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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
f5adfaa3
ZY
59int acpi_power_nocheck;
60module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
61
4be44fcd
LB
62static int acpi_power_add(struct acpi_device *device);
63static int acpi_power_remove(struct acpi_device *device, int type);
e8363f33 64static int acpi_power_resume(struct acpi_device *device);
1da177e4 65
c97adf9e 66static const struct acpi_device_id power_device_ids[] = {
1ba90e3a
TR
67 {ACPI_POWER_HID, 0},
68 {"", 0},
69};
70MODULE_DEVICE_TABLE(acpi, power_device_ids);
71
1da177e4 72static struct acpi_driver acpi_power_driver = {
c2b6705b 73 .name = "power",
4be44fcd 74 .class = ACPI_POWER_CLASS,
1ba90e3a 75 .ids = power_device_ids,
4be44fcd
LB
76 .ops = {
77 .add = acpi_power_add,
78 .remove = acpi_power_remove,
0a613902 79 .resume = acpi_power_resume,
4be44fcd 80 },
1da177e4
LT
81};
82
4be44fcd 83struct acpi_power_resource {
41598572 84 struct acpi_device * device;
4be44fcd
LB
85 acpi_bus_id name;
86 u32 system_level;
87 u32 order;
3e384ee6 88 unsigned int ref_count;
0a613902 89 struct mutex resource_lock;
1da177e4
LT
90};
91
4be44fcd 92static struct list_head acpi_power_resource_list;
1da177e4 93
1da177e4
LT
94/* --------------------------------------------------------------------------
95 Power Resource Management
96 -------------------------------------------------------------------------- */
97
98static int
4be44fcd
LB
99acpi_power_get_context(acpi_handle handle,
100 struct acpi_power_resource **resource)
1da177e4 101{
4be44fcd
LB
102 int result = 0;
103 struct acpi_device *device = NULL;
1da177e4 104
1da177e4
LT
105
106 if (!resource)
d550d98d 107 return -ENODEV;
1da177e4
LT
108
109 result = acpi_bus_get_device(handle, &device);
110 if (result) {
cece9296 111 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
d550d98d 112 return result;
1da177e4
LT
113 }
114
50dd0969 115 *resource = acpi_driver_data(device);
a815ab8b 116 if (!*resource)
d550d98d 117 return -ENODEV;
1da177e4 118
d550d98d 119 return 0;
1da177e4
LT
120}
121
a51e145f 122static int acpi_power_get_state(acpi_handle handle, int *state)
1da177e4 123{
4be44fcd 124 acpi_status status = AE_OK;
27663c58 125 unsigned long long sta = 0;
60a4ce7f
LM
126 char node_name[5];
127 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1da177e4 128
1da177e4 129
a51e145f 130 if (!handle || !state)
d550d98d 131 return -EINVAL;
1da177e4 132
a51e145f 133 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
1da177e4 134 if (ACPI_FAILURE(status))
d550d98d 135 return -ENODEV;
1da177e4 136
c35923bc
AS
137 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
138 ACPI_POWER_RESOURCE_STATE_OFF;
1da177e4 139
60a4ce7f
LM
140 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
141
1da177e4 142 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
60a4ce7f 143 node_name,
b1b57fbe 144 *state ? "on" : "off"));
1da177e4 145
d550d98d 146 return 0;
1da177e4
LT
147}
148
4be44fcd 149static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
1da177e4 150{
c35923bc 151 int result = 0, state1;
4be44fcd 152 u32 i = 0;
1da177e4 153
1da177e4
LT
154
155 if (!list || !state)
d550d98d 156 return -EINVAL;
1da177e4
LT
157
158 /* The state of the list is 'on' IFF all resources are 'on'. */
159
4be44fcd 160 for (i = 0; i < list->count; i++) {
a51e145f
ZY
161 /*
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.
165 */
166 result = acpi_power_get_state(list->handles[i], &state1);
1da177e4 167 if (result)
d550d98d 168 return result;
1da177e4 169
c35923bc 170 *state = state1;
1da177e4
LT
171
172 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
173 break;
174 }
175
176 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
4be44fcd 177 *state ? "on" : "off"));
1da177e4 178
d550d98d 179 return result;
1da177e4
LT
180}
181
3e384ee6 182static int __acpi_power_on(struct acpi_power_resource *resource)
1da177e4 183{
4be44fcd 184 acpi_status status = AE_OK;
1da177e4 185
3e384ee6
RW
186 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
187 if (ACPI_FAILURE(status))
188 return -ENODEV;
189
190 /* Update the power resource's _device_ power state */
191 resource->device->power.state = ACPI_STATE_D0;
192
193 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
194 resource->name));
195
196 return 0;
197}
198
199static int acpi_power_on(acpi_handle handle)
200{
201 int result = 0;
202 struct acpi_power_resource *resource = NULL;
1da177e4
LT
203
204 result = acpi_power_get_context(handle, &resource);
205 if (result)
d550d98d 206 return result;
1da177e4 207
0a613902 208 mutex_lock(&resource->resource_lock);
0a613902 209
3e384ee6
RW
210 if (resource->ref_count++) {
211 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
212 "Power resource [%s] already on",
213 resource->name));
214 } else {
215 result = __acpi_power_on(resource);
0a613902 216 }
1da177e4 217
3e384ee6 218 mutex_unlock(&resource->resource_lock);
1da177e4 219
d550d98d 220 return 0;
1da177e4
LT
221}
222
3e384ee6 223static int acpi_power_off_device(acpi_handle handle)
1da177e4 224{
bdf43bbf 225 int result = 0;
4be44fcd 226 acpi_status status = AE_OK;
1da177e4 227 struct acpi_power_resource *resource = NULL;
0a613902 228
1da177e4
LT
229 result = acpi_power_get_context(handle, &resource);
230 if (result)
d550d98d 231 return result;
1da177e4 232
0a613902 233 mutex_lock(&resource->resource_lock);
3e384ee6
RW
234
235 if (!resource->ref_count) {
236 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
237 "Power resource [%s] already off",
238 resource->name));
239 goto unlock;
0a613902 240 }
1da177e4 241
3e384ee6
RW
242 if (--resource->ref_count) {
243 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
244 "Power resource [%s] still in use\n",
245 resource->name));
246 goto unlock;
1da177e4
LT
247 }
248
5fbc19ef 249 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
3e384ee6
RW
250 if (ACPI_FAILURE(status)) {
251 result = -ENODEV;
252 } else {
253 /* Update the power resource's _device_ power state */
254 resource->device->power.state = ACPI_STATE_D3;
1da177e4 255
3e384ee6
RW
256 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
257 "Power resource [%s] turned off\n",
258 resource->name));
259 }
1da177e4 260
3e384ee6
RW
261 unlock:
262 mutex_unlock(&resource->resource_lock);
1da177e4 263
3e384ee6 264 return result;
1da177e4
LT
265}
266
77e76609
RW
267/**
268 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
269 * ACPI 3.0) _PSW (Power State Wake)
270 * @dev: Device to handle.
271 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
272 * @sleep_state: Target sleep state of the system.
273 * @dev_state: Target power state of the device.
274 *
275 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
276 * State Wake) for the device, if present. On failure reset the device's
277 * wakeup.flags.valid flag.
278 *
279 * RETURN VALUE:
280 * 0 if either _DSW or _PSW has been successfully executed
281 * 0 if neither _DSW nor _PSW has been found
282 * -ENODEV if the execution of either _DSW or _PSW has failed
283 */
284int acpi_device_sleep_wake(struct acpi_device *dev,
285 int enable, int sleep_state, int dev_state)
286{
287 union acpi_object in_arg[3];
288 struct acpi_object_list arg_list = { 3, in_arg };
289 acpi_status status = AE_OK;
290
291 /*
292 * Try to execute _DSW first.
293 *
294 * Three agruments are needed for the _DSW object:
295 * Argument 0: enable/disable the wake capabilities
296 * Argument 1: target system state
297 * Argument 2: target device state
298 * When _DSW object is called to disable the wake capabilities, maybe
299 * the first argument is filled. The values of the other two agruments
300 * are meaningless.
301 */
302 in_arg[0].type = ACPI_TYPE_INTEGER;
303 in_arg[0].integer.value = enable;
304 in_arg[1].type = ACPI_TYPE_INTEGER;
305 in_arg[1].integer.value = sleep_state;
306 in_arg[2].type = ACPI_TYPE_INTEGER;
307 in_arg[2].integer.value = dev_state;
308 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
309 if (ACPI_SUCCESS(status)) {
310 return 0;
311 } else if (status != AE_NOT_FOUND) {
312 printk(KERN_ERR PREFIX "_DSW execution failed\n");
313 dev->wakeup.flags.valid = 0;
314 return -ENODEV;
315 }
316
317 /* Execute _PSW */
318 arg_list.count = 1;
319 in_arg[0].integer.value = enable;
320 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
321 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
322 printk(KERN_ERR PREFIX "_PSW execution failed\n");
323 dev->wakeup.flags.valid = 0;
324 return -ENODEV;
325 }
326
327 return 0;
328}
329
1da177e4
LT
330/*
331 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
332 * 1. Power on the power resources required for the wakeup device
77e76609
RW
333 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
334 * State Wake) for the device, if present
1da177e4 335 */
77e76609 336int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
1da177e4 337{
9b83ccd2 338 int i, err = 0;
1da177e4 339
1da177e4 340 if (!dev || !dev->wakeup.flags.valid)
77e76609 341 return -EINVAL;
1da177e4 342
9b83ccd2
RW
343 mutex_lock(&acpi_device_lock);
344
345 if (dev->wakeup.prepare_count++)
346 goto out;
0af4b8c4 347
1da177e4
LT
348 /* Open power resource */
349 for (i = 0; i < dev->wakeup.resources.count; i++) {
3e384ee6 350 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
1da177e4 351 if (ret) {
6468463a 352 printk(KERN_ERR PREFIX "Transition power state\n");
1da177e4 353 dev->wakeup.flags.valid = 0;
9b83ccd2
RW
354 err = -ENODEV;
355 goto err_out;
1da177e4
LT
356 }
357 }
358
77e76609
RW
359 /*
360 * Passing 3 as the third argument below means the device may be placed
361 * in arbitrary power state afterwards.
362 */
0af4b8c4 363 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
0af4b8c4 364
9b83ccd2
RW
365 err_out:
366 if (err)
367 dev->wakeup.prepare_count = 0;
368
369 out:
370 mutex_unlock(&acpi_device_lock);
0af4b8c4 371 return err;
1da177e4
LT
372}
373
374/*
375 * Shutdown a wakeup device, counterpart of above method
77e76609
RW
376 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
377 * State Wake) for the device, if present
1da177e4
LT
378 * 2. Shutdown down the power resources
379 */
4be44fcd 380int acpi_disable_wakeup_device_power(struct acpi_device *dev)
1da177e4 381{
9b83ccd2 382 int i, err = 0;
1da177e4
LT
383
384 if (!dev || !dev->wakeup.flags.valid)
77e76609 385 return -EINVAL;
1da177e4 386
9b83ccd2
RW
387 mutex_lock(&acpi_device_lock);
388
389 if (--dev->wakeup.prepare_count > 0)
390 goto out;
391
0af4b8c4 392 /*
9b83ccd2
RW
393 * Executing the code below even if prepare_count is already zero when
394 * the function is called may be useful, for example for initialisation.
0af4b8c4 395 */
9b83ccd2
RW
396 if (dev->wakeup.prepare_count < 0)
397 dev->wakeup.prepare_count = 0;
0af4b8c4 398
9b83ccd2
RW
399 err = acpi_device_sleep_wake(dev, 0, 0, 0);
400 if (err)
401 goto out;
1da177e4
LT
402
403 /* Close power resource */
404 for (i = 0; i < dev->wakeup.resources.count; i++) {
9b83ccd2 405 int ret = acpi_power_off_device(
3e384ee6 406 dev->wakeup.resources.handles[i]);
1da177e4 407 if (ret) {
6468463a 408 printk(KERN_ERR PREFIX "Transition power state\n");
1da177e4 409 dev->wakeup.flags.valid = 0;
9b83ccd2
RW
410 err = -ENODEV;
411 goto out;
1da177e4
LT
412 }
413 }
414
9b83ccd2
RW
415 out:
416 mutex_unlock(&acpi_device_lock);
417 return err;
1da177e4
LT
418}
419
420/* --------------------------------------------------------------------------
421 Device Power Management
422 -------------------------------------------------------------------------- */
423
4be44fcd 424int acpi_power_get_inferred_state(struct acpi_device *device)
1da177e4 425{
4be44fcd
LB
426 int result = 0;
427 struct acpi_handle_list *list = NULL;
428 int list_state = 0;
429 int i = 0;
1da177e4 430
1da177e4
LT
431
432 if (!device)
d550d98d 433 return -EINVAL;
1da177e4
LT
434
435 device->power.state = ACPI_STATE_UNKNOWN;
436
437 /*
438 * We know a device's inferred power state when all the resources
439 * required for a given D-state are 'on'.
440 */
4be44fcd 441 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
1da177e4
LT
442 list = &device->power.states[i].resources;
443 if (list->count < 1)
444 continue;
445
446 result = acpi_power_get_list_state(list, &list_state);
447 if (result)
d550d98d 448 return result;
1da177e4
LT
449
450 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
451 device->power.state = i;
d550d98d 452 return 0;
1da177e4
LT
453 }
454 }
455
456 device->power.state = ACPI_STATE_D3;
457
d550d98d 458 return 0;
1da177e4
LT
459}
460
4be44fcd 461int acpi_power_transition(struct acpi_device *device, int state)
1da177e4 462{
4be44fcd
LB
463 int result = 0;
464 struct acpi_handle_list *cl = NULL; /* Current Resources */
465 struct acpi_handle_list *tl = NULL; /* Target Resources */
466 int i = 0;
1da177e4 467
1da177e4
LT
468
469 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
d550d98d 470 return -EINVAL;
1da177e4 471
4be44fcd
LB
472 if ((device->power.state < ACPI_STATE_D0)
473 || (device->power.state > ACPI_STATE_D3))
d550d98d 474 return -ENODEV;
1da177e4
LT
475
476 cl = &device->power.states[device->power.state].resources;
477 tl = &device->power.states[state].resources;
478
1da177e4
LT
479 /* TBD: Resources must be ordered. */
480
481 /*
482 * First we reference all power resources required in the target list
483 * (e.g. so the device doesn't lose power while transitioning).
484 */
4be44fcd 485 for (i = 0; i < tl->count; i++) {
3e384ee6 486 result = acpi_power_on(tl->handles[i]);
1da177e4
LT
487 if (result)
488 goto end;
489 }
490
b1028c54
KK
491 if (device->power.state == state) {
492 goto end;
493 }
494
1da177e4
LT
495 /*
496 * Then we dereference all power resources used in the current list.
497 */
4be44fcd 498 for (i = 0; i < cl->count; i++) {
3e384ee6 499 result = acpi_power_off_device(cl->handles[i]);
1da177e4
LT
500 if (result)
501 goto end;
502 }
503
72925760 504 end:
e76d5f7e 505 if (result)
72925760 506 device->power.state = ACPI_STATE_UNKNOWN;
e76d5f7e 507 else {
72925760
KK
508 /* We shouldn't change the state till all above operations succeed */
509 device->power.state = state;
510 }
1da177e4 511
d550d98d 512 return result;
1da177e4
LT
513}
514
1da177e4
LT
515/* --------------------------------------------------------------------------
516 Driver Interface
517 -------------------------------------------------------------------------- */
518
4be44fcd 519static int acpi_power_add(struct acpi_device *device)
1da177e4 520{
c35923bc 521 int result = 0, state;
4be44fcd 522 acpi_status status = AE_OK;
1da177e4 523 struct acpi_power_resource *resource = NULL;
4be44fcd
LB
524 union acpi_object acpi_object;
525 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
1da177e4 526
1da177e4
LT
527
528 if (!device)
d550d98d 529 return -EINVAL;
1da177e4 530
36bcbec7 531 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
1da177e4 532 if (!resource)
d550d98d 533 return -ENOMEM;
1da177e4 534
41598572 535 resource->device = device;
0a613902 536 mutex_init(&resource->resource_lock);
1da177e4
LT
537 strcpy(resource->name, device->pnp.bus_id);
538 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
539 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
db89b4f0 540 device->driver_data = resource;
1da177e4
LT
541
542 /* Evalute the object to get the system level and resource order. */
5fbc19ef 543 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
1da177e4
LT
544 if (ACPI_FAILURE(status)) {
545 result = -ENODEV;
546 goto end;
547 }
548 resource->system_level = acpi_object.power_resource.system_level;
549 resource->order = acpi_object.power_resource.resource_order;
550
a51e145f 551 result = acpi_power_get_state(device->handle, &state);
1da177e4
LT
552 if (result)
553 goto end;
554
c35923bc 555 switch (state) {
1da177e4
LT
556 case ACPI_POWER_RESOURCE_STATE_ON:
557 device->power.state = ACPI_STATE_D0;
558 break;
559 case ACPI_POWER_RESOURCE_STATE_OFF:
560 device->power.state = ACPI_STATE_D3;
561 break;
562 default:
563 device->power.state = ACPI_STATE_UNKNOWN;
564 break;
565 }
566
1da177e4 567 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
c35923bc 568 acpi_device_bid(device), state ? "on" : "off");
1da177e4 569
4be44fcd 570 end:
1da177e4
LT
571 if (result)
572 kfree(resource);
4be44fcd 573
d550d98d 574 return result;
1da177e4
LT
575}
576
4be44fcd 577static int acpi_power_remove(struct acpi_device *device, int type)
1da177e4 578{
3e384ee6 579 struct acpi_power_resource *resource;
1da177e4 580
3e384ee6 581 if (!device)
d550d98d 582 return -EINVAL;
1da177e4 583
50dd0969 584 resource = acpi_driver_data(device);
3e384ee6
RW
585 if (!resource)
586 return -EINVAL;
0a613902 587
1da177e4
LT
588 kfree(resource);
589
d550d98d 590 return 0;
1da177e4
LT
591}
592
e8363f33 593static int acpi_power_resume(struct acpi_device *device)
0a613902 594{
c35923bc 595 int result = 0, state;
3e384ee6 596 struct acpi_power_resource *resource;
0a613902 597
3e384ee6 598 if (!device)
0a613902
KK
599 return -EINVAL;
600
db89b4f0 601 resource = acpi_driver_data(device);
3e384ee6
RW
602 if (!resource)
603 return -EINVAL;
604
605 mutex_lock(&resource->resource_lock);
0a613902 606
a51e145f 607 result = acpi_power_get_state(device->handle, &state);
0a613902 608 if (result)
3e384ee6 609 goto unlock;
0a613902 610
3e384ee6
RW
611 if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
612 result = __acpi_power_on(resource);
0a613902 613
3e384ee6 614 unlock:
0a613902 615 mutex_unlock(&resource->resource_lock);
3e384ee6
RW
616
617 return result;
0a613902
KK
618}
619
44515374 620int __init acpi_power_init(void)
1da177e4 621{
1da177e4 622 INIT_LIST_HEAD(&acpi_power_resource_list);
06af7eb0 623 return acpi_bus_register_driver(&acpi_power_driver);
1da177e4 624}