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/proc_fs.h>
43 #include <linux/seq_file.h>
44 #include <acpi/acpi_bus.h>
45 #include <acpi/acpi_drivers.h>
47 #define _COMPONENT ACPI_POWER_COMPONENT
48 ACPI_MODULE_NAME("power");
49 #define ACPI_POWER_COMPONENT 0x00800000
50 #define ACPI_POWER_CLASS "power_resource"
51 #define ACPI_POWER_DEVICE_NAME "Power Resource"
52 #define ACPI_POWER_FILE_INFO "info"
53 #define ACPI_POWER_FILE_STATUS "state"
54 #define ACPI_POWER_RESOURCE_STATE_OFF 0x00
55 #define ACPI_POWER_RESOURCE_STATE_ON 0x01
56 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
57 static int acpi_power_add(struct acpi_device *device);
58 static int acpi_power_remove(struct acpi_device *device, int type);
59 static int acpi_power_resume(struct acpi_device *device);
60 static int acpi_power_open_fs(struct inode *inode, struct file *file);
62 static struct acpi_device_id power_device_ids[] = {
66 MODULE_DEVICE_TABLE(acpi, power_device_ids);
68 static struct acpi_driver acpi_power_driver = {
70 .class = ACPI_POWER_CLASS,
71 .ids = power_device_ids,
73 .add = acpi_power_add,
74 .remove = acpi_power_remove,
75 .resume = acpi_power_resume,
79 struct acpi_power_reference {
80 struct list_head node;
81 struct acpi_device *device;
84 struct acpi_power_resource {
85 struct acpi_device * device;
89 struct mutex resource_lock;
90 struct list_head reference;
93 static struct list_head acpi_power_resource_list;
95 static const struct file_operations acpi_power_fops = {
97 .open = acpi_power_open_fs,
100 .release = single_release,
103 /* --------------------------------------------------------------------------
104 Power Resource Management
105 -------------------------------------------------------------------------- */
108 acpi_power_get_context(acpi_handle handle,
109 struct acpi_power_resource **resource)
112 struct acpi_device *device = NULL;
118 result = acpi_bus_get_device(handle, &device);
120 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
124 *resource = acpi_driver_data(device);
131 static int acpi_power_get_state(acpi_handle handle, int *state)
133 acpi_status status = AE_OK;
134 unsigned long sta = 0;
137 if (!handle || !state)
140 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
141 if (ACPI_FAILURE(status))
144 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
145 ACPI_POWER_RESOURCE_STATE_OFF;
147 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
148 acpi_ut_get_node_name(handle), state ? "on" : "off"));
153 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
155 int result = 0, state1;
162 /* The state of the list is 'on' IFF all resources are 'on'. */
165 for (i = 0; i < list->count; i++) {
167 * The state of the power resource can be obtained by
168 * using the ACPI handle. In such case it is unnecessary to
169 * get the Power resource first and then get its state again.
171 result = acpi_power_get_state(list->handles[i], &state1);
177 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
181 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
182 *state ? "on" : "off"));
187 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
189 int result = 0, state;
191 acpi_status status = AE_OK;
192 struct acpi_power_resource *resource = NULL;
193 struct list_head *node, *next;
194 struct acpi_power_reference *ref;
197 result = acpi_power_get_context(handle, &resource);
201 mutex_lock(&resource->resource_lock);
202 list_for_each_safe(node, next, &resource->reference) {
203 ref = container_of(node, struct acpi_power_reference, node);
204 if (dev->handle == ref->device->handle) {
205 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
206 dev->pnp.bus_id, resource->name));
213 ref = kmalloc(sizeof (struct acpi_power_reference),
214 irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
216 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
217 mutex_unlock(&resource->resource_lock);
220 list_add_tail(&ref->node, &resource->reference);
222 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
223 dev->pnp.bus_id, resource->name));
225 mutex_unlock(&resource->resource_lock);
227 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
228 if (ACPI_FAILURE(status))
231 result = acpi_power_get_state(resource->device->handle, &state);
234 if (state != ACPI_POWER_RESOURCE_STATE_ON)
237 /* Update the power resource's _device_ power state */
238 resource->device->power.state = ACPI_STATE_D0;
240 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
245 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
247 int result = 0, state;
248 acpi_status status = AE_OK;
249 struct acpi_power_resource *resource = NULL;
250 struct list_head *node, *next;
251 struct acpi_power_reference *ref;
254 result = acpi_power_get_context(handle, &resource);
258 mutex_lock(&resource->resource_lock);
259 list_for_each_safe(node, next, &resource->reference) {
260 ref = container_of(node, struct acpi_power_reference, node);
261 if (dev->handle == ref->device->handle) {
262 list_del(&ref->node);
264 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
265 dev->pnp.bus_id, resource->name));
270 if (!list_empty(&resource->reference)) {
271 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
273 mutex_unlock(&resource->resource_lock);
276 mutex_unlock(&resource->resource_lock);
278 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
279 if (ACPI_FAILURE(status))
282 result = acpi_power_get_state(handle, &state);
285 if (state != ACPI_POWER_RESOURCE_STATE_OFF)
288 /* Update the power resource's _device_ power state */
289 resource->device->power.state = ACPI_STATE_D3;
291 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
298 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
299 * ACPI 3.0) _PSW (Power State Wake)
300 * @dev: Device to handle.
301 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
302 * @sleep_state: Target sleep state of the system.
303 * @dev_state: Target power state of the device.
305 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
306 * State Wake) for the device, if present. On failure reset the device's
307 * wakeup.flags.valid flag.
310 * 0 if either _DSW or _PSW has been successfully executed
311 * 0 if neither _DSW nor _PSW has been found
312 * -ENODEV if the execution of either _DSW or _PSW has failed
314 int acpi_device_sleep_wake(struct acpi_device *dev,
315 int enable, int sleep_state, int dev_state)
317 union acpi_object in_arg[3];
318 struct acpi_object_list arg_list = { 3, in_arg };
319 acpi_status status = AE_OK;
322 * Try to execute _DSW first.
324 * Three agruments are needed for the _DSW object:
325 * Argument 0: enable/disable the wake capabilities
326 * Argument 1: target system state
327 * Argument 2: target device state
328 * When _DSW object is called to disable the wake capabilities, maybe
329 * the first argument is filled. The values of the other two agruments
332 in_arg[0].type = ACPI_TYPE_INTEGER;
333 in_arg[0].integer.value = enable;
334 in_arg[1].type = ACPI_TYPE_INTEGER;
335 in_arg[1].integer.value = sleep_state;
336 in_arg[2].type = ACPI_TYPE_INTEGER;
337 in_arg[2].integer.value = dev_state;
338 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
339 if (ACPI_SUCCESS(status)) {
341 } else if (status != AE_NOT_FOUND) {
342 printk(KERN_ERR PREFIX "_DSW execution failed\n");
343 dev->wakeup.flags.valid = 0;
349 in_arg[0].integer.value = enable;
350 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
351 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
352 printk(KERN_ERR PREFIX "_PSW execution failed\n");
353 dev->wakeup.flags.valid = 0;
361 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
362 * 1. Power on the power resources required for the wakeup device
363 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
364 * State Wake) for the device, if present
366 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
370 if (!dev || !dev->wakeup.flags.valid)
374 * Do not execute the code below twice in a row without calling
375 * acpi_disable_wakeup_device_power() in between for the same device
377 if (dev->wakeup.flags.prepared)
380 /* Open power resource */
381 for (i = 0; i < dev->wakeup.resources.count; i++) {
382 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
384 printk(KERN_ERR PREFIX "Transition power state\n");
385 dev->wakeup.flags.valid = 0;
391 * Passing 3 as the third argument below means the device may be placed
392 * in arbitrary power state afterwards.
394 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
396 dev->wakeup.flags.prepared = 1;
402 * Shutdown a wakeup device, counterpart of above method
403 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
404 * State Wake) for the device, if present
405 * 2. Shutdown down the power resources
407 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
411 if (!dev || !dev->wakeup.flags.valid)
415 * Do not execute the code below twice in a row without calling
416 * acpi_enable_wakeup_device_power() in between for the same device
418 if (!dev->wakeup.flags.prepared)
421 dev->wakeup.flags.prepared = 0;
423 ret = acpi_device_sleep_wake(dev, 0, 0, 0);
427 /* Close power resource */
428 for (i = 0; i < dev->wakeup.resources.count; i++) {
429 ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
431 printk(KERN_ERR PREFIX "Transition power state\n");
432 dev->wakeup.flags.valid = 0;
440 /* --------------------------------------------------------------------------
441 Device Power Management
442 -------------------------------------------------------------------------- */
444 int acpi_power_get_inferred_state(struct acpi_device *device)
447 struct acpi_handle_list *list = NULL;
455 device->power.state = ACPI_STATE_UNKNOWN;
458 * We know a device's inferred power state when all the resources
459 * required for a given D-state are 'on'.
461 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
462 list = &device->power.states[i].resources;
466 result = acpi_power_get_list_state(list, &list_state);
470 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
471 device->power.state = i;
476 device->power.state = ACPI_STATE_D3;
481 int acpi_power_transition(struct acpi_device *device, int state)
484 struct acpi_handle_list *cl = NULL; /* Current Resources */
485 struct acpi_handle_list *tl = NULL; /* Target Resources */
489 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
492 if ((device->power.state < ACPI_STATE_D0)
493 || (device->power.state > ACPI_STATE_D3))
496 cl = &device->power.states[device->power.state].resources;
497 tl = &device->power.states[state].resources;
499 if (!cl->count && !tl->count) {
504 /* TBD: Resources must be ordered. */
507 * First we reference all power resources required in the target list
508 * (e.g. so the device doesn't lose power while transitioning).
510 for (i = 0; i < tl->count; i++) {
511 result = acpi_power_on(tl->handles[i], device);
516 if (device->power.state == state) {
521 * Then we dereference all power resources used in the current list.
523 for (i = 0; i < cl->count; i++) {
524 result = acpi_power_off_device(cl->handles[i], device);
531 device->power.state = ACPI_STATE_UNKNOWN;
533 /* We shouldn't change the state till all above operations succeed */
534 device->power.state = state;
540 /* --------------------------------------------------------------------------
542 -------------------------------------------------------------------------- */
544 static struct proc_dir_entry *acpi_power_dir;
546 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
549 int result = 0, state;
550 struct acpi_power_resource *resource = NULL;
551 struct list_head *node, *next;
552 struct acpi_power_reference *ref;
555 resource = seq->private;
560 result = acpi_power_get_state(resource->device->handle, &state);
564 seq_puts(seq, "state: ");
566 case ACPI_POWER_RESOURCE_STATE_ON:
567 seq_puts(seq, "on\n");
569 case ACPI_POWER_RESOURCE_STATE_OFF:
570 seq_puts(seq, "off\n");
573 seq_puts(seq, "unknown\n");
577 mutex_lock(&resource->resource_lock);
578 list_for_each_safe(node, next, &resource->reference) {
579 ref = container_of(node, struct acpi_power_reference, node);
582 mutex_unlock(&resource->resource_lock);
584 seq_printf(seq, "system level: S%d\n"
586 "reference count: %d\n",
587 resource->system_level,
588 resource->order, count);
594 static int acpi_power_open_fs(struct inode *inode, struct file *file)
596 return single_open(file, acpi_power_seq_show, PDE(inode)->data);
599 static int acpi_power_add_fs(struct acpi_device *device)
601 struct proc_dir_entry *entry = NULL;
607 if (!acpi_device_dir(device)) {
608 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
610 if (!acpi_device_dir(device))
615 entry = proc_create_data(ACPI_POWER_FILE_STATUS,
616 S_IRUGO, acpi_device_dir(device),
617 &acpi_power_fops, acpi_driver_data(device));
623 static int acpi_power_remove_fs(struct acpi_device *device)
626 if (acpi_device_dir(device)) {
627 remove_proc_entry(ACPI_POWER_FILE_STATUS,
628 acpi_device_dir(device));
629 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
630 acpi_device_dir(device) = NULL;
636 /* --------------------------------------------------------------------------
638 -------------------------------------------------------------------------- */
640 static int acpi_power_add(struct acpi_device *device)
642 int result = 0, state;
643 acpi_status status = AE_OK;
644 struct acpi_power_resource *resource = NULL;
645 union acpi_object acpi_object;
646 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
652 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
656 resource->device = device;
657 mutex_init(&resource->resource_lock);
658 INIT_LIST_HEAD(&resource->reference);
659 strcpy(resource->name, device->pnp.bus_id);
660 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
661 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
662 acpi_driver_data(device) = resource;
664 /* Evalute the object to get the system level and resource order. */
665 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
666 if (ACPI_FAILURE(status)) {
670 resource->system_level = acpi_object.power_resource.system_level;
671 resource->order = acpi_object.power_resource.resource_order;
673 result = acpi_power_get_state(device->handle, &state);
678 case ACPI_POWER_RESOURCE_STATE_ON:
679 device->power.state = ACPI_STATE_D0;
681 case ACPI_POWER_RESOURCE_STATE_OFF:
682 device->power.state = ACPI_STATE_D3;
685 device->power.state = ACPI_STATE_UNKNOWN;
689 result = acpi_power_add_fs(device);
693 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
694 acpi_device_bid(device), state ? "on" : "off");
703 static int acpi_power_remove(struct acpi_device *device, int type)
705 struct acpi_power_resource *resource = NULL;
706 struct list_head *node, *next;
709 if (!device || !acpi_driver_data(device))
712 resource = acpi_driver_data(device);
714 acpi_power_remove_fs(device);
716 mutex_lock(&resource->resource_lock);
717 list_for_each_safe(node, next, &resource->reference) {
718 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
719 list_del(&ref->node);
722 mutex_unlock(&resource->resource_lock);
729 static int acpi_power_resume(struct acpi_device *device)
731 int result = 0, state;
732 struct acpi_power_resource *resource = NULL;
733 struct acpi_power_reference *ref;
735 if (!device || !acpi_driver_data(device))
738 resource = (struct acpi_power_resource *)acpi_driver_data(device);
740 result = acpi_power_get_state(device->handle, &state);
744 mutex_lock(&resource->resource_lock);
745 if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
746 !list_empty(&resource->reference)) {
747 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
748 mutex_unlock(&resource->resource_lock);
749 result = acpi_power_on(device->handle, ref->device);
753 mutex_unlock(&resource->resource_lock);
757 static int __init acpi_power_init(void)
765 INIT_LIST_HEAD(&acpi_power_resource_list);
767 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
771 result = acpi_bus_register_driver(&acpi_power_driver);
773 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
780 subsys_initcall(acpi_power_init);