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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * drivers/acpi/power.c - ACPI Power Resources management.
4 *
5 * Copyright (C) 2001 - 2015 Intel Corp.
6 * Author: Andy Grover <andrew.grover@intel.com>
7 * Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
8 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
9 */
10
11/*
12 * ACPI power-managed devices may be controlled in two ways:
13 * 1. via "Device Specific (D-State) Control"
14 * 2. via "Power Resource Control".
15 * The code below deals with ACPI Power Resources control.
16 *
17 * An ACPI "power resource object" represents a software controllable power
18 * plane, clock plane, or other resource depended on by a device.
19 *
20 * A device may rely on multiple power resources, and a power resource
21 * may be shared by multiple devices.
22 */
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/types.h>
28#include <linux/slab.h>
29#include <linux/pm_runtime.h>
30#include <linux/sysfs.h>
31#include <linux/acpi.h>
32#include "sleep.h"
33#include "internal.h"
34
35#define _COMPONENT ACPI_POWER_COMPONENT
36ACPI_MODULE_NAME("power");
37#define ACPI_POWER_CLASS "power_resource"
38#define ACPI_POWER_DEVICE_NAME "Power Resource"
39#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
40#define ACPI_POWER_RESOURCE_STATE_ON 0x01
41#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
42
43struct acpi_power_dependent_device {
44 struct device *dev;
45 struct list_head node;
46};
47
48struct acpi_power_resource {
49 struct acpi_device device;
50 struct list_head list_node;
51 char *name;
52 u32 system_level;
53 u32 order;
54 unsigned int ref_count;
55 bool wakeup_enabled;
56 struct mutex resource_lock;
57 struct list_head dependents;
58};
59
60struct acpi_power_resource_entry {
61 struct list_head node;
62 struct acpi_power_resource *resource;
63};
64
65static LIST_HEAD(acpi_power_resource_list);
66static DEFINE_MUTEX(power_resource_list_lock);
67
68/* --------------------------------------------------------------------------
69 Power Resource Management
70 -------------------------------------------------------------------------- */
71
72static inline
73struct acpi_power_resource *to_power_resource(struct acpi_device *device)
74{
75 return container_of(device, struct acpi_power_resource, device);
76}
77
78static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
79{
80 struct acpi_device *device;
81
82 if (acpi_bus_get_device(handle, &device))
83 return NULL;
84
85 return to_power_resource(device);
86}
87
88static int acpi_power_resources_list_add(acpi_handle handle,
89 struct list_head *list)
90{
91 struct acpi_power_resource *resource = acpi_power_get_context(handle);
92 struct acpi_power_resource_entry *entry;
93
94 if (!resource || !list)
95 return -EINVAL;
96
97 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
98 if (!entry)
99 return -ENOMEM;
100
101 entry->resource = resource;
102 if (!list_empty(list)) {
103 struct acpi_power_resource_entry *e;
104
105 list_for_each_entry(e, list, node)
106 if (e->resource->order > resource->order) {
107 list_add_tail(&entry->node, &e->node);
108 return 0;
109 }
110 }
111 list_add_tail(&entry->node, list);
112 return 0;
113}
114
115void acpi_power_resources_list_free(struct list_head *list)
116{
117 struct acpi_power_resource_entry *entry, *e;
118
119 list_for_each_entry_safe(entry, e, list, node) {
120 list_del(&entry->node);
121 kfree(entry);
122 }
123}
124
125static bool acpi_power_resource_is_dup(union acpi_object *package,
126 unsigned int start, unsigned int i)
127{
128 acpi_handle rhandle, dup;
129 unsigned int j;
130
131 /* The caller is expected to check the package element types */
132 rhandle = package->package.elements[i].reference.handle;
133 for (j = start; j < i; j++) {
134 dup = package->package.elements[j].reference.handle;
135 if (dup == rhandle)
136 return true;
137 }
138
139 return false;
140}
141
142int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
143 struct list_head *list)
144{
145 unsigned int i;
146 int err = 0;
147
148 for (i = start; i < package->package.count; i++) {
149 union acpi_object *element = &package->package.elements[i];
150 acpi_handle rhandle;
151
152 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
153 err = -ENODATA;
154 break;
155 }
156 rhandle = element->reference.handle;
157 if (!rhandle) {
158 err = -ENODEV;
159 break;
160 }
161
162 /* Some ACPI tables contain duplicate power resource references */
163 if (acpi_power_resource_is_dup(package, start, i))
164 continue;
165
166 err = acpi_add_power_resource(rhandle);
167 if (err)
168 break;
169
170 err = acpi_power_resources_list_add(rhandle, list);
171 if (err)
172 break;
173 }
174 if (err)
175 acpi_power_resources_list_free(list);
176
177 return err;
178}
179
180static int acpi_power_get_state(acpi_handle handle, int *state)
181{
182 acpi_status status = AE_OK;
183 unsigned long long sta = 0;
184 char node_name[5];
185 struct acpi_buffer buffer = { sizeof(node_name), node_name };
186
187
188 if (!handle || !state)
189 return -EINVAL;
190
191 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
192 if (ACPI_FAILURE(status))
193 return -ENODEV;
194
195 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
196 ACPI_POWER_RESOURCE_STATE_OFF;
197
198 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
199
200 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
201 node_name,
202 *state ? "on" : "off"));
203
204 return 0;
205}
206
207static int acpi_power_get_list_state(struct list_head *list, int *state)
208{
209 struct acpi_power_resource_entry *entry;
210 int cur_state;
211
212 if (!list || !state)
213 return -EINVAL;
214
215 /* The state of the list is 'on' IFF all resources are 'on'. */
216 cur_state = 0;
217 list_for_each_entry(entry, list, node) {
218 struct acpi_power_resource *resource = entry->resource;
219 acpi_handle handle = resource->device.handle;
220 int result;
221
222 mutex_lock(&resource->resource_lock);
223 result = acpi_power_get_state(handle, &cur_state);
224 mutex_unlock(&resource->resource_lock);
225 if (result)
226 return result;
227
228 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
229 break;
230 }
231
232 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
233 cur_state ? "on" : "off"));
234
235 *state = cur_state;
236 return 0;
237}
238
239static int
240acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
241 struct device *dev)
242{
243 struct acpi_power_dependent_device *dep;
244 int ret = 0;
245
246 mutex_lock(&resource->resource_lock);
247 list_for_each_entry(dep, &resource->dependents, node) {
248 /* Only add it once */
249 if (dep->dev == dev)
250 goto unlock;
251 }
252
253 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
254 if (!dep) {
255 ret = -ENOMEM;
256 goto unlock;
257 }
258
259 dep->dev = dev;
260 list_add_tail(&dep->node, &resource->dependents);
261 dev_dbg(dev, "added power dependency to [%s]\n", resource->name);
262
263unlock:
264 mutex_unlock(&resource->resource_lock);
265 return ret;
266}
267
268static void
269acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
270 struct device *dev)
271{
272 struct acpi_power_dependent_device *dep;
273
274 mutex_lock(&resource->resource_lock);
275 list_for_each_entry(dep, &resource->dependents, node) {
276 if (dep->dev == dev) {
277 list_del(&dep->node);
278 kfree(dep);
279 dev_dbg(dev, "removed power dependency to [%s]\n",
280 resource->name);
281 break;
282 }
283 }
284 mutex_unlock(&resource->resource_lock);
285}
286
287/**
288 * acpi_device_power_add_dependent - Add dependent device of this ACPI device
289 * @adev: ACPI device pointer
290 * @dev: Dependent device
291 *
292 * If @adev has non-empty _PR0 the @dev is added as dependent device to all
293 * power resources returned by it. This means that whenever these power
294 * resources are turned _ON the dependent devices get runtime resumed. This
295 * is needed for devices such as PCI to allow its driver to re-initialize
296 * it after it went to D0uninitialized.
297 *
298 * If @adev does not have _PR0 this does nothing.
299 *
300 * Returns %0 in case of success and negative errno otherwise.
301 */
302int acpi_device_power_add_dependent(struct acpi_device *adev,
303 struct device *dev)
304{
305 struct acpi_power_resource_entry *entry;
306 struct list_head *resources;
307 int ret;
308
309 if (!adev->flags.power_manageable)
310 return 0;
311
312 resources = &adev->power.states[ACPI_STATE_D0].resources;
313 list_for_each_entry(entry, resources, node) {
314 ret = acpi_power_resource_add_dependent(entry->resource, dev);
315 if (ret)
316 goto err;
317 }
318
319 return 0;
320
321err:
322 list_for_each_entry(entry, resources, node)
323 acpi_power_resource_remove_dependent(entry->resource, dev);
324
325 return ret;
326}
327
328/**
329 * acpi_device_power_remove_dependent - Remove dependent device
330 * @adev: ACPI device pointer
331 * @dev: Dependent device
332 *
333 * Does the opposite of acpi_device_power_add_dependent() and removes the
334 * dependent device if it is found. Can be called to @adev that does not
335 * have _PR0 as well.
336 */
337void acpi_device_power_remove_dependent(struct acpi_device *adev,
338 struct device *dev)
339{
340 struct acpi_power_resource_entry *entry;
341 struct list_head *resources;
342
343 if (!adev->flags.power_manageable)
344 return;
345
346 resources = &adev->power.states[ACPI_STATE_D0].resources;
347 list_for_each_entry_reverse(entry, resources, node)
348 acpi_power_resource_remove_dependent(entry->resource, dev);
349}
350
351static int __acpi_power_on(struct acpi_power_resource *resource)
352{
353 struct acpi_power_dependent_device *dep;
354 acpi_status status = AE_OK;
355
356 status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
357 if (ACPI_FAILURE(status))
358 return -ENODEV;
359
360 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
361 resource->name));
362
363 /*
364 * If there are other dependents on this power resource we need to
365 * resume them now so that their drivers can re-initialize the
366 * hardware properly after it went back to D0.
367 */
368 if (list_empty(&resource->dependents) ||
369 list_is_singular(&resource->dependents))
370 return 0;
371
372 list_for_each_entry(dep, &resource->dependents, node) {
373 dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
374 resource->name);
375 pm_request_resume(dep->dev);
376 }
377
378 return 0;
379}
380
381static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
382{
383 int result = 0;
384
385 if (resource->ref_count++) {
386 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
387 "Power resource [%s] already on\n",
388 resource->name));
389 } else {
390 result = __acpi_power_on(resource);
391 if (result)
392 resource->ref_count--;
393 }
394 return result;
395}
396
397static int acpi_power_on(struct acpi_power_resource *resource)
398{
399 int result;
400
401 mutex_lock(&resource->resource_lock);
402 result = acpi_power_on_unlocked(resource);
403 mutex_unlock(&resource->resource_lock);
404 return result;
405}
406
407static int __acpi_power_off(struct acpi_power_resource *resource)
408{
409 acpi_status status;
410
411 status = acpi_evaluate_object(resource->device.handle, "_OFF",
412 NULL, NULL);
413 if (ACPI_FAILURE(status))
414 return -ENODEV;
415
416 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
417 resource->name));
418 return 0;
419}
420
421static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
422{
423 int result = 0;
424
425 if (!resource->ref_count) {
426 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
427 "Power resource [%s] already off\n",
428 resource->name));
429 return 0;
430 }
431
432 if (--resource->ref_count) {
433 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
434 "Power resource [%s] still in use\n",
435 resource->name));
436 } else {
437 result = __acpi_power_off(resource);
438 if (result)
439 resource->ref_count++;
440 }
441 return result;
442}
443
444static int acpi_power_off(struct acpi_power_resource *resource)
445{
446 int result;
447
448 mutex_lock(&resource->resource_lock);
449 result = acpi_power_off_unlocked(resource);
450 mutex_unlock(&resource->resource_lock);
451 return result;
452}
453
454static int acpi_power_off_list(struct list_head *list)
455{
456 struct acpi_power_resource_entry *entry;
457 int result = 0;
458
459 list_for_each_entry_reverse(entry, list, node) {
460 result = acpi_power_off(entry->resource);
461 if (result)
462 goto err;
463 }
464 return 0;
465
466 err:
467 list_for_each_entry_continue(entry, list, node)
468 acpi_power_on(entry->resource);
469
470 return result;
471}
472
473static int acpi_power_on_list(struct list_head *list)
474{
475 struct acpi_power_resource_entry *entry;
476 int result = 0;
477
478 list_for_each_entry(entry, list, node) {
479 result = acpi_power_on(entry->resource);
480 if (result)
481 goto err;
482 }
483 return 0;
484
485 err:
486 list_for_each_entry_continue_reverse(entry, list, node)
487 acpi_power_off(entry->resource);
488
489 return result;
490}
491
492static struct attribute *attrs[] = {
493 NULL,
494};
495
496static const struct attribute_group attr_groups[] = {
497 [ACPI_STATE_D0] = {
498 .name = "power_resources_D0",
499 .attrs = attrs,
500 },
501 [ACPI_STATE_D1] = {
502 .name = "power_resources_D1",
503 .attrs = attrs,
504 },
505 [ACPI_STATE_D2] = {
506 .name = "power_resources_D2",
507 .attrs = attrs,
508 },
509 [ACPI_STATE_D3_HOT] = {
510 .name = "power_resources_D3hot",
511 .attrs = attrs,
512 },
513};
514
515static const struct attribute_group wakeup_attr_group = {
516 .name = "power_resources_wakeup",
517 .attrs = attrs,
518};
519
520static void acpi_power_hide_list(struct acpi_device *adev,
521 struct list_head *resources,
522 const struct attribute_group *attr_group)
523{
524 struct acpi_power_resource_entry *entry;
525
526 if (list_empty(resources))
527 return;
528
529 list_for_each_entry_reverse(entry, resources, node) {
530 struct acpi_device *res_dev = &entry->resource->device;
531
532 sysfs_remove_link_from_group(&adev->dev.kobj,
533 attr_group->name,
534 dev_name(&res_dev->dev));
535 }
536 sysfs_remove_group(&adev->dev.kobj, attr_group);
537}
538
539static void acpi_power_expose_list(struct acpi_device *adev,
540 struct list_head *resources,
541 const struct attribute_group *attr_group)
542{
543 struct acpi_power_resource_entry *entry;
544 int ret;
545
546 if (list_empty(resources))
547 return;
548
549 ret = sysfs_create_group(&adev->dev.kobj, attr_group);
550 if (ret)
551 return;
552
553 list_for_each_entry(entry, resources, node) {
554 struct acpi_device *res_dev = &entry->resource->device;
555
556 ret = sysfs_add_link_to_group(&adev->dev.kobj,
557 attr_group->name,
558 &res_dev->dev.kobj,
559 dev_name(&res_dev->dev));
560 if (ret) {
561 acpi_power_hide_list(adev, resources, attr_group);
562 break;
563 }
564 }
565}
566
567static void acpi_power_expose_hide(struct acpi_device *adev,
568 struct list_head *resources,
569 const struct attribute_group *attr_group,
570 bool expose)
571{
572 if (expose)
573 acpi_power_expose_list(adev, resources, attr_group);
574 else
575 acpi_power_hide_list(adev, resources, attr_group);
576}
577
578void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
579{
580 int state;
581
582 if (adev->wakeup.flags.valid)
583 acpi_power_expose_hide(adev, &adev->wakeup.resources,
584 &wakeup_attr_group, add);
585
586 if (!adev->power.flags.power_resources)
587 return;
588
589 for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
590 acpi_power_expose_hide(adev,
591 &adev->power.states[state].resources,
592 &attr_groups[state], add);
593}
594
595int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
596{
597 struct acpi_power_resource_entry *entry;
598 int system_level = 5;
599
600 list_for_each_entry(entry, list, node) {
601 struct acpi_power_resource *resource = entry->resource;
602 acpi_handle handle = resource->device.handle;
603 int result;
604 int state;
605
606 mutex_lock(&resource->resource_lock);
607
608 result = acpi_power_get_state(handle, &state);
609 if (result) {
610 mutex_unlock(&resource->resource_lock);
611 return result;
612 }
613 if (state == ACPI_POWER_RESOURCE_STATE_ON) {
614 resource->ref_count++;
615 resource->wakeup_enabled = true;
616 }
617 if (system_level > resource->system_level)
618 system_level = resource->system_level;
619
620 mutex_unlock(&resource->resource_lock);
621 }
622 *system_level_p = system_level;
623 return 0;
624}
625
626/* --------------------------------------------------------------------------
627 Device Power Management
628 -------------------------------------------------------------------------- */
629
630/**
631 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
632 * ACPI 3.0) _PSW (Power State Wake)
633 * @dev: Device to handle.
634 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
635 * @sleep_state: Target sleep state of the system.
636 * @dev_state: Target power state of the device.
637 *
638 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
639 * State Wake) for the device, if present. On failure reset the device's
640 * wakeup.flags.valid flag.
641 *
642 * RETURN VALUE:
643 * 0 if either _DSW or _PSW has been successfully executed
644 * 0 if neither _DSW nor _PSW has been found
645 * -ENODEV if the execution of either _DSW or _PSW has failed
646 */
647int acpi_device_sleep_wake(struct acpi_device *dev,
648 int enable, int sleep_state, int dev_state)
649{
650 union acpi_object in_arg[3];
651 struct acpi_object_list arg_list = { 3, in_arg };
652 acpi_status status = AE_OK;
653
654 /*
655 * Try to execute _DSW first.
656 *
657 * Three arguments are needed for the _DSW object:
658 * Argument 0: enable/disable the wake capabilities
659 * Argument 1: target system state
660 * Argument 2: target device state
661 * When _DSW object is called to disable the wake capabilities, maybe
662 * the first argument is filled. The values of the other two arguments
663 * are meaningless.
664 */
665 in_arg[0].type = ACPI_TYPE_INTEGER;
666 in_arg[0].integer.value = enable;
667 in_arg[1].type = ACPI_TYPE_INTEGER;
668 in_arg[1].integer.value = sleep_state;
669 in_arg[2].type = ACPI_TYPE_INTEGER;
670 in_arg[2].integer.value = dev_state;
671 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
672 if (ACPI_SUCCESS(status)) {
673 return 0;
674 } else if (status != AE_NOT_FOUND) {
675 printk(KERN_ERR PREFIX "_DSW execution failed\n");
676 dev->wakeup.flags.valid = 0;
677 return -ENODEV;
678 }
679
680 /* Execute _PSW */
681 status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
682 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
683 printk(KERN_ERR PREFIX "_PSW execution failed\n");
684 dev->wakeup.flags.valid = 0;
685 return -ENODEV;
686 }
687
688 return 0;
689}
690
691/*
692 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
693 * 1. Power on the power resources required for the wakeup device
694 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
695 * State Wake) for the device, if present
696 */
697int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
698{
699 struct acpi_power_resource_entry *entry;
700 int err = 0;
701
702 if (!dev || !dev->wakeup.flags.valid)
703 return -EINVAL;
704
705 mutex_lock(&acpi_device_lock);
706
707 if (dev->wakeup.prepare_count++)
708 goto out;
709
710 list_for_each_entry(entry, &dev->wakeup.resources, node) {
711 struct acpi_power_resource *resource = entry->resource;
712
713 mutex_lock(&resource->resource_lock);
714
715 if (!resource->wakeup_enabled) {
716 err = acpi_power_on_unlocked(resource);
717 if (!err)
718 resource->wakeup_enabled = true;
719 }
720
721 mutex_unlock(&resource->resource_lock);
722
723 if (err) {
724 dev_err(&dev->dev,
725 "Cannot turn wakeup power resources on\n");
726 dev->wakeup.flags.valid = 0;
727 goto out;
728 }
729 }
730 /*
731 * Passing 3 as the third argument below means the device may be
732 * put into arbitrary power state afterward.
733 */
734 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
735 if (err)
736 dev->wakeup.prepare_count = 0;
737
738 out:
739 mutex_unlock(&acpi_device_lock);
740 return err;
741}
742
743/*
744 * Shutdown a wakeup device, counterpart of above method
745 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
746 * State Wake) for the device, if present
747 * 2. Shutdown down the power resources
748 */
749int acpi_disable_wakeup_device_power(struct acpi_device *dev)
750{
751 struct acpi_power_resource_entry *entry;
752 int err = 0;
753
754 if (!dev || !dev->wakeup.flags.valid)
755 return -EINVAL;
756
757 mutex_lock(&acpi_device_lock);
758
759 if (--dev->wakeup.prepare_count > 0)
760 goto out;
761
762 /*
763 * Executing the code below even if prepare_count is already zero when
764 * the function is called may be useful, for example for initialisation.
765 */
766 if (dev->wakeup.prepare_count < 0)
767 dev->wakeup.prepare_count = 0;
768
769 err = acpi_device_sleep_wake(dev, 0, 0, 0);
770 if (err)
771 goto out;
772
773 list_for_each_entry(entry, &dev->wakeup.resources, node) {
774 struct acpi_power_resource *resource = entry->resource;
775
776 mutex_lock(&resource->resource_lock);
777
778 if (resource->wakeup_enabled) {
779 err = acpi_power_off_unlocked(resource);
780 if (!err)
781 resource->wakeup_enabled = false;
782 }
783
784 mutex_unlock(&resource->resource_lock);
785
786 if (err) {
787 dev_err(&dev->dev,
788 "Cannot turn wakeup power resources off\n");
789 dev->wakeup.flags.valid = 0;
790 break;
791 }
792 }
793
794 out:
795 mutex_unlock(&acpi_device_lock);
796 return err;
797}
798
799int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
800{
801 int result = 0;
802 int list_state = 0;
803 int i = 0;
804
805 if (!device || !state)
806 return -EINVAL;
807
808 /*
809 * We know a device's inferred power state when all the resources
810 * required for a given D-state are 'on'.
811 */
812 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
813 struct list_head *list = &device->power.states[i].resources;
814
815 if (list_empty(list))
816 continue;
817
818 result = acpi_power_get_list_state(list, &list_state);
819 if (result)
820 return result;
821
822 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
823 *state = i;
824 return 0;
825 }
826 }
827
828 *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
829 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
830 return 0;
831}
832
833int acpi_power_on_resources(struct acpi_device *device, int state)
834{
835 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
836 return -EINVAL;
837
838 return acpi_power_on_list(&device->power.states[state].resources);
839}
840
841int acpi_power_transition(struct acpi_device *device, int state)
842{
843 int result = 0;
844
845 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
846 return -EINVAL;
847
848 if (device->power.state == state || !device->flags.power_manageable)
849 return 0;
850
851 if ((device->power.state < ACPI_STATE_D0)
852 || (device->power.state > ACPI_STATE_D3_COLD))
853 return -ENODEV;
854
855 /*
856 * First we reference all power resources required in the target list
857 * (e.g. so the device doesn't lose power while transitioning). Then,
858 * we dereference all power resources used in the current list.
859 */
860 if (state < ACPI_STATE_D3_COLD)
861 result = acpi_power_on_list(
862 &device->power.states[state].resources);
863
864 if (!result && device->power.state < ACPI_STATE_D3_COLD)
865 acpi_power_off_list(
866 &device->power.states[device->power.state].resources);
867
868 /* We shouldn't change the state unless the above operations succeed. */
869 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
870
871 return result;
872}
873
874static void acpi_release_power_resource(struct device *dev)
875{
876 struct acpi_device *device = to_acpi_device(dev);
877 struct acpi_power_resource *resource;
878
879 resource = container_of(device, struct acpi_power_resource, device);
880
881 mutex_lock(&power_resource_list_lock);
882 list_del(&resource->list_node);
883 mutex_unlock(&power_resource_list_lock);
884
885 acpi_free_pnp_ids(&device->pnp);
886 kfree(resource);
887}
888
889static ssize_t acpi_power_in_use_show(struct device *dev,
890 struct device_attribute *attr,
891 char *buf) {
892 struct acpi_power_resource *resource;
893
894 resource = to_power_resource(to_acpi_device(dev));
895 return sprintf(buf, "%u\n", !!resource->ref_count);
896}
897static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
898
899static void acpi_power_sysfs_remove(struct acpi_device *device)
900{
901 device_remove_file(&device->dev, &dev_attr_resource_in_use);
902}
903
904static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
905{
906 mutex_lock(&power_resource_list_lock);
907
908 if (!list_empty(&acpi_power_resource_list)) {
909 struct acpi_power_resource *r;
910
911 list_for_each_entry(r, &acpi_power_resource_list, list_node)
912 if (r->order > resource->order) {
913 list_add_tail(&resource->list_node, &r->list_node);
914 goto out;
915 }
916 }
917 list_add_tail(&resource->list_node, &acpi_power_resource_list);
918
919 out:
920 mutex_unlock(&power_resource_list_lock);
921}
922
923int acpi_add_power_resource(acpi_handle handle)
924{
925 struct acpi_power_resource *resource;
926 struct acpi_device *device = NULL;
927 union acpi_object acpi_object;
928 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
929 acpi_status status;
930 int state, result = -ENODEV;
931
932 acpi_bus_get_device(handle, &device);
933 if (device)
934 return 0;
935
936 resource = kzalloc(sizeof(*resource), GFP_KERNEL);
937 if (!resource)
938 return -ENOMEM;
939
940 device = &resource->device;
941 acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
942 ACPI_STA_DEFAULT);
943 mutex_init(&resource->resource_lock);
944 INIT_LIST_HEAD(&resource->list_node);
945 INIT_LIST_HEAD(&resource->dependents);
946 resource->name = device->pnp.bus_id;
947 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
948 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
949 device->power.state = ACPI_STATE_UNKNOWN;
950
951 /* Evalute the object to get the system level and resource order. */
952 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
953 if (ACPI_FAILURE(status))
954 goto err;
955
956 resource->system_level = acpi_object.power_resource.system_level;
957 resource->order = acpi_object.power_resource.resource_order;
958
959 result = acpi_power_get_state(handle, &state);
960 if (result)
961 goto err;
962
963 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
964 acpi_device_bid(device), state ? "on" : "off");
965
966 device->flags.match_driver = true;
967 result = acpi_device_add(device, acpi_release_power_resource);
968 if (result)
969 goto err;
970
971 if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
972 device->remove = acpi_power_sysfs_remove;
973
974 acpi_power_add_resource_to_list(resource);
975 acpi_device_add_finalize(device);
976 return 0;
977
978 err:
979 acpi_release_power_resource(&device->dev);
980 return result;
981}
982
983#ifdef CONFIG_ACPI_SLEEP
984void acpi_resume_power_resources(void)
985{
986 struct acpi_power_resource *resource;
987
988 mutex_lock(&power_resource_list_lock);
989
990 list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
991 int result, state;
992
993 mutex_lock(&resource->resource_lock);
994
995 result = acpi_power_get_state(resource->device.handle, &state);
996 if (result) {
997 mutex_unlock(&resource->resource_lock);
998 continue;
999 }
1000
1001 if (state == ACPI_POWER_RESOURCE_STATE_OFF
1002 && resource->ref_count) {
1003 dev_info(&resource->device.dev, "Turning ON\n");
1004 __acpi_power_on(resource);
1005 }
1006
1007 mutex_unlock(&resource->resource_lock);
1008 }
1009
1010 mutex_unlock(&power_resource_list_lock);
1011}
1012
1013void acpi_turn_off_unused_power_resources(void)
1014{
1015 struct acpi_power_resource *resource;
1016
1017 mutex_lock(&power_resource_list_lock);
1018
1019 list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
1020 int result, state;
1021
1022 mutex_lock(&resource->resource_lock);
1023
1024 result = acpi_power_get_state(resource->device.handle, &state);
1025 if (result) {
1026 mutex_unlock(&resource->resource_lock);
1027 continue;
1028 }
1029
1030 if (state == ACPI_POWER_RESOURCE_STATE_ON
1031 && !resource->ref_count) {
1032 dev_info(&resource->device.dev, "Turning OFF\n");
1033 __acpi_power_off(resource);
1034 }
1035
1036 mutex_unlock(&resource->resource_lock);
1037 }
1038
1039 mutex_unlock(&power_resource_list_lock);
1040}
1041#endif
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * drivers/acpi/power.c - ACPI Power Resources management.
4 *
5 * Copyright (C) 2001 - 2015 Intel Corp.
6 * Author: Andy Grover <andrew.grover@intel.com>
7 * Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
8 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
9 */
10
11/*
12 * ACPI power-managed devices may be controlled in two ways:
13 * 1. via "Device Specific (D-State) Control"
14 * 2. via "Power Resource Control".
15 * The code below deals with ACPI Power Resources control.
16 *
17 * An ACPI "power resource object" represents a software controllable power
18 * plane, clock plane, or other resource depended on by a device.
19 *
20 * A device may rely on multiple power resources, and a power resource
21 * may be shared by multiple devices.
22 */
23
24#define pr_fmt(fmt) "ACPI: PM: " fmt
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/slab.h>
31#include <linux/pm_runtime.h>
32#include <linux/sysfs.h>
33#include <linux/acpi.h>
34#include "sleep.h"
35#include "internal.h"
36
37#define ACPI_POWER_CLASS "power_resource"
38#define ACPI_POWER_DEVICE_NAME "Power Resource"
39#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
40#define ACPI_POWER_RESOURCE_STATE_ON 0x01
41#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
42
43struct acpi_power_dependent_device {
44 struct device *dev;
45 struct list_head node;
46};
47
48struct acpi_power_resource {
49 struct acpi_device device;
50 struct list_head list_node;
51 u32 system_level;
52 u32 order;
53 unsigned int ref_count;
54 u8 state;
55 struct mutex resource_lock;
56 struct list_head dependents;
57};
58
59struct acpi_power_resource_entry {
60 struct list_head node;
61 struct acpi_power_resource *resource;
62};
63
64static LIST_HEAD(acpi_power_resource_list);
65static DEFINE_MUTEX(power_resource_list_lock);
66
67/* --------------------------------------------------------------------------
68 Power Resource Management
69 -------------------------------------------------------------------------- */
70
71static inline const char *resource_dev_name(struct acpi_power_resource *pr)
72{
73 return dev_name(&pr->device.dev);
74}
75
76static inline
77struct acpi_power_resource *to_power_resource(struct acpi_device *device)
78{
79 return container_of(device, struct acpi_power_resource, device);
80}
81
82static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
83{
84 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
85
86 if (!device)
87 return NULL;
88
89 return to_power_resource(device);
90}
91
92static int acpi_power_resources_list_add(acpi_handle handle,
93 struct list_head *list)
94{
95 struct acpi_power_resource *resource = acpi_power_get_context(handle);
96 struct acpi_power_resource_entry *entry;
97
98 if (!resource || !list)
99 return -EINVAL;
100
101 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
102 if (!entry)
103 return -ENOMEM;
104
105 entry->resource = resource;
106 if (!list_empty(list)) {
107 struct acpi_power_resource_entry *e;
108
109 list_for_each_entry(e, list, node)
110 if (e->resource->order > resource->order) {
111 list_add_tail(&entry->node, &e->node);
112 return 0;
113 }
114 }
115 list_add_tail(&entry->node, list);
116 return 0;
117}
118
119void acpi_power_resources_list_free(struct list_head *list)
120{
121 struct acpi_power_resource_entry *entry, *e;
122
123 list_for_each_entry_safe(entry, e, list, node) {
124 list_del(&entry->node);
125 kfree(entry);
126 }
127}
128
129static bool acpi_power_resource_is_dup(union acpi_object *package,
130 unsigned int start, unsigned int i)
131{
132 acpi_handle rhandle, dup;
133 unsigned int j;
134
135 /* The caller is expected to check the package element types */
136 rhandle = package->package.elements[i].reference.handle;
137 for (j = start; j < i; j++) {
138 dup = package->package.elements[j].reference.handle;
139 if (dup == rhandle)
140 return true;
141 }
142
143 return false;
144}
145
146int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
147 struct list_head *list)
148{
149 unsigned int i;
150 int err = 0;
151
152 for (i = start; i < package->package.count; i++) {
153 union acpi_object *element = &package->package.elements[i];
154 struct acpi_device *rdev;
155 acpi_handle rhandle;
156
157 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
158 err = -ENODATA;
159 break;
160 }
161 rhandle = element->reference.handle;
162 if (!rhandle) {
163 err = -ENODEV;
164 break;
165 }
166
167 /* Some ACPI tables contain duplicate power resource references */
168 if (acpi_power_resource_is_dup(package, start, i))
169 continue;
170
171 rdev = acpi_add_power_resource(rhandle);
172 if (!rdev) {
173 err = -ENODEV;
174 break;
175 }
176 err = acpi_power_resources_list_add(rhandle, list);
177 if (err)
178 break;
179 }
180 if (err)
181 acpi_power_resources_list_free(list);
182
183 return err;
184}
185
186static int __get_state(acpi_handle handle, u8 *state)
187{
188 acpi_status status = AE_OK;
189 unsigned long long sta = 0;
190 u8 cur_state;
191
192 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
193 if (ACPI_FAILURE(status))
194 return -ENODEV;
195
196 cur_state = sta & ACPI_POWER_RESOURCE_STATE_ON;
197
198 acpi_handle_debug(handle, "Power resource is %s\n",
199 cur_state ? "on" : "off");
200
201 *state = cur_state;
202 return 0;
203}
204
205static int acpi_power_get_state(struct acpi_power_resource *resource, u8 *state)
206{
207 if (resource->state == ACPI_POWER_RESOURCE_STATE_UNKNOWN) {
208 int ret;
209
210 ret = __get_state(resource->device.handle, &resource->state);
211 if (ret)
212 return ret;
213 }
214
215 *state = resource->state;
216 return 0;
217}
218
219static int acpi_power_get_list_state(struct list_head *list, u8 *state)
220{
221 struct acpi_power_resource_entry *entry;
222 u8 cur_state = ACPI_POWER_RESOURCE_STATE_OFF;
223
224 if (!list || !state)
225 return -EINVAL;
226
227 /* The state of the list is 'on' IFF all resources are 'on'. */
228 list_for_each_entry(entry, list, node) {
229 struct acpi_power_resource *resource = entry->resource;
230 int result;
231
232 mutex_lock(&resource->resource_lock);
233 result = acpi_power_get_state(resource, &cur_state);
234 mutex_unlock(&resource->resource_lock);
235 if (result)
236 return result;
237
238 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
239 break;
240 }
241
242 pr_debug("Power resource list is %s\n", cur_state ? "on" : "off");
243
244 *state = cur_state;
245 return 0;
246}
247
248static int
249acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
250 struct device *dev)
251{
252 struct acpi_power_dependent_device *dep;
253 int ret = 0;
254
255 mutex_lock(&resource->resource_lock);
256 list_for_each_entry(dep, &resource->dependents, node) {
257 /* Only add it once */
258 if (dep->dev == dev)
259 goto unlock;
260 }
261
262 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
263 if (!dep) {
264 ret = -ENOMEM;
265 goto unlock;
266 }
267
268 dep->dev = dev;
269 list_add_tail(&dep->node, &resource->dependents);
270 dev_dbg(dev, "added power dependency to [%s]\n",
271 resource_dev_name(resource));
272
273unlock:
274 mutex_unlock(&resource->resource_lock);
275 return ret;
276}
277
278static void
279acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
280 struct device *dev)
281{
282 struct acpi_power_dependent_device *dep;
283
284 mutex_lock(&resource->resource_lock);
285 list_for_each_entry(dep, &resource->dependents, node) {
286 if (dep->dev == dev) {
287 list_del(&dep->node);
288 kfree(dep);
289 dev_dbg(dev, "removed power dependency to [%s]\n",
290 resource_dev_name(resource));
291 break;
292 }
293 }
294 mutex_unlock(&resource->resource_lock);
295}
296
297/**
298 * acpi_device_power_add_dependent - Add dependent device of this ACPI device
299 * @adev: ACPI device pointer
300 * @dev: Dependent device
301 *
302 * If @adev has non-empty _PR0 the @dev is added as dependent device to all
303 * power resources returned by it. This means that whenever these power
304 * resources are turned _ON the dependent devices get runtime resumed. This
305 * is needed for devices such as PCI to allow its driver to re-initialize
306 * it after it went to D0uninitialized.
307 *
308 * If @adev does not have _PR0 this does nothing.
309 *
310 * Returns %0 in case of success and negative errno otherwise.
311 */
312int acpi_device_power_add_dependent(struct acpi_device *adev,
313 struct device *dev)
314{
315 struct acpi_power_resource_entry *entry;
316 struct list_head *resources;
317 int ret;
318
319 if (!adev->flags.power_manageable)
320 return 0;
321
322 resources = &adev->power.states[ACPI_STATE_D0].resources;
323 list_for_each_entry(entry, resources, node) {
324 ret = acpi_power_resource_add_dependent(entry->resource, dev);
325 if (ret)
326 goto err;
327 }
328
329 return 0;
330
331err:
332 list_for_each_entry(entry, resources, node)
333 acpi_power_resource_remove_dependent(entry->resource, dev);
334
335 return ret;
336}
337
338/**
339 * acpi_device_power_remove_dependent - Remove dependent device
340 * @adev: ACPI device pointer
341 * @dev: Dependent device
342 *
343 * Does the opposite of acpi_device_power_add_dependent() and removes the
344 * dependent device if it is found. Can be called to @adev that does not
345 * have _PR0 as well.
346 */
347void acpi_device_power_remove_dependent(struct acpi_device *adev,
348 struct device *dev)
349{
350 struct acpi_power_resource_entry *entry;
351 struct list_head *resources;
352
353 if (!adev->flags.power_manageable)
354 return;
355
356 resources = &adev->power.states[ACPI_STATE_D0].resources;
357 list_for_each_entry_reverse(entry, resources, node)
358 acpi_power_resource_remove_dependent(entry->resource, dev);
359}
360
361static int __acpi_power_on(struct acpi_power_resource *resource)
362{
363 acpi_handle handle = resource->device.handle;
364 struct acpi_power_dependent_device *dep;
365 acpi_status status = AE_OK;
366
367 status = acpi_evaluate_object(handle, "_ON", NULL, NULL);
368 if (ACPI_FAILURE(status)) {
369 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
370 return -ENODEV;
371 }
372
373 resource->state = ACPI_POWER_RESOURCE_STATE_ON;
374
375 acpi_handle_debug(handle, "Power resource turned on\n");
376
377 /*
378 * If there are other dependents on this power resource we need to
379 * resume them now so that their drivers can re-initialize the
380 * hardware properly after it went back to D0.
381 */
382 if (list_empty(&resource->dependents) ||
383 list_is_singular(&resource->dependents))
384 return 0;
385
386 list_for_each_entry(dep, &resource->dependents, node) {
387 dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
388 resource_dev_name(resource));
389 pm_request_resume(dep->dev);
390 }
391
392 return 0;
393}
394
395static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
396{
397 int result = 0;
398
399 if (resource->ref_count++) {
400 acpi_handle_debug(resource->device.handle,
401 "Power resource already on\n");
402 } else {
403 result = __acpi_power_on(resource);
404 if (result)
405 resource->ref_count--;
406 }
407 return result;
408}
409
410static int acpi_power_on(struct acpi_power_resource *resource)
411{
412 int result;
413
414 mutex_lock(&resource->resource_lock);
415 result = acpi_power_on_unlocked(resource);
416 mutex_unlock(&resource->resource_lock);
417 return result;
418}
419
420static int __acpi_power_off(struct acpi_power_resource *resource)
421{
422 acpi_handle handle = resource->device.handle;
423 acpi_status status;
424
425 status = acpi_evaluate_object(handle, "_OFF", NULL, NULL);
426 if (ACPI_FAILURE(status)) {
427 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
428 return -ENODEV;
429 }
430
431 resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
432
433 acpi_handle_debug(handle, "Power resource turned off\n");
434
435 return 0;
436}
437
438static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
439{
440 int result = 0;
441
442 if (!resource->ref_count) {
443 acpi_handle_debug(resource->device.handle,
444 "Power resource already off\n");
445 return 0;
446 }
447
448 if (--resource->ref_count) {
449 acpi_handle_debug(resource->device.handle,
450 "Power resource still in use\n");
451 } else {
452 result = __acpi_power_off(resource);
453 if (result)
454 resource->ref_count++;
455 }
456 return result;
457}
458
459static int acpi_power_off(struct acpi_power_resource *resource)
460{
461 int result;
462
463 mutex_lock(&resource->resource_lock);
464 result = acpi_power_off_unlocked(resource);
465 mutex_unlock(&resource->resource_lock);
466 return result;
467}
468
469static int acpi_power_off_list(struct list_head *list)
470{
471 struct acpi_power_resource_entry *entry;
472 int result = 0;
473
474 list_for_each_entry_reverse(entry, list, node) {
475 result = acpi_power_off(entry->resource);
476 if (result)
477 goto err;
478 }
479 return 0;
480
481 err:
482 list_for_each_entry_continue(entry, list, node)
483 acpi_power_on(entry->resource);
484
485 return result;
486}
487
488static int acpi_power_on_list(struct list_head *list)
489{
490 struct acpi_power_resource_entry *entry;
491 int result = 0;
492
493 list_for_each_entry(entry, list, node) {
494 result = acpi_power_on(entry->resource);
495 if (result)
496 goto err;
497 }
498 return 0;
499
500 err:
501 list_for_each_entry_continue_reverse(entry, list, node)
502 acpi_power_off(entry->resource);
503
504 return result;
505}
506
507static struct attribute *attrs[] = {
508 NULL,
509};
510
511static const struct attribute_group attr_groups[] = {
512 [ACPI_STATE_D0] = {
513 .name = "power_resources_D0",
514 .attrs = attrs,
515 },
516 [ACPI_STATE_D1] = {
517 .name = "power_resources_D1",
518 .attrs = attrs,
519 },
520 [ACPI_STATE_D2] = {
521 .name = "power_resources_D2",
522 .attrs = attrs,
523 },
524 [ACPI_STATE_D3_HOT] = {
525 .name = "power_resources_D3hot",
526 .attrs = attrs,
527 },
528};
529
530static const struct attribute_group wakeup_attr_group = {
531 .name = "power_resources_wakeup",
532 .attrs = attrs,
533};
534
535static void acpi_power_hide_list(struct acpi_device *adev,
536 struct list_head *resources,
537 const struct attribute_group *attr_group)
538{
539 struct acpi_power_resource_entry *entry;
540
541 if (list_empty(resources))
542 return;
543
544 list_for_each_entry_reverse(entry, resources, node) {
545 struct acpi_device *res_dev = &entry->resource->device;
546
547 sysfs_remove_link_from_group(&adev->dev.kobj,
548 attr_group->name,
549 dev_name(&res_dev->dev));
550 }
551 sysfs_remove_group(&adev->dev.kobj, attr_group);
552}
553
554static void acpi_power_expose_list(struct acpi_device *adev,
555 struct list_head *resources,
556 const struct attribute_group *attr_group)
557{
558 struct acpi_power_resource_entry *entry;
559 int ret;
560
561 if (list_empty(resources))
562 return;
563
564 ret = sysfs_create_group(&adev->dev.kobj, attr_group);
565 if (ret)
566 return;
567
568 list_for_each_entry(entry, resources, node) {
569 struct acpi_device *res_dev = &entry->resource->device;
570
571 ret = sysfs_add_link_to_group(&adev->dev.kobj,
572 attr_group->name,
573 &res_dev->dev.kobj,
574 dev_name(&res_dev->dev));
575 if (ret) {
576 acpi_power_hide_list(adev, resources, attr_group);
577 break;
578 }
579 }
580}
581
582static void acpi_power_expose_hide(struct acpi_device *adev,
583 struct list_head *resources,
584 const struct attribute_group *attr_group,
585 bool expose)
586{
587 if (expose)
588 acpi_power_expose_list(adev, resources, attr_group);
589 else
590 acpi_power_hide_list(adev, resources, attr_group);
591}
592
593void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
594{
595 int state;
596
597 if (adev->wakeup.flags.valid)
598 acpi_power_expose_hide(adev, &adev->wakeup.resources,
599 &wakeup_attr_group, add);
600
601 if (!adev->power.flags.power_resources)
602 return;
603
604 for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
605 acpi_power_expose_hide(adev,
606 &adev->power.states[state].resources,
607 &attr_groups[state], add);
608}
609
610int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
611{
612 struct acpi_power_resource_entry *entry;
613 int system_level = 5;
614
615 list_for_each_entry(entry, list, node) {
616 struct acpi_power_resource *resource = entry->resource;
617 u8 state;
618
619 mutex_lock(&resource->resource_lock);
620
621 /*
622 * Make sure that the power resource state and its reference
623 * counter value are consistent with each other.
624 */
625 if (!resource->ref_count &&
626 !acpi_power_get_state(resource, &state) &&
627 state == ACPI_POWER_RESOURCE_STATE_ON)
628 __acpi_power_off(resource);
629
630 if (system_level > resource->system_level)
631 system_level = resource->system_level;
632
633 mutex_unlock(&resource->resource_lock);
634 }
635 *system_level_p = system_level;
636 return 0;
637}
638
639/* --------------------------------------------------------------------------
640 Device Power Management
641 -------------------------------------------------------------------------- */
642
643/**
644 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
645 * ACPI 3.0) _PSW (Power State Wake)
646 * @dev: Device to handle.
647 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
648 * @sleep_state: Target sleep state of the system.
649 * @dev_state: Target power state of the device.
650 *
651 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
652 * State Wake) for the device, if present. On failure reset the device's
653 * wakeup.flags.valid flag.
654 *
655 * RETURN VALUE:
656 * 0 if either _DSW or _PSW has been successfully executed
657 * 0 if neither _DSW nor _PSW has been found
658 * -ENODEV if the execution of either _DSW or _PSW has failed
659 */
660int acpi_device_sleep_wake(struct acpi_device *dev,
661 int enable, int sleep_state, int dev_state)
662{
663 union acpi_object in_arg[3];
664 struct acpi_object_list arg_list = { 3, in_arg };
665 acpi_status status = AE_OK;
666
667 /*
668 * Try to execute _DSW first.
669 *
670 * Three arguments are needed for the _DSW object:
671 * Argument 0: enable/disable the wake capabilities
672 * Argument 1: target system state
673 * Argument 2: target device state
674 * When _DSW object is called to disable the wake capabilities, maybe
675 * the first argument is filled. The values of the other two arguments
676 * are meaningless.
677 */
678 in_arg[0].type = ACPI_TYPE_INTEGER;
679 in_arg[0].integer.value = enable;
680 in_arg[1].type = ACPI_TYPE_INTEGER;
681 in_arg[1].integer.value = sleep_state;
682 in_arg[2].type = ACPI_TYPE_INTEGER;
683 in_arg[2].integer.value = dev_state;
684 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
685 if (ACPI_SUCCESS(status)) {
686 return 0;
687 } else if (status != AE_NOT_FOUND) {
688 acpi_handle_info(dev->handle, "_DSW execution failed\n");
689 dev->wakeup.flags.valid = 0;
690 return -ENODEV;
691 }
692
693 /* Execute _PSW */
694 status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
695 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
696 acpi_handle_info(dev->handle, "_PSW execution failed\n");
697 dev->wakeup.flags.valid = 0;
698 return -ENODEV;
699 }
700
701 return 0;
702}
703
704/*
705 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
706 * 1. Power on the power resources required for the wakeup device
707 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
708 * State Wake) for the device, if present
709 */
710int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
711{
712 int err = 0;
713
714 if (!dev || !dev->wakeup.flags.valid)
715 return -EINVAL;
716
717 mutex_lock(&acpi_device_lock);
718
719 dev_dbg(&dev->dev, "Enabling wakeup power (count %d)\n",
720 dev->wakeup.prepare_count);
721
722 if (dev->wakeup.prepare_count++)
723 goto out;
724
725 err = acpi_power_on_list(&dev->wakeup.resources);
726 if (err) {
727 dev_err(&dev->dev, "Cannot turn on wakeup power resources\n");
728 dev->wakeup.flags.valid = 0;
729 goto out;
730 }
731
732 /*
733 * Passing 3 as the third argument below means the device may be
734 * put into arbitrary power state afterward.
735 */
736 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
737 if (err) {
738 acpi_power_off_list(&dev->wakeup.resources);
739 dev->wakeup.prepare_count = 0;
740 goto out;
741 }
742
743 dev_dbg(&dev->dev, "Wakeup power enabled\n");
744
745 out:
746 mutex_unlock(&acpi_device_lock);
747 return err;
748}
749
750/*
751 * Shutdown a wakeup device, counterpart of above method
752 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
753 * State Wake) for the device, if present
754 * 2. Shutdown down the power resources
755 */
756int acpi_disable_wakeup_device_power(struct acpi_device *dev)
757{
758 struct acpi_power_resource_entry *entry;
759 int err = 0;
760
761 if (!dev || !dev->wakeup.flags.valid)
762 return -EINVAL;
763
764 mutex_lock(&acpi_device_lock);
765
766 dev_dbg(&dev->dev, "Disabling wakeup power (count %d)\n",
767 dev->wakeup.prepare_count);
768
769 /* Do nothing if wakeup power has not been enabled for this device. */
770 if (dev->wakeup.prepare_count <= 0)
771 goto out;
772
773 if (--dev->wakeup.prepare_count > 0)
774 goto out;
775
776 err = acpi_device_sleep_wake(dev, 0, 0, 0);
777 if (err)
778 goto out;
779
780 /*
781 * All of the power resources in the list need to be turned off even if
782 * there are errors.
783 */
784 list_for_each_entry(entry, &dev->wakeup.resources, node) {
785 int ret;
786
787 ret = acpi_power_off(entry->resource);
788 if (ret && !err)
789 err = ret;
790 }
791 if (err) {
792 dev_err(&dev->dev, "Cannot turn off wakeup power resources\n");
793 dev->wakeup.flags.valid = 0;
794 goto out;
795 }
796
797 dev_dbg(&dev->dev, "Wakeup power disabled\n");
798
799 out:
800 mutex_unlock(&acpi_device_lock);
801 return err;
802}
803
804int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
805{
806 u8 list_state = ACPI_POWER_RESOURCE_STATE_OFF;
807 int result = 0;
808 int i = 0;
809
810 if (!device || !state)
811 return -EINVAL;
812
813 /*
814 * We know a device's inferred power state when all the resources
815 * required for a given D-state are 'on'.
816 */
817 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
818 struct list_head *list = &device->power.states[i].resources;
819
820 if (list_empty(list))
821 continue;
822
823 result = acpi_power_get_list_state(list, &list_state);
824 if (result)
825 return result;
826
827 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
828 *state = i;
829 return 0;
830 }
831 }
832
833 *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
834 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
835 return 0;
836}
837
838int acpi_power_on_resources(struct acpi_device *device, int state)
839{
840 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
841 return -EINVAL;
842
843 return acpi_power_on_list(&device->power.states[state].resources);
844}
845
846int acpi_power_transition(struct acpi_device *device, int state)
847{
848 int result = 0;
849
850 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
851 return -EINVAL;
852
853 if (device->power.state == state || !device->flags.power_manageable)
854 return 0;
855
856 if ((device->power.state < ACPI_STATE_D0)
857 || (device->power.state > ACPI_STATE_D3_COLD))
858 return -ENODEV;
859
860 /*
861 * First we reference all power resources required in the target list
862 * (e.g. so the device doesn't lose power while transitioning). Then,
863 * we dereference all power resources used in the current list.
864 */
865 if (state < ACPI_STATE_D3_COLD)
866 result = acpi_power_on_list(
867 &device->power.states[state].resources);
868
869 if (!result && device->power.state < ACPI_STATE_D3_COLD)
870 acpi_power_off_list(
871 &device->power.states[device->power.state].resources);
872
873 /* We shouldn't change the state unless the above operations succeed. */
874 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
875
876 return result;
877}
878
879static void acpi_release_power_resource(struct device *dev)
880{
881 struct acpi_device *device = to_acpi_device(dev);
882 struct acpi_power_resource *resource;
883
884 resource = container_of(device, struct acpi_power_resource, device);
885
886 mutex_lock(&power_resource_list_lock);
887 list_del(&resource->list_node);
888 mutex_unlock(&power_resource_list_lock);
889
890 acpi_free_pnp_ids(&device->pnp);
891 kfree(resource);
892}
893
894static ssize_t resource_in_use_show(struct device *dev,
895 struct device_attribute *attr,
896 char *buf)
897{
898 struct acpi_power_resource *resource;
899
900 resource = to_power_resource(to_acpi_device(dev));
901 return sprintf(buf, "%u\n", !!resource->ref_count);
902}
903static DEVICE_ATTR_RO(resource_in_use);
904
905static void acpi_power_sysfs_remove(struct acpi_device *device)
906{
907 device_remove_file(&device->dev, &dev_attr_resource_in_use);
908}
909
910static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
911{
912 mutex_lock(&power_resource_list_lock);
913
914 if (!list_empty(&acpi_power_resource_list)) {
915 struct acpi_power_resource *r;
916
917 list_for_each_entry(r, &acpi_power_resource_list, list_node)
918 if (r->order > resource->order) {
919 list_add_tail(&resource->list_node, &r->list_node);
920 goto out;
921 }
922 }
923 list_add_tail(&resource->list_node, &acpi_power_resource_list);
924
925 out:
926 mutex_unlock(&power_resource_list_lock);
927}
928
929struct acpi_device *acpi_add_power_resource(acpi_handle handle)
930{
931 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
932 struct acpi_power_resource *resource;
933 union acpi_object acpi_object;
934 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
935 acpi_status status;
936 u8 state_dummy;
937 int result;
938
939 if (device)
940 return device;
941
942 resource = kzalloc(sizeof(*resource), GFP_KERNEL);
943 if (!resource)
944 return NULL;
945
946 device = &resource->device;
947 acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
948 acpi_release_power_resource);
949 mutex_init(&resource->resource_lock);
950 INIT_LIST_HEAD(&resource->list_node);
951 INIT_LIST_HEAD(&resource->dependents);
952 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
953 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
954 device->power.state = ACPI_STATE_UNKNOWN;
955 device->flags.match_driver = true;
956
957 /* Evaluate the object to get the system level and resource order. */
958 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
959 if (ACPI_FAILURE(status))
960 goto err;
961
962 resource->system_level = acpi_object.power_resource.system_level;
963 resource->order = acpi_object.power_resource.resource_order;
964 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
965
966 /* Get the initial state or just flip it on if that fails. */
967 if (acpi_power_get_state(resource, &state_dummy))
968 __acpi_power_on(resource);
969
970 acpi_handle_info(handle, "New power resource\n");
971
972 result = acpi_tie_acpi_dev(device);
973 if (result)
974 goto err;
975
976 result = acpi_device_add(device);
977 if (result)
978 goto err;
979
980 if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
981 device->remove = acpi_power_sysfs_remove;
982
983 acpi_power_add_resource_to_list(resource);
984 acpi_device_add_finalize(device);
985 return device;
986
987 err:
988 acpi_release_power_resource(&device->dev);
989 return NULL;
990}
991
992#ifdef CONFIG_ACPI_SLEEP
993void acpi_resume_power_resources(void)
994{
995 struct acpi_power_resource *resource;
996
997 mutex_lock(&power_resource_list_lock);
998
999 list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
1000 int result;
1001 u8 state;
1002
1003 mutex_lock(&resource->resource_lock);
1004
1005 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
1006 result = acpi_power_get_state(resource, &state);
1007 if (result) {
1008 mutex_unlock(&resource->resource_lock);
1009 continue;
1010 }
1011
1012 if (state == ACPI_POWER_RESOURCE_STATE_OFF
1013 && resource->ref_count) {
1014 acpi_handle_debug(resource->device.handle, "Turning ON\n");
1015 __acpi_power_on(resource);
1016 }
1017
1018 mutex_unlock(&resource->resource_lock);
1019 }
1020
1021 mutex_unlock(&power_resource_list_lock);
1022}
1023#endif
1024
1025/**
1026 * acpi_turn_off_unused_power_resources - Turn off power resources not in use.
1027 */
1028void acpi_turn_off_unused_power_resources(void)
1029{
1030 struct acpi_power_resource *resource;
1031
1032 mutex_lock(&power_resource_list_lock);
1033
1034 list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
1035 mutex_lock(&resource->resource_lock);
1036
1037 if (!resource->ref_count &&
1038 resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
1039 acpi_handle_debug(resource->device.handle, "Turning OFF\n");
1040 __acpi_power_off(resource);
1041 }
1042
1043 mutex_unlock(&resource->resource_lock);
1044 }
1045
1046 mutex_unlock(&power_resource_list_lock);
1047}