we
608 * must not go into any power state deeper than the
609 * value returned from _SxD.
610 */
611 if (has_sxd && target_state > ACPI_STATE_S0)
612 d_max = d_min;
613 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
614 /* Fall back to D3cold if ret is not a valid state. */
615 if (!adev->power.states[ret].flags.valid)
616 ret = ACPI_STATE_D3_COLD;
617
618 d_max = ret > d_min ? ret : d_min;
619 } else {
620 return -ENODATA;
621 }
622 }
623
624 if (d_min_p)
625 *d_min_p = d_min;
626
627 if (d_max_p)
628 *d_max_p = d_max;
629
630 return 0;
631}
632
633/**
634 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
635 * @dev: Device whose preferred target power state to return.
636 * @d_min_p: Location to store the upper limit of the allowed states range.
637 * @d_max_in: Deepest low-power state to take into consideration.
638 * Return value: Preferred power state of the device on success, -ENODEV
639 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
640 * incorrect, or -ENODATA on ACPI method failure.
641 *
642 * The caller must ensure that @dev is valid before using this function.
643 */
644int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
645{
646 struct acpi_device *adev;
647 int ret, d_min, d_max;
648
649 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
650 return -EINVAL;
651
652 if (d_max_in > ACPI_STATE_D2) {
653 enum pm_qos_flags_status stat;
654
655 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
656 if (stat == PM_QOS_FLAGS_ALL)
657 d_max_in = ACPI_STATE_D2;
658 }
659
660 adev = ACPI_COMPANION(dev);
661 if (!adev) {
662 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
663 return -ENODEV;
664 }
665
666 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
667 &d_min, &d_max);
668 if (ret)
669 return ret;
670
671 if (d_max_in < d_min)
672 return -EINVAL;
673
674 if (d_max > d_max_in) {
675 for (d_max = d_max_in; d_max > d_min; d_max--) {
676 if (adev->power.states[d_max].flags.valid)
677 break;
678 }
679 }
680
681 if (d_min_p)
682 *d_min_p = d_min;
683
684 return d_max;
685}
686EXPORT_SYMBOL(acpi_pm_device_sleep_state);
687
688/**
689 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
690 * @context: Device wakeup context.
691 */
692static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
693{
694 struct device *dev = context->dev;
695
696 if (dev) {
697 pm_wakeup_event(dev, 0);
698 pm_request_resume(dev);
699 }
700}
701
702static DEFINE_MUTEX(acpi_wakeup_lock);
703
704static int __acpi_device_wakeup_enable(struct acpi_device *adev,
705 u32 target_state, int max_count)
706{
707 struct acpi_device_wakeup *wakeup = &adev->wakeup;
708 acpi_status status;
709 int error = 0;
710
711 mutex_lock(&acpi_wakeup_lock);
712
713 if (wakeup->enable_count >= max_count)
714 goto out;
715
716 if (wakeup->enable_count > 0)
717 goto inc;
718
719 error = acpi_enable_wakeup_device_power(adev, target_state);
720 if (error)
721 goto out;
722
723 status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
724 if (ACPI_FAILURE(status)) {
725 acpi_disable_wakeup_device_power(adev);
726 error = -EIO;
727 goto out;
728 }
729
730inc:
731 wakeup->enable_count++;
732
733out:
734 mutex_unlock(&acpi_wakeup_lock);
735 return error;
736}
737
738/**
739 * acpi_device_wakeup_enable - Enable wakeup functionality for device.
740 * @adev: ACPI device to enable wakeup functionality for.
741 * @target_state: State the system is transitioning into.
742 *
743 * Enable the GPE associated with @adev so that it can generate wakeup signals
744 * for the device in response to external (remote) events and enable wakeup
745 * power for it.
746 *
747 * Callers must ensure that @adev is a valid ACPI device node before executing
748 * this function.
749 */
750static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
751{
752 return __acpi_device_wakeup_enable(adev, target_state, 1);
753}
754
755/**
756 * acpi_device_wakeup_disable - Disable wakeup functionality for device.
757 * @adev: ACPI device to disable wakeup functionality for.
758 *
759 * Disable the GPE associated with @adev and disable wakeup power for it.
760 *
761 * Callers must ensure that @adev is a valid ACPI device node before executing
762 * this function.
763 */
764static void acpi_device_wakeup_disable(struct acpi_device *adev)
765{
766 struct acpi_device_wakeup *wakeup = &adev->wakeup;
767
768 mutex_lock(&acpi_wakeup_lock);
769
770 if (!wakeup->enable_count)
771 goto out;
772
773 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
774 acpi_disable_wakeup_device_power(adev);
775
776 wakeup->enable_count--;
777
778out:
779 mutex_unlock(&acpi_wakeup_lock);
780}
781
782static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable,
783 int max_count)
784{
785 struct acpi_device *adev;
786 int error;
787
788 adev = ACPI_COMPANION(dev);
789 if (!adev) {
790 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
791 return -ENODEV;
792 }
793
794 if (!acpi_device_can_wakeup(adev))
795 return -EINVAL;
796
797 if (!enable) {
798 acpi_device_wakeup_disable(adev);
799 dev_dbg(dev, "Wakeup disabled by ACPI\n");
800 return 0;
801 }
802
803 error = __acpi_device_wakeup_enable(adev, acpi_target_system_state(),
804 max_count);
805 if (!error)
806 dev_dbg(dev, "Wakeup enabled by ACPI\n");
807
808 return error;
809}
810
811/**
812 * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
813 * @dev: Device to enable/disable to generate wakeup events.
814 * @enable: Whether to enable or disable the wakeup functionality.
815 */
816int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
817{
818 return __acpi_pm_set_device_wakeup(dev, enable, 1);
819}
820EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
821
822/**
823 * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge.
824 * @dev: Bridge device to enable/disable to generate wakeup events.
825 * @enable: Whether to enable or disable the wakeup functionality.
826 */
827int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable)
828{
829 return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX);
830}
831EXPORT_SYMBOL_GPL(acpi_pm_set_bridge_wakeup);
832
833/**
834 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
835 * @dev: Device to put into a low-power state.
836 * @adev: ACPI device node corresponding to @dev.
837 * @system_state: System state to choose the device state for.
838 */
839static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
840 u32 system_state)
841{
842 int ret, state;
843
844 if (!acpi_device_power_manageable(adev))
845 return 0;
846
847 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
848 return ret ? ret : acpi_device_set_power(adev, state);
849}
850
851/**
852 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
853 * @adev: ACPI device node to put into the full-power state.
854 */
855static int acpi_dev_pm_full_power(struct acpi_device *adev)
856{
857 return acpi_device_power_manageable(adev) ?
858 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
859}
860
861/**
862 * acpi_dev_suspend - Put device into a low-power state using ACPI.
863 * @dev: Device to put into a low-power state.
864 * @wakeup: Whether or not to enable wakeup for the device.
865 *
866 * Put the given device into a low-power state using the standard ACPI
867 * mechanism. Set up remote wakeup if desired, choose the state to put the
868 * device into (this checks if remote wakeup is expected to work too), and set
869 * the power state of the device.
870 */
871int acpi_dev_suspend(struct device *dev, bool wakeup)
872{
873 struct acpi_device *adev = ACPI_COMPANION(dev);
874 u32 target_state = acpi_target_system_state();
875 int error;
876
877 if (!adev)
878 return 0;
879
880 if (wakeup && acpi_device_can_wakeup(adev)) {
881 error = acpi_device_wakeup_enable(adev, target_state);
882 if (error)
883 return -EAGAIN;
884 } else {
885 wakeup = false;
886 }
887
888 error = acpi_dev_pm_low_power(dev, adev, target_state);
889 if (error && wakeup)
890 acpi_device_wakeup_disable(adev);
891
892 return error;
893}
894EXPORT_SYMBOL_GPL(acpi_dev_suspend);
895
896/**
897 * acpi_dev_resume - Put device into the full-power state using ACPI.
898 * @dev: Device to put into the full-power state.
899 *
900 * Put the given device into the full-power state using the standard ACPI
901 * mechanism. Set the power state of the device to ACPI D0 and disable wakeup.
902 */
903int acpi_dev_resume(struct device *dev)
904{
905 struct acpi_device *adev = ACPI_COMPANION(dev);
906 int error;
907
908 if (!adev)
909 return 0;
910
911 error = acpi_dev_pm_full_power(adev);
912 acpi_device_wakeup_disable(adev);
913 return error;
914}
915EXPORT_SYMBOL_GPL(acpi_dev_resume);
916
917/**
918 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
919 * @dev: Device to suspend.
920 *
921 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
922 * it into a runtime low-power state.
923 */
924int acpi_subsys_runtime_suspend(struct device *dev)
925{
926 int ret = pm_generic_runtime_suspend(dev);
927 return ret ? ret : acpi_dev_suspend(dev, true);
928}
929EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
930
931/**
932 * acpi_subsys_runtime_resume - Resume device using ACPI.
933 * @dev: Device to Resume.
934 *
935 * Use ACPI to put the given device into the full-power state and carry out the
936 * generic runtime resume procedure for it.
937 */
938int acpi_subsys_runtime_resume(struct device *dev)
939{
940 int ret = acpi_dev_resume(dev);
941 return ret ? ret : pm_generic_runtime_resume(dev);
942}
943EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
944
945#ifdef CONFIG_PM_SLEEP
946static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
947{
948 u32 sys_target = acpi_target_system_state();
949 int ret, state;
950
951 if (!pm_runtime_suspended(dev) || !adev ||
952 device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
953 return true;
954
955 if (sys_target == ACPI_STATE_S0)
956 return false;
957
958 if (adev->power.flags.dsw_present)
959 return true;
960
961 ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
962 if (ret)
963 return true;
964
965 return state != adev->power.state;
966}
967
968/**
969 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
970 * @dev: Device to prepare.
971 */
972int acpi_subsys_prepare(struct device *dev)
973{
974 struct acpi_device *adev = ACPI_COMPANION(dev);
975
976 if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
977 int ret = dev->driver->pm->prepare(dev);
978
979 if (ret < 0)
980 return ret;
981
982 if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
983 return 0;
984 }
985
986 return !acpi_dev_needs_resume(dev, adev);
987}
988EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
989
990/**
991 * acpi_subsys_complete - Finalize device's resume during system resume.
992 * @dev: Device to handle.
993 */
994void acpi_subsys_complete(struct device *dev)
995{
996 pm_generic_complete(dev);
997 /*
998 * If the device had been runtime-suspended before the system went into
999 * the sleep state it is going out of and it has never been resumed till
1000 * now, resume it in case the firmware powered it up.
1001 */
1002 if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1003 pm_request_resume(dev);
1004}
1005EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1006
1007/**
1008 * acpi_subsys_suspend - Run the device driver's suspend callback.
1009 * @dev: Device to handle.
1010 *
1011 * Follow PCI and resume devices from runtime suspend before running their
1012 * system suspend callbacks, unless the driver can cope with runtime-suspended
1013 * devices during system suspend and there are no ACPI-specific reasons for
1014 * resuming them.
1015 */
1016int acpi_subsys_suspend(struct device *dev)
1017{
1018 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1019 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1020 pm_runtime_resume(dev);
1021
1022 return pm_generic_suspend(dev);
1023}
1024EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1025
1026/**
1027 * acpi_subsys_suspend_late - Suspend device using ACPI.
1028 * @dev: Device to suspend.
1029 *
1030 * Carry out the generic late suspend procedure for @dev and use ACPI to put
1031 * it into a low-power state during system transition into a sleep state.
1032 */
1033int acpi_subsys_suspend_late(struct device *dev)
1034{
1035 int ret;
1036
1037 if (dev_pm_smart_suspend_and_suspended(dev))
1038 return 0;
1039
1040 ret = pm_generic_suspend_late(dev);
1041 return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1042}
1043EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1044
1045/**
1046 * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1047 * @dev: Device to suspend.
1048 */
1049int acpi_subsys_suspend_noirq(struct device *dev)
1050{
1051 int ret;
1052
1053 if (dev_pm_smart_suspend_and_suspended(dev)) {
1054 dev->power.may_skip_resume = true;
1055 return 0;
1056 }
1057
1058 ret = pm_generic_suspend_noirq(dev);
1059 if (ret)
1060 return ret;
1061
1062 /*
1063 * If the target system sleep state is suspend-to-idle, it is sufficient
1064 * to check whether or not the device's wakeup settings are good for
1065 * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause
1066 * acpi_subsys_complete() to take care of fixing up the device's state
1067 * anyway, if need be.
1068 */
1069 dev->power.may_skip_resume = device_may_wakeup(dev) ||
1070 !device_can_wakeup(dev);
1071
1072 return 0;
1073}
1074EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1075
1076/**
1077 * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1078 * @dev: Device to handle.
1079 */
1080int acpi_subsys_resume_noirq(struct device *dev)
1081{
1082 if (dev_pm_may_skip_resume(dev))
1083 return 0;
1084
1085 /*
1086 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
1087 * during system suspend, so update their runtime PM status to "active"
1088 * as they will be put into D0 going forward.
1089 */
1090 if (dev_pm_smart_suspend_and_suspended(dev))
1091 pm_runtime_set_active(dev);
1092
1093 return pm_generic_resume_noirq(dev);
1094}
1095EXPORT_SYMBOL_GPL(acpi_subsys_resume_noirq);
1096
1097/**
1098 * acpi_subsys_resume_early - Resume device using ACPI.
1099 * @dev: Device to Resume.
1100 *
1101 * Use ACPI to put the given device into the full-power state and carry out the
1102 * generic early resume procedure for it during system transition into the
1103 * working state.
1104 */
1105int acpi_subsys_resume_early(struct device *dev)
1106{
1107 int ret = acpi_dev_resume(dev);
1108 return ret ? ret : pm_generic_resume_early(dev);
1109}
1110EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
1111
1112/**
1113 * acpi_subsys_freeze - Run the device driver's freeze callback.
1114 * @dev: Device to handle.
1115 */
1116int acpi_subsys_freeze(struct device *dev)
1117{
1118 /*
1119 * This used to be done in acpi_subsys_prepare() for all devices and
1120 * some drivers may depend on it, so do it here. Ideally, however,
1121 * runtime-suspended devices should not be touched during freeze/thaw
1122 * transitions.
1123 */
1124 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
1125 pm_runtime_resume(dev);
1126
1127 return pm_generic_freeze(dev);
1128}
1129EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1130
1131/**
1132 * acpi_subsys_freeze_late - Run the device driver's "late" freeze callback.
1133 * @dev: Device to handle.
1134 */
1135int acpi_subsys_freeze_late(struct device *dev)
1136{
1137
1138 if (dev_pm_smart_suspend_and_suspended(dev))
1139 return 0;
1140
1141 return pm_generic_freeze_late(dev);
1142}
1143EXPORT_SYMBOL_GPL(acpi_subsys_freeze_late);
1144
1145/**
1146 * acpi_subsys_freeze_noirq - Run the device driver's "noirq" freeze callback.
1147 * @dev: Device to handle.
1148 */
1149int acpi_subsys_freeze_noirq(struct device *dev)
1150{
1151
1152 if (dev_pm_smart_suspend_and_suspended(dev))
1153 return 0;
1154
1155 return pm_generic_freeze_noirq(dev);
1156}
1157EXPORT_SYMBOL_GPL(acpi_subsys_freeze_noirq);
1158
1159/**
1160 * acpi_subsys_thaw_noirq - Run the device driver's "noirq" thaw callback.
1161 * @dev: Device to handle.
1162 */
1163int acpi_subsys_thaw_noirq(struct device *dev)
1164{
1165 /*
1166 * If the device is in runtime suspend, the "thaw" code may not work
1167 * correctly with it, so skip the driver callback and make the PM core
1168 * skip all of the subsequent "thaw" callbacks for the device.
1169 */
1170 if (dev_pm_smart_suspend_and_suspended(dev)) {
1171 dev_pm_skip_next_resume_phases(dev);
1172 return 0;
1173 }
1174
1175 return pm_generic_thaw_noirq(dev);
1176}
1177EXPORT_SYMBOL_GPL(acpi_subsys_thaw_noirq);
1178#endif /* CONFIG_PM_SLEEP */
1179
1180static struct dev_pm_domain acpi_general_pm_domain = {
1181 .ops = {
1182 .runtime_suspend = acpi_subsys_runtime_suspend,
1183 .runtime_resume = acpi_subsys_runtime_resume,
1184#ifdef CONFIG_PM_SLEEP
1185 .prepare = acpi_subsys_prepare,
1186 .complete = acpi_subsys_complete,
1187 .suspend = acpi_subsys_suspend,
1188 .suspend_late = acpi_subsys_suspend_late,
1189 .suspend_noirq = acpi_subsys_suspend_noirq,
1190 .resume_noirq = acpi_subsys_resume_noirq,
1191 .resume_early = acpi_subsys_resume_early,
1192 .freeze = acpi_subsys_freeze,
1193 .freeze_late = acpi_subsys_freeze_late,
1194 .freeze_noirq = acpi_subsys_freeze_noirq,
1195 .thaw_noirq = acpi_subsys_thaw_noirq,
1196 .poweroff = acpi_subsys_suspend,
1197 .poweroff_late = acpi_subsys_suspend_late,
1198 .poweroff_noirq = acpi_subsys_suspend_noirq,
1199 .restore_noirq = acpi_subsys_resume_noirq,
1200 .restore_early = acpi_subsys_resume_early,
1201#endif
1202 },
1203};
1204
1205/**
1206 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1207 * @dev: Device to take care of.
1208 * @power_off: Whether or not to try to remove power from the device.
1209 *
1210 * Remove the device from the general ACPI PM domain and remove its wakeup
1211 * notifier. If @power_off is set, additionally remove power from the device if
1212 * possible.
1213 *
1214 * Callers must ensure proper synchronization of this function with power
1215 * management callbacks.
1216 */
1217static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1218{
1219 struct acpi_device *adev = ACPI_COMPANION(dev);
1220
1221 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1222 dev_pm_domain_set(dev, NULL);
1223 acpi_remove_pm_notifier(adev);
1224 if (power_off) {
1225 /*
1226 * If the device's PM QoS resume latency limit or flags
1227 * have been exposed to user space, they have to be
1228 * hidden at this point, so that they don't affect the
1229 * choice of the low-power state to put the device into.
1230 */
1231 dev_pm_qos_hide_latency_limit(dev);
1232 dev_pm_qos_hide_flags(dev);
1233 acpi_device_wakeup_disable(adev);
1234 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1235 }
1236 }
1237}
1238
1239/**
1240 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1241 * @dev: Device to prepare.
1242 * @power_on: Whether or not to power on the device.
1243 *
1244 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1245 * attached to it, install a wakeup notification handler for the device and
1246 * add it to the general ACPI PM domain. If @power_on is set, the device will
1247 * be put into the ACPI D0 state before the function returns.
1248 *
1249 * This assumes that the @dev's bus type uses generic power management callbacks
1250 * (or doesn't use any power management callbacks at all).
1251 *
1252 * Callers must ensure proper synchronization of this function with power
1253 * management callbacks.
1254 */
1255int acpi_dev_pm_attach(struct device *dev, bool power_on)
1256{
1257 struct acpi_device *adev = ACPI_COMPANION(dev);
1258
1259 if (!adev)
1260 return -ENODEV;
1261
1262 if (dev->pm_domain)
1263 return -EEXIST;
1264
1265 /*
1266 * Only attach the power domain to the first device if the
1267 * companion is shared by multiple. This is to prevent doing power
1268 * management twice.
1269 */
1270 if (!acpi_device_is_first_physical_node(adev, dev))
1271 return -EBUSY;
1272
1273 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1274 dev_pm_domain_set(dev, &acpi_general_pm_domain);
1275 if (power_on) {
1276 acpi_dev_pm_full_power(adev);
1277 acpi_device_wakeup_disable(adev);
1278 }
1279
1280 dev->pm_domain->detach = acpi_dev_pm_detach;
1281 return 0;
1282}
1283EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1284#endif /* CONFIG_PM */