Linux 3.3
[deliverable/linux.git] / drivers / acpi / power.c
CommitLineData
1da177e4
LT
1/*
2 * acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
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.
13 *
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.
18 *
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.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
25
26/*
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.
31 *
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.
36 */
37
38#include <linux/kernel.h>
39#include <linux/module.h>
40#include <linux/init.h>
41#include <linux/types.h>
5a0e3ad6 42#include <linux/slab.h>
1da177e4
LT
43#include <acpi/acpi_bus.h>
44#include <acpi/acpi_drivers.h>
9b83ccd2
RW
45#include "sleep.h"
46
a192a958
LB
47#define PREFIX "ACPI: "
48
89595b8f 49#define _COMPONENT ACPI_POWER_COMPONENT
f52fd66d 50ACPI_MODULE_NAME("power");
1da177e4 51#define ACPI_POWER_CLASS "power_resource"
1da177e4
LT
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
f5adfaa3 58
4be44fcd
LB
59static int acpi_power_add(struct acpi_device *device);
60static int acpi_power_remove(struct acpi_device *device, int type);
e8363f33 61static int acpi_power_resume(struct acpi_device *device);
1da177e4 62
c97adf9e 63static const struct acpi_device_id power_device_ids[] = {
1ba90e3a
TR
64 {ACPI_POWER_HID, 0},
65 {"", 0},
66};
67MODULE_DEVICE_TABLE(acpi, power_device_ids);
68
1da177e4 69static struct acpi_driver acpi_power_driver = {
c2b6705b 70 .name = "power",
4be44fcd 71 .class = ACPI_POWER_CLASS,
1ba90e3a 72 .ids = power_device_ids,
4be44fcd
LB
73 .ops = {
74 .add = acpi_power_add,
75 .remove = acpi_power_remove,
0a613902 76 .resume = acpi_power_resume,
4be44fcd 77 },
1da177e4
LT
78};
79
4be44fcd 80struct acpi_power_resource {
41598572 81 struct acpi_device * device;
4be44fcd
LB
82 acpi_bus_id name;
83 u32 system_level;
84 u32 order;
3e384ee6 85 unsigned int ref_count;
0a613902 86 struct mutex resource_lock;
1da177e4
LT
87};
88
4be44fcd 89static struct list_head acpi_power_resource_list;
1da177e4 90
1da177e4
LT
91/* --------------------------------------------------------------------------
92 Power Resource Management
93 -------------------------------------------------------------------------- */
94
95static int
4be44fcd
LB
96acpi_power_get_context(acpi_handle handle,
97 struct acpi_power_resource **resource)
1da177e4 98{
4be44fcd
LB
99 int result = 0;
100 struct acpi_device *device = NULL;
1da177e4 101
1da177e4
LT
102
103 if (!resource)
d550d98d 104 return -ENODEV;
1da177e4
LT
105
106 result = acpi_bus_get_device(handle, &device);
107 if (result) {
cece9296 108 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
d550d98d 109 return result;
1da177e4
LT
110 }
111
50dd0969 112 *resource = acpi_driver_data(device);
a815ab8b 113 if (!*resource)
d550d98d 114 return -ENODEV;
1da177e4 115
d550d98d 116 return 0;
1da177e4
LT
117}
118
a51e145f 119static int acpi_power_get_state(acpi_handle handle, int *state)
1da177e4 120{
4be44fcd 121 acpi_status status = AE_OK;
27663c58 122 unsigned long long sta = 0;
60a4ce7f
LM
123 char node_name[5];
124 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1da177e4 125
1da177e4 126
a51e145f 127 if (!handle || !state)
d550d98d 128 return -EINVAL;
1da177e4 129
a51e145f 130 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
1da177e4 131 if (ACPI_FAILURE(status))
d550d98d 132 return -ENODEV;
1da177e4 133
c35923bc
AS
134 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
135 ACPI_POWER_RESOURCE_STATE_OFF;
1da177e4 136
60a4ce7f
LM
137 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
138
1da177e4 139 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
60a4ce7f 140 node_name,
b1b57fbe 141 *state ? "on" : "off"));
1da177e4 142
d550d98d 143 return 0;
1da177e4
LT
144}
145
4be44fcd 146static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
1da177e4 147{
d0515d9f
RW
148 int cur_state;
149 int i = 0;
1da177e4
LT
150
151 if (!list || !state)
d550d98d 152 return -EINVAL;
1da177e4
LT
153
154 /* The state of the list is 'on' IFF all resources are 'on'. */
155
4be44fcd 156 for (i = 0; i < list->count; i++) {
d0515d9f
RW
157 struct acpi_power_resource *resource;
158 acpi_handle handle = list->handles[i];
159 int result;
160
161 result = acpi_power_get_context(handle, &resource);
1da177e4 162 if (result)
d550d98d 163 return result;
1da177e4 164
d0515d9f
RW
165 mutex_lock(&resource->resource_lock);
166
167 result = acpi_power_get_state(handle, &cur_state);
1da177e4 168
d0515d9f
RW
169 mutex_unlock(&resource->resource_lock);
170
171 if (result)
172 return result;
173
174 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
1da177e4
LT
175 break;
176 }
177
178 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
d0515d9f 179 cur_state ? "on" : "off"));
1da177e4 180
d0515d9f
RW
181 *state = cur_state;
182
183 return 0;
1da177e4
LT
184}
185
3e384ee6 186static int __acpi_power_on(struct acpi_power_resource *resource)
1da177e4 187{
4be44fcd 188 acpi_status status = AE_OK;
1da177e4 189
3e384ee6
RW
190 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
191 if (ACPI_FAILURE(status))
192 return -ENODEV;
193
194 /* Update the power resource's _device_ power state */
195 resource->device->power.state = ACPI_STATE_D0;
196
197 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
198 resource->name));
199
200 return 0;
201}
202
203static int acpi_power_on(acpi_handle handle)
204{
205 int result = 0;
206 struct acpi_power_resource *resource = NULL;
1da177e4
LT
207
208 result = acpi_power_get_context(handle, &resource);
209 if (result)
d550d98d 210 return result;
1da177e4 211
0a613902 212 mutex_lock(&resource->resource_lock);
0a613902 213
3e384ee6
RW
214 if (resource->ref_count++) {
215 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
216 "Power resource [%s] already on",
217 resource->name));
218 } else {
219 result = __acpi_power_on(resource);
12b3b5af
RW
220 if (result)
221 resource->ref_count--;
0a613902 222 }
1da177e4 223
3e384ee6 224 mutex_unlock(&resource->resource_lock);
1da177e4 225
12b3b5af 226 return result;
1da177e4
LT
227}
228
36237fa0 229static int acpi_power_off(acpi_handle handle)
1da177e4 230{
bdf43bbf 231 int result = 0;
4be44fcd 232 acpi_status status = AE_OK;
1da177e4 233 struct acpi_power_resource *resource = NULL;
0a613902 234
1da177e4
LT
235 result = acpi_power_get_context(handle, &resource);
236 if (result)
d550d98d 237 return result;
1da177e4 238
0a613902 239 mutex_lock(&resource->resource_lock);
3e384ee6
RW
240
241 if (!resource->ref_count) {
242 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
243 "Power resource [%s] already off",
244 resource->name));
245 goto unlock;
0a613902 246 }
1da177e4 247
3e384ee6
RW
248 if (--resource->ref_count) {
249 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
250 "Power resource [%s] still in use\n",
251 resource->name));
252 goto unlock;
1da177e4
LT
253 }
254
5fbc19ef 255 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
3e384ee6
RW
256 if (ACPI_FAILURE(status)) {
257 result = -ENODEV;
258 } else {
259 /* Update the power resource's _device_ power state */
260 resource->device->power.state = ACPI_STATE_D3;
1da177e4 261
3e384ee6
RW
262 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
263 "Power resource [%s] turned off\n",
264 resource->name));
265 }
1da177e4 266
3e384ee6
RW
267 unlock:
268 mutex_unlock(&resource->resource_lock);
1da177e4 269
3e384ee6 270 return result;
1da177e4
LT
271}
272
d2ef555b
RW
273static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
274{
275 int i;
276
277 for (i = num_res - 1; i >= 0 ; i--)
36237fa0 278 acpi_power_off(list->handles[i]);
d2ef555b
RW
279}
280
281static void acpi_power_off_list(struct acpi_handle_list *list)
282{
283 __acpi_power_off_list(list, list->count);
284}
285
286static int acpi_power_on_list(struct acpi_handle_list *list)
287{
288 int result = 0;
289 int i;
290
291 for (i = 0; i < list->count; i++) {
292 result = acpi_power_on(list->handles[i]);
293 if (result) {
294 __acpi_power_off_list(list, i);
295 break;
296 }
297 }
298
299 return result;
300}
301
77e76609
RW
302/**
303 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
304 * ACPI 3.0) _PSW (Power State Wake)
305 * @dev: Device to handle.
306 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
307 * @sleep_state: Target sleep state of the system.
308 * @dev_state: Target power state of the device.
309 *
310 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
311 * State Wake) for the device, if present. On failure reset the device's
312 * wakeup.flags.valid flag.
313 *
314 * RETURN VALUE:
315 * 0 if either _DSW or _PSW has been successfully executed
316 * 0 if neither _DSW nor _PSW has been found
317 * -ENODEV if the execution of either _DSW or _PSW has failed
318 */
319int acpi_device_sleep_wake(struct acpi_device *dev,
320 int enable, int sleep_state, int dev_state)
321{
322 union acpi_object in_arg[3];
323 struct acpi_object_list arg_list = { 3, in_arg };
324 acpi_status status = AE_OK;
325
326 /*
327 * Try to execute _DSW first.
328 *
329 * Three agruments are needed for the _DSW object:
330 * Argument 0: enable/disable the wake capabilities
331 * Argument 1: target system state
332 * Argument 2: target device state
333 * When _DSW object is called to disable the wake capabilities, maybe
334 * the first argument is filled. The values of the other two agruments
335 * are meaningless.
336 */
337 in_arg[0].type = ACPI_TYPE_INTEGER;
338 in_arg[0].integer.value = enable;
339 in_arg[1].type = ACPI_TYPE_INTEGER;
340 in_arg[1].integer.value = sleep_state;
341 in_arg[2].type = ACPI_TYPE_INTEGER;
342 in_arg[2].integer.value = dev_state;
343 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
344 if (ACPI_SUCCESS(status)) {
345 return 0;
346 } else if (status != AE_NOT_FOUND) {
347 printk(KERN_ERR PREFIX "_DSW execution failed\n");
348 dev->wakeup.flags.valid = 0;
349 return -ENODEV;
350 }
351
352 /* Execute _PSW */
353 arg_list.count = 1;
354 in_arg[0].integer.value = enable;
355 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
356 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
357 printk(KERN_ERR PREFIX "_PSW execution failed\n");
358 dev->wakeup.flags.valid = 0;
359 return -ENODEV;
360 }
361
362 return 0;
363}
364
1da177e4
LT
365/*
366 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
367 * 1. Power on the power resources required for the wakeup device
77e76609
RW
368 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
369 * State Wake) for the device, if present
1da177e4 370 */
77e76609 371int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
1da177e4 372{
9b83ccd2 373 int i, err = 0;
1da177e4 374
1da177e4 375 if (!dev || !dev->wakeup.flags.valid)
77e76609 376 return -EINVAL;
1da177e4 377
9b83ccd2
RW
378 mutex_lock(&acpi_device_lock);
379
380 if (dev->wakeup.prepare_count++)
381 goto out;
0af4b8c4 382
1da177e4
LT
383 /* Open power resource */
384 for (i = 0; i < dev->wakeup.resources.count; i++) {
3e384ee6 385 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
1da177e4 386 if (ret) {
6468463a 387 printk(KERN_ERR PREFIX "Transition power state\n");
1da177e4 388 dev->wakeup.flags.valid = 0;
9b83ccd2
RW
389 err = -ENODEV;
390 goto err_out;
1da177e4
LT
391 }
392 }
393
77e76609
RW
394 /*
395 * Passing 3 as the third argument below means the device may be placed
396 * in arbitrary power state afterwards.
397 */
0af4b8c4 398 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
0af4b8c4 399
9b83ccd2
RW
400 err_out:
401 if (err)
402 dev->wakeup.prepare_count = 0;
403
404 out:
405 mutex_unlock(&acpi_device_lock);
0af4b8c4 406 return err;
1da177e4
LT
407}
408
409/*
410 * Shutdown a wakeup device, counterpart of above method
77e76609
RW
411 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
412 * State Wake) for the device, if present
1da177e4
LT
413 * 2. Shutdown down the power resources
414 */
4be44fcd 415int acpi_disable_wakeup_device_power(struct acpi_device *dev)
1da177e4 416{
9b83ccd2 417 int i, err = 0;
1da177e4
LT
418
419 if (!dev || !dev->wakeup.flags.valid)
77e76609 420 return -EINVAL;
1da177e4 421
9b83ccd2
RW
422 mutex_lock(&acpi_device_lock);
423
424 if (--dev->wakeup.prepare_count > 0)
425 goto out;
426
0af4b8c4 427 /*
9b83ccd2
RW
428 * Executing the code below even if prepare_count is already zero when
429 * the function is called may be useful, for example for initialisation.
0af4b8c4 430 */
9b83ccd2
RW
431 if (dev->wakeup.prepare_count < 0)
432 dev->wakeup.prepare_count = 0;
0af4b8c4 433
9b83ccd2
RW
434 err = acpi_device_sleep_wake(dev, 0, 0, 0);
435 if (err)
436 goto out;
1da177e4
LT
437
438 /* Close power resource */
439 for (i = 0; i < dev->wakeup.resources.count; i++) {
36237fa0 440 int ret = acpi_power_off(dev->wakeup.resources.handles[i]);
1da177e4 441 if (ret) {
6468463a 442 printk(KERN_ERR PREFIX "Transition power state\n");
1da177e4 443 dev->wakeup.flags.valid = 0;
9b83ccd2
RW
444 err = -ENODEV;
445 goto out;
1da177e4
LT
446 }
447 }
448
9b83ccd2
RW
449 out:
450 mutex_unlock(&acpi_device_lock);
451 return err;
1da177e4
LT
452}
453
454/* --------------------------------------------------------------------------
455 Device Power Management
456 -------------------------------------------------------------------------- */
457
32a00d27 458int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
1da177e4 459{
4be44fcd
LB
460 int result = 0;
461 struct acpi_handle_list *list = NULL;
462 int list_state = 0;
463 int i = 0;
1da177e4 464
32a00d27 465 if (!device || !state)
d550d98d 466 return -EINVAL;
1da177e4 467
1da177e4
LT
468 /*
469 * We know a device's inferred power state when all the resources
470 * required for a given D-state are 'on'.
471 */
4be44fcd 472 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
1da177e4
LT
473 list = &device->power.states[i].resources;
474 if (list->count < 1)
475 continue;
476
477 result = acpi_power_get_list_state(list, &list_state);
478 if (result)
d550d98d 479 return result;
1da177e4
LT
480
481 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
32a00d27 482 *state = i;
d550d98d 483 return 0;
1da177e4
LT
484 }
485 }
486
32a00d27 487 *state = ACPI_STATE_D3;
d550d98d 488 return 0;
1da177e4
LT
489}
490
30d3df41
RW
491int acpi_power_on_resources(struct acpi_device *device, int state)
492{
493 if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
494 return -EINVAL;
495
496 return acpi_power_on_list(&device->power.states[state].resources);
497}
498
4be44fcd 499int acpi_power_transition(struct acpi_device *device, int state)
1da177e4 500{
d2ef555b 501 int result;
1da177e4 502
1da177e4 503 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
d550d98d 504 return -EINVAL;
1da177e4 505
212967c6
RW
506 if (device->power.state == state)
507 return 0;
508
4be44fcd
LB
509 if ((device->power.state < ACPI_STATE_D0)
510 || (device->power.state > ACPI_STATE_D3))
d550d98d 511 return -ENODEV;
1da177e4 512
1da177e4
LT
513 /* TBD: Resources must be ordered. */
514
515 /*
516 * First we reference all power resources required in the target list
d2ef555b
RW
517 * (e.g. so the device doesn't lose power while transitioning). Then,
518 * we dereference all power resources used in the current list.
1da177e4 519 */
d2ef555b
RW
520 result = acpi_power_on_list(&device->power.states[state].resources);
521 if (!result)
522 acpi_power_off_list(
523 &device->power.states[device->power.state].resources);
1da177e4 524
d2ef555b
RW
525 /* We shouldn't change the state unless the above operations succeed. */
526 device->power.state = result ? ACPI_STATE_UNKNOWN : state;
1da177e4 527
d550d98d 528 return result;
1da177e4
LT
529}
530
1da177e4
LT
531/* --------------------------------------------------------------------------
532 Driver Interface
533 -------------------------------------------------------------------------- */
534
4be44fcd 535static int acpi_power_add(struct acpi_device *device)
1da177e4 536{
c35923bc 537 int result = 0, state;
4be44fcd 538 acpi_status status = AE_OK;
1da177e4 539 struct acpi_power_resource *resource = NULL;
4be44fcd
LB
540 union acpi_object acpi_object;
541 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
1da177e4 542
1da177e4
LT
543
544 if (!device)
d550d98d 545 return -EINVAL;
1da177e4 546
36bcbec7 547 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
1da177e4 548 if (!resource)
d550d98d 549 return -ENOMEM;
1da177e4 550
41598572 551 resource->device = device;
0a613902 552 mutex_init(&resource->resource_lock);
1da177e4
LT
553 strcpy(resource->name, device->pnp.bus_id);
554 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
555 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
db89b4f0 556 device->driver_data = resource;
1da177e4
LT
557
558 /* Evalute the object to get the system level and resource order. */
5fbc19ef 559 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
1da177e4
LT
560 if (ACPI_FAILURE(status)) {
561 result = -ENODEV;
562 goto end;
563 }
564 resource->system_level = acpi_object.power_resource.system_level;
565 resource->order = acpi_object.power_resource.resource_order;
566
a51e145f 567 result = acpi_power_get_state(device->handle, &state);
1da177e4
LT
568 if (result)
569 goto end;
570
c35923bc 571 switch (state) {
1da177e4
LT
572 case ACPI_POWER_RESOURCE_STATE_ON:
573 device->power.state = ACPI_STATE_D0;
574 break;
575 case ACPI_POWER_RESOURCE_STATE_OFF:
576 device->power.state = ACPI_STATE_D3;
577 break;
578 default:
579 device->power.state = ACPI_STATE_UNKNOWN;
580 break;
581 }
582
1da177e4 583 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
c35923bc 584 acpi_device_bid(device), state ? "on" : "off");
1da177e4 585
4be44fcd 586 end:
1da177e4
LT
587 if (result)
588 kfree(resource);
4be44fcd 589
d550d98d 590 return result;
1da177e4
LT
591}
592
4be44fcd 593static int acpi_power_remove(struct acpi_device *device, int type)
1da177e4 594{
3e384ee6 595 struct acpi_power_resource *resource;
1da177e4 596
3e384ee6 597 if (!device)
d550d98d 598 return -EINVAL;
1da177e4 599
50dd0969 600 resource = acpi_driver_data(device);
3e384ee6
RW
601 if (!resource)
602 return -EINVAL;
0a613902 603
1da177e4
LT
604 kfree(resource);
605
d550d98d 606 return 0;
1da177e4
LT
607}
608
e8363f33 609static int acpi_power_resume(struct acpi_device *device)
0a613902 610{
c35923bc 611 int result = 0, state;
3e384ee6 612 struct acpi_power_resource *resource;
0a613902 613
3e384ee6 614 if (!device)
0a613902
KK
615 return -EINVAL;
616
db89b4f0 617 resource = acpi_driver_data(device);
3e384ee6
RW
618 if (!resource)
619 return -EINVAL;
620
621 mutex_lock(&resource->resource_lock);
0a613902 622
a51e145f 623 result = acpi_power_get_state(device->handle, &state);
0a613902 624 if (result)
3e384ee6 625 goto unlock;
0a613902 626
3e384ee6
RW
627 if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
628 result = __acpi_power_on(resource);
0a613902 629
3e384ee6 630 unlock:
0a613902 631 mutex_unlock(&resource->resource_lock);
3e384ee6
RW
632
633 return result;
0a613902
KK
634}
635
44515374 636int __init acpi_power_init(void)
1da177e4 637{
1da177e4 638 INIT_LIST_HEAD(&acpi_power_resource_list);
06af7eb0 639 return acpi_bus_register_driver(&acpi_power_driver);
1da177e4 640}
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