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 <linux/sysfs.h>
45#include <linux/acpi.h>
46#include "sleep.h"
47#include "internal.h"
48
49#define _COMPONENT			ACPI_POWER_COMPONENT
50ACPI_MODULE_NAME("power");
51#define ACPI_POWER_CLASS		"power_resource"
52#define ACPI_POWER_DEVICE_NAME		"Power Resource"
53#define ACPI_POWER_FILE_INFO		"info"
54#define ACPI_POWER_FILE_STATUS		"state"
55#define ACPI_POWER_RESOURCE_STATE_OFF	0x00
56#define ACPI_POWER_RESOURCE_STATE_ON	0x01
57#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
58
59struct acpi_power_resource {
60	struct acpi_device device;
61	struct list_head list_node;
62	char *name;
63	u32 system_level;
64	u32 order;
65	unsigned int ref_count;
66	bool wakeup_enabled;
67	struct mutex resource_lock;
68};
69
70struct acpi_power_resource_entry {
71	struct list_head node;
72	struct acpi_power_resource *resource;
73};
74
75static LIST_HEAD(acpi_power_resource_list);
76static DEFINE_MUTEX(power_resource_list_lock);
77
78/* --------------------------------------------------------------------------
79                             Power Resource Management
80   -------------------------------------------------------------------------- */
81
82static inline
83struct acpi_power_resource *to_power_resource(struct acpi_device *device)
84{
85	return container_of(device, struct acpi_power_resource, device);
86}
87
88static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
89{
90	struct acpi_device *device;
91
92	if (acpi_bus_get_device(handle, &device))
93		return NULL;
94
95	return to_power_resource(device);
96}
97
98static int acpi_power_resources_list_add(acpi_handle handle,
99					 struct list_head *list)
100{
101	struct acpi_power_resource *resource = acpi_power_get_context(handle);
102	struct acpi_power_resource_entry *entry;
103
104	if (!resource || !list)
105		return -EINVAL;
106
107	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
108	if (!entry)
109		return -ENOMEM;
110
111	entry->resource = resource;
112	if (!list_empty(list)) {
113		struct acpi_power_resource_entry *e;
114
115		list_for_each_entry(e, list, node)
116			if (e->resource->order > resource->order) {
117				list_add_tail(&entry->node, &e->node);
118				return 0;
119			}
120	}
121	list_add_tail(&entry->node, list);
122	return 0;
123}
124
125void acpi_power_resources_list_free(struct list_head *list)
126{
127	struct acpi_power_resource_entry *entry, *e;
128
129	list_for_each_entry_safe(entry, e, list, node) {
130		list_del(&entry->node);
131		kfree(entry);
132	}
133}
134
135int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
136				 struct list_head *list)
137{
138	unsigned int i;
139	int err = 0;
140
141	for (i = start; i < package->package.count; i++) {
142		union acpi_object *element = &package->package.elements[i];
143		acpi_handle rhandle;
144
145		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
146			err = -ENODATA;
147			break;
148		}
149		rhandle = element->reference.handle;
150		if (!rhandle) {
151			err = -ENODEV;
152			break;
153		}
154		err = acpi_add_power_resource(rhandle);
155		if (err)
156			break;
157
158		err = acpi_power_resources_list_add(rhandle, list);
159		if (err)
160			break;
161	}
162	if (err)
163		acpi_power_resources_list_free(list);
164
165	return err;
166}
167
168static int acpi_power_get_state(acpi_handle handle, int *state)
169{
170	acpi_status status = AE_OK;
171	unsigned long long sta = 0;
172	char node_name[5];
173	struct acpi_buffer buffer = { sizeof(node_name), node_name };
174
175
176	if (!handle || !state)
177		return -EINVAL;
178
179	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
180	if (ACPI_FAILURE(status))
181		return -ENODEV;
182
183	*state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
184			      ACPI_POWER_RESOURCE_STATE_OFF;
185
186	acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
187
188	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
189			  node_name,
190				*state ? "on" : "off"));
191
192	return 0;
193}
194
195static int acpi_power_get_list_state(struct list_head *list, int *state)
196{
197	struct acpi_power_resource_entry *entry;
198	int cur_state;
199
200	if (!list || !state)
201		return -EINVAL;
202
203	/* The state of the list is 'on' IFF all resources are 'on'. */
204	list_for_each_entry(entry, list, node) {
205		struct acpi_power_resource *resource = entry->resource;
206		acpi_handle handle = resource->device.handle;
207		int result;
208
209		mutex_lock(&resource->resource_lock);
210		result = acpi_power_get_state(handle, &cur_state);
211		mutex_unlock(&resource->resource_lock);
212		if (result)
213			return result;
214
215		if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
216			break;
217	}
218
219	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
220			  cur_state ? "on" : "off"));
221
222	*state = cur_state;
223	return 0;
224}
225
226static int __acpi_power_on(struct acpi_power_resource *resource)
227{
228	acpi_status status = AE_OK;
229
230	status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
231	if (ACPI_FAILURE(status))
232		return -ENODEV;
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_unlocked(struct acpi_power_resource *resource)
241{
242	int result = 0;
243
244	if (resource->ref_count++) {
245		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
246				  "Power resource [%s] already on\n",
247				  resource->name));
248	} else {
249		result = __acpi_power_on(resource);
250		if (result)
251			resource->ref_count--;
252	}
253	return result;
254}
255
256static int acpi_power_on(struct acpi_power_resource *resource)
257{
258	int result;
259
260	mutex_lock(&resource->resource_lock);
261	result = acpi_power_on_unlocked(resource);
262	mutex_unlock(&resource->resource_lock);
263	return result;
264}
265
266static int __acpi_power_off(struct acpi_power_resource *resource)
267{
268	acpi_status status;
269
270	status = acpi_evaluate_object(resource->device.handle, "_OFF",
271				      NULL, NULL);
272	if (ACPI_FAILURE(status))
273		return -ENODEV;
274
275	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
276			  resource->name));
277	return 0;
278}
279
280static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
281{
282	int result = 0;
283
284	if (!resource->ref_count) {
285		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
286				  "Power resource [%s] already off\n",
287				  resource->name));
288		return 0;
289	}
290
291	if (--resource->ref_count) {
292		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
293				  "Power resource [%s] still in use\n",
294				  resource->name));
295	} else {
296		result = __acpi_power_off(resource);
297		if (result)
298			resource->ref_count++;
299	}
300	return result;
301}
302
303static int acpi_power_off(struct acpi_power_resource *resource)
304{
305	int result;
306
307	mutex_lock(&resource->resource_lock);
308	result = acpi_power_off_unlocked(resource);
309	mutex_unlock(&resource->resource_lock);
310	return result;
311}
312
313static int acpi_power_off_list(struct list_head *list)
314{
315	struct acpi_power_resource_entry *entry;
316	int result = 0;
317
318	list_for_each_entry_reverse(entry, list, node) {
319		result = acpi_power_off(entry->resource);
320		if (result)
321			goto err;
322	}
323	return 0;
324
325 err:
326	list_for_each_entry_continue(entry, list, node)
327		acpi_power_on(entry->resource);
328
329	return result;
330}
331
332static int acpi_power_on_list(struct list_head *list)
333{
334	struct acpi_power_resource_entry *entry;
335	int result = 0;
336
337	list_for_each_entry(entry, list, node) {
338		result = acpi_power_on(entry->resource);
339		if (result)
340			goto err;
341	}
342	return 0;
343
344 err:
345	list_for_each_entry_continue_reverse(entry, list, node)
346		acpi_power_off(entry->resource);
347
348	return result;
349}
350
351static struct attribute *attrs[] = {
352	NULL,
353};
354
355static struct attribute_group attr_groups[] = {
356	[ACPI_STATE_D0] = {
357		.name = "power_resources_D0",
358		.attrs = attrs,
359	},
360	[ACPI_STATE_D1] = {
361		.name = "power_resources_D1",
362		.attrs = attrs,
363	},
364	[ACPI_STATE_D2] = {
365		.name = "power_resources_D2",
366		.attrs = attrs,
367	},
368	[ACPI_STATE_D3_HOT] = {
369		.name = "power_resources_D3hot",
370		.attrs = attrs,
371	},
372};
373
374static struct attribute_group wakeup_attr_group = {
375	.name = "power_resources_wakeup",
376	.attrs = attrs,
377};
378
379static void acpi_power_hide_list(struct acpi_device *adev,
380				 struct list_head *resources,
381				 struct attribute_group *attr_group)
382{
383	struct acpi_power_resource_entry *entry;
384
385	if (list_empty(resources))
386		return;
387
388	list_for_each_entry_reverse(entry, resources, node) {
389		struct acpi_device *res_dev = &entry->resource->device;
390
391		sysfs_remove_link_from_group(&adev->dev.kobj,
392					     attr_group->name,
393					     dev_name(&res_dev->dev));
394	}
395	sysfs_remove_group(&adev->dev.kobj, attr_group);
396}
397
398static void acpi_power_expose_list(struct acpi_device *adev,
399				   struct list_head *resources,
400				   struct attribute_group *attr_group)
401{
402	struct acpi_power_resource_entry *entry;
403	int ret;
404
405	if (list_empty(resources))
406		return;
407
408	ret = sysfs_create_group(&adev->dev.kobj, attr_group);
409	if (ret)
410		return;
411
412	list_for_each_entry(entry, resources, node) {
413		struct acpi_device *res_dev = &entry->resource->device;
414
415		ret = sysfs_add_link_to_group(&adev->dev.kobj,
416					      attr_group->name,
417					      &res_dev->dev.kobj,
418					      dev_name(&res_dev->dev));
419		if (ret) {
420			acpi_power_hide_list(adev, resources, attr_group);
421			break;
422		}
423	}
424}
425
426static void acpi_power_expose_hide(struct acpi_device *adev,
427				   struct list_head *resources,
428				   struct attribute_group *attr_group,
429				   bool expose)
430{
431	if (expose)
432		acpi_power_expose_list(adev, resources, attr_group);
433	else
434		acpi_power_hide_list(adev, resources, attr_group);
435}
436
437void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
438{
439	int state;
440
441	if (adev->wakeup.flags.valid)
442		acpi_power_expose_hide(adev, &adev->wakeup.resources,
443				       &wakeup_attr_group, add);
444
445	if (!adev->power.flags.power_resources)
446		return;
447
448	for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
449		acpi_power_expose_hide(adev,
450				       &adev->power.states[state].resources,
451				       &attr_groups[state], add);
452}
453
454int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
455{
456	struct acpi_power_resource_entry *entry;
457	int system_level = 5;
458
459	list_for_each_entry(entry, list, node) {
460		struct acpi_power_resource *resource = entry->resource;
461		acpi_handle handle = resource->device.handle;
462		int result;
463		int state;
464
465		mutex_lock(&resource->resource_lock);
466
467		result = acpi_power_get_state(handle, &state);
468		if (result) {
469			mutex_unlock(&resource->resource_lock);
470			return result;
471		}
472		if (state == ACPI_POWER_RESOURCE_STATE_ON) {
473			resource->ref_count++;
474			resource->wakeup_enabled = true;
475		}
476		if (system_level > resource->system_level)
477			system_level = resource->system_level;
478
479		mutex_unlock(&resource->resource_lock);
480	}
481	*system_level_p = system_level;
482	return 0;
483}
484
485/* --------------------------------------------------------------------------
486                             Device Power Management
487   -------------------------------------------------------------------------- */
488
489/**
490 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
491 *                          ACPI 3.0) _PSW (Power State Wake)
492 * @dev: Device to handle.
493 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
494 * @sleep_state: Target sleep state of the system.
495 * @dev_state: Target power state of the device.
496 *
497 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
498 * State Wake) for the device, if present.  On failure reset the device's
499 * wakeup.flags.valid flag.
500 *
501 * RETURN VALUE:
502 * 0 if either _DSW or _PSW has been successfully executed
503 * 0 if neither _DSW nor _PSW has been found
504 * -ENODEV if the execution of either _DSW or _PSW has failed
505 */
506int acpi_device_sleep_wake(struct acpi_device *dev,
507                           int enable, int sleep_state, int dev_state)
508{
509	union acpi_object in_arg[3];
510	struct acpi_object_list arg_list = { 3, in_arg };
511	acpi_status status = AE_OK;
512
513	/*
514	 * Try to execute _DSW first.
515	 *
516	 * Three agruments are needed for the _DSW object:
517	 * Argument 0: enable/disable the wake capabilities
518	 * Argument 1: target system state
519	 * Argument 2: target device state
520	 * When _DSW object is called to disable the wake capabilities, maybe
521	 * the first argument is filled. The values of the other two agruments
522	 * are meaningless.
523	 */
524	in_arg[0].type = ACPI_TYPE_INTEGER;
525	in_arg[0].integer.value = enable;
526	in_arg[1].type = ACPI_TYPE_INTEGER;
527	in_arg[1].integer.value = sleep_state;
528	in_arg[2].type = ACPI_TYPE_INTEGER;
529	in_arg[2].integer.value = dev_state;
530	status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
531	if (ACPI_SUCCESS(status)) {
532		return 0;
533	} else if (status != AE_NOT_FOUND) {
534		printk(KERN_ERR PREFIX "_DSW execution failed\n");
535		dev->wakeup.flags.valid = 0;
536		return -ENODEV;
537	}
538
539	/* Execute _PSW */
540	status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
541	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
542		printk(KERN_ERR PREFIX "_PSW execution failed\n");
543		dev->wakeup.flags.valid = 0;
544		return -ENODEV;
545	}
546
547	return 0;
548}
549
550/*
551 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
552 * 1. Power on the power resources required for the wakeup device
553 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
554 *    State Wake) for the device, if present
555 */
556int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
557{
558	struct acpi_power_resource_entry *entry;
559	int err = 0;
560
561	if (!dev || !dev->wakeup.flags.valid)
562		return -EINVAL;
563
564	mutex_lock(&acpi_device_lock);
565
566	if (dev->wakeup.prepare_count++)
567		goto out;
568
569	list_for_each_entry(entry, &dev->wakeup.resources, node) {
570		struct acpi_power_resource *resource = entry->resource;
571
572		mutex_lock(&resource->resource_lock);
573
574		if (!resource->wakeup_enabled) {
575			err = acpi_power_on_unlocked(resource);
576			if (!err)
577				resource->wakeup_enabled = true;
578		}
579
580		mutex_unlock(&resource->resource_lock);
581
582		if (err) {
583			dev_err(&dev->dev,
584				"Cannot turn wakeup power resources on\n");
585			dev->wakeup.flags.valid = 0;
586			goto out;
587		}
588	}
589	/*
590	 * Passing 3 as the third argument below means the device may be
591	 * put into arbitrary power state afterward.
592	 */
593	err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
594	if (err)
595		dev->wakeup.prepare_count = 0;
596
597 out:
598	mutex_unlock(&acpi_device_lock);
599	return err;
600}
601
602/*
603 * Shutdown a wakeup device, counterpart of above method
604 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
605 *    State Wake) for the device, if present
606 * 2. Shutdown down the power resources
607 */
608int acpi_disable_wakeup_device_power(struct acpi_device *dev)
609{
610	struct acpi_power_resource_entry *entry;
611	int err = 0;
612
613	if (!dev || !dev->wakeup.flags.valid)
614		return -EINVAL;
615
616	mutex_lock(&acpi_device_lock);
617
618	if (--dev->wakeup.prepare_count > 0)
619		goto out;
620
621	/*
622	 * Executing the code below even if prepare_count is already zero when
623	 * the function is called may be useful, for example for initialisation.
624	 */
625	if (dev->wakeup.prepare_count < 0)
626		dev->wakeup.prepare_count = 0;
627
628	err = acpi_device_sleep_wake(dev, 0, 0, 0);
629	if (err)
630		goto out;
631
632	list_for_each_entry(entry, &dev->wakeup.resources, node) {
633		struct acpi_power_resource *resource = entry->resource;
634
635		mutex_lock(&resource->resource_lock);
636
637		if (resource->wakeup_enabled) {
638			err = acpi_power_off_unlocked(resource);
639			if (!err)
640				resource->wakeup_enabled = false;
641		}
642
643		mutex_unlock(&resource->resource_lock);
644
645		if (err) {
646			dev_err(&dev->dev,
647				"Cannot turn wakeup power resources off\n");
648			dev->wakeup.flags.valid = 0;
649			break;
650		}
651	}
652
653 out:
654	mutex_unlock(&acpi_device_lock);
655	return err;
656}
657
658int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
659{
660	int result = 0;
661	int list_state = 0;
662	int i = 0;
663
664	if (!device || !state)
665		return -EINVAL;
666
667	/*
668	 * We know a device's inferred power state when all the resources
669	 * required for a given D-state are 'on'.
670	 */
671	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
672		struct list_head *list = &device->power.states[i].resources;
673
674		if (list_empty(list))
675			continue;
676
677		result = acpi_power_get_list_state(list, &list_state);
678		if (result)
679			return result;
680
681		if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
682			*state = i;
683			return 0;
684		}
685	}
686
687	*state = ACPI_STATE_D3_COLD;
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	/* TBD: Resources must be ordered. */
714
715	/*
716	 * First we reference all power resources required in the target list
717	 * (e.g. so the device doesn't lose power while transitioning).  Then,
718	 * we dereference all power resources used in the current list.
719	 */
720	if (state < ACPI_STATE_D3_COLD)
721		result = acpi_power_on_list(
722			&device->power.states[state].resources);
723
724	if (!result && device->power.state < ACPI_STATE_D3_COLD)
725		acpi_power_off_list(
726			&device->power.states[device->power.state].resources);
727
728	/* We shouldn't change the state unless the above operations succeed. */
729	device->power.state = result ? ACPI_STATE_UNKNOWN : state;
730
731	return result;
732}
733
734static void acpi_release_power_resource(struct device *dev)
735{
736	struct acpi_device *device = to_acpi_device(dev);
737	struct acpi_power_resource *resource;
738
739	resource = container_of(device, struct acpi_power_resource, device);
740
741	mutex_lock(&power_resource_list_lock);
742	list_del(&resource->list_node);
743	mutex_unlock(&power_resource_list_lock);
744
745	acpi_free_pnp_ids(&device->pnp);
746	kfree(resource);
747}
748
749static ssize_t acpi_power_in_use_show(struct device *dev,
750				      struct device_attribute *attr,
751				      char *buf) {
752	struct acpi_power_resource *resource;
753
754	resource = to_power_resource(to_acpi_device(dev));
755	return sprintf(buf, "%u\n", !!resource->ref_count);
756}
757static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
758
759static void acpi_power_sysfs_remove(struct acpi_device *device)
760{
761	device_remove_file(&device->dev, &dev_attr_resource_in_use);
762}
763
764int acpi_add_power_resource(acpi_handle handle)
765{
766	struct acpi_power_resource *resource;
767	struct acpi_device *device = NULL;
768	union acpi_object acpi_object;
769	struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
770	acpi_status status;
771	int state, result = -ENODEV;
772
773	acpi_bus_get_device(handle, &device);
774	if (device)
775		return 0;
776
777	resource = kzalloc(sizeof(*resource), GFP_KERNEL);
778	if (!resource)
779		return -ENOMEM;
780
781	device = &resource->device;
782	acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
783				ACPI_STA_DEFAULT);
784	mutex_init(&resource->resource_lock);
785	INIT_LIST_HEAD(&resource->list_node);
786	resource->name = device->pnp.bus_id;
787	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
788	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
789	device->power.state = ACPI_STATE_UNKNOWN;
790
791	/* Evalute the object to get the system level and resource order. */
792	status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
793	if (ACPI_FAILURE(status))
794		goto err;
795
796	resource->system_level = acpi_object.power_resource.system_level;
797	resource->order = acpi_object.power_resource.resource_order;
798
799	result = acpi_power_get_state(handle, &state);
800	if (result)
801		goto err;
802
803	printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
804	       acpi_device_bid(device), state ? "on" : "off");
805
806	device->flags.match_driver = true;
807	result = acpi_device_add(device, acpi_release_power_resource);
808	if (result)
809		goto err;
810
811	if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
812		device->remove = acpi_power_sysfs_remove;
813
814	mutex_lock(&power_resource_list_lock);
815	list_add(&resource->list_node, &acpi_power_resource_list);
816	mutex_unlock(&power_resource_list_lock);
817	acpi_device_add_finalize(device);
818	return 0;
819
820 err:
821	acpi_release_power_resource(&device->dev);
822	return result;
823}
824
825#ifdef CONFIG_ACPI_SLEEP
826void acpi_resume_power_resources(void)
827{
828	struct acpi_power_resource *resource;
829
830	mutex_lock(&power_resource_list_lock);
831
832	list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
833		int result, state;
834
835		mutex_lock(&resource->resource_lock);
836
837		result = acpi_power_get_state(resource->device.handle, &state);
838		if (result) {
839			mutex_unlock(&resource->resource_lock);
840			continue;
841		}
842
843		if (state == ACPI_POWER_RESOURCE_STATE_OFF
844		    && resource->ref_count) {
845			dev_info(&resource->device.dev, "Turning ON\n");
846			__acpi_power_on(resource);
847		} else if (state == ACPI_POWER_RESOURCE_STATE_ON
848		    && !resource->ref_count) {
849			dev_info(&resource->device.dev, "Turning OFF\n");
850			__acpi_power_off(resource);
851		}
852
853		mutex_unlock(&resource->resource_lock);
854	}
855
856	mutex_unlock(&power_resource_list_lock);
857}
858#endif
859