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