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