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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#define pr_fmt(fmt) "ACPI: PM: " fmt
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/slab.h>
31#include <linux/pm_runtime.h>
32#include <linux/sysfs.h>
33#include <linux/acpi.h>
34#include "sleep.h"
35#include "internal.h"
36
37#define ACPI_POWER_CLASS "power_resource"
38#define ACPI_POWER_DEVICE_NAME "Power Resource"
39#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
40#define ACPI_POWER_RESOURCE_STATE_ON 0x01
41#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
42
43struct acpi_power_dependent_device {
44 struct device *dev;
45 struct list_head node;
46};
47
48struct acpi_power_resource {
49 struct acpi_device device;
50 struct list_head list_node;
51 char *name;
52 u32 system_level;
53 u32 order;
54 unsigned int ref_count;
55 u8 state;
56 bool wakeup_enabled;
57 struct mutex resource_lock;
58 struct list_head dependents;
59};
60
61struct acpi_power_resource_entry {
62 struct list_head node;
63 struct acpi_power_resource *resource;
64};
65
66static LIST_HEAD(acpi_power_resource_list);
67static DEFINE_MUTEX(power_resource_list_lock);
68
69/* --------------------------------------------------------------------------
70 Power Resource Management
71 -------------------------------------------------------------------------- */
72
73static inline
74struct acpi_power_resource *to_power_resource(struct acpi_device *device)
75{
76 return container_of(device, struct acpi_power_resource, device);
77}
78
79static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
80{
81 struct acpi_device *device;
82
83 if (acpi_bus_get_device(handle, &device))
84 return NULL;
85
86 return to_power_resource(device);
87}
88
89static int acpi_power_resources_list_add(acpi_handle handle,
90 struct list_head *list)
91{
92 struct acpi_power_resource *resource = acpi_power_get_context(handle);
93 struct acpi_power_resource_entry *entry;
94
95 if (!resource || !list)
96 return -EINVAL;
97
98 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
99 if (!entry)
100 return -ENOMEM;
101
102 entry->resource = resource;
103 if (!list_empty(list)) {
104 struct acpi_power_resource_entry *e;
105
106 list_for_each_entry(e, list, node)
107 if (e->resource->order > resource->order) {
108 list_add_tail(&entry->node, &e->node);
109 return 0;
110 }
111 }
112 list_add_tail(&entry->node, list);
113 return 0;
114}
115
116void acpi_power_resources_list_free(struct list_head *list)
117{
118 struct acpi_power_resource_entry *entry, *e;
119
120 list_for_each_entry_safe(entry, e, list, node) {
121 list_del(&entry->node);
122 kfree(entry);
123 }
124}
125
126static bool acpi_power_resource_is_dup(union acpi_object *package,
127 unsigned int start, unsigned int i)
128{
129 acpi_handle rhandle, dup;
130 unsigned int j;
131
132 /* The caller is expected to check the package element types */
133 rhandle = package->package.elements[i].reference.handle;
134 for (j = start; j < i; j++) {
135 dup = package->package.elements[j].reference.handle;
136 if (dup == rhandle)
137 return true;
138 }
139
140 return false;
141}
142
143int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
144 struct list_head *list)
145{
146 unsigned int i;
147 int err = 0;
148
149 for (i = start; i < package->package.count; i++) {
150 union acpi_object *element = &package->package.elements[i];
151 struct acpi_device *rdev;
152 acpi_handle rhandle;
153
154 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
155 err = -ENODATA;
156 break;
157 }
158 rhandle = element->reference.handle;
159 if (!rhandle) {
160 err = -ENODEV;
161 break;
162 }
163
164 /* Some ACPI tables contain duplicate power resource references */
165 if (acpi_power_resource_is_dup(package, start, i))
166 continue;
167
168 rdev = acpi_add_power_resource(rhandle);
169 if (!rdev) {
170 err = -ENODEV;
171 break;
172 }
173 err = acpi_power_resources_list_add(rhandle, list);
174 if (err)
175 break;
176 }
177 if (err)
178 acpi_power_resources_list_free(list);
179
180 return err;
181}
182
183static int __get_state(acpi_handle handle, u8 *state)
184{
185 acpi_status status = AE_OK;
186 unsigned long long sta = 0;
187 u8 cur_state;
188
189 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
190 if (ACPI_FAILURE(status))
191 return -ENODEV;
192
193 cur_state = sta & ACPI_POWER_RESOURCE_STATE_ON;
194
195 acpi_handle_debug(handle, "Power resource is %s\n",
196 cur_state ? "on" : "off");
197
198 *state = cur_state;
199 return 0;
200}
201
202static int acpi_power_get_state(struct acpi_power_resource *resource, u8 *state)
203{
204 if (resource->state == ACPI_POWER_RESOURCE_STATE_UNKNOWN) {
205 int ret;
206
207 ret = __get_state(resource->device.handle, &resource->state);
208 if (ret)
209 return ret;
210 }
211
212 *state = resource->state;
213 return 0;
214}
215
216static int acpi_power_get_list_state(struct list_head *list, u8 *state)
217{
218 struct acpi_power_resource_entry *entry;
219 u8 cur_state = ACPI_POWER_RESOURCE_STATE_OFF;
220
221 if (!list || !state)
222 return -EINVAL;
223
224 /* The state of the list is 'on' IFF all resources are 'on'. */
225 list_for_each_entry(entry, list, node) {
226 struct acpi_power_resource *resource = entry->resource;
227 int result;
228
229 mutex_lock(&resource->resource_lock);
230 result = acpi_power_get_state(resource, &cur_state);
231 mutex_unlock(&resource->resource_lock);
232 if (result)
233 return result;
234
235 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
236 break;
237 }
238
239 pr_debug("Power resource list is %s\n", cur_state ? "on" : "off");
240
241 *state = cur_state;
242 return 0;
243}
244
245static int
246acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
247 struct device *dev)
248{
249 struct acpi_power_dependent_device *dep;
250 int ret = 0;
251
252 mutex_lock(&resource->resource_lock);
253 list_for_each_entry(dep, &resource->dependents, node) {
254 /* Only add it once */
255 if (dep->dev == dev)
256 goto unlock;
257 }
258
259 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
260 if (!dep) {
261 ret = -ENOMEM;
262 goto unlock;
263 }
264
265 dep->dev = dev;
266 list_add_tail(&dep->node, &resource->dependents);
267 dev_dbg(dev, "added power dependency to [%s]\n", resource->name);
268
269unlock:
270 mutex_unlock(&resource->resource_lock);
271 return ret;
272}
273
274static void
275acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
276 struct device *dev)
277{
278 struct acpi_power_dependent_device *dep;
279
280 mutex_lock(&resource->resource_lock);
281 list_for_each_entry(dep, &resource->dependents, node) {
282 if (dep->dev == dev) {
283 list_del(&dep->node);
284 kfree(dep);
285 dev_dbg(dev, "removed power dependency to [%s]\n",
286 resource->name);
287 break;
288 }
289 }
290 mutex_unlock(&resource->resource_lock);
291}
292
293/**
294 * acpi_device_power_add_dependent - Add dependent device of this ACPI device
295 * @adev: ACPI device pointer
296 * @dev: Dependent device
297 *
298 * If @adev has non-empty _PR0 the @dev is added as dependent device to all
299 * power resources returned by it. This means that whenever these power
300 * resources are turned _ON the dependent devices get runtime resumed. This
301 * is needed for devices such as PCI to allow its driver to re-initialize
302 * it after it went to D0uninitialized.
303 *
304 * If @adev does not have _PR0 this does nothing.
305 *
306 * Returns %0 in case of success and negative errno otherwise.
307 */
308int acpi_device_power_add_dependent(struct acpi_device *adev,
309 struct device *dev)
310{
311 struct acpi_power_resource_entry *entry;
312 struct list_head *resources;
313 int ret;
314
315 if (!adev->flags.power_manageable)
316 return 0;
317
318 resources = &adev->power.states[ACPI_STATE_D0].resources;
319 list_for_each_entry(entry, resources, node) {
320 ret = acpi_power_resource_add_dependent(entry->resource, dev);
321 if (ret)
322 goto err;
323 }
324
325 return 0;
326
327err:
328 list_for_each_entry(entry, resources, node)
329 acpi_power_resource_remove_dependent(entry->resource, dev);
330
331 return ret;
332}
333
334/**
335 * acpi_device_power_remove_dependent - Remove dependent device
336 * @adev: ACPI device pointer
337 * @dev: Dependent device
338 *
339 * Does the opposite of acpi_device_power_add_dependent() and removes the
340 * dependent device if it is found. Can be called to @adev that does not
341 * have _PR0 as well.
342 */
343void acpi_device_power_remove_dependent(struct acpi_device *adev,
344 struct device *dev)
345{
346 struct acpi_power_resource_entry *entry;
347 struct list_head *resources;
348
349 if (!adev->flags.power_manageable)
350 return;
351
352 resources = &adev->power.states[ACPI_STATE_D0].resources;
353 list_for_each_entry_reverse(entry, resources, node)
354 acpi_power_resource_remove_dependent(entry->resource, dev);
355}
356
357static int __acpi_power_on(struct acpi_power_resource *resource)
358{
359 struct acpi_power_dependent_device *dep;
360 acpi_status status = AE_OK;
361
362 status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
363 if (ACPI_FAILURE(status)) {
364 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
365 return -ENODEV;
366 }
367
368 resource->state = ACPI_POWER_RESOURCE_STATE_ON;
369
370 pr_debug("Power resource [%s] turned on\n", resource->name);
371
372 /*
373 * If there are other dependents on this power resource we need to
374 * resume them now so that their drivers can re-initialize the
375 * hardware properly after it went back to D0.
376 */
377 if (list_empty(&resource->dependents) ||
378 list_is_singular(&resource->dependents))
379 return 0;
380
381 list_for_each_entry(dep, &resource->dependents, node) {
382 dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
383 resource->name);
384 pm_request_resume(dep->dev);
385 }
386
387 return 0;
388}
389
390static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
391{
392 int result = 0;
393
394 if (resource->ref_count++) {
395 pr_debug("Power resource [%s] already on\n", resource->name);
396 } else {
397 result = __acpi_power_on(resource);
398 if (result)
399 resource->ref_count--;
400 }
401 return result;
402}
403
404static int acpi_power_on(struct acpi_power_resource *resource)
405{
406 int result;
407
408 mutex_lock(&resource->resource_lock);
409 result = acpi_power_on_unlocked(resource);
410 mutex_unlock(&resource->resource_lock);
411 return result;
412}
413
414static int __acpi_power_off(struct acpi_power_resource *resource)
415{
416 acpi_status status;
417
418 status = acpi_evaluate_object(resource->device.handle, "_OFF",
419 NULL, NULL);
420 if (ACPI_FAILURE(status)) {
421 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
422 return -ENODEV;
423 }
424
425 resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
426
427 pr_debug("Power resource [%s] turned off\n", resource->name);
428
429 return 0;
430}
431
432static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
433{
434 int result = 0;
435
436 if (!resource->ref_count) {
437 pr_debug("Power resource [%s] already off\n", resource->name);
438 return 0;
439 }
440
441 if (--resource->ref_count) {
442 pr_debug("Power resource [%s] still in use\n", resource->name);
443 } else {
444 result = __acpi_power_off(resource);
445 if (result)
446 resource->ref_count++;
447 }
448 return result;
449}
450
451static int acpi_power_off(struct acpi_power_resource *resource)
452{
453 int result;
454
455 mutex_lock(&resource->resource_lock);
456 result = acpi_power_off_unlocked(resource);
457 mutex_unlock(&resource->resource_lock);
458 return result;
459}
460
461static int acpi_power_off_list(struct list_head *list)
462{
463 struct acpi_power_resource_entry *entry;
464 int result = 0;
465
466 list_for_each_entry_reverse(entry, list, node) {
467 result = acpi_power_off(entry->resource);
468 if (result)
469 goto err;
470 }
471 return 0;
472
473 err:
474 list_for_each_entry_continue(entry, list, node)
475 acpi_power_on(entry->resource);
476
477 return result;
478}
479
480static int acpi_power_on_list(struct list_head *list)
481{
482 struct acpi_power_resource_entry *entry;
483 int result = 0;
484
485 list_for_each_entry(entry, list, node) {
486 result = acpi_power_on(entry->resource);
487 if (result)
488 goto err;
489 }
490 return 0;
491
492 err:
493 list_for_each_entry_continue_reverse(entry, list, node)
494 acpi_power_off(entry->resource);
495
496 return result;
497}
498
499static struct attribute *attrs[] = {
500 NULL,
501};
502
503static const struct attribute_group attr_groups[] = {
504 [ACPI_STATE_D0] = {
505 .name = "power_resources_D0",
506 .attrs = attrs,
507 },
508 [ACPI_STATE_D1] = {
509 .name = "power_resources_D1",
510 .attrs = attrs,
511 },
512 [ACPI_STATE_D2] = {
513 .name = "power_resources_D2",
514 .attrs = attrs,
515 },
516 [ACPI_STATE_D3_HOT] = {
517 .name = "power_resources_D3hot",
518 .attrs = attrs,
519 },
520};
521
522static const struct attribute_group wakeup_attr_group = {
523 .name = "power_resources_wakeup",
524 .attrs = attrs,
525};
526
527static void acpi_power_hide_list(struct acpi_device *adev,
528 struct list_head *resources,
529 const struct attribute_group *attr_group)
530{
531 struct acpi_power_resource_entry *entry;
532
533 if (list_empty(resources))
534 return;
535
536 list_for_each_entry_reverse(entry, resources, node) {
537 struct acpi_device *res_dev = &entry->resource->device;
538
539 sysfs_remove_link_from_group(&adev->dev.kobj,
540 attr_group->name,
541 dev_name(&res_dev->dev));
542 }
543 sysfs_remove_group(&adev->dev.kobj, attr_group);
544}
545
546static void acpi_power_expose_list(struct acpi_device *adev,
547 struct list_head *resources,
548 const struct attribute_group *attr_group)
549{
550 struct acpi_power_resource_entry *entry;
551 int ret;
552
553 if (list_empty(resources))
554 return;
555
556 ret = sysfs_create_group(&adev->dev.kobj, attr_group);
557 if (ret)
558 return;
559
560 list_for_each_entry(entry, resources, node) {
561 struct acpi_device *res_dev = &entry->resource->device;
562
563 ret = sysfs_add_link_to_group(&adev->dev.kobj,
564 attr_group->name,
565 &res_dev->dev.kobj,
566 dev_name(&res_dev->dev));
567 if (ret) {
568 acpi_power_hide_list(adev, resources, attr_group);
569 break;
570 }
571 }
572}
573
574static void acpi_power_expose_hide(struct acpi_device *adev,
575 struct list_head *resources,
576 const struct attribute_group *attr_group,
577 bool expose)
578{
579 if (expose)
580 acpi_power_expose_list(adev, resources, attr_group);
581 else
582 acpi_power_hide_list(adev, resources, attr_group);
583}
584
585void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
586{
587 int state;
588
589 if (adev->wakeup.flags.valid)
590 acpi_power_expose_hide(adev, &adev->wakeup.resources,
591 &wakeup_attr_group, add);
592
593 if (!adev->power.flags.power_resources)
594 return;
595
596 for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
597 acpi_power_expose_hide(adev,
598 &adev->power.states[state].resources,
599 &attr_groups[state], add);
600}
601
602int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
603{
604 struct acpi_power_resource_entry *entry;
605 int system_level = 5;
606
607 list_for_each_entry(entry, list, node) {
608 struct acpi_power_resource *resource = entry->resource;
609 int result;
610 u8 state;
611
612 mutex_lock(&resource->resource_lock);
613
614 result = acpi_power_get_state(resource, &state);
615 if (result) {
616 mutex_unlock(&resource->resource_lock);
617 return result;
618 }
619 if (state == ACPI_POWER_RESOURCE_STATE_ON) {
620 resource->ref_count++;
621 resource->wakeup_enabled = true;
622 }
623 if (system_level > resource->system_level)
624 system_level = resource->system_level;
625
626 mutex_unlock(&resource->resource_lock);
627 }
628 *system_level_p = system_level;
629 return 0;
630}
631
632/* --------------------------------------------------------------------------
633 Device Power Management
634 -------------------------------------------------------------------------- */
635
636/**
637 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
638 * ACPI 3.0) _PSW (Power State Wake)
639 * @dev: Device to handle.
640 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
641 * @sleep_state: Target sleep state of the system.
642 * @dev_state: Target power state of the device.
643 *
644 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
645 * State Wake) for the device, if present. On failure reset the device's
646 * wakeup.flags.valid flag.
647 *
648 * RETURN VALUE:
649 * 0 if either _DSW or _PSW has been successfully executed
650 * 0 if neither _DSW nor _PSW has been found
651 * -ENODEV if the execution of either _DSW or _PSW has failed
652 */
653int acpi_device_sleep_wake(struct acpi_device *dev,
654 int enable, int sleep_state, int dev_state)
655{
656 union acpi_object in_arg[3];
657 struct acpi_object_list arg_list = { 3, in_arg };
658 acpi_status status = AE_OK;
659
660 /*
661 * Try to execute _DSW first.
662 *
663 * Three arguments are needed for the _DSW object:
664 * Argument 0: enable/disable the wake capabilities
665 * Argument 1: target system state
666 * Argument 2: target device state
667 * When _DSW object is called to disable the wake capabilities, maybe
668 * the first argument is filled. The values of the other two arguments
669 * are meaningless.
670 */
671 in_arg[0].type = ACPI_TYPE_INTEGER;
672 in_arg[0].integer.value = enable;
673 in_arg[1].type = ACPI_TYPE_INTEGER;
674 in_arg[1].integer.value = sleep_state;
675 in_arg[2].type = ACPI_TYPE_INTEGER;
676 in_arg[2].integer.value = dev_state;
677 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
678 if (ACPI_SUCCESS(status)) {
679 return 0;
680 } else if (status != AE_NOT_FOUND) {
681 acpi_handle_info(dev->handle, "_DSW execution failed\n");
682 dev->wakeup.flags.valid = 0;
683 return -ENODEV;
684 }
685
686 /* Execute _PSW */
687 status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
688 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
689 acpi_handle_info(dev->handle, "_PSW execution failed\n");
690 dev->wakeup.flags.valid = 0;
691 return -ENODEV;
692 }
693
694 return 0;
695}
696
697/*
698 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
699 * 1. Power on the power resources required for the wakeup device
700 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
701 * State Wake) for the device, if present
702 */
703int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
704{
705 struct acpi_power_resource_entry *entry;
706 int err = 0;
707
708 if (!dev || !dev->wakeup.flags.valid)
709 return -EINVAL;
710
711 mutex_lock(&acpi_device_lock);
712
713 if (dev->wakeup.prepare_count++)
714 goto out;
715
716 list_for_each_entry(entry, &dev->wakeup.resources, node) {
717 struct acpi_power_resource *resource = entry->resource;
718
719 mutex_lock(&resource->resource_lock);
720
721 if (!resource->wakeup_enabled) {
722 err = acpi_power_on_unlocked(resource);
723 if (!err)
724 resource->wakeup_enabled = true;
725 }
726
727 mutex_unlock(&resource->resource_lock);
728
729 if (err) {
730 dev_err(&dev->dev,
731 "Cannot turn wakeup power resources on\n");
732 dev->wakeup.flags.valid = 0;
733 goto out;
734 }
735 }
736 /*
737 * Passing 3 as the third argument below means the device may be
738 * put into arbitrary power state afterward.
739 */
740 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
741 if (err)
742 dev->wakeup.prepare_count = 0;
743
744 out:
745 mutex_unlock(&acpi_device_lock);
746 return err;
747}
748
749/*
750 * Shutdown a wakeup device, counterpart of above method
751 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
752 * State Wake) for the device, if present
753 * 2. Shutdown down the power resources
754 */
755int acpi_disable_wakeup_device_power(struct acpi_device *dev)
756{
757 struct acpi_power_resource_entry *entry;
758 int err = 0;
759
760 if (!dev || !dev->wakeup.flags.valid)
761 return -EINVAL;
762
763 mutex_lock(&acpi_device_lock);
764
765 if (--dev->wakeup.prepare_count > 0)
766 goto out;
767
768 /*
769 * Executing the code below even if prepare_count is already zero when
770 * the function is called may be useful, for example for initialisation.
771 */
772 if (dev->wakeup.prepare_count < 0)
773 dev->wakeup.prepare_count = 0;
774
775 err = acpi_device_sleep_wake(dev, 0, 0, 0);
776 if (err)
777 goto out;
778
779 list_for_each_entry(entry, &dev->wakeup.resources, node) {
780 struct acpi_power_resource *resource = entry->resource;
781
782 mutex_lock(&resource->resource_lock);
783
784 if (resource->wakeup_enabled) {
785 err = acpi_power_off_unlocked(resource);
786 if (!err)
787 resource->wakeup_enabled = false;
788 }
789
790 mutex_unlock(&resource->resource_lock);
791
792 if (err) {
793 dev_err(&dev->dev,
794 "Cannot turn wakeup power resources off\n");
795 dev->wakeup.flags.valid = 0;
796 break;
797 }
798 }
799
800 out:
801 mutex_unlock(&acpi_device_lock);
802 return err;
803}
804
805int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
806{
807 u8 list_state = ACPI_POWER_RESOURCE_STATE_OFF;
808 int result = 0;
809 int i = 0;
810
811 if (!device || !state)
812 return -EINVAL;
813
814 /*
815 * We know a device's inferred power state when all the resources
816 * required for a given D-state are 'on'.
817 */
818 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
819 struct list_head *list = &device->power.states[i].resources;
820
821 if (list_empty(list))
822 continue;
823
824 result = acpi_power_get_list_state(list, &list_state);
825 if (result)
826 return result;
827
828 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
829 *state = i;
830 return 0;
831 }
832 }
833
834 *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
835 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
836 return 0;
837}
838
839int acpi_power_on_resources(struct acpi_device *device, int state)
840{
841 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
842 return -EINVAL;
843
844 return acpi_power_on_list(&device->power.states[state].resources);
845}
846
847int acpi_power_transition(struct acpi_device *device, int state)
848{
849 int result = 0;
850
851 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
852 return -EINVAL;
853
854 if (device->power.state == state || !device->flags.power_manageable)
855 return 0;
856
857 if ((device->power.state < ACPI_STATE_D0)
858 || (device->power.state > ACPI_STATE_D3_COLD))
859 return -ENODEV;
860
861 /*
862 * First we reference all power resources required in the target list
863 * (e.g. so the device doesn't lose power while transitioning). Then,
864 * we dereference all power resources used in the current list.
865 */
866 if (state < ACPI_STATE_D3_COLD)
867 result = acpi_power_on_list(
868 &device->power.states[state].resources);
869
870 if (!result && device->power.state < ACPI_STATE_D3_COLD)
871 acpi_power_off_list(
872 &device->power.states[device->power.state].resources);
873
874 /* We shouldn't change the state unless the above operations succeed. */
875 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
876
877 return result;
878}
879
880static void acpi_release_power_resource(struct device *dev)
881{
882 struct acpi_device *device = to_acpi_device(dev);
883 struct acpi_power_resource *resource;
884
885 resource = container_of(device, struct acpi_power_resource, device);
886
887 mutex_lock(&power_resource_list_lock);
888 list_del(&resource->list_node);
889 mutex_unlock(&power_resource_list_lock);
890
891 acpi_free_pnp_ids(&device->pnp);
892 kfree(resource);
893}
894
895static ssize_t resource_in_use_show(struct device *dev,
896 struct device_attribute *attr,
897 char *buf)
898{
899 struct acpi_power_resource *resource;
900
901 resource = to_power_resource(to_acpi_device(dev));
902 return sprintf(buf, "%u\n", !!resource->ref_count);
903}
904static DEVICE_ATTR_RO(resource_in_use);
905
906static void acpi_power_sysfs_remove(struct acpi_device *device)
907{
908 device_remove_file(&device->dev, &dev_attr_resource_in_use);
909}
910
911static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
912{
913 mutex_lock(&power_resource_list_lock);
914
915 if (!list_empty(&acpi_power_resource_list)) {
916 struct acpi_power_resource *r;
917
918 list_for_each_entry(r, &acpi_power_resource_list, list_node)
919 if (r->order > resource->order) {
920 list_add_tail(&resource->list_node, &r->list_node);
921 goto out;
922 }
923 }
924 list_add_tail(&resource->list_node, &acpi_power_resource_list);
925
926 out:
927 mutex_unlock(&power_resource_list_lock);
928}
929
930struct acpi_device *acpi_add_power_resource(acpi_handle handle)
931{
932 struct acpi_power_resource *resource;
933 struct acpi_device *device = NULL;
934 union acpi_object acpi_object;
935 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
936 acpi_status status;
937 int result;
938
939 acpi_bus_get_device(handle, &device);
940 if (device)
941 return device;
942
943 resource = kzalloc(sizeof(*resource), GFP_KERNEL);
944 if (!resource)
945 return NULL;
946
947 device = &resource->device;
948 acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER);
949 mutex_init(&resource->resource_lock);
950 INIT_LIST_HEAD(&resource->list_node);
951 INIT_LIST_HEAD(&resource->dependents);
952 resource->name = device->pnp.bus_id;
953 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
954 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
955 device->power.state = ACPI_STATE_UNKNOWN;
956
957 /* Evaluate the object to get the system level and resource order. */
958 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
959 if (ACPI_FAILURE(status))
960 goto err;
961
962 resource->system_level = acpi_object.power_resource.system_level;
963 resource->order = acpi_object.power_resource.resource_order;
964 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
965
966 pr_info("%s [%s]\n", acpi_device_name(device), acpi_device_bid(device));
967
968 device->flags.match_driver = true;
969 result = acpi_device_add(device, acpi_release_power_resource);
970 if (result)
971 goto err;
972
973 if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
974 device->remove = acpi_power_sysfs_remove;
975
976 acpi_power_add_resource_to_list(resource);
977 acpi_device_add_finalize(device);
978 return device;
979
980 err:
981 acpi_release_power_resource(&device->dev);
982 return NULL;
983}
984
985#ifdef CONFIG_ACPI_SLEEP
986void acpi_resume_power_resources(void)
987{
988 struct acpi_power_resource *resource;
989
990 mutex_lock(&power_resource_list_lock);
991
992 list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
993 int result;
994 u8 state;
995
996 mutex_lock(&resource->resource_lock);
997
998 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
999 result = acpi_power_get_state(resource, &state);
1000 if (result) {
1001 mutex_unlock(&resource->resource_lock);
1002 continue;
1003 }
1004
1005 if (state == ACPI_POWER_RESOURCE_STATE_OFF
1006 && resource->ref_count) {
1007 dev_dbg(&resource->device.dev, "Turning ON\n");
1008 __acpi_power_on(resource);
1009 }
1010
1011 mutex_unlock(&resource->resource_lock);
1012 }
1013
1014 mutex_unlock(&power_resource_list_lock);
1015}
1016#endif
1017
1018/**
1019 * acpi_turn_off_unused_power_resources - Turn off power resources not in use.
1020 */
1021void acpi_turn_off_unused_power_resources(void)
1022{
1023 struct acpi_power_resource *resource;
1024
1025 mutex_lock(&power_resource_list_lock);
1026
1027 list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
1028 mutex_lock(&resource->resource_lock);
1029
1030 /*
1031 * Turn off power resources in an unknown state too, because the
1032 * platform firmware on some system expects the OS to turn off
1033 * power resources without any users unconditionally.
1034 */
1035 if (!resource->ref_count &&
1036 resource->state != ACPI_POWER_RESOURCE_STATE_OFF) {
1037 dev_dbg(&resource->device.dev, "Turning OFF\n");
1038 __acpi_power_off(resource);
1039 }
1040
1041 mutex_unlock(&resource->resource_lock);
1042 }
1043
1044 mutex_unlock(&power_resource_list_lock);
1045}