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 	struct acpi_device *parent;
79 	int error;
80 
81 	if (!device || !state)
82 		return -EINVAL;
83 
84 	parent = acpi_dev_parent(device);
85 
86 	if (!device->flags.power_manageable) {
87 		/* TBD: Non-recursive algorithm for walking up hierarchy. */
88 		*state = parent ? parent->power.state : ACPI_STATE_D0;
89 		goto out;
90 	}
91 
92 	/*
93 	 * Get the device's power state from power resources settings and _PSC,
94 	 * if available.
95 	 */
96 	if (device->power.flags.power_resources) {
97 		error = acpi_power_get_inferred_state(device, &result);
98 		if (error)
99 			return error;
100 	}
101 	if (device->power.flags.explicit_get) {
102 		int psc;
103 
104 		error = acpi_dev_pm_explicit_get(device, &psc);
105 		if (error)
106 			return error;
107 
108 		/*
109 		 * The power resources settings may indicate a power state
110 		 * shallower than the actual power state of the device, because
111 		 * the same power resources may be referenced by other devices.
112 		 *
113 		 * For systems predating ACPI 4.0 we assume that D3hot is the
114 		 * deepest state that can be supported.
115 		 */
116 		if (psc > result && psc < ACPI_STATE_D3_COLD)
117 			result = psc;
118 		else if (result == ACPI_STATE_UNKNOWN)
119 			result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
120 	}
121 
122 	/*
123 	 * If we were unsure about the device parent's power state up to this
124 	 * point, the fact that the device is in D0 implies that the parent has
125 	 * to be in D0 too, except if ignore_parent is set.
126 	 */
127 	if (!device->power.flags.ignore_parent && parent &&
128 	    parent->power.state == ACPI_STATE_UNKNOWN &&
129 	    result == ACPI_STATE_D0)
130 		parent->power.state = ACPI_STATE_D0;
131 
132 	*state = result;
133 
134  out:
135 	acpi_handle_debug(device->handle, "Power state: %s\n",
136 			  acpi_power_state_string(*state));
137 
138 	return 0;
139 }
140 
acpi_dev_pm_explicit_set(struct acpi_device * adev,int state)141 static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
142 {
143 	if (adev->power.states[state].flags.explicit_set) {
144 		char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
145 		acpi_status status;
146 
147 		status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
148 		if (ACPI_FAILURE(status))
149 			return -ENODEV;
150 	}
151 	return 0;
152 }
153 
154 /**
155  * acpi_device_set_power - Set power state of an ACPI device.
156  * @device: Device to set the power state of.
157  * @state: New power state to set.
158  *
159  * Callers must ensure that the device is power manageable before using this
160  * function.
161  */
acpi_device_set_power(struct acpi_device * device,int state)162 int acpi_device_set_power(struct acpi_device *device, int state)
163 {
164 	int target_state = state;
165 	int result = 0;
166 
167 	if (!device || !device->flags.power_manageable
168 	    || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
169 		return -EINVAL;
170 
171 	acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",
172 			  acpi_power_state_string(device->power.state),
173 			  acpi_power_state_string(state));
174 
175 	/* Make sure this is a valid target state */
176 
177 	/* There is a special case for D0 addressed below. */
178 	if (state > ACPI_STATE_D0 && state == device->power.state)
179 		goto no_change;
180 
181 	if (state == ACPI_STATE_D3_COLD) {
182 		/*
183 		 * For transitions to D3cold we need to execute _PS3 and then
184 		 * possibly drop references to the power resources in use.
185 		 */
186 		state = ACPI_STATE_D3_HOT;
187 		/* If D3cold is not supported, use D3hot as the target state. */
188 		if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
189 			target_state = state;
190 	} else if (!device->power.states[state].flags.valid) {
191 		acpi_handle_debug(device->handle, "Power state %s not supported\n",
192 				  acpi_power_state_string(state));
193 		return -ENODEV;
194 	}
195 
196 	if (!device->power.flags.ignore_parent) {
197 		struct acpi_device *parent;
198 
199 		parent = acpi_dev_parent(device);
200 		if (parent && state < parent->power.state) {
201 			acpi_handle_debug(device->handle,
202 					  "Cannot transition to %s for parent in %s\n",
203 					  acpi_power_state_string(state),
204 					  acpi_power_state_string(parent->power.state));
205 			return -ENODEV;
206 		}
207 	}
208 
209 	/*
210 	 * Transition Power
211 	 * ----------------
212 	 * In accordance with ACPI 6, _PSx is executed before manipulating power
213 	 * resources, unless the target state is D0, in which case _PS0 is
214 	 * supposed to be executed after turning the power resources on.
215 	 */
216 	if (state > ACPI_STATE_D0) {
217 		/*
218 		 * According to ACPI 6, devices cannot go from lower-power
219 		 * (deeper) states to higher-power (shallower) states.
220 		 */
221 		if (state < device->power.state) {
222 			acpi_handle_debug(device->handle,
223 					  "Cannot transition from %s to %s\n",
224 					  acpi_power_state_string(device->power.state),
225 					  acpi_power_state_string(state));
226 			return -ENODEV;
227 		}
228 
229 		/*
230 		 * If the device goes from D3hot to D3cold, _PS3 has been
231 		 * evaluated for it already, so skip it in that case.
232 		 */
233 		if (device->power.state < ACPI_STATE_D3_HOT) {
234 			result = acpi_dev_pm_explicit_set(device, state);
235 			if (result)
236 				goto end;
237 		}
238 
239 		if (device->power.flags.power_resources)
240 			result = acpi_power_transition(device, target_state);
241 	} else {
242 		int cur_state = device->power.state;
243 
244 		if (device->power.flags.power_resources) {
245 			result = acpi_power_transition(device, ACPI_STATE_D0);
246 			if (result)
247 				goto end;
248 		}
249 
250 		if (cur_state == ACPI_STATE_D0) {
251 			int psc;
252 
253 			/* Nothing to do here if _PSC is not present. */
254 			if (!device->power.flags.explicit_get)
255 				goto no_change;
256 
257 			/*
258 			 * The power state of the device was set to D0 last
259 			 * time, but that might have happened before a
260 			 * system-wide transition involving the platform
261 			 * firmware, so it may be necessary to evaluate _PS0
262 			 * for the device here.  However, use extra care here
263 			 * and evaluate _PSC to check the device's current power
264 			 * state, and only invoke _PS0 if the evaluation of _PSC
265 			 * is successful and it returns a power state different
266 			 * from D0.
267 			 */
268 			result = acpi_dev_pm_explicit_get(device, &psc);
269 			if (result || psc == ACPI_STATE_D0)
270 				goto no_change;
271 		}
272 
273 		result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
274 	}
275 
276 end:
277 	if (result) {
278 		acpi_handle_debug(device->handle,
279 				  "Failed to change power state to %s\n",
280 				  acpi_power_state_string(target_state));
281 	} else {
282 		device->power.state = target_state;
283 		acpi_handle_debug(device->handle, "Power state changed to %s\n",
284 				  acpi_power_state_string(target_state));
285 	}
286 
287 	return result;
288 
289 no_change:
290 	acpi_handle_debug(device->handle, "Already in %s\n",
291 			  acpi_power_state_string(state));
292 	return 0;
293 }
294 EXPORT_SYMBOL(acpi_device_set_power);
295 
acpi_bus_set_power(acpi_handle handle,int state)296 int acpi_bus_set_power(acpi_handle handle, int state)
297 {
298 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
299 
300 	if (device)
301 		return acpi_device_set_power(device, state);
302 
303 	return -ENODEV;
304 }
305 EXPORT_SYMBOL(acpi_bus_set_power);
306 
acpi_bus_init_power(struct acpi_device * device)307 int acpi_bus_init_power(struct acpi_device *device)
308 {
309 	int state;
310 	int result;
311 
312 	if (!device)
313 		return -EINVAL;
314 
315 	device->power.state = ACPI_STATE_UNKNOWN;
316 	if (!acpi_device_is_present(device)) {
317 		device->flags.initialized = false;
318 		return -ENXIO;
319 	}
320 
321 	result = acpi_device_get_power(device, &state);
322 	if (result)
323 		return result;
324 
325 	if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
326 		/* Reference count the power resources. */
327 		result = acpi_power_on_resources(device, state);
328 		if (result)
329 			return result;
330 
331 		if (state == ACPI_STATE_D0) {
332 			/*
333 			 * If _PSC is not present and the state inferred from
334 			 * power resources appears to be D0, it still may be
335 			 * necessary to execute _PS0 at this point, because
336 			 * another device using the same power resources may
337 			 * have been put into D0 previously and that's why we
338 			 * see D0 here.
339 			 */
340 			result = acpi_dev_pm_explicit_set(device, state);
341 			if (result)
342 				return result;
343 		}
344 	} else if (state == ACPI_STATE_UNKNOWN) {
345 		/*
346 		 * No power resources and missing _PSC?  Cross fingers and make
347 		 * it D0 in hope that this is what the BIOS put the device into.
348 		 * [We tried to force D0 here by executing _PS0, but that broke
349 		 * Toshiba P870-303 in a nasty way.]
350 		 */
351 		state = ACPI_STATE_D0;
352 	}
353 	device->power.state = state;
354 	return 0;
355 }
356 
357 /**
358  * acpi_device_fix_up_power - Force device with missing _PSC into D0.
359  * @device: Device object whose power state is to be fixed up.
360  *
361  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
362  * are assumed to be put into D0 by the BIOS.  However, in some cases that may
363  * not be the case and this function should be used then.
364  */
acpi_device_fix_up_power(struct acpi_device * device)365 int acpi_device_fix_up_power(struct acpi_device *device)
366 {
367 	int ret = 0;
368 
369 	if (!device->power.flags.power_resources
370 	    && !device->power.flags.explicit_get
371 	    && device->power.state == ACPI_STATE_D0)
372 		ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
373 
374 	return ret;
375 }
376 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
377 
fix_up_power_if_applicable(struct acpi_device * adev,void * not_used)378 static int fix_up_power_if_applicable(struct acpi_device *adev, void *not_used)
379 {
380 	if (adev->status.present && adev->status.enabled)
381 		acpi_device_fix_up_power(adev);
382 
383 	return 0;
384 }
385 
386 /**
387  * acpi_device_fix_up_power_extended - Force device and its children into D0.
388  * @adev: Parent device object whose power state is to be fixed up.
389  *
390  * Call acpi_device_fix_up_power() for @adev and its children so long as they
391  * are reported as present and enabled.
392  */
acpi_device_fix_up_power_extended(struct acpi_device * adev)393 void acpi_device_fix_up_power_extended(struct acpi_device *adev)
394 {
395 	acpi_device_fix_up_power(adev);
396 	acpi_dev_for_each_child(adev, fix_up_power_if_applicable, NULL);
397 }
398 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power_extended);
399 
acpi_device_update_power(struct acpi_device * device,int * state_p)400 int acpi_device_update_power(struct acpi_device *device, int *state_p)
401 {
402 	int state;
403 	int result;
404 
405 	if (device->power.state == ACPI_STATE_UNKNOWN) {
406 		result = acpi_bus_init_power(device);
407 		if (!result && state_p)
408 			*state_p = device->power.state;
409 
410 		return result;
411 	}
412 
413 	result = acpi_device_get_power(device, &state);
414 	if (result)
415 		return result;
416 
417 	if (state == ACPI_STATE_UNKNOWN) {
418 		state = ACPI_STATE_D0;
419 		result = acpi_device_set_power(device, state);
420 		if (result)
421 			return result;
422 	} else {
423 		if (device->power.flags.power_resources) {
424 			/*
425 			 * We don't need to really switch the state, bu we need
426 			 * to update the power resources' reference counters.
427 			 */
428 			result = acpi_power_transition(device, state);
429 			if (result)
430 				return result;
431 		}
432 		device->power.state = state;
433 	}
434 	if (state_p)
435 		*state_p = state;
436 
437 	return 0;
438 }
439 EXPORT_SYMBOL_GPL(acpi_device_update_power);
440 
acpi_bus_update_power(acpi_handle handle,int * state_p)441 int acpi_bus_update_power(acpi_handle handle, int *state_p)
442 {
443 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
444 
445 	if (device)
446 		return acpi_device_update_power(device, state_p);
447 
448 	return -ENODEV;
449 }
450 EXPORT_SYMBOL_GPL(acpi_bus_update_power);
451 
acpi_bus_power_manageable(acpi_handle handle)452 bool acpi_bus_power_manageable(acpi_handle handle)
453 {
454 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
455 
456 	return device && device->flags.power_manageable;
457 }
458 EXPORT_SYMBOL(acpi_bus_power_manageable);
459 
acpi_power_up_if_adr_present(struct acpi_device * adev,void * not_used)460 static int acpi_power_up_if_adr_present(struct acpi_device *adev, void *not_used)
461 {
462 	if (!(adev->flags.power_manageable && adev->pnp.type.bus_address))
463 		return 0;
464 
465 	acpi_handle_debug(adev->handle, "Power state: %s\n",
466 			  acpi_power_state_string(adev->power.state));
467 
468 	if (adev->power.state == ACPI_STATE_D3_COLD)
469 		return acpi_device_set_power(adev, ACPI_STATE_D0);
470 
471 	return 0;
472 }
473 
474 /**
475  * acpi_dev_power_up_children_with_adr - Power up childres with valid _ADR
476  * @adev: Parent ACPI device object.
477  *
478  * Change the power states of the direct children of @adev that are in D3cold
479  * and hold valid _ADR objects to D0 in order to allow bus (e.g. PCI)
480  * enumeration code to access them.
481  */
acpi_dev_power_up_children_with_adr(struct acpi_device * adev)482 void acpi_dev_power_up_children_with_adr(struct acpi_device *adev)
483 {
484 	acpi_dev_for_each_child(adev, acpi_power_up_if_adr_present, NULL);
485 }
486 
487 #ifdef CONFIG_PM
488 static DEFINE_MUTEX(acpi_pm_notifier_lock);
489 static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
490 
acpi_pm_wakeup_event(struct device * dev)491 void acpi_pm_wakeup_event(struct device *dev)
492 {
493 	pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
494 }
495 EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
496 
acpi_pm_notify_handler(acpi_handle handle,u32 val,void * not_used)497 static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
498 {
499 	struct acpi_device *adev;
500 
501 	if (val != ACPI_NOTIFY_DEVICE_WAKE)
502 		return;
503 
504 	acpi_handle_debug(handle, "Wake notify\n");
505 
506 	adev = acpi_get_acpi_dev(handle);
507 	if (!adev)
508 		return;
509 
510 	mutex_lock(&acpi_pm_notifier_lock);
511 
512 	if (adev->wakeup.flags.notifier_present) {
513 		pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
514 		if (adev->wakeup.context.func) {
515 			acpi_handle_debug(handle, "Running %pS for %s\n",
516 					  adev->wakeup.context.func,
517 					  dev_name(adev->wakeup.context.dev));
518 			adev->wakeup.context.func(&adev->wakeup.context);
519 		}
520 	}
521 
522 	mutex_unlock(&acpi_pm_notifier_lock);
523 
524 	acpi_put_acpi_dev(adev);
525 }
526 
527 /**
528  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
529  * @adev: ACPI device to add the notify handler for.
530  * @dev: Device to generate a wakeup event for while handling the notification.
531  * @func: Work function to execute when handling the notification.
532  *
533  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
534  * PM wakeup events.  For example, wakeup events may be generated for bridges
535  * if one of the devices below the bridge is signaling wakeup, even if the
536  * bridge itself doesn't have a wakeup GPE associated with it.
537  */
acpi_add_pm_notifier(struct acpi_device * adev,struct device * dev,void (* func)(struct acpi_device_wakeup_context * context))538 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
539 			void (*func)(struct acpi_device_wakeup_context *context))
540 {
541 	acpi_status status = AE_ALREADY_EXISTS;
542 
543 	if (!dev && !func)
544 		return AE_BAD_PARAMETER;
545 
546 	mutex_lock(&acpi_pm_notifier_install_lock);
547 
548 	if (adev->wakeup.flags.notifier_present)
549 		goto out;
550 
551 	status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
552 					     acpi_pm_notify_handler, NULL);
553 	if (ACPI_FAILURE(status))
554 		goto out;
555 
556 	mutex_lock(&acpi_pm_notifier_lock);
557 	adev->wakeup.ws = wakeup_source_register(&adev->dev,
558 						 dev_name(&adev->dev));
559 	adev->wakeup.context.dev = dev;
560 	adev->wakeup.context.func = func;
561 	adev->wakeup.flags.notifier_present = true;
562 	mutex_unlock(&acpi_pm_notifier_lock);
563 
564  out:
565 	mutex_unlock(&acpi_pm_notifier_install_lock);
566 	return status;
567 }
568 
569 /**
570  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
571  * @adev: ACPI device to remove the notifier from.
572  */
acpi_remove_pm_notifier(struct acpi_device * adev)573 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
574 {
575 	acpi_status status = AE_BAD_PARAMETER;
576 
577 	mutex_lock(&acpi_pm_notifier_install_lock);
578 
579 	if (!adev->wakeup.flags.notifier_present)
580 		goto out;
581 
582 	status = acpi_remove_notify_handler(adev->handle,
583 					    ACPI_SYSTEM_NOTIFY,
584 					    acpi_pm_notify_handler);
585 	if (ACPI_FAILURE(status))
586 		goto out;
587 
588 	mutex_lock(&acpi_pm_notifier_lock);
589 	adev->wakeup.context.func = NULL;
590 	adev->wakeup.context.dev = NULL;
591 	wakeup_source_unregister(adev->wakeup.ws);
592 	adev->wakeup.flags.notifier_present = false;
593 	mutex_unlock(&acpi_pm_notifier_lock);
594 
595  out:
596 	mutex_unlock(&acpi_pm_notifier_install_lock);
597 	return status;
598 }
599 
acpi_bus_can_wakeup(acpi_handle handle)600 bool acpi_bus_can_wakeup(acpi_handle handle)
601 {
602 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
603 
604 	return device && device->wakeup.flags.valid;
605 }
606 EXPORT_SYMBOL(acpi_bus_can_wakeup);
607 
acpi_pm_device_can_wakeup(struct device * dev)608 bool acpi_pm_device_can_wakeup(struct device *dev)
609 {
610 	struct acpi_device *adev = ACPI_COMPANION(dev);
611 
612 	return adev ? acpi_device_can_wakeup(adev) : false;
613 }
614 
615 /**
616  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
617  * @dev: Device whose preferred target power state to return.
618  * @adev: ACPI device node corresponding to @dev.
619  * @target_state: System state to match the resultant device state.
620  * @d_min_p: Location to store the highest power state available to the device.
621  * @d_max_p: Location to store the lowest power state available to the device.
622  *
623  * Find the lowest power (highest number) and highest power (lowest number) ACPI
624  * device power states that the device can be in while the system is in the
625  * state represented by @target_state.  Store the integer numbers representing
626  * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
627  * respectively.
628  *
629  * Callers must ensure that @dev and @adev are valid pointers and that @adev
630  * actually corresponds to @dev before using this function.
631  *
632  * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
633  * returns a value that doesn't make sense.  The memory locations pointed to by
634  * @d_max_p and @d_min_p are only modified on success.
635  */
acpi_dev_pm_get_state(struct device * dev,struct acpi_device * adev,u32 target_state,int * d_min_p,int * d_max_p)636 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
637 				 u32 target_state, int *d_min_p, int *d_max_p)
638 {
639 	char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
640 	acpi_handle handle = adev->handle;
641 	unsigned long long ret;
642 	int d_min, d_max;
643 	bool wakeup = false;
644 	bool has_sxd = false;
645 	acpi_status status;
646 
647 	/*
648 	 * If the system state is S0, the lowest power state the device can be
649 	 * in is D3cold, unless the device has _S0W and is supposed to signal
650 	 * wakeup, in which case the return value of _S0W has to be used as the
651 	 * lowest power state available to the device.
652 	 */
653 	d_min = ACPI_STATE_D0;
654 	d_max = ACPI_STATE_D3_COLD;
655 
656 	/*
657 	 * If present, _SxD methods return the minimum D-state (highest power
658 	 * state) we can use for the corresponding S-states.  Otherwise, the
659 	 * minimum D-state is D0 (ACPI 3.x).
660 	 */
661 	if (target_state > ACPI_STATE_S0) {
662 		/*
663 		 * We rely on acpi_evaluate_integer() not clobbering the integer
664 		 * provided if AE_NOT_FOUND is returned.
665 		 */
666 		ret = d_min;
667 		status = acpi_evaluate_integer(handle, method, NULL, &ret);
668 		if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
669 		    || ret > ACPI_STATE_D3_COLD)
670 			return -ENODATA;
671 
672 		/*
673 		 * We need to handle legacy systems where D3hot and D3cold are
674 		 * the same and 3 is returned in both cases, so fall back to
675 		 * D3cold if D3hot is not a valid state.
676 		 */
677 		if (!adev->power.states[ret].flags.valid) {
678 			if (ret == ACPI_STATE_D3_HOT)
679 				ret = ACPI_STATE_D3_COLD;
680 			else
681 				return -ENODATA;
682 		}
683 
684 		if (status == AE_OK)
685 			has_sxd = true;
686 
687 		d_min = ret;
688 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
689 			&& adev->wakeup.sleep_state >= target_state;
690 	} else if (device_may_wakeup(dev) && dev->power.wakeirq) {
691 		/*
692 		 * The ACPI subsystem doesn't manage the wake bit for IRQs
693 		 * defined with ExclusiveAndWake and SharedAndWake. Instead we
694 		 * expect them to be managed via the PM subsystem. Drivers
695 		 * should call dev_pm_set_wake_irq to register an IRQ as a wake
696 		 * source.
697 		 *
698 		 * If a device has a wake IRQ attached we need to check the
699 		 * _S0W method to get the correct wake D-state. Otherwise we
700 		 * end up putting the device into D3Cold which will more than
701 		 * likely disable wake functionality.
702 		 */
703 		wakeup = true;
704 	} else {
705 		/* ACPI GPE is specified in _PRW. */
706 		wakeup = adev->wakeup.flags.valid;
707 	}
708 
709 	/*
710 	 * If _PRW says we can wake up the system from the target sleep state,
711 	 * the D-state returned by _SxD is sufficient for that (we assume a
712 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
713 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
714 	 * can wake the system.  _S0W may be valid, too.
715 	 */
716 	if (wakeup) {
717 		method[3] = 'W';
718 		status = acpi_evaluate_integer(handle, method, NULL, &ret);
719 		if (status == AE_NOT_FOUND) {
720 			/* No _SxW. In this case, the ACPI spec says that we
721 			 * must not go into any power state deeper than the
722 			 * value returned from _SxD.
723 			 */
724 			if (has_sxd && target_state > ACPI_STATE_S0)
725 				d_max = d_min;
726 		} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
727 			/* Fall back to D3cold if ret is not a valid state. */
728 			if (!adev->power.states[ret].flags.valid)
729 				ret = ACPI_STATE_D3_COLD;
730 
731 			d_max = ret > d_min ? ret : d_min;
732 		} else {
733 			return -ENODATA;
734 		}
735 	}
736 
737 	if (d_min_p)
738 		*d_min_p = d_min;
739 
740 	if (d_max_p)
741 		*d_max_p = d_max;
742 
743 	return 0;
744 }
745 
746 /**
747  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
748  * @dev: Device whose preferred target power state to return.
749  * @d_min_p: Location to store the upper limit of the allowed states range.
750  * @d_max_in: Deepest low-power state to take into consideration.
751  * Return value: Preferred power state of the device on success, -ENODEV
752  * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
753  * incorrect, or -ENODATA on ACPI method failure.
754  *
755  * The caller must ensure that @dev is valid before using this function.
756  */
acpi_pm_device_sleep_state(struct device * dev,int * d_min_p,int d_max_in)757 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
758 {
759 	struct acpi_device *adev;
760 	int ret, d_min, d_max;
761 
762 	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
763 		return -EINVAL;
764 
765 	if (d_max_in > ACPI_STATE_D2) {
766 		enum pm_qos_flags_status stat;
767 
768 		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
769 		if (stat == PM_QOS_FLAGS_ALL)
770 			d_max_in = ACPI_STATE_D2;
771 	}
772 
773 	adev = ACPI_COMPANION(dev);
774 	if (!adev) {
775 		dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
776 		return -ENODEV;
777 	}
778 
779 	ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
780 				    &d_min, &d_max);
781 	if (ret)
782 		return ret;
783 
784 	if (d_max_in < d_min)
785 		return -EINVAL;
786 
787 	if (d_max > d_max_in) {
788 		for (d_max = d_max_in; d_max > d_min; d_max--) {
789 			if (adev->power.states[d_max].flags.valid)
790 				break;
791 		}
792 	}
793 
794 	if (d_min_p)
795 		*d_min_p = d_min;
796 
797 	return d_max;
798 }
799 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
800 
801 /**
802  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
803  * @context: Device wakeup context.
804  */
acpi_pm_notify_work_func(struct acpi_device_wakeup_context * context)805 static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
806 {
807 	struct device *dev = context->dev;
808 
809 	if (dev) {
810 		pm_wakeup_event(dev, 0);
811 		pm_request_resume(dev);
812 	}
813 }
814 
815 static DEFINE_MUTEX(acpi_wakeup_lock);
816 
__acpi_device_wakeup_enable(struct acpi_device * adev,u32 target_state)817 static int __acpi_device_wakeup_enable(struct acpi_device *adev,
818 				       u32 target_state)
819 {
820 	struct acpi_device_wakeup *wakeup = &adev->wakeup;
821 	acpi_status status;
822 	int error = 0;
823 
824 	mutex_lock(&acpi_wakeup_lock);
825 
826 	/*
827 	 * If the device wakeup power is already enabled, disable it and enable
828 	 * it again in case it depends on the configuration of subordinate
829 	 * devices and the conditions have changed since it was enabled last
830 	 * time.
831 	 */
832 	if (wakeup->enable_count > 0)
833 		acpi_disable_wakeup_device_power(adev);
834 
835 	error = acpi_enable_wakeup_device_power(adev, target_state);
836 	if (error) {
837 		if (wakeup->enable_count > 0) {
838 			acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
839 			wakeup->enable_count = 0;
840 		}
841 		goto out;
842 	}
843 
844 	if (wakeup->enable_count > 0)
845 		goto inc;
846 
847 	status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
848 	if (ACPI_FAILURE(status)) {
849 		acpi_disable_wakeup_device_power(adev);
850 		error = -EIO;
851 		goto out;
852 	}
853 
854 	acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
855 			  (unsigned int)wakeup->gpe_number);
856 
857 inc:
858 	if (wakeup->enable_count < INT_MAX)
859 		wakeup->enable_count++;
860 	else
861 		acpi_handle_info(adev->handle, "Wakeup enable count out of bounds!\n");
862 
863 out:
864 	mutex_unlock(&acpi_wakeup_lock);
865 	return error;
866 }
867 
868 /**
869  * acpi_device_wakeup_enable - Enable wakeup functionality for device.
870  * @adev: ACPI device to enable wakeup functionality for.
871  * @target_state: State the system is transitioning into.
872  *
873  * Enable the GPE associated with @adev so that it can generate wakeup signals
874  * for the device in response to external (remote) events and enable wakeup
875  * power for it.
876  *
877  * Callers must ensure that @adev is a valid ACPI device node before executing
878  * this function.
879  */
acpi_device_wakeup_enable(struct acpi_device * adev,u32 target_state)880 static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
881 {
882 	return __acpi_device_wakeup_enable(adev, target_state);
883 }
884 
885 /**
886  * acpi_device_wakeup_disable - Disable wakeup functionality for device.
887  * @adev: ACPI device to disable wakeup functionality for.
888  *
889  * Disable the GPE associated with @adev and disable wakeup power for it.
890  *
891  * Callers must ensure that @adev is a valid ACPI device node before executing
892  * this function.
893  */
acpi_device_wakeup_disable(struct acpi_device * adev)894 static void acpi_device_wakeup_disable(struct acpi_device *adev)
895 {
896 	struct acpi_device_wakeup *wakeup = &adev->wakeup;
897 
898 	mutex_lock(&acpi_wakeup_lock);
899 
900 	if (!wakeup->enable_count)
901 		goto out;
902 
903 	acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
904 	acpi_disable_wakeup_device_power(adev);
905 
906 	wakeup->enable_count--;
907 
908 out:
909 	mutex_unlock(&acpi_wakeup_lock);
910 }
911 
912 /**
913  * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
914  * @dev: Device to enable/disable to generate wakeup events.
915  * @enable: Whether to enable or disable the wakeup functionality.
916  */
acpi_pm_set_device_wakeup(struct device * dev,bool enable)917 int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
918 {
919 	struct acpi_device *adev;
920 	int error;
921 
922 	adev = ACPI_COMPANION(dev);
923 	if (!adev) {
924 		dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
925 		return -ENODEV;
926 	}
927 
928 	if (!acpi_device_can_wakeup(adev))
929 		return -EINVAL;
930 
931 	if (!enable) {
932 		acpi_device_wakeup_disable(adev);
933 		dev_dbg(dev, "Wakeup disabled by ACPI\n");
934 		return 0;
935 	}
936 
937 	error = __acpi_device_wakeup_enable(adev, acpi_target_system_state());
938 	if (!error)
939 		dev_dbg(dev, "Wakeup enabled by ACPI\n");
940 
941 	return error;
942 }
943 EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
944 
945 /**
946  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
947  * @dev: Device to put into a low-power state.
948  * @adev: ACPI device node corresponding to @dev.
949  * @system_state: System state to choose the device state for.
950  */
acpi_dev_pm_low_power(struct device * dev,struct acpi_device * adev,u32 system_state)951 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
952 				 u32 system_state)
953 {
954 	int ret, state;
955 
956 	if (!acpi_device_power_manageable(adev))
957 		return 0;
958 
959 	ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
960 	return ret ? ret : acpi_device_set_power(adev, state);
961 }
962 
963 /**
964  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
965  * @adev: ACPI device node to put into the full-power state.
966  */
acpi_dev_pm_full_power(struct acpi_device * adev)967 static int acpi_dev_pm_full_power(struct acpi_device *adev)
968 {
969 	return acpi_device_power_manageable(adev) ?
970 		acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
971 }
972 
973 /**
974  * acpi_dev_suspend - Put device into a low-power state using ACPI.
975  * @dev: Device to put into a low-power state.
976  * @wakeup: Whether or not to enable wakeup for the device.
977  *
978  * Put the given device into a low-power state using the standard ACPI
979  * mechanism.  Set up remote wakeup if desired, choose the state to put the
980  * device into (this checks if remote wakeup is expected to work too), and set
981  * the power state of the device.
982  */
acpi_dev_suspend(struct device * dev,bool wakeup)983 int acpi_dev_suspend(struct device *dev, bool wakeup)
984 {
985 	struct acpi_device *adev = ACPI_COMPANION(dev);
986 	u32 target_state = acpi_target_system_state();
987 	int error;
988 
989 	if (!adev)
990 		return 0;
991 
992 	if (wakeup && acpi_device_can_wakeup(adev)) {
993 		error = acpi_device_wakeup_enable(adev, target_state);
994 		if (error)
995 			return -EAGAIN;
996 	} else {
997 		wakeup = false;
998 	}
999 
1000 	error = acpi_dev_pm_low_power(dev, adev, target_state);
1001 	if (error && wakeup)
1002 		acpi_device_wakeup_disable(adev);
1003 
1004 	return error;
1005 }
1006 EXPORT_SYMBOL_GPL(acpi_dev_suspend);
1007 
1008 /**
1009  * acpi_dev_resume - Put device into the full-power state using ACPI.
1010  * @dev: Device to put into the full-power state.
1011  *
1012  * Put the given device into the full-power state using the standard ACPI
1013  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
1014  */
acpi_dev_resume(struct device * dev)1015 int acpi_dev_resume(struct device *dev)
1016 {
1017 	struct acpi_device *adev = ACPI_COMPANION(dev);
1018 	int error;
1019 
1020 	if (!adev)
1021 		return 0;
1022 
1023 	error = acpi_dev_pm_full_power(adev);
1024 	acpi_device_wakeup_disable(adev);
1025 	return error;
1026 }
1027 EXPORT_SYMBOL_GPL(acpi_dev_resume);
1028 
1029 /**
1030  * acpi_subsys_runtime_suspend - Suspend device using ACPI.
1031  * @dev: Device to suspend.
1032  *
1033  * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
1034  * it into a runtime low-power state.
1035  */
acpi_subsys_runtime_suspend(struct device * dev)1036 int acpi_subsys_runtime_suspend(struct device *dev)
1037 {
1038 	int ret = pm_generic_runtime_suspend(dev);
1039 
1040 	return ret ? ret : acpi_dev_suspend(dev, true);
1041 }
1042 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
1043 
1044 /**
1045  * acpi_subsys_runtime_resume - Resume device using ACPI.
1046  * @dev: Device to Resume.
1047  *
1048  * Use ACPI to put the given device into the full-power state and carry out the
1049  * generic runtime resume procedure for it.
1050  */
acpi_subsys_runtime_resume(struct device * dev)1051 int acpi_subsys_runtime_resume(struct device *dev)
1052 {
1053 	int ret = acpi_dev_resume(dev);
1054 
1055 	return ret ? ret : pm_generic_runtime_resume(dev);
1056 }
1057 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
1058 
1059 #ifdef CONFIG_PM_SLEEP
acpi_dev_needs_resume(struct device * dev,struct acpi_device * adev)1060 static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
1061 {
1062 	u32 sys_target = acpi_target_system_state();
1063 	int ret, state;
1064 
1065 	if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
1066 	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
1067 		return true;
1068 
1069 	if (sys_target == ACPI_STATE_S0)
1070 		return false;
1071 
1072 	if (adev->power.flags.dsw_present)
1073 		return true;
1074 
1075 	ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
1076 	if (ret)
1077 		return true;
1078 
1079 	return state != adev->power.state;
1080 }
1081 
1082 /**
1083  * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1084  * @dev: Device to prepare.
1085  */
acpi_subsys_prepare(struct device * dev)1086 int acpi_subsys_prepare(struct device *dev)
1087 {
1088 	struct acpi_device *adev = ACPI_COMPANION(dev);
1089 
1090 	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
1091 		int ret = dev->driver->pm->prepare(dev);
1092 
1093 		if (ret < 0)
1094 			return ret;
1095 
1096 		if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
1097 			return 0;
1098 	}
1099 
1100 	return !acpi_dev_needs_resume(dev, adev);
1101 }
1102 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
1103 
1104 /**
1105  * acpi_subsys_complete - Finalize device's resume during system resume.
1106  * @dev: Device to handle.
1107  */
acpi_subsys_complete(struct device * dev)1108 void acpi_subsys_complete(struct device *dev)
1109 {
1110 	pm_generic_complete(dev);
1111 	/*
1112 	 * If the device had been runtime-suspended before the system went into
1113 	 * the sleep state it is going out of and it has never been resumed till
1114 	 * now, resume it in case the firmware powered it up.
1115 	 */
1116 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1117 		pm_request_resume(dev);
1118 }
1119 EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1120 
1121 /**
1122  * acpi_subsys_suspend - Run the device driver's suspend callback.
1123  * @dev: Device to handle.
1124  *
1125  * Follow PCI and resume devices from runtime suspend before running their
1126  * system suspend callbacks, unless the driver can cope with runtime-suspended
1127  * devices during system suspend and there are no ACPI-specific reasons for
1128  * resuming them.
1129  */
acpi_subsys_suspend(struct device * dev)1130 int acpi_subsys_suspend(struct device *dev)
1131 {
1132 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1133 	    acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1134 		pm_runtime_resume(dev);
1135 
1136 	return pm_generic_suspend(dev);
1137 }
1138 EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1139 
1140 /**
1141  * acpi_subsys_suspend_late - Suspend device using ACPI.
1142  * @dev: Device to suspend.
1143  *
1144  * Carry out the generic late suspend procedure for @dev and use ACPI to put
1145  * it into a low-power state during system transition into a sleep state.
1146  */
acpi_subsys_suspend_late(struct device * dev)1147 int acpi_subsys_suspend_late(struct device *dev)
1148 {
1149 	int ret;
1150 
1151 	if (dev_pm_skip_suspend(dev))
1152 		return 0;
1153 
1154 	ret = pm_generic_suspend_late(dev);
1155 	return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1156 }
1157 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1158 
1159 /**
1160  * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1161  * @dev: Device to suspend.
1162  */
acpi_subsys_suspend_noirq(struct device * dev)1163 int acpi_subsys_suspend_noirq(struct device *dev)
1164 {
1165 	int ret;
1166 
1167 	if (dev_pm_skip_suspend(dev))
1168 		return 0;
1169 
1170 	ret = pm_generic_suspend_noirq(dev);
1171 	if (ret)
1172 		return ret;
1173 
1174 	/*
1175 	 * If the target system sleep state is suspend-to-idle, it is sufficient
1176 	 * to check whether or not the device's wakeup settings are good for
1177 	 * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
1178 	 * acpi_subsys_complete() to take care of fixing up the device's state
1179 	 * anyway, if need be.
1180 	 */
1181 	if (device_can_wakeup(dev) && !device_may_wakeup(dev))
1182 		dev->power.may_skip_resume = false;
1183 
1184 	return 0;
1185 }
1186 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1187 
1188 /**
1189  * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1190  * @dev: Device to handle.
1191  */
acpi_subsys_resume_noirq(struct device * dev)1192 static int acpi_subsys_resume_noirq(struct device *dev)
1193 {
1194 	if (dev_pm_skip_resume(dev))
1195 		return 0;
1196 
1197 	return pm_generic_resume_noirq(dev);
1198 }
1199 
1200 /**
1201  * acpi_subsys_resume_early - Resume device using ACPI.
1202  * @dev: Device to Resume.
1203  *
1204  * Use ACPI to put the given device into the full-power state and carry out the
1205  * generic early resume procedure for it during system transition into the
1206  * working state, but only do that if device either defines early resume
1207  * handler, or does not define power operations at all. Otherwise powering up
1208  * of the device is postponed to the normal resume phase.
1209  */
acpi_subsys_resume_early(struct device * dev)1210 static int acpi_subsys_resume_early(struct device *dev)
1211 {
1212 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1213 	int ret;
1214 
1215 	if (dev_pm_skip_resume(dev))
1216 		return 0;
1217 
1218 	if (pm && !pm->resume_early) {
1219 		dev_dbg(dev, "postponing D0 transition to normal resume stage\n");
1220 		return 0;
1221 	}
1222 
1223 	ret = acpi_dev_resume(dev);
1224 	return ret ? ret : pm_generic_resume_early(dev);
1225 }
1226 
1227 /**
1228  * acpi_subsys_resume - Resume device using ACPI.
1229  * @dev: Device to Resume.
1230  *
1231  * Use ACPI to put the given device into the full-power state if it has not been
1232  * powered up during early resume phase, and carry out the generic resume
1233  * procedure for it during system transition into the working state.
1234  */
acpi_subsys_resume(struct device * dev)1235 static int acpi_subsys_resume(struct device *dev)
1236 {
1237 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1238 	int ret = 0;
1239 
1240 	if (!dev_pm_skip_resume(dev) && pm && !pm->resume_early) {
1241 		dev_dbg(dev, "executing postponed D0 transition\n");
1242 		ret = acpi_dev_resume(dev);
1243 	}
1244 
1245 	return ret ? ret : pm_generic_resume(dev);
1246 }
1247 
1248 /**
1249  * acpi_subsys_freeze - Run the device driver's freeze callback.
1250  * @dev: Device to handle.
1251  */
acpi_subsys_freeze(struct device * dev)1252 int acpi_subsys_freeze(struct device *dev)
1253 {
1254 	/*
1255 	 * Resume all runtime-suspended devices before creating a snapshot
1256 	 * image of system memory, because the restore kernel generally cannot
1257 	 * be expected to always handle them consistently and they need to be
1258 	 * put into the runtime-active metastate during system resume anyway,
1259 	 * so it is better to ensure that the state saved in the image will be
1260 	 * always consistent with that.
1261 	 */
1262 	pm_runtime_resume(dev);
1263 
1264 	return pm_generic_freeze(dev);
1265 }
1266 EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1267 
1268 /**
1269  * acpi_subsys_restore_early - Restore device using ACPI.
1270  * @dev: Device to restore.
1271  */
acpi_subsys_restore_early(struct device * dev)1272 int acpi_subsys_restore_early(struct device *dev)
1273 {
1274 	int ret = acpi_dev_resume(dev);
1275 
1276 	return ret ? ret : pm_generic_restore_early(dev);
1277 }
1278 EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1279 
1280 /**
1281  * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1282  * @dev: Device to handle.
1283  *
1284  * Follow PCI and resume devices from runtime suspend before running their
1285  * system poweroff callbacks, unless the driver can cope with runtime-suspended
1286  * devices during system suspend and there are no ACPI-specific reasons for
1287  * resuming them.
1288  */
acpi_subsys_poweroff(struct device * dev)1289 int acpi_subsys_poweroff(struct device *dev)
1290 {
1291 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1292 	    acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1293 		pm_runtime_resume(dev);
1294 
1295 	return pm_generic_poweroff(dev);
1296 }
1297 EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1298 
1299 /**
1300  * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1301  * @dev: Device to handle.
1302  *
1303  * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1304  * it into a low-power state during system transition into a sleep state.
1305  */
acpi_subsys_poweroff_late(struct device * dev)1306 static int acpi_subsys_poweroff_late(struct device *dev)
1307 {
1308 	int ret;
1309 
1310 	if (dev_pm_skip_suspend(dev))
1311 		return 0;
1312 
1313 	ret = pm_generic_poweroff_late(dev);
1314 	if (ret)
1315 		return ret;
1316 
1317 	return acpi_dev_suspend(dev, device_may_wakeup(dev));
1318 }
1319 
1320 /**
1321  * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1322  * @dev: Device to suspend.
1323  */
acpi_subsys_poweroff_noirq(struct device * dev)1324 static int acpi_subsys_poweroff_noirq(struct device *dev)
1325 {
1326 	if (dev_pm_skip_suspend(dev))
1327 		return 0;
1328 
1329 	return pm_generic_poweroff_noirq(dev);
1330 }
1331 #endif /* CONFIG_PM_SLEEP */
1332 
1333 static struct dev_pm_domain acpi_general_pm_domain = {
1334 	.ops = {
1335 		.runtime_suspend = acpi_subsys_runtime_suspend,
1336 		.runtime_resume = acpi_subsys_runtime_resume,
1337 #ifdef CONFIG_PM_SLEEP
1338 		.prepare = acpi_subsys_prepare,
1339 		.complete = acpi_subsys_complete,
1340 		.suspend = acpi_subsys_suspend,
1341 		.resume = acpi_subsys_resume,
1342 		.suspend_late = acpi_subsys_suspend_late,
1343 		.suspend_noirq = acpi_subsys_suspend_noirq,
1344 		.resume_noirq = acpi_subsys_resume_noirq,
1345 		.resume_early = acpi_subsys_resume_early,
1346 		.freeze = acpi_subsys_freeze,
1347 		.poweroff = acpi_subsys_poweroff,
1348 		.poweroff_late = acpi_subsys_poweroff_late,
1349 		.poweroff_noirq = acpi_subsys_poweroff_noirq,
1350 		.restore_early = acpi_subsys_restore_early,
1351 #endif
1352 	},
1353 };
1354 
1355 /**
1356  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1357  * @dev: Device to take care of.
1358  * @power_off: Whether or not to try to remove power from the device.
1359  *
1360  * Remove the device from the general ACPI PM domain and remove its wakeup
1361  * notifier.  If @power_off is set, additionally remove power from the device if
1362  * possible.
1363  *
1364  * Callers must ensure proper synchronization of this function with power
1365  * management callbacks.
1366  */
acpi_dev_pm_detach(struct device * dev,bool power_off)1367 static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1368 {
1369 	struct acpi_device *adev = ACPI_COMPANION(dev);
1370 
1371 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1372 		dev_pm_domain_set(dev, NULL);
1373 		acpi_remove_pm_notifier(adev);
1374 		if (power_off) {
1375 			/*
1376 			 * If the device's PM QoS resume latency limit or flags
1377 			 * have been exposed to user space, they have to be
1378 			 * hidden at this point, so that they don't affect the
1379 			 * choice of the low-power state to put the device into.
1380 			 */
1381 			dev_pm_qos_hide_latency_limit(dev);
1382 			dev_pm_qos_hide_flags(dev);
1383 			acpi_device_wakeup_disable(adev);
1384 			acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1385 		}
1386 	}
1387 }
1388 
1389 /**
1390  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1391  * @dev: Device to prepare.
1392  * @power_on: Whether or not to power on the device.
1393  *
1394  * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1395  * attached to it, install a wakeup notification handler for the device and
1396  * add it to the general ACPI PM domain.  If @power_on is set, the device will
1397  * be put into the ACPI D0 state before the function returns.
1398  *
1399  * This assumes that the @dev's bus type uses generic power management callbacks
1400  * (or doesn't use any power management callbacks at all).
1401  *
1402  * Callers must ensure proper synchronization of this function with power
1403  * management callbacks.
1404  */
acpi_dev_pm_attach(struct device * dev,bool power_on)1405 int acpi_dev_pm_attach(struct device *dev, bool power_on)
1406 {
1407 	/*
1408 	 * Skip devices whose ACPI companions match the device IDs below,
1409 	 * because they require special power management handling incompatible
1410 	 * with the generic ACPI PM domain.
1411 	 */
1412 	static const struct acpi_device_id special_pm_ids[] = {
1413 		ACPI_FAN_DEVICE_IDS,
1414 		{}
1415 	};
1416 	struct acpi_device *adev = ACPI_COMPANION(dev);
1417 
1418 	if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
1419 		return 0;
1420 
1421 	/*
1422 	 * Only attach the power domain to the first device if the
1423 	 * companion is shared by multiple. This is to prevent doing power
1424 	 * management twice.
1425 	 */
1426 	if (!acpi_device_is_first_physical_node(adev, dev))
1427 		return 0;
1428 
1429 	acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1430 	dev_pm_domain_set(dev, &acpi_general_pm_domain);
1431 	if (power_on) {
1432 		acpi_dev_pm_full_power(adev);
1433 		acpi_device_wakeup_disable(adev);
1434 	}
1435 
1436 	dev->pm_domain->detach = acpi_dev_pm_detach;
1437 	return 1;
1438 }
1439 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1440 
1441 /**
1442  * acpi_storage_d3 - Check if D3 should be used in the suspend path
1443  * @dev: Device to check
1444  *
1445  * Return %true if the platform firmware wants @dev to be programmed
1446  * into D3hot or D3cold (if supported) in the suspend path, or %false
1447  * when there is no specific preference. On some platforms, if this
1448  * hint is ignored, @dev may remain unresponsive after suspending the
1449  * platform as a whole.
1450  *
1451  * Although the property has storage in the name it actually is
1452  * applied to the PCIe slot and plugging in a non-storage device the
1453  * same platform restrictions will likely apply.
1454  */
acpi_storage_d3(struct device * dev)1455 bool acpi_storage_d3(struct device *dev)
1456 {
1457 	struct acpi_device *adev = ACPI_COMPANION(dev);
1458 	u8 val;
1459 
1460 	if (force_storage_d3())
1461 		return true;
1462 
1463 	if (!adev)
1464 		return false;
1465 	if (fwnode_property_read_u8(acpi_fwnode_handle(adev), "StorageD3Enable",
1466 			&val))
1467 		return false;
1468 	return val == 1;
1469 }
1470 EXPORT_SYMBOL_GPL(acpi_storage_d3);
1471 
1472 /**
1473  * acpi_dev_state_d0 - Tell if the device is in D0 power state
1474  * @dev: Physical device the ACPI power state of which to check
1475  *
1476  * On a system without ACPI, return true. On a system with ACPI, return true if
1477  * the current ACPI power state of the device is D0, or false otherwise.
1478  *
1479  * Note that the power state of a device is not well-defined after it has been
1480  * passed to acpi_device_set_power() and before that function returns, so it is
1481  * not valid to ask for the ACPI power state of the device in that time frame.
1482  *
1483  * This function is intended to be used in a driver's probe or remove
1484  * function. See Documentation/firmware-guide/acpi/non-d0-probe.rst for
1485  * more information.
1486  */
acpi_dev_state_d0(struct device * dev)1487 bool acpi_dev_state_d0(struct device *dev)
1488 {
1489 	struct acpi_device *adev = ACPI_COMPANION(dev);
1490 
1491 	if (!adev)
1492 		return true;
1493 
1494 	return adev->power.state == ACPI_STATE_D0;
1495 }
1496 EXPORT_SYMBOL_GPL(acpi_dev_state_d0);
1497 
1498 #endif /* CONFIG_PM */
1499