2 * acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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>
49 #define PREFIX "ACPI: "
51 #define _COMPONENT ACPI_POWER_COMPONENT
52 ACPI_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
61 static int acpi_power_add(struct acpi_device *device);
62 static int acpi_power_remove(struct acpi_device *device, int type);
64 static const struct acpi_device_id power_device_ids[] = {
68 MODULE_DEVICE_TABLE(acpi, power_device_ids);
70 #ifdef CONFIG_PM_SLEEP
71 static int acpi_power_resume(struct device *dev);
73 static SIMPLE_DEV_PM_OPS(acpi_power_pm, NULL, acpi_power_resume);
75 static struct acpi_driver acpi_power_driver = {
77 .class = ACPI_POWER_CLASS,
78 .ids = power_device_ids,
80 .add = acpi_power_add,
81 .remove = acpi_power_remove,
83 .drv.pm = &acpi_power_pm,
87 * A power managed device
88 * A device may rely on multiple power resources.
90 struct acpi_power_managed_device {
91 struct device *dev; /* The physical device */
95 struct acpi_power_resource_device {
96 struct acpi_power_managed_device *device;
97 struct acpi_power_resource_device *next;
100 struct acpi_power_resource {
101 struct acpi_device * device;
105 unsigned int ref_count;
106 struct mutex resource_lock;
108 /* List of devices relying on this power resource */
109 struct acpi_power_resource_device *devices;
112 static struct list_head acpi_power_resource_list;
114 /* --------------------------------------------------------------------------
115 Power Resource Management
116 -------------------------------------------------------------------------- */
119 acpi_power_get_context(acpi_handle handle,
120 struct acpi_power_resource **resource)
123 struct acpi_device *device = NULL;
129 result = acpi_bus_get_device(handle, &device);
131 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
135 *resource = acpi_driver_data(device);
142 static int acpi_power_get_state(acpi_handle handle, int *state)
144 acpi_status status = AE_OK;
145 unsigned long long sta = 0;
147 struct acpi_buffer buffer = { sizeof(node_name), node_name };
150 if (!handle || !state)
153 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
154 if (ACPI_FAILURE(status))
157 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
158 ACPI_POWER_RESOURCE_STATE_OFF;
160 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
162 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
164 *state ? "on" : "off"));
169 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
177 /* The state of the list is 'on' IFF all resources are 'on'. */
179 for (i = 0; i < list->count; i++) {
180 struct acpi_power_resource *resource;
181 acpi_handle handle = list->handles[i];
184 result = acpi_power_get_context(handle, &resource);
188 mutex_lock(&resource->resource_lock);
190 result = acpi_power_get_state(handle, &cur_state);
192 mutex_unlock(&resource->resource_lock);
197 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
201 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
202 cur_state ? "on" : "off"));
209 /* Resume the device when all power resources in _PR0 are on */
210 static void acpi_power_on_device(struct acpi_power_managed_device *device)
212 struct acpi_device *acpi_dev;
213 acpi_handle handle = device->handle;
216 if (acpi_bus_get_device(handle, &acpi_dev))
219 if(acpi_power_get_inferred_state(acpi_dev, &state))
222 if (state == ACPI_STATE_D0 && pm_runtime_suspended(device->dev))
223 pm_request_resume(device->dev);
226 static int __acpi_power_on(struct acpi_power_resource *resource)
228 struct acpi_power_resource_device *device_list = resource->devices;
229 acpi_status status = AE_OK;
231 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
232 if (ACPI_FAILURE(status))
235 /* Update the power resource's _device_ power state */
236 resource->device->power.state = ACPI_STATE_D0;
238 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
241 while (device_list) {
242 acpi_power_on_device(device_list->device);
244 device_list = device_list->next;
250 static int acpi_power_on(acpi_handle handle)
253 struct acpi_power_resource *resource = NULL;
255 result = acpi_power_get_context(handle, &resource);
259 mutex_lock(&resource->resource_lock);
261 if (resource->ref_count++) {
262 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
263 "Power resource [%s] already on",
266 result = __acpi_power_on(resource);
268 resource->ref_count--;
271 mutex_unlock(&resource->resource_lock);
276 static int acpi_power_off(acpi_handle handle)
279 acpi_status status = AE_OK;
280 struct acpi_power_resource *resource = NULL;
282 result = acpi_power_get_context(handle, &resource);
286 mutex_lock(&resource->resource_lock);
288 if (!resource->ref_count) {
289 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
290 "Power resource [%s] already off",
295 if (--resource->ref_count) {
296 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
297 "Power resource [%s] still in use\n",
302 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
303 if (ACPI_FAILURE(status)) {
306 /* Update the power resource's _device_ power state */
307 resource->device->power.state = ACPI_STATE_D3;
309 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
310 "Power resource [%s] turned off\n",
315 mutex_unlock(&resource->resource_lock);
320 static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
324 for (i = num_res - 1; i >= 0 ; i--)
325 acpi_power_off(list->handles[i]);
328 static void acpi_power_off_list(struct acpi_handle_list *list)
330 __acpi_power_off_list(list, list->count);
333 static int acpi_power_on_list(struct acpi_handle_list *list)
338 for (i = 0; i < list->count; i++) {
339 result = acpi_power_on(list->handles[i]);
341 __acpi_power_off_list(list, i);
349 static void __acpi_power_resource_unregister_device(struct device *dev,
350 acpi_handle res_handle)
352 struct acpi_power_resource *resource = NULL;
353 struct acpi_power_resource_device *prev, *curr;
355 if (acpi_power_get_context(res_handle, &resource))
358 mutex_lock(&resource->resource_lock);
360 curr = resource->devices;
362 if (curr->device->dev == dev) {
364 resource->devices = curr->next;
366 prev->next = curr->next;
375 mutex_unlock(&resource->resource_lock);
378 /* Unlink dev from all power resources in _PR0 */
379 void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle)
381 struct acpi_device *acpi_dev;
382 struct acpi_handle_list *list;
388 if (acpi_bus_get_device(handle, &acpi_dev))
391 list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
393 for (i = 0; i < list->count; i++)
394 __acpi_power_resource_unregister_device(dev,
397 EXPORT_SYMBOL_GPL(acpi_power_resource_unregister_device);
399 static int __acpi_power_resource_register_device(
400 struct acpi_power_managed_device *powered_device, acpi_handle handle)
402 struct acpi_power_resource *resource = NULL;
403 struct acpi_power_resource_device *power_resource_device;
406 result = acpi_power_get_context(handle, &resource);
410 power_resource_device = kzalloc(
411 sizeof(*power_resource_device), GFP_KERNEL);
412 if (!power_resource_device)
415 power_resource_device->device = powered_device;
417 mutex_lock(&resource->resource_lock);
418 power_resource_device->next = resource->devices;
419 resource->devices = power_resource_device;
420 mutex_unlock(&resource->resource_lock);
425 /* Link dev to all power resources in _PR0 */
426 int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
428 struct acpi_device *acpi_dev;
429 struct acpi_handle_list *list;
430 struct acpi_power_managed_device *powered_device;
436 ret = acpi_bus_get_device(handle, &acpi_dev);
438 goto no_power_resource;
440 if (!acpi_dev->power.flags.power_resources)
441 goto no_power_resource;
443 powered_device = kzalloc(sizeof(*powered_device), GFP_KERNEL);
447 powered_device->dev = dev;
448 powered_device->handle = handle;
450 list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
452 for (i = 0; i < list->count; i++) {
453 ret = __acpi_power_resource_register_device(powered_device,
457 acpi_power_resource_unregister_device(dev, handle);
465 printk(KERN_WARNING PREFIX "Invalid Power Resource to register!");
468 EXPORT_SYMBOL_GPL(acpi_power_resource_register_device);
471 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
472 * ACPI 3.0) _PSW (Power State Wake)
473 * @dev: Device to handle.
474 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
475 * @sleep_state: Target sleep state of the system.
476 * @dev_state: Target power state of the device.
478 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
479 * State Wake) for the device, if present. On failure reset the device's
480 * wakeup.flags.valid flag.
483 * 0 if either _DSW or _PSW has been successfully executed
484 * 0 if neither _DSW nor _PSW has been found
485 * -ENODEV if the execution of either _DSW or _PSW has failed
487 int acpi_device_sleep_wake(struct acpi_device *dev,
488 int enable, int sleep_state, int dev_state)
490 union acpi_object in_arg[3];
491 struct acpi_object_list arg_list = { 3, in_arg };
492 acpi_status status = AE_OK;
495 * Try to execute _DSW first.
497 * Three agruments are needed for the _DSW object:
498 * Argument 0: enable/disable the wake capabilities
499 * Argument 1: target system state
500 * Argument 2: target device state
501 * When _DSW object is called to disable the wake capabilities, maybe
502 * the first argument is filled. The values of the other two agruments
505 in_arg[0].type = ACPI_TYPE_INTEGER;
506 in_arg[0].integer.value = enable;
507 in_arg[1].type = ACPI_TYPE_INTEGER;
508 in_arg[1].integer.value = sleep_state;
509 in_arg[2].type = ACPI_TYPE_INTEGER;
510 in_arg[2].integer.value = dev_state;
511 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
512 if (ACPI_SUCCESS(status)) {
514 } else if (status != AE_NOT_FOUND) {
515 printk(KERN_ERR PREFIX "_DSW execution failed\n");
516 dev->wakeup.flags.valid = 0;
522 in_arg[0].integer.value = enable;
523 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
524 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
525 printk(KERN_ERR PREFIX "_PSW execution failed\n");
526 dev->wakeup.flags.valid = 0;
534 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
535 * 1. Power on the power resources required for the wakeup device
536 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
537 * State Wake) for the device, if present
539 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
543 if (!dev || !dev->wakeup.flags.valid)
546 mutex_lock(&acpi_device_lock);
548 if (dev->wakeup.prepare_count++)
551 /* Open power resource */
552 for (i = 0; i < dev->wakeup.resources.count; i++) {
553 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
555 printk(KERN_ERR PREFIX "Transition power state\n");
556 dev->wakeup.flags.valid = 0;
563 * Passing 3 as the third argument below means the device may be placed
564 * in arbitrary power state afterwards.
566 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
570 dev->wakeup.prepare_count = 0;
573 mutex_unlock(&acpi_device_lock);
578 * Shutdown a wakeup device, counterpart of above method
579 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
580 * State Wake) for the device, if present
581 * 2. Shutdown down the power resources
583 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
587 if (!dev || !dev->wakeup.flags.valid)
590 mutex_lock(&acpi_device_lock);
592 if (--dev->wakeup.prepare_count > 0)
596 * Executing the code below even if prepare_count is already zero when
597 * the function is called may be useful, for example for initialisation.
599 if (dev->wakeup.prepare_count < 0)
600 dev->wakeup.prepare_count = 0;
602 err = acpi_device_sleep_wake(dev, 0, 0, 0);
606 /* Close power resource */
607 for (i = 0; i < dev->wakeup.resources.count; i++) {
608 int ret = acpi_power_off(dev->wakeup.resources.handles[i]);
610 printk(KERN_ERR PREFIX "Transition power state\n");
611 dev->wakeup.flags.valid = 0;
618 mutex_unlock(&acpi_device_lock);
622 /* --------------------------------------------------------------------------
623 Device Power Management
624 -------------------------------------------------------------------------- */
626 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
629 struct acpi_handle_list *list = NULL;
633 if (!device || !state)
637 * We know a device's inferred power state when all the resources
638 * required for a given D-state are 'on'.
640 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
641 list = &device->power.states[i].resources;
645 result = acpi_power_get_list_state(list, &list_state);
649 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
655 *state = ACPI_STATE_D3;
659 int acpi_power_on_resources(struct acpi_device *device, int state)
661 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
664 return acpi_power_on_list(&device->power.states[state].resources);
667 int acpi_power_transition(struct acpi_device *device, int state)
671 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
674 if (device->power.state == state)
677 if ((device->power.state < ACPI_STATE_D0)
678 || (device->power.state > ACPI_STATE_D3_COLD))
681 /* TBD: Resources must be ordered. */
684 * First we reference all power resources required in the target list
685 * (e.g. so the device doesn't lose power while transitioning). Then,
686 * we dereference all power resources used in the current list.
688 if (state < ACPI_STATE_D3_COLD)
689 result = acpi_power_on_list(
690 &device->power.states[state].resources);
692 if (!result && device->power.state < ACPI_STATE_D3_COLD)
694 &device->power.states[device->power.state].resources);
696 /* We shouldn't change the state unless the above operations succeed. */
697 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
702 /* --------------------------------------------------------------------------
704 -------------------------------------------------------------------------- */
706 static int acpi_power_add(struct acpi_device *device)
708 int result = 0, state;
709 acpi_status status = AE_OK;
710 struct acpi_power_resource *resource = NULL;
711 union acpi_object acpi_object;
712 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
718 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
722 resource->device = device;
723 mutex_init(&resource->resource_lock);
724 strcpy(resource->name, device->pnp.bus_id);
725 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
726 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
727 device->driver_data = resource;
729 /* Evalute the object to get the system level and resource order. */
730 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
731 if (ACPI_FAILURE(status)) {
735 resource->system_level = acpi_object.power_resource.system_level;
736 resource->order = acpi_object.power_resource.resource_order;
738 result = acpi_power_get_state(device->handle, &state);
743 case ACPI_POWER_RESOURCE_STATE_ON:
744 device->power.state = ACPI_STATE_D0;
746 case ACPI_POWER_RESOURCE_STATE_OFF:
747 device->power.state = ACPI_STATE_D3;
750 device->power.state = ACPI_STATE_UNKNOWN;
754 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
755 acpi_device_bid(device), state ? "on" : "off");
764 static int acpi_power_remove(struct acpi_device *device, int type)
766 struct acpi_power_resource *resource;
771 resource = acpi_driver_data(device);
780 #ifdef CONFIG_PM_SLEEP
781 static int acpi_power_resume(struct device *dev)
783 int result = 0, state;
784 struct acpi_device *device;
785 struct acpi_power_resource *resource;
790 device = to_acpi_device(dev);
791 resource = acpi_driver_data(device);
795 mutex_lock(&resource->resource_lock);
797 result = acpi_power_get_state(device->handle, &state);
801 if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
802 result = __acpi_power_on(resource);
805 mutex_unlock(&resource->resource_lock);
811 int __init acpi_power_init(void)
813 INIT_LIST_HEAD(&acpi_power_resource_list);
814 return acpi_bus_register_driver(&acpi_power_driver);