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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}
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