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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/*
2 * acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
25
26/*
27 * ACPI power-managed devices may be controlled in two ways:
28 * 1. via "Device Specific (D-State) Control"
29 * 2. via "Power Resource Control".
30 * This module is used to manage devices relying on Power Resource Control.
31 *
32 * An ACPI "power resource object" describes a software controllable power
33 * plane, clock plane, or other resource used by a power managed device.
34 * A device may rely on multiple power resources, and a power resource
35 * may be shared by multiple devices.
36 */
37
38#include <linux/kernel.h>
39#include <linux/module.h>
40#include <linux/init.h>
41#include <linux/types.h>
42#include <linux/slab.h>
43#include <linux/pm_runtime.h>
44#include <acpi/acpi_bus.h>
45#include <acpi/acpi_drivers.h>
46#include "sleep.h"
47#include "internal.h"
48
49#define PREFIX "ACPI: "
50
51#define _COMPONENT ACPI_POWER_COMPONENT
52ACPI_MODULE_NAME("power");
53#define ACPI_POWER_CLASS "power_resource"
54#define ACPI_POWER_DEVICE_NAME "Power Resource"
55#define ACPI_POWER_FILE_INFO "info"
56#define ACPI_POWER_FILE_STATUS "state"
57#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
58#define ACPI_POWER_RESOURCE_STATE_ON 0x01
59#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
60
61static int acpi_power_add(struct acpi_device *device);
62static int acpi_power_remove(struct acpi_device *device, int type);
63static int acpi_power_resume(struct acpi_device *device);
64
65static const struct acpi_device_id power_device_ids[] = {
66 {ACPI_POWER_HID, 0},
67 {"", 0},
68};
69MODULE_DEVICE_TABLE(acpi, power_device_ids);
70
71static struct acpi_driver acpi_power_driver = {
72 .name = "power",
73 .class = ACPI_POWER_CLASS,
74 .ids = power_device_ids,
75 .ops = {
76 .add = acpi_power_add,
77 .remove = acpi_power_remove,
78 .resume = acpi_power_resume,
79 },
80};
81
82/*
83 * A power managed device
84 * A device may rely on multiple power resources.
85 * */
86struct acpi_power_managed_device {
87 struct device *dev; /* The physical device */
88 acpi_handle *handle;
89};
90
91struct acpi_power_resource_device {
92 struct acpi_power_managed_device *device;
93 struct acpi_power_resource_device *next;
94};
95
96struct acpi_power_resource {
97 struct acpi_device * device;
98 acpi_bus_id name;
99 u32 system_level;
100 u32 order;
101 unsigned int ref_count;
102 struct mutex resource_lock;
103
104 /* List of devices relying on this power resource */
105 struct acpi_power_resource_device *devices;
106 struct mutex devices_lock;
107};
108
109static struct list_head acpi_power_resource_list;
110
111/* --------------------------------------------------------------------------
112 Power Resource Management
113 -------------------------------------------------------------------------- */
114
115static int
116acpi_power_get_context(acpi_handle handle,
117 struct acpi_power_resource **resource)
118{
119 int result = 0;
120 struct acpi_device *device = NULL;
121
122
123 if (!resource)
124 return -ENODEV;
125
126 result = acpi_bus_get_device(handle, &device);
127 if (result) {
128 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
129 return result;
130 }
131
132 *resource = acpi_driver_data(device);
133 if (!*resource)
134 return -ENODEV;
135
136 return 0;
137}
138
139static int acpi_power_get_state(acpi_handle handle, int *state)
140{
141 acpi_status status = AE_OK;
142 unsigned long long sta = 0;
143 char node_name[5];
144 struct acpi_buffer buffer = { sizeof(node_name), node_name };
145
146
147 if (!handle || !state)
148 return -EINVAL;
149
150 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
151 if (ACPI_FAILURE(status))
152 return -ENODEV;
153
154 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
155 ACPI_POWER_RESOURCE_STATE_OFF;
156
157 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
158
159 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
160 node_name,
161 *state ? "on" : "off"));
162
163 return 0;
164}
165
166static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
167{
168 int cur_state;
169 int i = 0;
170
171 if (!list || !state)
172 return -EINVAL;
173
174 /* The state of the list is 'on' IFF all resources are 'on'. */
175
176 for (i = 0; i < list->count; i++) {
177 struct acpi_power_resource *resource;
178 acpi_handle handle = list->handles[i];
179 int result;
180
181 result = acpi_power_get_context(handle, &resource);
182 if (result)
183 return result;
184
185 mutex_lock(&resource->resource_lock);
186
187 result = acpi_power_get_state(handle, &cur_state);
188
189 mutex_unlock(&resource->resource_lock);
190
191 if (result)
192 return result;
193
194 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
195 break;
196 }
197
198 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
199 cur_state ? "on" : "off"));
200
201 *state = cur_state;
202
203 return 0;
204}
205
206/* Resume the device when all power resources in _PR0 are on */
207static void acpi_power_on_device(struct acpi_power_managed_device *device)
208{
209 struct acpi_device *acpi_dev;
210 acpi_handle handle = device->handle;
211 int state;
212
213 if (acpi_bus_get_device(handle, &acpi_dev))
214 return;
215
216 if(acpi_power_get_inferred_state(acpi_dev, &state))
217 return;
218
219 if (state == ACPI_STATE_D0 && pm_runtime_suspended(device->dev))
220 pm_request_resume(device->dev);
221}
222
223static int __acpi_power_on(struct acpi_power_resource *resource)
224{
225 acpi_status status = AE_OK;
226
227 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
228 if (ACPI_FAILURE(status))
229 return -ENODEV;
230
231 /* Update the power resource's _device_ power state */
232 resource->device->power.state = ACPI_STATE_D0;
233
234 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
235 resource->name));
236
237 return 0;
238}
239
240static int acpi_power_on(acpi_handle handle)
241{
242 int result = 0;
243 bool resume_device = false;
244 struct acpi_power_resource *resource = NULL;
245 struct acpi_power_resource_device *device_list;
246
247 result = acpi_power_get_context(handle, &resource);
248 if (result)
249 return result;
250
251 mutex_lock(&resource->resource_lock);
252
253 if (resource->ref_count++) {
254 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
255 "Power resource [%s] already on",
256 resource->name));
257 } else {
258 result = __acpi_power_on(resource);
259 if (result)
260 resource->ref_count--;
261 else
262 resume_device = true;
263 }
264
265 mutex_unlock(&resource->resource_lock);
266
267 if (!resume_device)
268 return result;
269
270 mutex_lock(&resource->devices_lock);
271
272 device_list = resource->devices;
273 while (device_list) {
274 acpi_power_on_device(device_list->device);
275 device_list = device_list->next;
276 }
277
278 mutex_unlock(&resource->devices_lock);
279
280 return result;
281}
282
283static int acpi_power_off(acpi_handle handle)
284{
285 int result = 0;
286 acpi_status status = AE_OK;
287 struct acpi_power_resource *resource = NULL;
288
289 result = acpi_power_get_context(handle, &resource);
290 if (result)
291 return result;
292
293 mutex_lock(&resource->resource_lock);
294
295 if (!resource->ref_count) {
296 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
297 "Power resource [%s] already off",
298 resource->name));
299 goto unlock;
300 }
301
302 if (--resource->ref_count) {
303 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
304 "Power resource [%s] still in use\n",
305 resource->name));
306 goto unlock;
307 }
308
309 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
310 if (ACPI_FAILURE(status)) {
311 result = -ENODEV;
312 } else {
313 /* Update the power resource's _device_ power state */
314 resource->device->power.state = ACPI_STATE_D3;
315
316 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
317 "Power resource [%s] turned off\n",
318 resource->name));
319 }
320
321 unlock:
322 mutex_unlock(&resource->resource_lock);
323
324 return result;
325}
326
327static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
328{
329 int i;
330
331 for (i = num_res - 1; i >= 0 ; i--)
332 acpi_power_off(list->handles[i]);
333}
334
335static void acpi_power_off_list(struct acpi_handle_list *list)
336{
337 __acpi_power_off_list(list, list->count);
338}
339
340static int acpi_power_on_list(struct acpi_handle_list *list)
341{
342 int result = 0;
343 int i;
344
345 for (i = 0; i < list->count; i++) {
346 result = acpi_power_on(list->handles[i]);
347 if (result) {
348 __acpi_power_off_list(list, i);
349 break;
350 }
351 }
352
353 return result;
354}
355
356static void __acpi_power_resource_unregister_device(struct device *dev,
357 acpi_handle res_handle)
358{
359 struct acpi_power_resource *resource = NULL;
360 struct acpi_power_resource_device *prev, *curr;
361
362 if (acpi_power_get_context(res_handle, &resource))
363 return;
364
365 mutex_lock(&resource->devices_lock);
366 prev = NULL;
367 curr = resource->devices;
368 while (curr) {
369 if (curr->device->dev == dev) {
370 if (!prev)
371 resource->devices = curr->next;
372 else
373 prev->next = curr->next;
374
375 kfree(curr);
376 break;
377 }
378
379 prev = curr;
380 curr = curr->next;
381 }
382 mutex_unlock(&resource->devices_lock);
383}
384
385/* Unlink dev from all power resources in _PR0 */
386void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle)
387{
388 struct acpi_device *acpi_dev;
389 struct acpi_handle_list *list;
390 int i;
391
392 if (!dev || !handle)
393 return;
394
395 if (acpi_bus_get_device(handle, &acpi_dev))
396 return;
397
398 list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
399
400 for (i = 0; i < list->count; i++)
401 __acpi_power_resource_unregister_device(dev,
402 list->handles[i]);
403}
404
405static int __acpi_power_resource_register_device(
406 struct acpi_power_managed_device *powered_device, acpi_handle handle)
407{
408 struct acpi_power_resource *resource = NULL;
409 struct acpi_power_resource_device *power_resource_device;
410 int result;
411
412 result = acpi_power_get_context(handle, &resource);
413 if (result)
414 return result;
415
416 power_resource_device = kzalloc(
417 sizeof(*power_resource_device), GFP_KERNEL);
418 if (!power_resource_device)
419 return -ENOMEM;
420
421 power_resource_device->device = powered_device;
422
423 mutex_lock(&resource->devices_lock);
424 power_resource_device->next = resource->devices;
425 resource->devices = power_resource_device;
426 mutex_unlock(&resource->devices_lock);
427
428 return 0;
429}
430
431/* Link dev to all power resources in _PR0 */
432int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
433{
434 struct acpi_device *acpi_dev;
435 struct acpi_handle_list *list;
436 struct acpi_power_managed_device *powered_device;
437 int i, ret;
438
439 if (!dev || !handle)
440 return -ENODEV;
441
442 ret = acpi_bus_get_device(handle, &acpi_dev);
443 if (ret)
444 goto no_power_resource;
445
446 if (!acpi_dev->power.flags.power_resources)
447 goto no_power_resource;
448
449 powered_device = kzalloc(sizeof(*powered_device), GFP_KERNEL);
450 if (!powered_device)
451 return -ENOMEM;
452
453 powered_device->dev = dev;
454 powered_device->handle = handle;
455
456 list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
457
458 for (i = 0; i < list->count; i++) {
459 ret = __acpi_power_resource_register_device(powered_device,
460 list->handles[i]);
461
462 if (ret) {
463 acpi_power_resource_unregister_device(dev, handle);
464 break;
465 }
466 }
467
468 return ret;
469
470no_power_resource:
471 printk(KERN_DEBUG PREFIX "Invalid Power Resource to register!");
472 return -ENODEV;
473}
474
475/**
476 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
477 * ACPI 3.0) _PSW (Power State Wake)
478 * @dev: Device to handle.
479 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
480 * @sleep_state: Target sleep state of the system.
481 * @dev_state: Target power state of the device.
482 *
483 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
484 * State Wake) for the device, if present. On failure reset the device's
485 * wakeup.flags.valid flag.
486 *
487 * RETURN VALUE:
488 * 0 if either _DSW or _PSW has been successfully executed
489 * 0 if neither _DSW nor _PSW has been found
490 * -ENODEV if the execution of either _DSW or _PSW has failed
491 */
492int acpi_device_sleep_wake(struct acpi_device *dev,
493 int enable, int sleep_state, int dev_state)
494{
495 union acpi_object in_arg[3];
496 struct acpi_object_list arg_list = { 3, in_arg };
497 acpi_status status = AE_OK;
498
499 /*
500 * Try to execute _DSW first.
501 *
502 * Three agruments are needed for the _DSW object:
503 * Argument 0: enable/disable the wake capabilities
504 * Argument 1: target system state
505 * Argument 2: target device state
506 * When _DSW object is called to disable the wake capabilities, maybe
507 * the first argument is filled. The values of the other two agruments
508 * are meaningless.
509 */
510 in_arg[0].type = ACPI_TYPE_INTEGER;
511 in_arg[0].integer.value = enable;
512 in_arg[1].type = ACPI_TYPE_INTEGER;
513 in_arg[1].integer.value = sleep_state;
514 in_arg[2].type = ACPI_TYPE_INTEGER;
515 in_arg[2].integer.value = dev_state;
516 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
517 if (ACPI_SUCCESS(status)) {
518 return 0;
519 } else if (status != AE_NOT_FOUND) {
520 printk(KERN_ERR PREFIX "_DSW execution failed\n");
521 dev->wakeup.flags.valid = 0;
522 return -ENODEV;
523 }
524
525 /* Execute _PSW */
526 arg_list.count = 1;
527 in_arg[0].integer.value = enable;
528 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
529 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
530 printk(KERN_ERR PREFIX "_PSW execution failed\n");
531 dev->wakeup.flags.valid = 0;
532 return -ENODEV;
533 }
534
535 return 0;
536}
537
538/*
539 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
540 * 1. Power on the power resources required for the wakeup device
541 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
542 * State Wake) for the device, if present
543 */
544int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
545{
546 int i, err = 0;
547
548 if (!dev || !dev->wakeup.flags.valid)
549 return -EINVAL;
550
551 mutex_lock(&acpi_device_lock);
552
553 if (dev->wakeup.prepare_count++)
554 goto out;
555
556 /* Open power resource */
557 for (i = 0; i < dev->wakeup.resources.count; i++) {
558 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
559 if (ret) {
560 printk(KERN_ERR PREFIX "Transition power state\n");
561 dev->wakeup.flags.valid = 0;
562 err = -ENODEV;
563 goto err_out;
564 }
565 }
566
567 /*
568 * Passing 3 as the third argument below means the device may be placed
569 * in arbitrary power state afterwards.
570 */
571 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
572
573 err_out:
574 if (err)
575 dev->wakeup.prepare_count = 0;
576
577 out:
578 mutex_unlock(&acpi_device_lock);
579 return err;
580}
581
582/*
583 * Shutdown a wakeup device, counterpart of above method
584 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
585 * State Wake) for the device, if present
586 * 2. Shutdown down the power resources
587 */
588int acpi_disable_wakeup_device_power(struct acpi_device *dev)
589{
590 int i, err = 0;
591
592 if (!dev || !dev->wakeup.flags.valid)
593 return -EINVAL;
594
595 mutex_lock(&acpi_device_lock);
596
597 if (--dev->wakeup.prepare_count > 0)
598 goto out;
599
600 /*
601 * Executing the code below even if prepare_count is already zero when
602 * the function is called may be useful, for example for initialisation.
603 */
604 if (dev->wakeup.prepare_count < 0)
605 dev->wakeup.prepare_count = 0;
606
607 err = acpi_device_sleep_wake(dev, 0, 0, 0);
608 if (err)
609 goto out;
610
611 /* Close power resource */
612 for (i = 0; i < dev->wakeup.resources.count; i++) {
613 int ret = acpi_power_off(dev->wakeup.resources.handles[i]);
614 if (ret) {
615 printk(KERN_ERR PREFIX "Transition power state\n");
616 dev->wakeup.flags.valid = 0;
617 err = -ENODEV;
618 goto out;
619 }
620 }
621
622 out:
623 mutex_unlock(&acpi_device_lock);
624 return err;
625}
626
627/* --------------------------------------------------------------------------
628 Device Power Management
629 -------------------------------------------------------------------------- */
630
631int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
632{
633 int result = 0;
634 struct acpi_handle_list *list = NULL;
635 int list_state = 0;
636 int i = 0;
637
638 if (!device || !state)
639 return -EINVAL;
640
641 /*
642 * We know a device's inferred power state when all the resources
643 * required for a given D-state are 'on'.
644 */
645 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
646 list = &device->power.states[i].resources;
647 if (list->count < 1)
648 continue;
649
650 result = acpi_power_get_list_state(list, &list_state);
651 if (result)
652 return result;
653
654 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
655 *state = i;
656 return 0;
657 }
658 }
659
660 *state = ACPI_STATE_D3;
661 return 0;
662}
663
664int acpi_power_on_resources(struct acpi_device *device, int state)
665{
666 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
667 return -EINVAL;
668
669 return acpi_power_on_list(&device->power.states[state].resources);
670}
671
672int acpi_power_transition(struct acpi_device *device, int state)
673{
674 int result = 0;
675
676 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
677 return -EINVAL;
678
679 if (device->power.state == state)
680 return 0;
681
682 if ((device->power.state < ACPI_STATE_D0)
683 || (device->power.state > ACPI_STATE_D3_COLD))
684 return -ENODEV;
685
686 /* TBD: Resources must be ordered. */
687
688 /*
689 * First we reference all power resources required in the target list
690 * (e.g. so the device doesn't lose power while transitioning). Then,
691 * we dereference all power resources used in the current list.
692 */
693 if (state < ACPI_STATE_D3_COLD)
694 result = acpi_power_on_list(
695 &device->power.states[state].resources);
696
697 if (!result && device->power.state < ACPI_STATE_D3_COLD)
698 acpi_power_off_list(
699 &device->power.states[device->power.state].resources);
700
701 /* We shouldn't change the state unless the above operations succeed. */
702 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
703
704 return result;
705}
706
707/* --------------------------------------------------------------------------
708 Driver Interface
709 -------------------------------------------------------------------------- */
710
711static int acpi_power_add(struct acpi_device *device)
712{
713 int result = 0, state;
714 acpi_status status = AE_OK;
715 struct acpi_power_resource *resource = NULL;
716 union acpi_object acpi_object;
717 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
718
719
720 if (!device)
721 return -EINVAL;
722
723 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
724 if (!resource)
725 return -ENOMEM;
726
727 resource->device = device;
728 mutex_init(&resource->resource_lock);
729 mutex_init(&resource->devices_lock);
730 strcpy(resource->name, device->pnp.bus_id);
731 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
732 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
733 device->driver_data = resource;
734
735 /* Evalute the object to get the system level and resource order. */
736 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
737 if (ACPI_FAILURE(status)) {
738 result = -ENODEV;
739 goto end;
740 }
741 resource->system_level = acpi_object.power_resource.system_level;
742 resource->order = acpi_object.power_resource.resource_order;
743
744 result = acpi_power_get_state(device->handle, &state);
745 if (result)
746 goto end;
747
748 switch (state) {
749 case ACPI_POWER_RESOURCE_STATE_ON:
750 device->power.state = ACPI_STATE_D0;
751 break;
752 case ACPI_POWER_RESOURCE_STATE_OFF:
753 device->power.state = ACPI_STATE_D3;
754 break;
755 default:
756 device->power.state = ACPI_STATE_UNKNOWN;
757 break;
758 }
759
760 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
761 acpi_device_bid(device), state ? "on" : "off");
762
763 end:
764 if (result)
765 kfree(resource);
766
767 return result;
768}
769
770static int acpi_power_remove(struct acpi_device *device, int type)
771{
772 struct acpi_power_resource *resource;
773
774 if (!device)
775 return -EINVAL;
776
777 resource = acpi_driver_data(device);
778 if (!resource)
779 return -EINVAL;
780
781 kfree(resource);
782
783 return 0;
784}
785
786static int acpi_power_resume(struct acpi_device *device)
787{
788 int result = 0, state;
789 struct acpi_power_resource *resource;
790
791 if (!device)
792 return -EINVAL;
793
794 resource = acpi_driver_data(device);
795 if (!resource)
796 return -EINVAL;
797
798 mutex_lock(&resource->resource_lock);
799
800 result = acpi_power_get_state(device->handle, &state);
801 if (result)
802 goto unlock;
803
804 if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
805 result = __acpi_power_on(resource);
806
807 unlock:
808 mutex_unlock(&resource->resource_lock);
809
810 return result;
811}
812
813int __init acpi_power_init(void)
814{
815 INIT_LIST_HEAD(&acpi_power_resource_list);
816 return acpi_bus_register_driver(&acpi_power_driver);
817}