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_resource {
84 struct acpi_device * device;
88 unsigned int ref_count;
89 struct mutex resource_lock;
92 static struct list_head acpi_power_resource_list;
94 /* --------------------------------------------------------------------------
95 Power Resource Management
96 -------------------------------------------------------------------------- */
99 acpi_power_get_context(acpi_handle handle,
100 struct acpi_power_resource **resource)
103 struct acpi_device *device = NULL;
109 result = acpi_bus_get_device(handle, &device);
111 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
115 *resource = acpi_driver_data(device);
122 static int acpi_power_get_state(acpi_handle handle, int *state)
124 acpi_status status = AE_OK;
125 unsigned long long sta = 0;
127 struct acpi_buffer buffer = { sizeof(node_name), node_name };
130 if (!handle || !state)
133 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
134 if (ACPI_FAILURE(status))
137 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
138 ACPI_POWER_RESOURCE_STATE_OFF;
140 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
142 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
144 *state ? "on" : "off"));
149 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
151 int result = 0, state1;
158 /* The state of the list is 'on' IFF all resources are 'on'. */
160 for (i = 0; i < list->count; i++) {
162 * The state of the power resource can be obtained by
163 * using the ACPI handle. In such case it is unnecessary to
164 * get the Power resource first and then get its state again.
166 result = acpi_power_get_state(list->handles[i], &state1);
172 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
176 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
177 *state ? "on" : "off"));
182 static int __acpi_power_on(struct acpi_power_resource *resource)
184 acpi_status status = AE_OK;
186 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
187 if (ACPI_FAILURE(status))
190 /* Update the power resource's _device_ power state */
191 resource->device->power.state = ACPI_STATE_D0;
193 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
199 static int acpi_power_on(acpi_handle handle)
202 struct acpi_power_resource *resource = NULL;
204 result = acpi_power_get_context(handle, &resource);
208 mutex_lock(&resource->resource_lock);
210 if (resource->ref_count++) {
211 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
212 "Power resource [%s] already on",
215 result = __acpi_power_on(resource);
217 resource->ref_count--;
220 mutex_unlock(&resource->resource_lock);
225 static int acpi_power_off_device(acpi_handle handle)
228 acpi_status status = AE_OK;
229 struct acpi_power_resource *resource = NULL;
231 result = acpi_power_get_context(handle, &resource);
235 mutex_lock(&resource->resource_lock);
237 if (!resource->ref_count) {
238 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
239 "Power resource [%s] already off",
244 if (--resource->ref_count) {
245 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
246 "Power resource [%s] still in use\n",
251 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
252 if (ACPI_FAILURE(status)) {
255 /* Update the power resource's _device_ power state */
256 resource->device->power.state = ACPI_STATE_D3;
258 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
259 "Power resource [%s] turned off\n",
264 mutex_unlock(&resource->resource_lock);
270 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
271 * ACPI 3.0) _PSW (Power State Wake)
272 * @dev: Device to handle.
273 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
274 * @sleep_state: Target sleep state of the system.
275 * @dev_state: Target power state of the device.
277 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
278 * State Wake) for the device, if present. On failure reset the device's
279 * wakeup.flags.valid flag.
282 * 0 if either _DSW or _PSW has been successfully executed
283 * 0 if neither _DSW nor _PSW has been found
284 * -ENODEV if the execution of either _DSW or _PSW has failed
286 int acpi_device_sleep_wake(struct acpi_device *dev,
287 int enable, int sleep_state, int dev_state)
289 union acpi_object in_arg[3];
290 struct acpi_object_list arg_list = { 3, in_arg };
291 acpi_status status = AE_OK;
294 * Try to execute _DSW first.
296 * Three agruments are needed for the _DSW object:
297 * Argument 0: enable/disable the wake capabilities
298 * Argument 1: target system state
299 * Argument 2: target device state
300 * When _DSW object is called to disable the wake capabilities, maybe
301 * the first argument is filled. The values of the other two agruments
304 in_arg[0].type = ACPI_TYPE_INTEGER;
305 in_arg[0].integer.value = enable;
306 in_arg[1].type = ACPI_TYPE_INTEGER;
307 in_arg[1].integer.value = sleep_state;
308 in_arg[2].type = ACPI_TYPE_INTEGER;
309 in_arg[2].integer.value = dev_state;
310 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
311 if (ACPI_SUCCESS(status)) {
313 } else if (status != AE_NOT_FOUND) {
314 printk(KERN_ERR PREFIX "_DSW execution failed\n");
315 dev->wakeup.flags.valid = 0;
321 in_arg[0].integer.value = enable;
322 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
323 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
324 printk(KERN_ERR PREFIX "_PSW execution failed\n");
325 dev->wakeup.flags.valid = 0;
333 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
334 * 1. Power on the power resources required for the wakeup device
335 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
336 * State Wake) for the device, if present
338 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
342 if (!dev || !dev->wakeup.flags.valid)
345 mutex_lock(&acpi_device_lock);
347 if (dev->wakeup.prepare_count++)
350 /* Open power resource */
351 for (i = 0; i < dev->wakeup.resources.count; i++) {
352 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
354 printk(KERN_ERR PREFIX "Transition power state\n");
355 dev->wakeup.flags.valid = 0;
362 * Passing 3 as the third argument below means the device may be placed
363 * in arbitrary power state afterwards.
365 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
369 dev->wakeup.prepare_count = 0;
372 mutex_unlock(&acpi_device_lock);
377 * Shutdown a wakeup device, counterpart of above method
378 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
379 * State Wake) for the device, if present
380 * 2. Shutdown down the power resources
382 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
386 if (!dev || !dev->wakeup.flags.valid)
389 mutex_lock(&acpi_device_lock);
391 if (--dev->wakeup.prepare_count > 0)
395 * Executing the code below even if prepare_count is already zero when
396 * the function is called may be useful, for example for initialisation.
398 if (dev->wakeup.prepare_count < 0)
399 dev->wakeup.prepare_count = 0;
401 err = acpi_device_sleep_wake(dev, 0, 0, 0);
405 /* Close power resource */
406 for (i = 0; i < dev->wakeup.resources.count; i++) {
407 int ret = acpi_power_off_device(
408 dev->wakeup.resources.handles[i]);
410 printk(KERN_ERR PREFIX "Transition power state\n");
411 dev->wakeup.flags.valid = 0;
418 mutex_unlock(&acpi_device_lock);
422 /* --------------------------------------------------------------------------
423 Device Power Management
424 -------------------------------------------------------------------------- */
426 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
429 struct acpi_handle_list *list = NULL;
433 if (!device || !state)
437 * We know a device's inferred power state when all the resources
438 * required for a given D-state are 'on'.
440 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
441 list = &device->power.states[i].resources;
445 result = acpi_power_get_list_state(list, &list_state);
449 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
455 *state = ACPI_STATE_D3;
459 int acpi_power_transition(struct acpi_device *device, int state)
462 struct acpi_handle_list *cl = NULL; /* Current Resources */
463 struct acpi_handle_list *tl = NULL; /* Target Resources */
466 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
469 if (device->power.state == state)
472 if ((device->power.state < ACPI_STATE_D0)
473 || (device->power.state > ACPI_STATE_D3))
476 cl = &device->power.states[device->power.state].resources;
477 tl = &device->power.states[state].resources;
479 /* TBD: Resources must be ordered. */
482 * First we reference all power resources required in the target list
483 * (e.g. so the device doesn't lose power while transitioning).
485 for (i = 0; i < tl->count; i++) {
486 result = acpi_power_on(tl->handles[i]);
492 * Then we dereference all power resources used in the current list.
494 for (i = 0; i < cl->count; i++) {
495 result = acpi_power_off_device(cl->handles[i]);
502 device->power.state = ACPI_STATE_UNKNOWN;
504 /* We shouldn't change the state till all above operations succeed */
505 device->power.state = state;
511 /* --------------------------------------------------------------------------
513 -------------------------------------------------------------------------- */
515 static int acpi_power_add(struct acpi_device *device)
517 int result = 0, state;
518 acpi_status status = AE_OK;
519 struct acpi_power_resource *resource = NULL;
520 union acpi_object acpi_object;
521 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
527 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
531 resource->device = device;
532 mutex_init(&resource->resource_lock);
533 strcpy(resource->name, device->pnp.bus_id);
534 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
535 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
536 device->driver_data = resource;
538 /* Evalute the object to get the system level and resource order. */
539 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
540 if (ACPI_FAILURE(status)) {
544 resource->system_level = acpi_object.power_resource.system_level;
545 resource->order = acpi_object.power_resource.resource_order;
547 result = acpi_power_get_state(device->handle, &state);
552 case ACPI_POWER_RESOURCE_STATE_ON:
553 device->power.state = ACPI_STATE_D0;
555 case ACPI_POWER_RESOURCE_STATE_OFF:
556 device->power.state = ACPI_STATE_D3;
559 device->power.state = ACPI_STATE_UNKNOWN;
563 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
564 acpi_device_bid(device), state ? "on" : "off");
573 static int acpi_power_remove(struct acpi_device *device, int type)
575 struct acpi_power_resource *resource;
580 resource = acpi_driver_data(device);
589 static int acpi_power_resume(struct acpi_device *device)
591 int result = 0, state;
592 struct acpi_power_resource *resource;
597 resource = acpi_driver_data(device);
601 mutex_lock(&resource->resource_lock);
603 result = acpi_power_get_state(device->handle, &state);
607 if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
608 result = __acpi_power_on(resource);
611 mutex_unlock(&resource->resource_lock);
616 int __init acpi_power_init(void)
618 INIT_LIST_HEAD(&acpi_power_resource_list);
619 return acpi_bus_register_driver(&acpi_power_driver);