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