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_CLASS "power_resource"
50 #define ACPI_POWER_DEVICE_NAME "Power Resource"
51 #define ACPI_POWER_FILE_INFO "info"
52 #define ACPI_POWER_FILE_STATUS "state"
53 #define ACPI_POWER_RESOURCE_STATE_OFF 0x00
54 #define ACPI_POWER_RESOURCE_STATE_ON 0x01
55 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
57 #ifdef MODULE_PARAM_PREFIX
58 #undef MODULE_PARAM_PREFIX
60 #define MODULE_PARAM_PREFIX "acpi."
61 int acpi_power_nocheck;
62 module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
64 static int acpi_power_add(struct acpi_device *device);
65 static int acpi_power_remove(struct acpi_device *device, int type);
66 static int acpi_power_resume(struct acpi_device *device);
67 static int acpi_power_open_fs(struct inode *inode, struct file *file);
69 static struct acpi_device_id power_device_ids[] = {
73 MODULE_DEVICE_TABLE(acpi, power_device_ids);
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,
82 .resume = acpi_power_resume,
86 struct acpi_power_reference {
87 struct list_head node;
88 struct acpi_device *device;
91 struct acpi_power_resource {
92 struct acpi_device * device;
96 struct mutex resource_lock;
97 struct list_head reference;
100 static struct list_head acpi_power_resource_list;
102 static const struct file_operations acpi_power_fops = {
103 .owner = THIS_MODULE,
104 .open = acpi_power_open_fs,
107 .release = single_release,
110 /* --------------------------------------------------------------------------
111 Power Resource Management
112 -------------------------------------------------------------------------- */
115 acpi_power_get_context(acpi_handle handle,
116 struct acpi_power_resource **resource)
119 struct acpi_device *device = NULL;
125 result = acpi_bus_get_device(handle, &device);
127 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
131 *resource = acpi_driver_data(device);
138 static int acpi_power_get_state(acpi_handle handle, int *state)
140 acpi_status status = AE_OK;
141 unsigned long long sta = 0;
144 if (!handle || !state)
147 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
148 if (ACPI_FAILURE(status))
151 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
152 ACPI_POWER_RESOURCE_STATE_OFF;
154 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
155 acpi_ut_get_node_name(handle), state ? "on" : "off"));
160 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
162 int result = 0, state1;
169 /* The state of the list is 'on' IFF all resources are 'on'. */
172 for (i = 0; i < list->count; i++) {
174 * The state of the power resource can be obtained by
175 * using the ACPI handle. In such case it is unnecessary to
176 * get the Power resource first and then get its state again.
178 result = acpi_power_get_state(list->handles[i], &state1);
184 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
188 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
189 *state ? "on" : "off"));
194 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
196 int result = 0, state;
198 acpi_status status = AE_OK;
199 struct acpi_power_resource *resource = NULL;
200 struct list_head *node, *next;
201 struct acpi_power_reference *ref;
204 result = acpi_power_get_context(handle, &resource);
208 mutex_lock(&resource->resource_lock);
209 list_for_each_safe(node, next, &resource->reference) {
210 ref = container_of(node, struct acpi_power_reference, node);
211 if (dev->handle == ref->device->handle) {
212 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
213 dev->pnp.bus_id, resource->name));
220 ref = kmalloc(sizeof (struct acpi_power_reference),
221 irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
223 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
224 mutex_unlock(&resource->resource_lock);
227 list_add_tail(&ref->node, &resource->reference);
229 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
230 dev->pnp.bus_id, resource->name));
232 mutex_unlock(&resource->resource_lock);
234 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
235 if (ACPI_FAILURE(status))
238 if (!acpi_power_nocheck) {
240 * If acpi_power_nocheck is set, it is unnecessary to check
241 * the power state after power transition.
243 result = acpi_power_get_state(resource->device->handle,
247 if (state != ACPI_POWER_RESOURCE_STATE_ON)
250 /* Update the power resource's _device_ power state */
251 resource->device->power.state = ACPI_STATE_D0;
253 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
258 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
260 int result = 0, state;
261 acpi_status status = AE_OK;
262 struct acpi_power_resource *resource = NULL;
263 struct list_head *node, *next;
264 struct acpi_power_reference *ref;
267 result = acpi_power_get_context(handle, &resource);
271 mutex_lock(&resource->resource_lock);
272 list_for_each_safe(node, next, &resource->reference) {
273 ref = container_of(node, struct acpi_power_reference, node);
274 if (dev->handle == ref->device->handle) {
275 list_del(&ref->node);
277 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
278 dev->pnp.bus_id, resource->name));
283 if (!list_empty(&resource->reference)) {
284 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
286 mutex_unlock(&resource->resource_lock);
289 mutex_unlock(&resource->resource_lock);
291 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
292 if (ACPI_FAILURE(status))
295 if (!acpi_power_nocheck) {
297 * If acpi_power_nocheck is set, it is unnecessary to check
298 * the power state after power transition.
300 result = acpi_power_get_state(handle, &state);
303 if (state != ACPI_POWER_RESOURCE_STATE_OFF)
307 /* Update the power resource's _device_ power state */
308 resource->device->power.state = ACPI_STATE_D3;
310 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
317 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
318 * ACPI 3.0) _PSW (Power State Wake)
319 * @dev: Device to handle.
320 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
321 * @sleep_state: Target sleep state of the system.
322 * @dev_state: Target power state of the device.
324 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
325 * State Wake) for the device, if present. On failure reset the device's
326 * wakeup.flags.valid flag.
329 * 0 if either _DSW or _PSW has been successfully executed
330 * 0 if neither _DSW nor _PSW has been found
331 * -ENODEV if the execution of either _DSW or _PSW has failed
333 int acpi_device_sleep_wake(struct acpi_device *dev,
334 int enable, int sleep_state, int dev_state)
336 union acpi_object in_arg[3];
337 struct acpi_object_list arg_list = { 3, in_arg };
338 acpi_status status = AE_OK;
341 * Try to execute _DSW first.
343 * Three agruments are needed for the _DSW object:
344 * Argument 0: enable/disable the wake capabilities
345 * Argument 1: target system state
346 * Argument 2: target device state
347 * When _DSW object is called to disable the wake capabilities, maybe
348 * the first argument is filled. The values of the other two agruments
351 in_arg[0].type = ACPI_TYPE_INTEGER;
352 in_arg[0].integer.value = enable;
353 in_arg[1].type = ACPI_TYPE_INTEGER;
354 in_arg[1].integer.value = sleep_state;
355 in_arg[2].type = ACPI_TYPE_INTEGER;
356 in_arg[2].integer.value = dev_state;
357 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
358 if (ACPI_SUCCESS(status)) {
360 } else if (status != AE_NOT_FOUND) {
361 printk(KERN_ERR PREFIX "_DSW execution failed\n");
362 dev->wakeup.flags.valid = 0;
368 in_arg[0].integer.value = enable;
369 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
370 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
371 printk(KERN_ERR PREFIX "_PSW execution failed\n");
372 dev->wakeup.flags.valid = 0;
380 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
381 * 1. Power on the power resources required for the wakeup device
382 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
383 * State Wake) for the device, if present
385 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
389 if (!dev || !dev->wakeup.flags.valid)
393 * Do not execute the code below twice in a row without calling
394 * acpi_disable_wakeup_device_power() in between for the same device
396 if (dev->wakeup.flags.prepared)
399 /* Open power resource */
400 for (i = 0; i < dev->wakeup.resources.count; i++) {
401 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
403 printk(KERN_ERR PREFIX "Transition power state\n");
404 dev->wakeup.flags.valid = 0;
410 * Passing 3 as the third argument below means the device may be placed
411 * in arbitrary power state afterwards.
413 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
415 dev->wakeup.flags.prepared = 1;
421 * Shutdown a wakeup device, counterpart of above method
422 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
423 * State Wake) for the device, if present
424 * 2. Shutdown down the power resources
426 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
430 if (!dev || !dev->wakeup.flags.valid)
434 * Do not execute the code below twice in a row without calling
435 * acpi_enable_wakeup_device_power() in between for the same device
437 if (!dev->wakeup.flags.prepared)
440 dev->wakeup.flags.prepared = 0;
442 ret = acpi_device_sleep_wake(dev, 0, 0, 0);
446 /* Close power resource */
447 for (i = 0; i < dev->wakeup.resources.count; i++) {
448 ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
450 printk(KERN_ERR PREFIX "Transition power state\n");
451 dev->wakeup.flags.valid = 0;
459 /* --------------------------------------------------------------------------
460 Device Power Management
461 -------------------------------------------------------------------------- */
463 int acpi_power_get_inferred_state(struct acpi_device *device)
466 struct acpi_handle_list *list = NULL;
474 device->power.state = ACPI_STATE_UNKNOWN;
477 * We know a device's inferred power state when all the resources
478 * required for a given D-state are 'on'.
480 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
481 list = &device->power.states[i].resources;
485 result = acpi_power_get_list_state(list, &list_state);
489 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
490 device->power.state = i;
495 device->power.state = ACPI_STATE_D3;
500 int acpi_power_transition(struct acpi_device *device, int state)
503 struct acpi_handle_list *cl = NULL; /* Current Resources */
504 struct acpi_handle_list *tl = NULL; /* Target Resources */
508 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
511 if ((device->power.state < ACPI_STATE_D0)
512 || (device->power.state > ACPI_STATE_D3))
515 cl = &device->power.states[device->power.state].resources;
516 tl = &device->power.states[state].resources;
518 if (!cl->count && !tl->count) {
523 /* TBD: Resources must be ordered. */
526 * First we reference all power resources required in the target list
527 * (e.g. so the device doesn't lose power while transitioning).
529 for (i = 0; i < tl->count; i++) {
530 result = acpi_power_on(tl->handles[i], device);
535 if (device->power.state == state) {
540 * Then we dereference all power resources used in the current list.
542 for (i = 0; i < cl->count; i++) {
543 result = acpi_power_off_device(cl->handles[i], device);
550 device->power.state = ACPI_STATE_UNKNOWN;
552 /* We shouldn't change the state till all above operations succeed */
553 device->power.state = state;
559 /* --------------------------------------------------------------------------
561 -------------------------------------------------------------------------- */
563 static struct proc_dir_entry *acpi_power_dir;
565 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
568 int result = 0, state;
569 struct acpi_power_resource *resource = NULL;
570 struct list_head *node, *next;
571 struct acpi_power_reference *ref;
574 resource = seq->private;
579 result = acpi_power_get_state(resource->device->handle, &state);
583 seq_puts(seq, "state: ");
585 case ACPI_POWER_RESOURCE_STATE_ON:
586 seq_puts(seq, "on\n");
588 case ACPI_POWER_RESOURCE_STATE_OFF:
589 seq_puts(seq, "off\n");
592 seq_puts(seq, "unknown\n");
596 mutex_lock(&resource->resource_lock);
597 list_for_each_safe(node, next, &resource->reference) {
598 ref = container_of(node, struct acpi_power_reference, node);
601 mutex_unlock(&resource->resource_lock);
603 seq_printf(seq, "system level: S%d\n"
605 "reference count: %d\n",
606 resource->system_level,
607 resource->order, count);
613 static int acpi_power_open_fs(struct inode *inode, struct file *file)
615 return single_open(file, acpi_power_seq_show, PDE(inode)->data);
618 static int acpi_power_add_fs(struct acpi_device *device)
620 struct proc_dir_entry *entry = NULL;
626 if (!acpi_device_dir(device)) {
627 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
629 if (!acpi_device_dir(device))
634 entry = proc_create_data(ACPI_POWER_FILE_STATUS,
635 S_IRUGO, acpi_device_dir(device),
636 &acpi_power_fops, acpi_driver_data(device));
642 static int acpi_power_remove_fs(struct acpi_device *device)
645 if (acpi_device_dir(device)) {
646 remove_proc_entry(ACPI_POWER_FILE_STATUS,
647 acpi_device_dir(device));
648 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
649 acpi_device_dir(device) = NULL;
655 /* --------------------------------------------------------------------------
657 -------------------------------------------------------------------------- */
659 static int acpi_power_add(struct acpi_device *device)
661 int result = 0, state;
662 acpi_status status = AE_OK;
663 struct acpi_power_resource *resource = NULL;
664 union acpi_object acpi_object;
665 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
671 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
675 resource->device = device;
676 mutex_init(&resource->resource_lock);
677 INIT_LIST_HEAD(&resource->reference);
678 strcpy(resource->name, device->pnp.bus_id);
679 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
680 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
681 device->driver_data = resource;
683 /* Evalute the object to get the system level and resource order. */
684 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
685 if (ACPI_FAILURE(status)) {
689 resource->system_level = acpi_object.power_resource.system_level;
690 resource->order = acpi_object.power_resource.resource_order;
692 result = acpi_power_get_state(device->handle, &state);
697 case ACPI_POWER_RESOURCE_STATE_ON:
698 device->power.state = ACPI_STATE_D0;
700 case ACPI_POWER_RESOURCE_STATE_OFF:
701 device->power.state = ACPI_STATE_D3;
704 device->power.state = ACPI_STATE_UNKNOWN;
708 result = acpi_power_add_fs(device);
712 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
713 acpi_device_bid(device), state ? "on" : "off");
722 static int acpi_power_remove(struct acpi_device *device, int type)
724 struct acpi_power_resource *resource = NULL;
725 struct list_head *node, *next;
728 if (!device || !acpi_driver_data(device))
731 resource = acpi_driver_data(device);
733 acpi_power_remove_fs(device);
735 mutex_lock(&resource->resource_lock);
736 list_for_each_safe(node, next, &resource->reference) {
737 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
738 list_del(&ref->node);
741 mutex_unlock(&resource->resource_lock);
748 static int acpi_power_resume(struct acpi_device *device)
750 int result = 0, state;
751 struct acpi_power_resource *resource = NULL;
752 struct acpi_power_reference *ref;
754 if (!device || !acpi_driver_data(device))
757 resource = acpi_driver_data(device);
759 result = acpi_power_get_state(device->handle, &state);
763 mutex_lock(&resource->resource_lock);
764 if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
765 !list_empty(&resource->reference)) {
766 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
767 mutex_unlock(&resource->resource_lock);
768 result = acpi_power_on(device->handle, ref->device);
772 mutex_unlock(&resource->resource_lock);
776 static int __init acpi_power_init(void)
784 INIT_LIST_HEAD(&acpi_power_resource_list);
786 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
790 result = acpi_bus_register_driver(&acpi_power_driver);
792 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
799 subsys_initcall(acpi_power_init);