xref: /openbmc/linux/drivers/acpi/device_pm.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * drivers/acpi/device_pm.c - ACPI device power management routines.
4  *
5  * Copyright (C) 2012, Intel Corp.
6  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
7  *
8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/export.h>
15 #include <linux/mutex.h>
16 #include <linux/pm_qos.h>
17 #include <linux/pm_domain.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/suspend.h>
20 
21 #include "internal.h"
22 
23 #define _COMPONENT	ACPI_POWER_COMPONENT
24 ACPI_MODULE_NAME("device_pm");
25 
26 /**
27  * acpi_power_state_string - String representation of ACPI device power state.
28  * @state: ACPI device power state to return the string representation of.
29  */
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 
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  */
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_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
134 			  device->pnp.bus_id, acpi_power_state_string(*state)));
135 
136 	return 0;
137 }
138 
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  */
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 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
178 				  device->pnp.bus_id,
179 				  acpi_power_state_string(state)));
180 		return 0;
181 	}
182 
183 	if (state == ACPI_STATE_D3_COLD) {
184 		/*
185 		 * For transitions to D3cold we need to execute _PS3 and then
186 		 * possibly drop references to the power resources in use.
187 		 */
188 		state = ACPI_STATE_D3_HOT;
189 		/* If _PR3 is not available, use D3hot as the target state. */
190 		if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
191 			target_state = state;
192 	} else if (!device->power.states[state].flags.valid) {
193 		dev_warn(&device->dev, "Power state %s not supported\n",
194 			 acpi_power_state_string(state));
195 		return -ENODEV;
196 	}
197 
198 	if (!device->power.flags.ignore_parent &&
199 	    device->parent && (state < device->parent->power.state)) {
200 		dev_warn(&device->dev,
201 			 "Cannot transition to power state %s for parent in %s\n",
202 			 acpi_power_state_string(state),
203 			 acpi_power_state_string(device->parent->power.state));
204 		return -ENODEV;
205 	}
206 
207 	/*
208 	 * Transition Power
209 	 * ----------------
210 	 * In accordance with ACPI 6, _PSx is executed before manipulating power
211 	 * resources, unless the target state is D0, in which case _PS0 is
212 	 * supposed to be executed after turning the power resources on.
213 	 */
214 	if (state > ACPI_STATE_D0) {
215 		/*
216 		 * According to ACPI 6, devices cannot go from lower-power
217 		 * (deeper) states to higher-power (shallower) states.
218 		 */
219 		if (state < device->power.state) {
220 			dev_warn(&device->dev, "Cannot transition from %s to %s\n",
221 				 acpi_power_state_string(device->power.state),
222 				 acpi_power_state_string(state));
223 			return -ENODEV;
224 		}
225 
226 		/*
227 		 * If the device goes from D3hot to D3cold, _PS3 has been
228 		 * evaluated for it already, so skip it in that case.
229 		 */
230 		if (device->power.state < ACPI_STATE_D3_HOT) {
231 			result = acpi_dev_pm_explicit_set(device, state);
232 			if (result)
233 				goto end;
234 		}
235 
236 		if (device->power.flags.power_resources)
237 			result = acpi_power_transition(device, target_state);
238 	} else {
239 		int cur_state = device->power.state;
240 
241 		if (device->power.flags.power_resources) {
242 			result = acpi_power_transition(device, ACPI_STATE_D0);
243 			if (result)
244 				goto end;
245 		}
246 
247 		if (cur_state == ACPI_STATE_D0) {
248 			int psc;
249 
250 			/* Nothing to do here if _PSC is not present. */
251 			if (!device->power.flags.explicit_get)
252 				return 0;
253 
254 			/*
255 			 * The power state of the device was set to D0 last
256 			 * time, but that might have happened before a
257 			 * system-wide transition involving the platform
258 			 * firmware, so it may be necessary to evaluate _PS0
259 			 * for the device here.  However, use extra care here
260 			 * and evaluate _PSC to check the device's current power
261 			 * state, and only invoke _PS0 if the evaluation of _PSC
262 			 * is successful and it returns a power state different
263 			 * from D0.
264 			 */
265 			result = acpi_dev_pm_explicit_get(device, &psc);
266 			if (result || psc == ACPI_STATE_D0)
267 				return 0;
268 		}
269 
270 		result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
271 	}
272 
273  end:
274 	if (result) {
275 		dev_warn(&device->dev, "Failed to change power state to %s\n",
276 			 acpi_power_state_string(state));
277 	} else {
278 		device->power.state = target_state;
279 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
280 				  "Device [%s] transitioned to %s\n",
281 				  device->pnp.bus_id,
282 				  acpi_power_state_string(state)));
283 	}
284 
285 	return result;
286 }
287 EXPORT_SYMBOL(acpi_device_set_power);
288 
289 int acpi_bus_set_power(acpi_handle handle, int state)
290 {
291 	struct acpi_device *device;
292 	int result;
293 
294 	result = acpi_bus_get_device(handle, &device);
295 	if (result)
296 		return result;
297 
298 	return acpi_device_set_power(device, state);
299 }
300 EXPORT_SYMBOL(acpi_bus_set_power);
301 
302 int acpi_bus_init_power(struct acpi_device *device)
303 {
304 	int state;
305 	int result;
306 
307 	if (!device)
308 		return -EINVAL;
309 
310 	device->power.state = ACPI_STATE_UNKNOWN;
311 	if (!acpi_device_is_present(device)) {
312 		device->flags.initialized = false;
313 		return -ENXIO;
314 	}
315 
316 	result = acpi_device_get_power(device, &state);
317 	if (result)
318 		return result;
319 
320 	if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
321 		/* Reference count the power resources. */
322 		result = acpi_power_on_resources(device, state);
323 		if (result)
324 			return result;
325 
326 		if (state == ACPI_STATE_D0) {
327 			/*
328 			 * If _PSC is not present and the state inferred from
329 			 * power resources appears to be D0, it still may be
330 			 * necessary to execute _PS0 at this point, because
331 			 * another device using the same power resources may
332 			 * have been put into D0 previously and that's why we
333 			 * see D0 here.
334 			 */
335 			result = acpi_dev_pm_explicit_set(device, state);
336 			if (result)
337 				return result;
338 		}
339 	} else if (state == ACPI_STATE_UNKNOWN) {
340 		/*
341 		 * No power resources and missing _PSC?  Cross fingers and make
342 		 * it D0 in hope that this is what the BIOS put the device into.
343 		 * [We tried to force D0 here by executing _PS0, but that broke
344 		 * Toshiba P870-303 in a nasty way.]
345 		 */
346 		state = ACPI_STATE_D0;
347 	}
348 	device->power.state = state;
349 	return 0;
350 }
351 
352 /**
353  * acpi_device_fix_up_power - Force device with missing _PSC into D0.
354  * @device: Device object whose power state is to be fixed up.
355  *
356  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
357  * are assumed to be put into D0 by the BIOS.  However, in some cases that may
358  * not be the case and this function should be used then.
359  */
360 int acpi_device_fix_up_power(struct acpi_device *device)
361 {
362 	int ret = 0;
363 
364 	if (!device->power.flags.power_resources
365 	    && !device->power.flags.explicit_get
366 	    && device->power.state == ACPI_STATE_D0)
367 		ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
368 
369 	return ret;
370 }
371 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
372 
373 int acpi_device_update_power(struct acpi_device *device, int *state_p)
374 {
375 	int state;
376 	int result;
377 
378 	if (device->power.state == ACPI_STATE_UNKNOWN) {
379 		result = acpi_bus_init_power(device);
380 		if (!result && state_p)
381 			*state_p = device->power.state;
382 
383 		return result;
384 	}
385 
386 	result = acpi_device_get_power(device, &state);
387 	if (result)
388 		return result;
389 
390 	if (state == ACPI_STATE_UNKNOWN) {
391 		state = ACPI_STATE_D0;
392 		result = acpi_device_set_power(device, state);
393 		if (result)
394 			return result;
395 	} else {
396 		if (device->power.flags.power_resources) {
397 			/*
398 			 * We don't need to really switch the state, bu we need
399 			 * to update the power resources' reference counters.
400 			 */
401 			result = acpi_power_transition(device, state);
402 			if (result)
403 				return result;
404 		}
405 		device->power.state = state;
406 	}
407 	if (state_p)
408 		*state_p = state;
409 
410 	return 0;
411 }
412 EXPORT_SYMBOL_GPL(acpi_device_update_power);
413 
414 int acpi_bus_update_power(acpi_handle handle, int *state_p)
415 {
416 	struct acpi_device *device;
417 	int result;
418 
419 	result = acpi_bus_get_device(handle, &device);
420 	return result ? result : acpi_device_update_power(device, state_p);
421 }
422 EXPORT_SYMBOL_GPL(acpi_bus_update_power);
423 
424 bool acpi_bus_power_manageable(acpi_handle handle)
425 {
426 	struct acpi_device *device;
427 	int result;
428 
429 	result = acpi_bus_get_device(handle, &device);
430 	return result ? false : device->flags.power_manageable;
431 }
432 EXPORT_SYMBOL(acpi_bus_power_manageable);
433 
434 #ifdef CONFIG_PM
435 static DEFINE_MUTEX(acpi_pm_notifier_lock);
436 static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
437 
438 void acpi_pm_wakeup_event(struct device *dev)
439 {
440 	pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
441 }
442 EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
443 
444 static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
445 {
446 	struct acpi_device *adev;
447 
448 	if (val != ACPI_NOTIFY_DEVICE_WAKE)
449 		return;
450 
451 	acpi_handle_debug(handle, "Wake notify\n");
452 
453 	adev = acpi_bus_get_acpi_device(handle);
454 	if (!adev)
455 		return;
456 
457 	mutex_lock(&acpi_pm_notifier_lock);
458 
459 	if (adev->wakeup.flags.notifier_present) {
460 		pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
461 		if (adev->wakeup.context.func) {
462 			acpi_handle_debug(handle, "Running %pS for %s\n",
463 					  adev->wakeup.context.func,
464 					  dev_name(adev->wakeup.context.dev));
465 			adev->wakeup.context.func(&adev->wakeup.context);
466 		}
467 	}
468 
469 	mutex_unlock(&acpi_pm_notifier_lock);
470 
471 	acpi_bus_put_acpi_device(adev);
472 }
473 
474 /**
475  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
476  * @adev: ACPI device to add the notify handler for.
477  * @dev: Device to generate a wakeup event for while handling the notification.
478  * @func: Work function to execute when handling the notification.
479  *
480  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
481  * PM wakeup events.  For example, wakeup events may be generated for bridges
482  * if one of the devices below the bridge is signaling wakeup, even if the
483  * bridge itself doesn't have a wakeup GPE associated with it.
484  */
485 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
486 			void (*func)(struct acpi_device_wakeup_context *context))
487 {
488 	acpi_status status = AE_ALREADY_EXISTS;
489 
490 	if (!dev && !func)
491 		return AE_BAD_PARAMETER;
492 
493 	mutex_lock(&acpi_pm_notifier_install_lock);
494 
495 	if (adev->wakeup.flags.notifier_present)
496 		goto out;
497 
498 	status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
499 					     acpi_pm_notify_handler, NULL);
500 	if (ACPI_FAILURE(status))
501 		goto out;
502 
503 	mutex_lock(&acpi_pm_notifier_lock);
504 	adev->wakeup.ws = wakeup_source_register(&adev->dev,
505 						 dev_name(&adev->dev));
506 	adev->wakeup.context.dev = dev;
507 	adev->wakeup.context.func = func;
508 	adev->wakeup.flags.notifier_present = true;
509 	mutex_unlock(&acpi_pm_notifier_lock);
510 
511  out:
512 	mutex_unlock(&acpi_pm_notifier_install_lock);
513 	return status;
514 }
515 
516 /**
517  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
518  * @adev: ACPI device to remove the notifier from.
519  */
520 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
521 {
522 	acpi_status status = AE_BAD_PARAMETER;
523 
524 	mutex_lock(&acpi_pm_notifier_install_lock);
525 
526 	if (!adev->wakeup.flags.notifier_present)
527 		goto out;
528 
529 	status = acpi_remove_notify_handler(adev->handle,
530 					    ACPI_SYSTEM_NOTIFY,
531 					    acpi_pm_notify_handler);
532 	if (ACPI_FAILURE(status))
533 		goto out;
534 
535 	mutex_lock(&acpi_pm_notifier_lock);
536 	adev->wakeup.context.func = NULL;
537 	adev->wakeup.context.dev = NULL;
538 	wakeup_source_unregister(adev->wakeup.ws);
539 	adev->wakeup.flags.notifier_present = false;
540 	mutex_unlock(&acpi_pm_notifier_lock);
541 
542  out:
543 	mutex_unlock(&acpi_pm_notifier_install_lock);
544 	return status;
545 }
546 
547 bool acpi_bus_can_wakeup(acpi_handle handle)
548 {
549 	struct acpi_device *device;
550 	int result;
551 
552 	result = acpi_bus_get_device(handle, &device);
553 	return result ? false : device->wakeup.flags.valid;
554 }
555 EXPORT_SYMBOL(acpi_bus_can_wakeup);
556 
557 bool acpi_pm_device_can_wakeup(struct device *dev)
558 {
559 	struct acpi_device *adev = ACPI_COMPANION(dev);
560 
561 	return adev ? acpi_device_can_wakeup(adev) : false;
562 }
563 
564 /**
565  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
566  * @dev: Device whose preferred target power state to return.
567  * @adev: ACPI device node corresponding to @dev.
568  * @target_state: System state to match the resultant device state.
569  * @d_min_p: Location to store the highest power state available to the device.
570  * @d_max_p: Location to store the lowest power state available to the device.
571  *
572  * Find the lowest power (highest number) and highest power (lowest number) ACPI
573  * device power states that the device can be in while the system is in the
574  * state represented by @target_state.  Store the integer numbers representing
575  * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
576  * respectively.
577  *
578  * Callers must ensure that @dev and @adev are valid pointers and that @adev
579  * actually corresponds to @dev before using this function.
580  *
581  * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
582  * returns a value that doesn't make sense.  The memory locations pointed to by
583  * @d_max_p and @d_min_p are only modified on success.
584  */
585 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
586 				 u32 target_state, int *d_min_p, int *d_max_p)
587 {
588 	char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
589 	acpi_handle handle = adev->handle;
590 	unsigned long long ret;
591 	int d_min, d_max;
592 	bool wakeup = false;
593 	bool has_sxd = false;
594 	acpi_status status;
595 
596 	/*
597 	 * If the system state is S0, the lowest power state the device can be
598 	 * in is D3cold, unless the device has _S0W and is supposed to signal
599 	 * wakeup, in which case the return value of _S0W has to be used as the
600 	 * lowest power state available to the device.
601 	 */
602 	d_min = ACPI_STATE_D0;
603 	d_max = ACPI_STATE_D3_COLD;
604 
605 	/*
606 	 * If present, _SxD methods return the minimum D-state (highest power
607 	 * state) we can use for the corresponding S-states.  Otherwise, the
608 	 * minimum D-state is D0 (ACPI 3.x).
609 	 */
610 	if (target_state > ACPI_STATE_S0) {
611 		/*
612 		 * We rely on acpi_evaluate_integer() not clobbering the integer
613 		 * provided if AE_NOT_FOUND is returned.
614 		 */
615 		ret = d_min;
616 		status = acpi_evaluate_integer(handle, method, NULL, &ret);
617 		if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
618 		    || ret > ACPI_STATE_D3_COLD)
619 			return -ENODATA;
620 
621 		/*
622 		 * We need to handle legacy systems where D3hot and D3cold are
623 		 * the same and 3 is returned in both cases, so fall back to
624 		 * D3cold if D3hot is not a valid state.
625 		 */
626 		if (!adev->power.states[ret].flags.valid) {
627 			if (ret == ACPI_STATE_D3_HOT)
628 				ret = ACPI_STATE_D3_COLD;
629 			else
630 				return -ENODATA;
631 		}
632 
633 		if (status == AE_OK)
634 			has_sxd = true;
635 
636 		d_min = ret;
637 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
638 			&& adev->wakeup.sleep_state >= target_state;
639 	} else {
640 		wakeup = adev->wakeup.flags.valid;
641 	}
642 
643 	/*
644 	 * If _PRW says we can wake up the system from the target sleep state,
645 	 * the D-state returned by _SxD is sufficient for that (we assume a
646 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
647 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
648 	 * can wake the system.  _S0W may be valid, too.
649 	 */
650 	if (wakeup) {
651 		method[3] = 'W';
652 		status = acpi_evaluate_integer(handle, method, NULL, &ret);
653 		if (status == AE_NOT_FOUND) {
654 			/* No _SxW. In this case, the ACPI spec says that we
655 			 * must not go into any power state deeper than the
656 			 * value returned from _SxD.
657 			 */
658 			if (has_sxd && target_state > ACPI_STATE_S0)
659 				d_max = d_min;
660 		} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
661 			/* Fall back to D3cold if ret is not a valid state. */
662 			if (!adev->power.states[ret].flags.valid)
663 				ret = ACPI_STATE_D3_COLD;
664 
665 			d_max = ret > d_min ? ret : d_min;
666 		} else {
667 			return -ENODATA;
668 		}
669 	}
670 
671 	if (d_min_p)
672 		*d_min_p = d_min;
673 
674 	if (d_max_p)
675 		*d_max_p = d_max;
676 
677 	return 0;
678 }
679 
680 /**
681  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
682  * @dev: Device whose preferred target power state to return.
683  * @d_min_p: Location to store the upper limit of the allowed states range.
684  * @d_max_in: Deepest low-power state to take into consideration.
685  * Return value: Preferred power state of the device on success, -ENODEV
686  * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
687  * incorrect, or -ENODATA on ACPI method failure.
688  *
689  * The caller must ensure that @dev is valid before using this function.
690  */
691 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
692 {
693 	struct acpi_device *adev;
694 	int ret, d_min, d_max;
695 
696 	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
697 		return -EINVAL;
698 
699 	if (d_max_in > ACPI_STATE_D2) {
700 		enum pm_qos_flags_status stat;
701 
702 		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
703 		if (stat == PM_QOS_FLAGS_ALL)
704 			d_max_in = ACPI_STATE_D2;
705 	}
706 
707 	adev = ACPI_COMPANION(dev);
708 	if (!adev) {
709 		dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
710 		return -ENODEV;
711 	}
712 
713 	ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
714 				    &d_min, &d_max);
715 	if (ret)
716 		return ret;
717 
718 	if (d_max_in < d_min)
719 		return -EINVAL;
720 
721 	if (d_max > d_max_in) {
722 		for (d_max = d_max_in; d_max > d_min; d_max--) {
723 			if (adev->power.states[d_max].flags.valid)
724 				break;
725 		}
726 	}
727 
728 	if (d_min_p)
729 		*d_min_p = d_min;
730 
731 	return d_max;
732 }
733 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
734 
735 /**
736  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
737  * @context: Device wakeup context.
738  */
739 static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
740 {
741 	struct device *dev = context->dev;
742 
743 	if (dev) {
744 		pm_wakeup_event(dev, 0);
745 		pm_request_resume(dev);
746 	}
747 }
748 
749 static DEFINE_MUTEX(acpi_wakeup_lock);
750 
751 static int __acpi_device_wakeup_enable(struct acpi_device *adev,
752 				       u32 target_state, int max_count)
753 {
754 	struct acpi_device_wakeup *wakeup = &adev->wakeup;
755 	acpi_status status;
756 	int error = 0;
757 
758 	mutex_lock(&acpi_wakeup_lock);
759 
760 	if (wakeup->enable_count >= max_count)
761 		goto out;
762 
763 	if (wakeup->enable_count > 0)
764 		goto inc;
765 
766 	error = acpi_enable_wakeup_device_power(adev, target_state);
767 	if (error)
768 		goto out;
769 
770 	status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
771 	if (ACPI_FAILURE(status)) {
772 		acpi_disable_wakeup_device_power(adev);
773 		error = -EIO;
774 		goto out;
775 	}
776 
777 	acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
778 			  (unsigned int)wakeup->gpe_number);
779 
780 inc:
781 	wakeup->enable_count++;
782 
783 out:
784 	mutex_unlock(&acpi_wakeup_lock);
785 	return error;
786 }
787 
788 /**
789  * acpi_device_wakeup_enable - Enable wakeup functionality for device.
790  * @adev: ACPI device to enable wakeup functionality for.
791  * @target_state: State the system is transitioning into.
792  *
793  * Enable the GPE associated with @adev so that it can generate wakeup signals
794  * for the device in response to external (remote) events and enable wakeup
795  * power for it.
796  *
797  * Callers must ensure that @adev is a valid ACPI device node before executing
798  * this function.
799  */
800 static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
801 {
802 	return __acpi_device_wakeup_enable(adev, target_state, 1);
803 }
804 
805 /**
806  * acpi_device_wakeup_disable - Disable wakeup functionality for device.
807  * @adev: ACPI device to disable wakeup functionality for.
808  *
809  * Disable the GPE associated with @adev and disable wakeup power for it.
810  *
811  * Callers must ensure that @adev is a valid ACPI device node before executing
812  * this function.
813  */
814 static void acpi_device_wakeup_disable(struct acpi_device *adev)
815 {
816 	struct acpi_device_wakeup *wakeup = &adev->wakeup;
817 
818 	mutex_lock(&acpi_wakeup_lock);
819 
820 	if (!wakeup->enable_count)
821 		goto out;
822 
823 	acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
824 	acpi_disable_wakeup_device_power(adev);
825 
826 	wakeup->enable_count--;
827 
828 out:
829 	mutex_unlock(&acpi_wakeup_lock);
830 }
831 
832 static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable,
833 				       int max_count)
834 {
835 	struct acpi_device *adev;
836 	int error;
837 
838 	adev = ACPI_COMPANION(dev);
839 	if (!adev) {
840 		dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
841 		return -ENODEV;
842 	}
843 
844 	if (!acpi_device_can_wakeup(adev))
845 		return -EINVAL;
846 
847 	if (!enable) {
848 		acpi_device_wakeup_disable(adev);
849 		dev_dbg(dev, "Wakeup disabled by ACPI\n");
850 		return 0;
851 	}
852 
853 	error = __acpi_device_wakeup_enable(adev, acpi_target_system_state(),
854 					    max_count);
855 	if (!error)
856 		dev_dbg(dev, "Wakeup enabled by ACPI\n");
857 
858 	return error;
859 }
860 
861 /**
862  * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
863  * @dev: Device to enable/disable to generate wakeup events.
864  * @enable: Whether to enable or disable the wakeup functionality.
865  */
866 int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
867 {
868 	return __acpi_pm_set_device_wakeup(dev, enable, 1);
869 }
870 EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
871 
872 /**
873  * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge.
874  * @dev: Bridge device to enable/disable to generate wakeup events.
875  * @enable: Whether to enable or disable the wakeup functionality.
876  */
877 int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable)
878 {
879 	return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX);
880 }
881 EXPORT_SYMBOL_GPL(acpi_pm_set_bridge_wakeup);
882 
883 /**
884  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
885  * @dev: Device to put into a low-power state.
886  * @adev: ACPI device node corresponding to @dev.
887  * @system_state: System state to choose the device state for.
888  */
889 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
890 				 u32 system_state)
891 {
892 	int ret, state;
893 
894 	if (!acpi_device_power_manageable(adev))
895 		return 0;
896 
897 	ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
898 	return ret ? ret : acpi_device_set_power(adev, state);
899 }
900 
901 /**
902  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
903  * @adev: ACPI device node to put into the full-power state.
904  */
905 static int acpi_dev_pm_full_power(struct acpi_device *adev)
906 {
907 	return acpi_device_power_manageable(adev) ?
908 		acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
909 }
910 
911 /**
912  * acpi_dev_suspend - Put device into a low-power state using ACPI.
913  * @dev: Device to put into a low-power state.
914  * @wakeup: Whether or not to enable wakeup for the device.
915  *
916  * Put the given device into a low-power state using the standard ACPI
917  * mechanism.  Set up remote wakeup if desired, choose the state to put the
918  * device into (this checks if remote wakeup is expected to work too), and set
919  * the power state of the device.
920  */
921 int acpi_dev_suspend(struct device *dev, bool wakeup)
922 {
923 	struct acpi_device *adev = ACPI_COMPANION(dev);
924 	u32 target_state = acpi_target_system_state();
925 	int error;
926 
927 	if (!adev)
928 		return 0;
929 
930 	if (wakeup && acpi_device_can_wakeup(adev)) {
931 		error = acpi_device_wakeup_enable(adev, target_state);
932 		if (error)
933 			return -EAGAIN;
934 	} else {
935 		wakeup = false;
936 	}
937 
938 	error = acpi_dev_pm_low_power(dev, adev, target_state);
939 	if (error && wakeup)
940 		acpi_device_wakeup_disable(adev);
941 
942 	return error;
943 }
944 EXPORT_SYMBOL_GPL(acpi_dev_suspend);
945 
946 /**
947  * acpi_dev_resume - Put device into the full-power state using ACPI.
948  * @dev: Device to put into the full-power state.
949  *
950  * Put the given device into the full-power state using the standard ACPI
951  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
952  */
953 int acpi_dev_resume(struct device *dev)
954 {
955 	struct acpi_device *adev = ACPI_COMPANION(dev);
956 	int error;
957 
958 	if (!adev)
959 		return 0;
960 
961 	error = acpi_dev_pm_full_power(adev);
962 	acpi_device_wakeup_disable(adev);
963 	return error;
964 }
965 EXPORT_SYMBOL_GPL(acpi_dev_resume);
966 
967 /**
968  * acpi_subsys_runtime_suspend - Suspend device using ACPI.
969  * @dev: Device to suspend.
970  *
971  * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
972  * it into a runtime low-power state.
973  */
974 int acpi_subsys_runtime_suspend(struct device *dev)
975 {
976 	int ret = pm_generic_runtime_suspend(dev);
977 	return ret ? ret : acpi_dev_suspend(dev, true);
978 }
979 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
980 
981 /**
982  * acpi_subsys_runtime_resume - Resume device using ACPI.
983  * @dev: Device to Resume.
984  *
985  * Use ACPI to put the given device into the full-power state and carry out the
986  * generic runtime resume procedure for it.
987  */
988 int acpi_subsys_runtime_resume(struct device *dev)
989 {
990 	int ret = acpi_dev_resume(dev);
991 	return ret ? ret : pm_generic_runtime_resume(dev);
992 }
993 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
994 
995 #ifdef CONFIG_PM_SLEEP
996 static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
997 {
998 	u32 sys_target = acpi_target_system_state();
999 	int ret, state;
1000 
1001 	if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
1002 	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
1003 		return true;
1004 
1005 	if (sys_target == ACPI_STATE_S0)
1006 		return false;
1007 
1008 	if (adev->power.flags.dsw_present)
1009 		return true;
1010 
1011 	ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
1012 	if (ret)
1013 		return true;
1014 
1015 	return state != adev->power.state;
1016 }
1017 
1018 /**
1019  * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1020  * @dev: Device to prepare.
1021  */
1022 int acpi_subsys_prepare(struct device *dev)
1023 {
1024 	struct acpi_device *adev = ACPI_COMPANION(dev);
1025 
1026 	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
1027 		int ret = dev->driver->pm->prepare(dev);
1028 
1029 		if (ret < 0)
1030 			return ret;
1031 
1032 		if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
1033 			return 0;
1034 	}
1035 
1036 	return !acpi_dev_needs_resume(dev, adev);
1037 }
1038 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
1039 
1040 /**
1041  * acpi_subsys_complete - Finalize device's resume during system resume.
1042  * @dev: Device to handle.
1043  */
1044 void acpi_subsys_complete(struct device *dev)
1045 {
1046 	pm_generic_complete(dev);
1047 	/*
1048 	 * If the device had been runtime-suspended before the system went into
1049 	 * the sleep state it is going out of and it has never been resumed till
1050 	 * now, resume it in case the firmware powered it up.
1051 	 */
1052 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1053 		pm_request_resume(dev);
1054 }
1055 EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1056 
1057 /**
1058  * acpi_subsys_suspend - Run the device driver's suspend callback.
1059  * @dev: Device to handle.
1060  *
1061  * Follow PCI and resume devices from runtime suspend before running their
1062  * system suspend callbacks, unless the driver can cope with runtime-suspended
1063  * devices during system suspend and there are no ACPI-specific reasons for
1064  * resuming them.
1065  */
1066 int acpi_subsys_suspend(struct device *dev)
1067 {
1068 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1069 	    acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1070 		pm_runtime_resume(dev);
1071 
1072 	return pm_generic_suspend(dev);
1073 }
1074 EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1075 
1076 /**
1077  * acpi_subsys_suspend_late - Suspend device using ACPI.
1078  * @dev: Device to suspend.
1079  *
1080  * Carry out the generic late suspend procedure for @dev and use ACPI to put
1081  * it into a low-power state during system transition into a sleep state.
1082  */
1083 int acpi_subsys_suspend_late(struct device *dev)
1084 {
1085 	int ret;
1086 
1087 	if (dev_pm_smart_suspend_and_suspended(dev))
1088 		return 0;
1089 
1090 	ret = pm_generic_suspend_late(dev);
1091 	return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1092 }
1093 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1094 
1095 /**
1096  * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1097  * @dev: Device to suspend.
1098  */
1099 int acpi_subsys_suspend_noirq(struct device *dev)
1100 {
1101 	int ret;
1102 
1103 	if (dev_pm_smart_suspend_and_suspended(dev)) {
1104 		dev->power.may_skip_resume = true;
1105 		return 0;
1106 	}
1107 
1108 	ret = pm_generic_suspend_noirq(dev);
1109 	if (ret)
1110 		return ret;
1111 
1112 	/*
1113 	 * If the target system sleep state is suspend-to-idle, it is sufficient
1114 	 * to check whether or not the device's wakeup settings are good for
1115 	 * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
1116 	 * acpi_subsys_complete() to take care of fixing up the device's state
1117 	 * anyway, if need be.
1118 	 */
1119 	dev->power.may_skip_resume = device_may_wakeup(dev) ||
1120 					!device_can_wakeup(dev);
1121 
1122 	return 0;
1123 }
1124 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1125 
1126 /**
1127  * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1128  * @dev: Device to handle.
1129  */
1130 static int acpi_subsys_resume_noirq(struct device *dev)
1131 {
1132 	if (dev_pm_may_skip_resume(dev))
1133 		return 0;
1134 
1135 	/*
1136 	 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
1137 	 * during system suspend, so update their runtime PM status to "active"
1138 	 * as they will be put into D0 going forward.
1139 	 */
1140 	if (dev_pm_smart_suspend_and_suspended(dev))
1141 		pm_runtime_set_active(dev);
1142 
1143 	return pm_generic_resume_noirq(dev);
1144 }
1145 
1146 /**
1147  * acpi_subsys_resume_early - Resume device using ACPI.
1148  * @dev: Device to Resume.
1149  *
1150  * Use ACPI to put the given device into the full-power state and carry out the
1151  * generic early resume procedure for it during system transition into the
1152  * working state.
1153  */
1154 static int acpi_subsys_resume_early(struct device *dev)
1155 {
1156 	int ret = acpi_dev_resume(dev);
1157 	return ret ? ret : pm_generic_resume_early(dev);
1158 }
1159 
1160 /**
1161  * acpi_subsys_freeze - Run the device driver's freeze callback.
1162  * @dev: Device to handle.
1163  */
1164 int acpi_subsys_freeze(struct device *dev)
1165 {
1166 	/*
1167 	 * Resume all runtime-suspended devices before creating a snapshot
1168 	 * image of system memory, because the restore kernel generally cannot
1169 	 * be expected to always handle them consistently and they need to be
1170 	 * put into the runtime-active metastate during system resume anyway,
1171 	 * so it is better to ensure that the state saved in the image will be
1172 	 * always consistent with that.
1173 	 */
1174 	pm_runtime_resume(dev);
1175 
1176 	return pm_generic_freeze(dev);
1177 }
1178 EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1179 
1180 /**
1181  * acpi_subsys_restore_early - Restore device using ACPI.
1182  * @dev: Device to restore.
1183  */
1184 int acpi_subsys_restore_early(struct device *dev)
1185 {
1186 	int ret = acpi_dev_resume(dev);
1187 	return ret ? ret : pm_generic_restore_early(dev);
1188 }
1189 EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1190 
1191 /**
1192  * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1193  * @dev: Device to handle.
1194  *
1195  * Follow PCI and resume devices from runtime suspend before running their
1196  * system poweroff callbacks, unless the driver can cope with runtime-suspended
1197  * devices during system suspend and there are no ACPI-specific reasons for
1198  * resuming them.
1199  */
1200 int acpi_subsys_poweroff(struct device *dev)
1201 {
1202 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1203 	    acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1204 		pm_runtime_resume(dev);
1205 
1206 	return pm_generic_poweroff(dev);
1207 }
1208 EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1209 
1210 /**
1211  * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1212  * @dev: Device to handle.
1213  *
1214  * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1215  * it into a low-power state during system transition into a sleep state.
1216  */
1217 static int acpi_subsys_poweroff_late(struct device *dev)
1218 {
1219 	int ret;
1220 
1221 	if (dev_pm_smart_suspend_and_suspended(dev))
1222 		return 0;
1223 
1224 	ret = pm_generic_poweroff_late(dev);
1225 	if (ret)
1226 		return ret;
1227 
1228 	return acpi_dev_suspend(dev, device_may_wakeup(dev));
1229 }
1230 
1231 /**
1232  * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1233  * @dev: Device to suspend.
1234  */
1235 static int acpi_subsys_poweroff_noirq(struct device *dev)
1236 {
1237 	if (dev_pm_smart_suspend_and_suspended(dev))
1238 		return 0;
1239 
1240 	return pm_generic_poweroff_noirq(dev);
1241 }
1242 #endif /* CONFIG_PM_SLEEP */
1243 
1244 static struct dev_pm_domain acpi_general_pm_domain = {
1245 	.ops = {
1246 		.runtime_suspend = acpi_subsys_runtime_suspend,
1247 		.runtime_resume = acpi_subsys_runtime_resume,
1248 #ifdef CONFIG_PM_SLEEP
1249 		.prepare = acpi_subsys_prepare,
1250 		.complete = acpi_subsys_complete,
1251 		.suspend = acpi_subsys_suspend,
1252 		.suspend_late = acpi_subsys_suspend_late,
1253 		.suspend_noirq = acpi_subsys_suspend_noirq,
1254 		.resume_noirq = acpi_subsys_resume_noirq,
1255 		.resume_early = acpi_subsys_resume_early,
1256 		.freeze = acpi_subsys_freeze,
1257 		.poweroff = acpi_subsys_poweroff,
1258 		.poweroff_late = acpi_subsys_poweroff_late,
1259 		.poweroff_noirq = acpi_subsys_poweroff_noirq,
1260 		.restore_early = acpi_subsys_restore_early,
1261 #endif
1262 	},
1263 };
1264 
1265 /**
1266  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1267  * @dev: Device to take care of.
1268  * @power_off: Whether or not to try to remove power from the device.
1269  *
1270  * Remove the device from the general ACPI PM domain and remove its wakeup
1271  * notifier.  If @power_off is set, additionally remove power from the device if
1272  * possible.
1273  *
1274  * Callers must ensure proper synchronization of this function with power
1275  * management callbacks.
1276  */
1277 static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1278 {
1279 	struct acpi_device *adev = ACPI_COMPANION(dev);
1280 
1281 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1282 		dev_pm_domain_set(dev, NULL);
1283 		acpi_remove_pm_notifier(adev);
1284 		if (power_off) {
1285 			/*
1286 			 * If the device's PM QoS resume latency limit or flags
1287 			 * have been exposed to user space, they have to be
1288 			 * hidden at this point, so that they don't affect the
1289 			 * choice of the low-power state to put the device into.
1290 			 */
1291 			dev_pm_qos_hide_latency_limit(dev);
1292 			dev_pm_qos_hide_flags(dev);
1293 			acpi_device_wakeup_disable(adev);
1294 			acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1295 		}
1296 	}
1297 }
1298 
1299 /**
1300  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1301  * @dev: Device to prepare.
1302  * @power_on: Whether or not to power on the device.
1303  *
1304  * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1305  * attached to it, install a wakeup notification handler for the device and
1306  * add it to the general ACPI PM domain.  If @power_on is set, the device will
1307  * be put into the ACPI D0 state before the function returns.
1308  *
1309  * This assumes that the @dev's bus type uses generic power management callbacks
1310  * (or doesn't use any power management callbacks at all).
1311  *
1312  * Callers must ensure proper synchronization of this function with power
1313  * management callbacks.
1314  */
1315 int acpi_dev_pm_attach(struct device *dev, bool power_on)
1316 {
1317 	/*
1318 	 * Skip devices whose ACPI companions match the device IDs below,
1319 	 * because they require special power management handling incompatible
1320 	 * with the generic ACPI PM domain.
1321 	 */
1322 	static const struct acpi_device_id special_pm_ids[] = {
1323 		{"PNP0C0B", }, /* Generic ACPI fan */
1324 		{"INT1044", }, /* Fan for Tiger Lake generation */
1325 		{"INT3404", }, /* Fan */
1326 		{}
1327 	};
1328 	struct acpi_device *adev = ACPI_COMPANION(dev);
1329 
1330 	if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
1331 		return 0;
1332 
1333 	/*
1334 	 * Only attach the power domain to the first device if the
1335 	 * companion is shared by multiple. This is to prevent doing power
1336 	 * management twice.
1337 	 */
1338 	if (!acpi_device_is_first_physical_node(adev, dev))
1339 		return 0;
1340 
1341 	acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1342 	dev_pm_domain_set(dev, &acpi_general_pm_domain);
1343 	if (power_on) {
1344 		acpi_dev_pm_full_power(adev);
1345 		acpi_device_wakeup_disable(adev);
1346 	}
1347 
1348 	dev->pm_domain->detach = acpi_dev_pm_detach;
1349 	return 1;
1350 }
1351 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1352 #endif /* CONFIG_PM */
1353