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 <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
47 #define PREFIX "ACPI: "
49 #define _COMPONENT ACPI_POWER_COMPONENT
50 ACPI_MODULE_NAME("power");
51 #define ACPI_POWER_CLASS "power_resource"
52 #define ACPI_POWER_DEVICE_NAME "Power Resource"
53 #define ACPI_POWER_FILE_INFO "info"
54 #define ACPI_POWER_FILE_STATUS "state"
55 #define ACPI_POWER_RESOURCE_STATE_OFF 0x00
56 #define ACPI_POWER_RESOURCE_STATE_ON 0x01
57 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
59 int acpi_power_nocheck;
60 module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
62 static int acpi_power_add(struct acpi_device *device);
63 static int acpi_power_remove(struct acpi_device *device, int type);
64 static int acpi_power_resume(struct acpi_device *device);
66 static const struct acpi_device_id power_device_ids[] = {
70 MODULE_DEVICE_TABLE(acpi, power_device_ids);
72 static struct acpi_driver acpi_power_driver = {
74 .class = ACPI_POWER_CLASS,
75 .ids = power_device_ids,
77 .add = acpi_power_add,
78 .remove = acpi_power_remove,
79 .resume = acpi_power_resume,
83 struct acpi_power_reference {
84 struct list_head node;
85 struct acpi_device *device;
88 struct acpi_power_resource {
89 struct acpi_device * device;
93 struct mutex resource_lock;
94 struct list_head reference;
97 static struct list_head acpi_power_resource_list;
99 /* --------------------------------------------------------------------------
100 Power Resource Management
101 -------------------------------------------------------------------------- */
104 acpi_power_get_context(acpi_handle handle,
105 struct acpi_power_resource **resource)
108 struct acpi_device *device = NULL;
114 result = acpi_bus_get_device(handle, &device);
116 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
120 *resource = acpi_driver_data(device);
127 static int acpi_power_get_state(acpi_handle handle, int *state)
129 acpi_status status = AE_OK;
130 unsigned long long sta = 0;
132 struct acpi_buffer buffer = { sizeof(node_name), node_name };
135 if (!handle || !state)
138 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
139 if (ACPI_FAILURE(status))
142 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
143 ACPI_POWER_RESOURCE_STATE_OFF;
145 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
147 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
149 *state ? "on" : "off"));
154 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
156 int result = 0, state1;
163 /* 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)
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 /* Update the power resource's _device_ power state */
232 resource->device->power.state = ACPI_STATE_D0;
234 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
239 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
242 acpi_status status = AE_OK;
243 struct acpi_power_resource *resource = NULL;
244 struct list_head *node, *next;
246 result = acpi_power_get_context(handle, &resource);
250 mutex_lock(&resource->resource_lock);
251 list_for_each_safe(node, next, &resource->reference) {
252 ref = container_of(node, struct acpi_power_reference, node);
253 if (dev->handle == ref->device->handle) {
254 list_del(&ref->node);
256 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
257 dev->pnp.bus_id, resource->name));
262 if (!list_empty(&resource->reference)) {
263 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
265 mutex_unlock(&resource->resource_lock);
268 mutex_unlock(&resource->resource_lock);
270 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
271 if (ACPI_FAILURE(status))
274 /* Update the power resource's _device_ power state */
275 resource->device->power.state = ACPI_STATE_D3;
277 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
284 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
285 * ACPI 3.0) _PSW (Power State Wake)
286 * @dev: Device to handle.
287 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
288 * @sleep_state: Target sleep state of the system.
289 * @dev_state: Target power state of the device.
291 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
292 * State Wake) for the device, if present. On failure reset the device's
293 * wakeup.flags.valid flag.
296 * 0 if either _DSW or _PSW has been successfully executed
297 * 0 if neither _DSW nor _PSW has been found
298 * -ENODEV if the execution of either _DSW or _PSW has failed
300 int acpi_device_sleep_wake(struct acpi_device *dev,
301 int enable, int sleep_state, int dev_state)
303 union acpi_object in_arg[3];
304 struct acpi_object_list arg_list = { 3, in_arg };
305 acpi_status status = AE_OK;
308 * Try to execute _DSW first.
310 * Three agruments are needed for the _DSW object:
311 * Argument 0: enable/disable the wake capabilities
312 * Argument 1: target system state
313 * Argument 2: target device state
314 * When _DSW object is called to disable the wake capabilities, maybe
315 * the first argument is filled. The values of the other two agruments
318 in_arg[0].type = ACPI_TYPE_INTEGER;
319 in_arg[0].integer.value = enable;
320 in_arg[1].type = ACPI_TYPE_INTEGER;
321 in_arg[1].integer.value = sleep_state;
322 in_arg[2].type = ACPI_TYPE_INTEGER;
323 in_arg[2].integer.value = dev_state;
324 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
325 if (ACPI_SUCCESS(status)) {
327 } else if (status != AE_NOT_FOUND) {
328 printk(KERN_ERR PREFIX "_DSW execution failed\n");
329 dev->wakeup.flags.valid = 0;
335 in_arg[0].integer.value = enable;
336 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
337 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
338 printk(KERN_ERR PREFIX "_PSW execution failed\n");
339 dev->wakeup.flags.valid = 0;
347 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
348 * 1. Power on the power resources required for the wakeup device
349 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
350 * State Wake) for the device, if present
352 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
356 if (!dev || !dev->wakeup.flags.valid)
359 mutex_lock(&acpi_device_lock);
361 if (dev->wakeup.prepare_count++)
364 /* Open power resource */
365 for (i = 0; i < dev->wakeup.resources.count; i++) {
366 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
368 printk(KERN_ERR PREFIX "Transition power state\n");
369 dev->wakeup.flags.valid = 0;
376 * Passing 3 as the third argument below means the device may be placed
377 * in arbitrary power state afterwards.
379 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
383 dev->wakeup.prepare_count = 0;
386 mutex_unlock(&acpi_device_lock);
391 * Shutdown a wakeup device, counterpart of above method
392 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
393 * State Wake) for the device, if present
394 * 2. Shutdown down the power resources
396 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
400 if (!dev || !dev->wakeup.flags.valid)
403 mutex_lock(&acpi_device_lock);
405 if (--dev->wakeup.prepare_count > 0)
409 * Executing the code below even if prepare_count is already zero when
410 * the function is called may be useful, for example for initialisation.
412 if (dev->wakeup.prepare_count < 0)
413 dev->wakeup.prepare_count = 0;
415 err = acpi_device_sleep_wake(dev, 0, 0, 0);
419 /* Close power resource */
420 for (i = 0; i < dev->wakeup.resources.count; i++) {
421 int ret = acpi_power_off_device(
422 dev->wakeup.resources.handles[i], dev);
424 printk(KERN_ERR PREFIX "Transition power state\n");
425 dev->wakeup.flags.valid = 0;
432 mutex_unlock(&acpi_device_lock);
436 /* --------------------------------------------------------------------------
437 Device Power Management
438 -------------------------------------------------------------------------- */
440 int acpi_power_get_inferred_state(struct acpi_device *device)
443 struct acpi_handle_list *list = NULL;
451 device->power.state = ACPI_STATE_UNKNOWN;
454 * We know a device's inferred power state when all the resources
455 * required for a given D-state are 'on'.
457 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
458 list = &device->power.states[i].resources;
462 result = acpi_power_get_list_state(list, &list_state);
466 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
467 device->power.state = i;
472 device->power.state = ACPI_STATE_D3;
477 int acpi_power_transition(struct acpi_device *device, int state)
480 struct acpi_handle_list *cl = NULL; /* Current Resources */
481 struct acpi_handle_list *tl = NULL; /* Target Resources */
485 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
488 if ((device->power.state < ACPI_STATE_D0)
489 || (device->power.state > ACPI_STATE_D3))
492 cl = &device->power.states[device->power.state].resources;
493 tl = &device->power.states[state].resources;
495 /* TBD: Resources must be ordered. */
498 * First we reference all power resources required in the target list
499 * (e.g. so the device doesn't lose power while transitioning).
501 for (i = 0; i < tl->count; i++) {
502 result = acpi_power_on(tl->handles[i], device);
507 if (device->power.state == state) {
512 * Then we dereference all power resources used in the current list.
514 for (i = 0; i < cl->count; i++) {
515 result = acpi_power_off_device(cl->handles[i], device);
522 device->power.state = ACPI_STATE_UNKNOWN;
524 /* We shouldn't change the state till all above operations succeed */
525 device->power.state = state;
531 /* --------------------------------------------------------------------------
533 -------------------------------------------------------------------------- */
535 static int acpi_power_add(struct acpi_device *device)
537 int result = 0, state;
538 acpi_status status = AE_OK;
539 struct acpi_power_resource *resource = NULL;
540 union acpi_object acpi_object;
541 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
547 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
551 resource->device = device;
552 mutex_init(&resource->resource_lock);
553 INIT_LIST_HEAD(&resource->reference);
554 strcpy(resource->name, device->pnp.bus_id);
555 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
556 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
557 device->driver_data = resource;
559 /* Evalute the object to get the system level and resource order. */
560 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
561 if (ACPI_FAILURE(status)) {
565 resource->system_level = acpi_object.power_resource.system_level;
566 resource->order = acpi_object.power_resource.resource_order;
568 result = acpi_power_get_state(device->handle, &state);
573 case ACPI_POWER_RESOURCE_STATE_ON:
574 device->power.state = ACPI_STATE_D0;
576 case ACPI_POWER_RESOURCE_STATE_OFF:
577 device->power.state = ACPI_STATE_D3;
580 device->power.state = ACPI_STATE_UNKNOWN;
584 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
585 acpi_device_bid(device), state ? "on" : "off");
594 static int acpi_power_remove(struct acpi_device *device, int type)
596 struct acpi_power_resource *resource = NULL;
597 struct list_head *node, *next;
600 if (!device || !acpi_driver_data(device))
603 resource = acpi_driver_data(device);
605 mutex_lock(&resource->resource_lock);
606 list_for_each_safe(node, next, &resource->reference) {
607 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
608 list_del(&ref->node);
611 mutex_unlock(&resource->resource_lock);
618 static int acpi_power_resume(struct acpi_device *device)
620 int result = 0, state;
621 struct acpi_power_resource *resource = NULL;
622 struct acpi_power_reference *ref;
624 if (!device || !acpi_driver_data(device))
627 resource = acpi_driver_data(device);
629 result = acpi_power_get_state(device->handle, &state);
633 mutex_lock(&resource->resource_lock);
634 if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
635 !list_empty(&resource->reference)) {
636 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
637 mutex_unlock(&resource->resource_lock);
638 result = acpi_power_on(device->handle, ref->device);
642 mutex_unlock(&resource->resource_lock);
646 int __init acpi_power_init(void)
648 INIT_LIST_HEAD(&acpi_power_resource_list);
649 return acpi_bus_register_driver(&acpi_power_driver);