ACPI: Introduce acpi_device_sleep_wake function
[linux-2.6/libata-dev.git] / drivers / acpi / power.c
blob2e959aa1ef0ef0f572855f7d1d6e9ece053da365
1 /*
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_COMPONENT 0x00800000
50 #define ACPI_POWER_CLASS "power_resource"
51 #define ACPI_POWER_DEVICE_NAME "Power Resource"
52 #define ACPI_POWER_FILE_INFO "info"
53 #define ACPI_POWER_FILE_STATUS "state"
54 #define ACPI_POWER_RESOURCE_STATE_OFF 0x00
55 #define ACPI_POWER_RESOURCE_STATE_ON 0x01
56 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
57 static int acpi_power_add(struct acpi_device *device);
58 static int acpi_power_remove(struct acpi_device *device, int type);
59 static int acpi_power_resume(struct acpi_device *device);
60 static int acpi_power_open_fs(struct inode *inode, struct file *file);
62 static struct acpi_device_id power_device_ids[] = {
63 {ACPI_POWER_HID, 0},
64 {"", 0},
66 MODULE_DEVICE_TABLE(acpi, power_device_ids);
68 static struct acpi_driver acpi_power_driver = {
69 .name = "power",
70 .class = ACPI_POWER_CLASS,
71 .ids = power_device_ids,
72 .ops = {
73 .add = acpi_power_add,
74 .remove = acpi_power_remove,
75 .resume = acpi_power_resume,
79 struct acpi_power_reference {
80 struct list_head node;
81 struct acpi_device *device;
84 struct acpi_power_resource {
85 struct acpi_device * device;
86 acpi_bus_id name;
87 u32 system_level;
88 u32 order;
89 struct mutex resource_lock;
90 struct list_head reference;
93 static struct list_head acpi_power_resource_list;
95 static const struct file_operations acpi_power_fops = {
96 .owner = THIS_MODULE,
97 .open = acpi_power_open_fs,
98 .read = seq_read,
99 .llseek = seq_lseek,
100 .release = single_release,
103 /* --------------------------------------------------------------------------
104 Power Resource Management
105 -------------------------------------------------------------------------- */
107 static int
108 acpi_power_get_context(acpi_handle handle,
109 struct acpi_power_resource **resource)
111 int result = 0;
112 struct acpi_device *device = NULL;
115 if (!resource)
116 return -ENODEV;
118 result = acpi_bus_get_device(handle, &device);
119 if (result) {
120 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
121 return result;
124 *resource = acpi_driver_data(device);
125 if (!*resource)
126 return -ENODEV;
128 return 0;
131 static int acpi_power_get_state(struct acpi_power_resource *resource, int *state)
133 acpi_status status = AE_OK;
134 unsigned long sta = 0;
137 if (!resource || !state)
138 return -EINVAL;
140 status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
141 if (ACPI_FAILURE(status))
142 return -ENODEV;
144 *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
145 ACPI_POWER_RESOURCE_STATE_OFF;
147 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
148 resource->name, state ? "on" : "off"));
150 return 0;
153 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
155 int result = 0, state1;
156 struct acpi_power_resource *resource = NULL;
157 u32 i = 0;
160 if (!list || !state)
161 return -EINVAL;
163 /* The state of the list is 'on' IFF all resources are 'on'. */
165 for (i = 0; i < list->count; i++) {
166 result = acpi_power_get_context(list->handles[i], &resource);
167 if (result)
168 return result;
169 result = acpi_power_get_state(resource, &state1);
170 if (result)
171 return result;
173 *state = state1;
175 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
176 break;
179 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
180 *state ? "on" : "off"));
182 return result;
185 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
187 int result = 0, state;
188 int found = 0;
189 acpi_status status = AE_OK;
190 struct acpi_power_resource *resource = NULL;
191 struct list_head *node, *next;
192 struct acpi_power_reference *ref;
195 result = acpi_power_get_context(handle, &resource);
196 if (result)
197 return result;
199 mutex_lock(&resource->resource_lock);
200 list_for_each_safe(node, next, &resource->reference) {
201 ref = container_of(node, struct acpi_power_reference, node);
202 if (dev->handle == ref->device->handle) {
203 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
204 dev->pnp.bus_id, resource->name));
205 found = 1;
206 break;
210 if (!found) {
211 ref = kmalloc(sizeof (struct acpi_power_reference),
212 irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
213 if (!ref) {
214 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
215 mutex_unlock(&resource->resource_lock);
216 return -ENOMEM;
218 list_add_tail(&ref->node, &resource->reference);
219 ref->device = dev;
220 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
221 dev->pnp.bus_id, resource->name));
223 mutex_unlock(&resource->resource_lock);
225 status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
226 if (ACPI_FAILURE(status))
227 return -ENODEV;
229 result = acpi_power_get_state(resource, &state);
230 if (result)
231 return result;
232 if (state != ACPI_POWER_RESOURCE_STATE_ON)
233 return -ENOEXEC;
235 /* Update the power resource's _device_ power state */
236 resource->device->power.state = ACPI_STATE_D0;
238 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
239 resource->name));
240 return 0;
243 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
245 int result = 0, state;
246 acpi_status status = AE_OK;
247 struct acpi_power_resource *resource = NULL;
248 struct list_head *node, *next;
249 struct acpi_power_reference *ref;
252 result = acpi_power_get_context(handle, &resource);
253 if (result)
254 return result;
256 mutex_lock(&resource->resource_lock);
257 list_for_each_safe(node, next, &resource->reference) {
258 ref = container_of(node, struct acpi_power_reference, node);
259 if (dev->handle == ref->device->handle) {
260 list_del(&ref->node);
261 kfree(ref);
262 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
263 dev->pnp.bus_id, resource->name));
264 break;
268 if (!list_empty(&resource->reference)) {
269 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
270 resource->name));
271 mutex_unlock(&resource->resource_lock);
272 return 0;
274 mutex_unlock(&resource->resource_lock);
276 status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
277 if (ACPI_FAILURE(status))
278 return -ENODEV;
280 result = acpi_power_get_state(resource, &state);
281 if (result)
282 return result;
283 if (state != ACPI_POWER_RESOURCE_STATE_OFF)
284 return -ENOEXEC;
286 /* Update the power resource's _device_ power state */
287 resource->device->power.state = ACPI_STATE_D3;
289 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
290 resource->name));
292 return 0;
296 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
297 * ACPI 3.0) _PSW (Power State Wake)
298 * @dev: Device to handle.
299 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
300 * @sleep_state: Target sleep state of the system.
301 * @dev_state: Target power state of the device.
303 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
304 * State Wake) for the device, if present. On failure reset the device's
305 * wakeup.flags.valid flag.
307 * RETURN VALUE:
308 * 0 if either _DSW or _PSW has been successfully executed
309 * 0 if neither _DSW nor _PSW has been found
310 * -ENODEV if the execution of either _DSW or _PSW has failed
312 int acpi_device_sleep_wake(struct acpi_device *dev,
313 int enable, int sleep_state, int dev_state)
315 union acpi_object in_arg[3];
316 struct acpi_object_list arg_list = { 3, in_arg };
317 acpi_status status = AE_OK;
320 * Try to execute _DSW first.
322 * Three agruments are needed for the _DSW object:
323 * Argument 0: enable/disable the wake capabilities
324 * Argument 1: target system state
325 * Argument 2: target device state
326 * When _DSW object is called to disable the wake capabilities, maybe
327 * the first argument is filled. The values of the other two agruments
328 * are meaningless.
330 in_arg[0].type = ACPI_TYPE_INTEGER;
331 in_arg[0].integer.value = enable;
332 in_arg[1].type = ACPI_TYPE_INTEGER;
333 in_arg[1].integer.value = sleep_state;
334 in_arg[2].type = ACPI_TYPE_INTEGER;
335 in_arg[2].integer.value = dev_state;
336 status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
337 if (ACPI_SUCCESS(status)) {
338 return 0;
339 } else if (status != AE_NOT_FOUND) {
340 printk(KERN_ERR PREFIX "_DSW execution failed\n");
341 dev->wakeup.flags.valid = 0;
342 return -ENODEV;
345 /* Execute _PSW */
346 arg_list.count = 1;
347 in_arg[0].integer.value = enable;
348 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
349 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
350 printk(KERN_ERR PREFIX "_PSW execution failed\n");
351 dev->wakeup.flags.valid = 0;
352 return -ENODEV;
355 return 0;
359 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
360 * 1. Power on the power resources required for the wakeup device
361 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
362 * State Wake) for the device, if present
364 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
366 int i;
368 if (!dev || !dev->wakeup.flags.valid)
369 return -EINVAL;
371 /* Open power resource */
372 for (i = 0; i < dev->wakeup.resources.count; i++) {
373 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
374 if (ret) {
375 printk(KERN_ERR PREFIX "Transition power state\n");
376 dev->wakeup.flags.valid = 0;
377 return -ENODEV;
382 * Passing 3 as the third argument below means the device may be placed
383 * in arbitrary power state afterwards.
385 return acpi_device_sleep_wake(dev, 1, sleep_state, 3);
389 * Shutdown a wakeup device, counterpart of above method
390 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
391 * State Wake) for the device, if present
392 * 2. Shutdown down the power resources
394 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
396 int i, ret;
398 if (!dev || !dev->wakeup.flags.valid)
399 return -EINVAL;
401 ret = acpi_device_sleep_wake(dev, 0, 0, 0);
402 if (ret)
403 return ret;
405 /* Close power resource */
406 for (i = 0; i < dev->wakeup.resources.count; i++) {
407 ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
408 if (ret) {
409 printk(KERN_ERR PREFIX "Transition power state\n");
410 dev->wakeup.flags.valid = 0;
411 return -ENODEV;
415 return ret;
418 /* --------------------------------------------------------------------------
419 Device Power Management
420 -------------------------------------------------------------------------- */
422 int acpi_power_get_inferred_state(struct acpi_device *device)
424 int result = 0;
425 struct acpi_handle_list *list = NULL;
426 int list_state = 0;
427 int i = 0;
430 if (!device)
431 return -EINVAL;
433 device->power.state = ACPI_STATE_UNKNOWN;
436 * We know a device's inferred power state when all the resources
437 * required for a given D-state are 'on'.
439 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
440 list = &device->power.states[i].resources;
441 if (list->count < 1)
442 continue;
444 result = acpi_power_get_list_state(list, &list_state);
445 if (result)
446 return result;
448 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
449 device->power.state = i;
450 return 0;
454 device->power.state = ACPI_STATE_D3;
456 return 0;
459 int acpi_power_transition(struct acpi_device *device, int state)
461 int result = 0;
462 struct acpi_handle_list *cl = NULL; /* Current Resources */
463 struct acpi_handle_list *tl = NULL; /* Target Resources */
464 int i = 0;
467 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
468 return -EINVAL;
470 if ((device->power.state < ACPI_STATE_D0)
471 || (device->power.state > ACPI_STATE_D3))
472 return -ENODEV;
474 cl = &device->power.states[device->power.state].resources;
475 tl = &device->power.states[state].resources;
477 if (!cl->count && !tl->count) {
478 result = -ENODEV;
479 goto end;
482 /* TBD: Resources must be ordered. */
485 * First we reference all power resources required in the target list
486 * (e.g. so the device doesn't lose power while transitioning).
488 for (i = 0; i < tl->count; i++) {
489 result = acpi_power_on(tl->handles[i], device);
490 if (result)
491 goto end;
494 if (device->power.state == state) {
495 goto end;
499 * Then we dereference all power resources used in the current list.
501 for (i = 0; i < cl->count; i++) {
502 result = acpi_power_off_device(cl->handles[i], device);
503 if (result)
504 goto end;
507 end:
508 if (result)
509 device->power.state = ACPI_STATE_UNKNOWN;
510 else {
511 /* We shouldn't change the state till all above operations succeed */
512 device->power.state = state;
515 return result;
518 /* --------------------------------------------------------------------------
519 FS Interface (/proc)
520 -------------------------------------------------------------------------- */
522 static struct proc_dir_entry *acpi_power_dir;
524 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
526 int count = 0;
527 int result = 0, state;
528 struct acpi_power_resource *resource = NULL;
529 struct list_head *node, *next;
530 struct acpi_power_reference *ref;
533 resource = seq->private;
535 if (!resource)
536 goto end;
538 result = acpi_power_get_state(resource, &state);
539 if (result)
540 goto end;
542 seq_puts(seq, "state: ");
543 switch (state) {
544 case ACPI_POWER_RESOURCE_STATE_ON:
545 seq_puts(seq, "on\n");
546 break;
547 case ACPI_POWER_RESOURCE_STATE_OFF:
548 seq_puts(seq, "off\n");
549 break;
550 default:
551 seq_puts(seq, "unknown\n");
552 break;
555 mutex_lock(&resource->resource_lock);
556 list_for_each_safe(node, next, &resource->reference) {
557 ref = container_of(node, struct acpi_power_reference, node);
558 count++;
560 mutex_unlock(&resource->resource_lock);
562 seq_printf(seq, "system level: S%d\n"
563 "order: %d\n"
564 "reference count: %d\n",
565 resource->system_level,
566 resource->order, count);
568 end:
569 return 0;
572 static int acpi_power_open_fs(struct inode *inode, struct file *file)
574 return single_open(file, acpi_power_seq_show, PDE(inode)->data);
577 static int acpi_power_add_fs(struct acpi_device *device)
579 struct proc_dir_entry *entry = NULL;
582 if (!device)
583 return -EINVAL;
585 if (!acpi_device_dir(device)) {
586 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
587 acpi_power_dir);
588 if (!acpi_device_dir(device))
589 return -ENODEV;
592 /* 'status' [R] */
593 entry = proc_create_data(ACPI_POWER_FILE_STATUS,
594 S_IRUGO, acpi_device_dir(device),
595 &acpi_power_fops, acpi_driver_data(device));
596 if (!entry)
597 return -EIO;
598 return 0;
601 static int acpi_power_remove_fs(struct acpi_device *device)
604 if (acpi_device_dir(device)) {
605 remove_proc_entry(ACPI_POWER_FILE_STATUS,
606 acpi_device_dir(device));
607 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
608 acpi_device_dir(device) = NULL;
611 return 0;
614 /* --------------------------------------------------------------------------
615 Driver Interface
616 -------------------------------------------------------------------------- */
618 static int acpi_power_add(struct acpi_device *device)
620 int result = 0, state;
621 acpi_status status = AE_OK;
622 struct acpi_power_resource *resource = NULL;
623 union acpi_object acpi_object;
624 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
627 if (!device)
628 return -EINVAL;
630 resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
631 if (!resource)
632 return -ENOMEM;
634 resource->device = device;
635 mutex_init(&resource->resource_lock);
636 INIT_LIST_HEAD(&resource->reference);
637 strcpy(resource->name, device->pnp.bus_id);
638 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
639 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
640 acpi_driver_data(device) = resource;
642 /* Evalute the object to get the system level and resource order. */
643 status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
644 if (ACPI_FAILURE(status)) {
645 result = -ENODEV;
646 goto end;
648 resource->system_level = acpi_object.power_resource.system_level;
649 resource->order = acpi_object.power_resource.resource_order;
651 result = acpi_power_get_state(resource, &state);
652 if (result)
653 goto end;
655 switch (state) {
656 case ACPI_POWER_RESOURCE_STATE_ON:
657 device->power.state = ACPI_STATE_D0;
658 break;
659 case ACPI_POWER_RESOURCE_STATE_OFF:
660 device->power.state = ACPI_STATE_D3;
661 break;
662 default:
663 device->power.state = ACPI_STATE_UNKNOWN;
664 break;
667 result = acpi_power_add_fs(device);
668 if (result)
669 goto end;
671 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
672 acpi_device_bid(device), state ? "on" : "off");
674 end:
675 if (result)
676 kfree(resource);
678 return result;
681 static int acpi_power_remove(struct acpi_device *device, int type)
683 struct acpi_power_resource *resource = NULL;
684 struct list_head *node, *next;
687 if (!device || !acpi_driver_data(device))
688 return -EINVAL;
690 resource = acpi_driver_data(device);
692 acpi_power_remove_fs(device);
694 mutex_lock(&resource->resource_lock);
695 list_for_each_safe(node, next, &resource->reference) {
696 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
697 list_del(&ref->node);
698 kfree(ref);
700 mutex_unlock(&resource->resource_lock);
702 kfree(resource);
704 return 0;
707 static int acpi_power_resume(struct acpi_device *device)
709 int result = 0, state;
710 struct acpi_power_resource *resource = NULL;
711 struct acpi_power_reference *ref;
713 if (!device || !acpi_driver_data(device))
714 return -EINVAL;
716 resource = (struct acpi_power_resource *)acpi_driver_data(device);
718 result = acpi_power_get_state(resource, &state);
719 if (result)
720 return result;
722 mutex_lock(&resource->resource_lock);
723 if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
724 !list_empty(&resource->reference)) {
725 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
726 mutex_unlock(&resource->resource_lock);
727 result = acpi_power_on(device->handle, ref->device);
728 return result;
731 mutex_unlock(&resource->resource_lock);
732 return 0;
735 static int __init acpi_power_init(void)
737 int result = 0;
740 if (acpi_disabled)
741 return 0;
743 INIT_LIST_HEAD(&acpi_power_resource_list);
745 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
746 if (!acpi_power_dir)
747 return -ENODEV;
749 result = acpi_bus_register_driver(&acpi_power_driver);
750 if (result < 0) {
751 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
752 return -ENODEV;
755 return 0;
758 subsys_initcall(acpi_power_init);