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
43 struct acpi_power_dependent_device {
44 struct device *dev;
45 struct list_head node;
46 };
47
48 struct acpi_power_resource {
49 struct acpi_device device;
50 struct list_head list_node;
51 u32 system_level;
52 u32 order;
53 unsigned int ref_count;
54 u8 state;
55 bool wakeup_enabled;
56 struct mutex resource_lock;
57 struct list_head dependents;
58 };
59
60 struct acpi_power_resource_entry {
61 struct list_head node;
62 struct acpi_power_resource *resource;
63 };
64
65 static LIST_HEAD(acpi_power_resource_list);
66 static DEFINE_MUTEX(power_resource_list_lock);
67
68 /* --------------------------------------------------------------------------
69 Power Resource Management
70 -------------------------------------------------------------------------- */
71
resource_dev_name(struct acpi_power_resource * pr)72 static inline const char *resource_dev_name(struct acpi_power_resource *pr)
73 {
74 return dev_name(&pr->device.dev);
75 }
76
77 static inline
to_power_resource(struct acpi_device * device)78 struct acpi_power_resource *to_power_resource(struct acpi_device *device)
79 {
80 return container_of(device, struct acpi_power_resource, device);
81 }
82
acpi_power_get_context(acpi_handle handle)83 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
84 {
85 struct acpi_device *device;
86
87 if (acpi_bus_get_device(handle, &device))
88 return NULL;
89
90 return to_power_resource(device);
91 }
92
acpi_power_resources_list_add(acpi_handle handle,struct list_head * list)93 static int acpi_power_resources_list_add(acpi_handle handle,
94 struct list_head *list)
95 {
96 struct acpi_power_resource *resource = acpi_power_get_context(handle);
97 struct acpi_power_resource_entry *entry;
98
99 if (!resource || !list)
100 return -EINVAL;
101
102 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
103 if (!entry)
104 return -ENOMEM;
105
106 entry->resource = resource;
107 if (!list_empty(list)) {
108 struct acpi_power_resource_entry *e;
109
110 list_for_each_entry(e, list, node)
111 if (e->resource->order > resource->order) {
112 list_add_tail(&entry->node, &e->node);
113 return 0;
114 }
115 }
116 list_add_tail(&entry->node, list);
117 return 0;
118 }
119
acpi_power_resources_list_free(struct list_head * list)120 void acpi_power_resources_list_free(struct list_head *list)
121 {
122 struct acpi_power_resource_entry *entry, *e;
123
124 list_for_each_entry_safe(entry, e, list, node) {
125 list_del(&entry->node);
126 kfree(entry);
127 }
128 }
129
acpi_power_resource_is_dup(union acpi_object * package,unsigned int start,unsigned int i)130 static bool acpi_power_resource_is_dup(union acpi_object *package,
131 unsigned int start, unsigned int i)
132 {
133 acpi_handle rhandle, dup;
134 unsigned int j;
135
136 /* The caller is expected to check the package element types */
137 rhandle = package->package.elements[i].reference.handle;
138 for (j = start; j < i; j++) {
139 dup = package->package.elements[j].reference.handle;
140 if (dup == rhandle)
141 return true;
142 }
143
144 return false;
145 }
146
acpi_extract_power_resources(union acpi_object * package,unsigned int start,struct list_head * list)147 int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
148 struct list_head *list)
149 {
150 unsigned int i;
151 int err = 0;
152
153 for (i = start; i < package->package.count; i++) {
154 union acpi_object *element = &package->package.elements[i];
155 struct acpi_device *rdev;
156 acpi_handle rhandle;
157
158 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
159 err = -ENODATA;
160 break;
161 }
162 rhandle = element->reference.handle;
163 if (!rhandle) {
164 err = -ENODEV;
165 break;
166 }
167
168 /* Some ACPI tables contain duplicate power resource references */
169 if (acpi_power_resource_is_dup(package, start, i))
170 continue;
171
172 rdev = acpi_add_power_resource(rhandle);
173 if (!rdev) {
174 err = -ENODEV;
175 break;
176 }
177 err = acpi_power_resources_list_add(rhandle, list);
178 if (err)
179 break;
180 }
181 if (err)
182 acpi_power_resources_list_free(list);
183
184 return err;
185 }
186
__get_state(acpi_handle handle,u8 * state)187 static int __get_state(acpi_handle handle, u8 *state)
188 {
189 acpi_status status = AE_OK;
190 unsigned long long sta = 0;
191 u8 cur_state;
192
193 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
194 if (ACPI_FAILURE(status))
195 return -ENODEV;
196
197 cur_state = sta & ACPI_POWER_RESOURCE_STATE_ON;
198
199 acpi_handle_debug(handle, "Power resource is %s\n",
200 cur_state ? "on" : "off");
201
202 *state = cur_state;
203 return 0;
204 }
205
acpi_power_get_state(struct acpi_power_resource * resource,u8 * state)206 static int acpi_power_get_state(struct acpi_power_resource *resource, u8 *state)
207 {
208 if (resource->state == ACPI_POWER_RESOURCE_STATE_UNKNOWN) {
209 int ret;
210
211 ret = __get_state(resource->device.handle, &resource->state);
212 if (ret)
213 return ret;
214 }
215
216 *state = resource->state;
217 return 0;
218 }
219
acpi_power_get_list_state(struct list_head * list,u8 * state)220 static int acpi_power_get_list_state(struct list_head *list, u8 *state)
221 {
222 struct acpi_power_resource_entry *entry;
223 u8 cur_state = ACPI_POWER_RESOURCE_STATE_OFF;
224
225 if (!list || !state)
226 return -EINVAL;
227
228 /* The state of the list is 'on' IFF all resources are 'on'. */
229 list_for_each_entry(entry, list, node) {
230 struct acpi_power_resource *resource = entry->resource;
231 int result;
232
233 mutex_lock(&resource->resource_lock);
234 result = acpi_power_get_state(resource, &cur_state);
235 mutex_unlock(&resource->resource_lock);
236 if (result)
237 return result;
238
239 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
240 break;
241 }
242
243 pr_debug("Power resource list is %s\n", cur_state ? "on" : "off");
244
245 *state = cur_state;
246 return 0;
247 }
248
249 static int
acpi_power_resource_add_dependent(struct acpi_power_resource * resource,struct device * dev)250 acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
251 struct device *dev)
252 {
253 struct acpi_power_dependent_device *dep;
254 int ret = 0;
255
256 mutex_lock(&resource->resource_lock);
257 list_for_each_entry(dep, &resource->dependents, node) {
258 /* Only add it once */
259 if (dep->dev == dev)
260 goto unlock;
261 }
262
263 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
264 if (!dep) {
265 ret = -ENOMEM;
266 goto unlock;
267 }
268
269 dep->dev = dev;
270 list_add_tail(&dep->node, &resource->dependents);
271 dev_dbg(dev, "added power dependency to [%s]\n",
272 resource_dev_name(resource));
273
274 unlock:
275 mutex_unlock(&resource->resource_lock);
276 return ret;
277 }
278
279 static void
acpi_power_resource_remove_dependent(struct acpi_power_resource * resource,struct device * dev)280 acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
281 struct device *dev)
282 {
283 struct acpi_power_dependent_device *dep;
284
285 mutex_lock(&resource->resource_lock);
286 list_for_each_entry(dep, &resource->dependents, node) {
287 if (dep->dev == dev) {
288 list_del(&dep->node);
289 kfree(dep);
290 dev_dbg(dev, "removed power dependency to [%s]\n",
291 resource_dev_name(resource));
292 break;
293 }
294 }
295 mutex_unlock(&resource->resource_lock);
296 }
297
298 /**
299 * acpi_device_power_add_dependent - Add dependent device of this ACPI device
300 * @adev: ACPI device pointer
301 * @dev: Dependent device
302 *
303 * If @adev has non-empty _PR0 the @dev is added as dependent device to all
304 * power resources returned by it. This means that whenever these power
305 * resources are turned _ON the dependent devices get runtime resumed. This
306 * is needed for devices such as PCI to allow its driver to re-initialize
307 * it after it went to D0uninitialized.
308 *
309 * If @adev does not have _PR0 this does nothing.
310 *
311 * Returns %0 in case of success and negative errno otherwise.
312 */
acpi_device_power_add_dependent(struct acpi_device * adev,struct device * dev)313 int acpi_device_power_add_dependent(struct acpi_device *adev,
314 struct device *dev)
315 {
316 struct acpi_power_resource_entry *entry;
317 struct list_head *resources;
318 int ret;
319
320 if (!adev->flags.power_manageable)
321 return 0;
322
323 resources = &adev->power.states[ACPI_STATE_D0].resources;
324 list_for_each_entry(entry, resources, node) {
325 ret = acpi_power_resource_add_dependent(entry->resource, dev);
326 if (ret)
327 goto err;
328 }
329
330 return 0;
331
332 err:
333 list_for_each_entry(entry, resources, node)
334 acpi_power_resource_remove_dependent(entry->resource, dev);
335
336 return ret;
337 }
338
339 /**
340 * acpi_device_power_remove_dependent - Remove dependent device
341 * @adev: ACPI device pointer
342 * @dev: Dependent device
343 *
344 * Does the opposite of acpi_device_power_add_dependent() and removes the
345 * dependent device if it is found. Can be called to @adev that does not
346 * have _PR0 as well.
347 */
acpi_device_power_remove_dependent(struct acpi_device * adev,struct device * dev)348 void acpi_device_power_remove_dependent(struct acpi_device *adev,
349 struct device *dev)
350 {
351 struct acpi_power_resource_entry *entry;
352 struct list_head *resources;
353
354 if (!adev->flags.power_manageable)
355 return;
356
357 resources = &adev->power.states[ACPI_STATE_D0].resources;
358 list_for_each_entry_reverse(entry, resources, node)
359 acpi_power_resource_remove_dependent(entry->resource, dev);
360 }
361
__acpi_power_on(struct acpi_power_resource * resource)362 static int __acpi_power_on(struct acpi_power_resource *resource)
363 {
364 acpi_handle handle = resource->device.handle;
365 struct acpi_power_dependent_device *dep;
366 acpi_status status = AE_OK;
367
368 status = acpi_evaluate_object(handle, "_ON", NULL, NULL);
369 if (ACPI_FAILURE(status)) {
370 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
371 return -ENODEV;
372 }
373
374 resource->state = ACPI_POWER_RESOURCE_STATE_ON;
375
376 acpi_handle_debug(handle, "Power resource turned on\n");
377
378 /*
379 * If there are other dependents on this power resource we need to
380 * resume them now so that their drivers can re-initialize the
381 * hardware properly after it went back to D0.
382 */
383 if (list_empty(&resource->dependents) ||
384 list_is_singular(&resource->dependents))
385 return 0;
386
387 list_for_each_entry(dep, &resource->dependents, node) {
388 dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
389 resource_dev_name(resource));
390 pm_request_resume(dep->dev);
391 }
392
393 return 0;
394 }
395
acpi_power_on_unlocked(struct acpi_power_resource * resource)396 static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
397 {
398 int result = 0;
399
400 if (resource->ref_count++) {
401 acpi_handle_debug(resource->device.handle,
402 "Power resource already on\n");
403 } else {
404 result = __acpi_power_on(resource);
405 if (result)
406 resource->ref_count--;
407 }
408 return result;
409 }
410
acpi_power_on(struct acpi_power_resource * resource)411 static int acpi_power_on(struct acpi_power_resource *resource)
412 {
413 int result;
414
415 mutex_lock(&resource->resource_lock);
416 result = acpi_power_on_unlocked(resource);
417 mutex_unlock(&resource->resource_lock);
418 return result;
419 }
420
__acpi_power_off(struct acpi_power_resource * resource)421 static int __acpi_power_off(struct acpi_power_resource *resource)
422 {
423 acpi_handle handle = resource->device.handle;
424 acpi_status status;
425
426 status = acpi_evaluate_object(handle, "_OFF", NULL, NULL);
427 if (ACPI_FAILURE(status)) {
428 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
429 return -ENODEV;
430 }
431
432 resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
433
434 acpi_handle_debug(handle, "Power resource turned off\n");
435
436 return 0;
437 }
438
acpi_power_off_unlocked(struct acpi_power_resource * resource)439 static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
440 {
441 int result = 0;
442
443 if (!resource->ref_count) {
444 acpi_handle_debug(resource->device.handle,
445 "Power resource already off\n");
446 return 0;
447 }
448
449 if (--resource->ref_count) {
450 acpi_handle_debug(resource->device.handle,
451 "Power resource still in use\n");
452 } else {
453 result = __acpi_power_off(resource);
454 if (result)
455 resource->ref_count++;
456 }
457 return result;
458 }
459
acpi_power_off(struct acpi_power_resource * resource)460 static int acpi_power_off(struct acpi_power_resource *resource)
461 {
462 int result;
463
464 mutex_lock(&resource->resource_lock);
465 result = acpi_power_off_unlocked(resource);
466 mutex_unlock(&resource->resource_lock);
467 return result;
468 }
469
acpi_power_off_list(struct list_head * list)470 static int acpi_power_off_list(struct list_head *list)
471 {
472 struct acpi_power_resource_entry *entry;
473 int result = 0;
474
475 list_for_each_entry_reverse(entry, list, node) {
476 result = acpi_power_off(entry->resource);
477 if (result)
478 goto err;
479 }
480 return 0;
481
482 err:
483 list_for_each_entry_continue(entry, list, node)
484 acpi_power_on(entry->resource);
485
486 return result;
487 }
488
acpi_power_on_list(struct list_head * list)489 static int acpi_power_on_list(struct list_head *list)
490 {
491 struct acpi_power_resource_entry *entry;
492 int result = 0;
493
494 list_for_each_entry(entry, list, node) {
495 result = acpi_power_on(entry->resource);
496 if (result)
497 goto err;
498 }
499 return 0;
500
501 err:
502 list_for_each_entry_continue_reverse(entry, list, node)
503 acpi_power_off(entry->resource);
504
505 return result;
506 }
507
508 static struct attribute *attrs[] = {
509 NULL,
510 };
511
512 static const struct attribute_group attr_groups[] = {
513 [ACPI_STATE_D0] = {
514 .name = "power_resources_D0",
515 .attrs = attrs,
516 },
517 [ACPI_STATE_D1] = {
518 .name = "power_resources_D1",
519 .attrs = attrs,
520 },
521 [ACPI_STATE_D2] = {
522 .name = "power_resources_D2",
523 .attrs = attrs,
524 },
525 [ACPI_STATE_D3_HOT] = {
526 .name = "power_resources_D3hot",
527 .attrs = attrs,
528 },
529 };
530
531 static const struct attribute_group wakeup_attr_group = {
532 .name = "power_resources_wakeup",
533 .attrs = attrs,
534 };
535
acpi_power_hide_list(struct acpi_device * adev,struct list_head * resources,const struct attribute_group * attr_group)536 static void acpi_power_hide_list(struct acpi_device *adev,
537 struct list_head *resources,
538 const struct attribute_group *attr_group)
539 {
540 struct acpi_power_resource_entry *entry;
541
542 if (list_empty(resources))
543 return;
544
545 list_for_each_entry_reverse(entry, resources, node) {
546 struct acpi_device *res_dev = &entry->resource->device;
547
548 sysfs_remove_link_from_group(&adev->dev.kobj,
549 attr_group->name,
550 dev_name(&res_dev->dev));
551 }
552 sysfs_remove_group(&adev->dev.kobj, attr_group);
553 }
554
acpi_power_expose_list(struct acpi_device * adev,struct list_head * resources,const struct attribute_group * attr_group)555 static void acpi_power_expose_list(struct acpi_device *adev,
556 struct list_head *resources,
557 const struct attribute_group *attr_group)
558 {
559 struct acpi_power_resource_entry *entry;
560 int ret;
561
562 if (list_empty(resources))
563 return;
564
565 ret = sysfs_create_group(&adev->dev.kobj, attr_group);
566 if (ret)
567 return;
568
569 list_for_each_entry(entry, resources, node) {
570 struct acpi_device *res_dev = &entry->resource->device;
571
572 ret = sysfs_add_link_to_group(&adev->dev.kobj,
573 attr_group->name,
574 &res_dev->dev.kobj,
575 dev_name(&res_dev->dev));
576 if (ret) {
577 acpi_power_hide_list(adev, resources, attr_group);
578 break;
579 }
580 }
581 }
582
acpi_power_expose_hide(struct acpi_device * adev,struct list_head * resources,const struct attribute_group * attr_group,bool expose)583 static void acpi_power_expose_hide(struct acpi_device *adev,
584 struct list_head *resources,
585 const struct attribute_group *attr_group,
586 bool expose)
587 {
588 if (expose)
589 acpi_power_expose_list(adev, resources, attr_group);
590 else
591 acpi_power_hide_list(adev, resources, attr_group);
592 }
593
acpi_power_add_remove_device(struct acpi_device * adev,bool add)594 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
595 {
596 int state;
597
598 if (adev->wakeup.flags.valid)
599 acpi_power_expose_hide(adev, &adev->wakeup.resources,
600 &wakeup_attr_group, add);
601
602 if (!adev->power.flags.power_resources)
603 return;
604
605 for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
606 acpi_power_expose_hide(adev,
607 &adev->power.states[state].resources,
608 &attr_groups[state], add);
609 }
610
acpi_power_wakeup_list_init(struct list_head * list,int * system_level_p)611 int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
612 {
613 struct acpi_power_resource_entry *entry;
614 int system_level = 5;
615
616 list_for_each_entry(entry, list, node) {
617 struct acpi_power_resource *resource = entry->resource;
618 int result;
619 u8 state;
620
621 mutex_lock(&resource->resource_lock);
622
623 result = acpi_power_get_state(resource, &state);
624 if (result) {
625 mutex_unlock(&resource->resource_lock);
626 return result;
627 }
628 if (state == ACPI_POWER_RESOURCE_STATE_ON) {
629 resource->ref_count++;
630 resource->wakeup_enabled = true;
631 }
632 if (system_level > resource->system_level)
633 system_level = resource->system_level;
634
635 mutex_unlock(&resource->resource_lock);
636 }
637 *system_level_p = system_level;
638 return 0;
639 }
640
641 /* --------------------------------------------------------------------------
642 Device Power Management
643 -------------------------------------------------------------------------- */
644
645 /**
646 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
647 * ACPI 3.0) _PSW (Power State Wake)
648 * @dev: Device to handle.
649 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
650 * @sleep_state: Target sleep state of the system.
651 * @dev_state: Target power state of the device.
652 *
653 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
654 * State Wake) for the device, if present. On failure reset the device's
655 * wakeup.flags.valid flag.
656 *
657 * RETURN VALUE:
658 * 0 if either _DSW or _PSW has been successfully executed
659 * 0 if neither _DSW nor _PSW has been found
660 * -ENODEV if the execution of either _DSW or _PSW has failed
661 */
acpi_device_sleep_wake(struct acpi_device * dev,int enable,int sleep_state,int dev_state)662 int acpi_device_sleep_wake(struct acpi_device *dev,
663 int enable, int sleep_state, int dev_state)
664 {
665 union acpi_object in_arg[3];
666 struct acpi_object_list arg_list = { 3, in_arg };
667 acpi_status status = AE_OK;
668
669 /*
670 * Try to execute _DSW first.
671 *
672 * Three arguments are needed for the _DSW object:
673 * Argument 0: enable/disable the wake capabilities
674 * Argument 1: target system state
675 * Argument 2: target device state
676 * When _DSW object is called to disable the wake capabilities, maybe
677 * the first argument is filled. The values of the other two arguments
678 * are meaningless.
679 */
680 in_arg[0].type = ACPI_TYPE_INTEGER;
681 in_arg[0].integer.value = enable;
682 in_arg[1].type = ACPI_TYPE_INTEGER;
683 in_arg[1].integer.value = sleep_state;
684 in_arg[2].type = ACPI_TYPE_INTEGER;
685 in_arg[2].integer.value = dev_state;
686 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
687 if (ACPI_SUCCESS(status)) {
688 return 0;
689 } else if (status != AE_NOT_FOUND) {
690 acpi_handle_info(dev->handle, "_DSW execution failed\n");
691 dev->wakeup.flags.valid = 0;
692 return -ENODEV;
693 }
694
695 /* Execute _PSW */
696 status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
697 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
698 acpi_handle_info(dev->handle, "_PSW execution failed\n");
699 dev->wakeup.flags.valid = 0;
700 return -ENODEV;
701 }
702
703 return 0;
704 }
705
706 /*
707 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
708 * 1. Power on the power resources required for the wakeup device
709 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
710 * State Wake) for the device, if present
711 */
acpi_enable_wakeup_device_power(struct acpi_device * dev,int sleep_state)712 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
713 {
714 struct acpi_power_resource_entry *entry;
715 int err = 0;
716
717 if (!dev || !dev->wakeup.flags.valid)
718 return -EINVAL;
719
720 mutex_lock(&acpi_device_lock);
721
722 if (dev->wakeup.prepare_count++)
723 goto out;
724
725 list_for_each_entry(entry, &dev->wakeup.resources, node) {
726 struct acpi_power_resource *resource = entry->resource;
727
728 mutex_lock(&resource->resource_lock);
729
730 if (!resource->wakeup_enabled) {
731 err = acpi_power_on_unlocked(resource);
732 if (!err)
733 resource->wakeup_enabled = true;
734 }
735
736 mutex_unlock(&resource->resource_lock);
737
738 if (err) {
739 dev_err(&dev->dev,
740 "Cannot turn wakeup power resources on\n");
741 dev->wakeup.flags.valid = 0;
742 goto out;
743 }
744 }
745 /*
746 * Passing 3 as the third argument below means the device may be
747 * put into arbitrary power state afterward.
748 */
749 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
750 if (err)
751 dev->wakeup.prepare_count = 0;
752
753 out:
754 mutex_unlock(&acpi_device_lock);
755 return err;
756 }
757
758 /*
759 * Shutdown a wakeup device, counterpart of above method
760 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
761 * State Wake) for the device, if present
762 * 2. Shutdown down the power resources
763 */
acpi_disable_wakeup_device_power(struct acpi_device * dev)764 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
765 {
766 struct acpi_power_resource_entry *entry;
767 int err = 0;
768
769 if (!dev || !dev->wakeup.flags.valid)
770 return -EINVAL;
771
772 mutex_lock(&acpi_device_lock);
773
774 if (--dev->wakeup.prepare_count > 0)
775 goto out;
776
777 /*
778 * Executing the code below even if prepare_count is already zero when
779 * the function is called may be useful, for example for initialisation.
780 */
781 if (dev->wakeup.prepare_count < 0)
782 dev->wakeup.prepare_count = 0;
783
784 err = acpi_device_sleep_wake(dev, 0, 0, 0);
785 if (err)
786 goto out;
787
788 list_for_each_entry(entry, &dev->wakeup.resources, node) {
789 struct acpi_power_resource *resource = entry->resource;
790
791 mutex_lock(&resource->resource_lock);
792
793 if (resource->wakeup_enabled) {
794 err = acpi_power_off_unlocked(resource);
795 if (!err)
796 resource->wakeup_enabled = false;
797 }
798
799 mutex_unlock(&resource->resource_lock);
800
801 if (err) {
802 dev_err(&dev->dev,
803 "Cannot turn wakeup power resources off\n");
804 dev->wakeup.flags.valid = 0;
805 break;
806 }
807 }
808
809 out:
810 mutex_unlock(&acpi_device_lock);
811 return err;
812 }
813
acpi_power_get_inferred_state(struct acpi_device * device,int * state)814 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
815 {
816 u8 list_state = ACPI_POWER_RESOURCE_STATE_OFF;
817 int result = 0;
818 int i = 0;
819
820 if (!device || !state)
821 return -EINVAL;
822
823 /*
824 * We know a device's inferred power state when all the resources
825 * required for a given D-state are 'on'.
826 */
827 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
828 struct list_head *list = &device->power.states[i].resources;
829
830 if (list_empty(list))
831 continue;
832
833 result = acpi_power_get_list_state(list, &list_state);
834 if (result)
835 return result;
836
837 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
838 *state = i;
839 return 0;
840 }
841 }
842
843 *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
844 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
845 return 0;
846 }
847
acpi_power_on_resources(struct acpi_device * device,int state)848 int acpi_power_on_resources(struct acpi_device *device, int state)
849 {
850 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
851 return -EINVAL;
852
853 return acpi_power_on_list(&device->power.states[state].resources);
854 }
855
acpi_power_transition(struct acpi_device * device,int state)856 int acpi_power_transition(struct acpi_device *device, int state)
857 {
858 int result = 0;
859
860 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
861 return -EINVAL;
862
863 if (device->power.state == state || !device->flags.power_manageable)
864 return 0;
865
866 if ((device->power.state < ACPI_STATE_D0)
867 || (device->power.state > ACPI_STATE_D3_COLD))
868 return -ENODEV;
869
870 /*
871 * First we reference all power resources required in the target list
872 * (e.g. so the device doesn't lose power while transitioning). Then,
873 * we dereference all power resources used in the current list.
874 */
875 if (state < ACPI_STATE_D3_COLD)
876 result = acpi_power_on_list(
877 &device->power.states[state].resources);
878
879 if (!result && device->power.state < ACPI_STATE_D3_COLD)
880 acpi_power_off_list(
881 &device->power.states[device->power.state].resources);
882
883 /* We shouldn't change the state unless the above operations succeed. */
884 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
885
886 return result;
887 }
888
acpi_release_power_resource(struct device * dev)889 static void acpi_release_power_resource(struct device *dev)
890 {
891 struct acpi_device *device = to_acpi_device(dev);
892 struct acpi_power_resource *resource;
893
894 resource = container_of(device, struct acpi_power_resource, device);
895
896 mutex_lock(&power_resource_list_lock);
897 list_del(&resource->list_node);
898 mutex_unlock(&power_resource_list_lock);
899
900 acpi_free_pnp_ids(&device->pnp);
901 kfree(resource);
902 }
903
resource_in_use_show(struct device * dev,struct device_attribute * attr,char * buf)904 static ssize_t resource_in_use_show(struct device *dev,
905 struct device_attribute *attr,
906 char *buf)
907 {
908 struct acpi_power_resource *resource;
909
910 resource = to_power_resource(to_acpi_device(dev));
911 return sprintf(buf, "%u\n", !!resource->ref_count);
912 }
913 static DEVICE_ATTR_RO(resource_in_use);
914
acpi_power_sysfs_remove(struct acpi_device * device)915 static void acpi_power_sysfs_remove(struct acpi_device *device)
916 {
917 device_remove_file(&device->dev, &dev_attr_resource_in_use);
918 }
919
acpi_power_add_resource_to_list(struct acpi_power_resource * resource)920 static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
921 {
922 mutex_lock(&power_resource_list_lock);
923
924 if (!list_empty(&acpi_power_resource_list)) {
925 struct acpi_power_resource *r;
926
927 list_for_each_entry(r, &acpi_power_resource_list, list_node)
928 if (r->order > resource->order) {
929 list_add_tail(&resource->list_node, &r->list_node);
930 goto out;
931 }
932 }
933 list_add_tail(&resource->list_node, &acpi_power_resource_list);
934
935 out:
936 mutex_unlock(&power_resource_list_lock);
937 }
938
acpi_add_power_resource(acpi_handle handle)939 struct acpi_device *acpi_add_power_resource(acpi_handle handle)
940 {
941 struct acpi_power_resource *resource;
942 struct acpi_device *device = NULL;
943 union acpi_object acpi_object;
944 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
945 acpi_status status;
946 int result;
947
948 acpi_bus_get_device(handle, &device);
949 if (device)
950 return device;
951
952 resource = kzalloc(sizeof(*resource), GFP_KERNEL);
953 if (!resource)
954 return NULL;
955
956 device = &resource->device;
957 acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER);
958 mutex_init(&resource->resource_lock);
959 INIT_LIST_HEAD(&resource->list_node);
960 INIT_LIST_HEAD(&resource->dependents);
961 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
962 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
963 device->power.state = ACPI_STATE_UNKNOWN;
964
965 /* Evaluate the object to get the system level and resource order. */
966 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
967 if (ACPI_FAILURE(status))
968 goto err;
969
970 resource->system_level = acpi_object.power_resource.system_level;
971 resource->order = acpi_object.power_resource.resource_order;
972 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
973
974 pr_info("%s [%s]\n", acpi_device_name(device), acpi_device_bid(device));
975
976 device->flags.match_driver = true;
977 result = acpi_device_add(device, acpi_release_power_resource);
978 if (result)
979 goto err;
980
981 if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
982 device->remove = acpi_power_sysfs_remove;
983
984 acpi_power_add_resource_to_list(resource);
985 acpi_device_add_finalize(device);
986 return device;
987
988 err:
989 acpi_release_power_resource(&device->dev);
990 return NULL;
991 }
992
993 #ifdef CONFIG_ACPI_SLEEP
acpi_resume_power_resources(void)994 void acpi_resume_power_resources(void)
995 {
996 struct acpi_power_resource *resource;
997
998 mutex_lock(&power_resource_list_lock);
999
1000 list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
1001 int result;
1002 u8 state;
1003
1004 mutex_lock(&resource->resource_lock);
1005
1006 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
1007 result = acpi_power_get_state(resource, &state);
1008 if (result) {
1009 mutex_unlock(&resource->resource_lock);
1010 continue;
1011 }
1012
1013 if (state == ACPI_POWER_RESOURCE_STATE_OFF
1014 && resource->ref_count) {
1015 acpi_handle_debug(resource->device.handle, "Turning ON\n");
1016 __acpi_power_on(resource);
1017 }
1018
1019 mutex_unlock(&resource->resource_lock);
1020 }
1021
1022 mutex_unlock(&power_resource_list_lock);
1023 }
1024 #endif
1025
1026 /**
1027 * acpi_turn_off_unused_power_resources - Turn off power resources not in use.
1028 */
acpi_turn_off_unused_power_resources(void)1029 void acpi_turn_off_unused_power_resources(void)
1030 {
1031 struct acpi_power_resource *resource;
1032
1033 mutex_lock(&power_resource_list_lock);
1034
1035 list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
1036 mutex_lock(&resource->resource_lock);
1037
1038 if (!resource->ref_count &&
1039 resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
1040 acpi_handle_debug(resource->device.handle, "Turning OFF\n");
1041 __acpi_power_off(resource);
1042 }
1043
1044 mutex_unlock(&resource->resource_lock);
1045 }
1046
1047 mutex_unlock(&power_resource_list_lock);
1048 }
1049