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
;
245 struct acpi_power_reference
*ref
;
247 result
= acpi_power_get_context(handle
, &resource
);
251 mutex_lock(&resource
->resource_lock
);
252 list_for_each_safe(node
, next
, &resource
->reference
) {
253 ref
= container_of(node
, struct acpi_power_reference
, node
);
254 if (dev
->handle
== ref
->device
->handle
) {
255 list_del(&ref
->node
);
257 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Device [%s] removed from resource [%s] references\n",
258 dev
->pnp
.bus_id
, resource
->name
));
263 if (!list_empty(&resource
->reference
)) {
264 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Cannot turn resource [%s] off - resource is in use\n",
266 mutex_unlock(&resource
->resource_lock
);
269 mutex_unlock(&resource
->resource_lock
);
271 status
= acpi_evaluate_object(resource
->device
->handle
, "_OFF", NULL
, NULL
);
272 if (ACPI_FAILURE(status
))
275 /* Update the power resource's _device_ power state */
276 resource
->device
->power
.state
= ACPI_STATE_D3
;
278 ACPI_DEBUG_PRINT((ACPI_DB_INFO
, "Resource [%s] turned off\n",
285 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
286 * ACPI 3.0) _PSW (Power State Wake)
287 * @dev: Device to handle.
288 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
289 * @sleep_state: Target sleep state of the system.
290 * @dev_state: Target power state of the device.
292 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
293 * State Wake) for the device, if present. On failure reset the device's
294 * wakeup.flags.valid flag.
297 * 0 if either _DSW or _PSW has been successfully executed
298 * 0 if neither _DSW nor _PSW has been found
299 * -ENODEV if the execution of either _DSW or _PSW has failed
301 int acpi_device_sleep_wake(struct acpi_device
*dev
,
302 int enable
, int sleep_state
, int dev_state
)
304 union acpi_object in_arg
[3];
305 struct acpi_object_list arg_list
= { 3, in_arg
};
306 acpi_status status
= AE_OK
;
309 * Try to execute _DSW first.
311 * Three agruments are needed for the _DSW object:
312 * Argument 0: enable/disable the wake capabilities
313 * Argument 1: target system state
314 * Argument 2: target device state
315 * When _DSW object is called to disable the wake capabilities, maybe
316 * the first argument is filled. The values of the other two agruments
319 in_arg
[0].type
= ACPI_TYPE_INTEGER
;
320 in_arg
[0].integer
.value
= enable
;
321 in_arg
[1].type
= ACPI_TYPE_INTEGER
;
322 in_arg
[1].integer
.value
= sleep_state
;
323 in_arg
[2].type
= ACPI_TYPE_INTEGER
;
324 in_arg
[2].integer
.value
= dev_state
;
325 status
= acpi_evaluate_object(dev
->handle
, "_DSW", &arg_list
, NULL
);
326 if (ACPI_SUCCESS(status
)) {
328 } else if (status
!= AE_NOT_FOUND
) {
329 printk(KERN_ERR PREFIX
"_DSW execution failed\n");
330 dev
->wakeup
.flags
.valid
= 0;
336 in_arg
[0].integer
.value
= enable
;
337 status
= acpi_evaluate_object(dev
->handle
, "_PSW", &arg_list
, NULL
);
338 if (ACPI_FAILURE(status
) && (status
!= AE_NOT_FOUND
)) {
339 printk(KERN_ERR PREFIX
"_PSW execution failed\n");
340 dev
->wakeup
.flags
.valid
= 0;
348 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
349 * 1. Power on the power resources required for the wakeup device
350 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
351 * State Wake) for the device, if present
353 int acpi_enable_wakeup_device_power(struct acpi_device
*dev
, int sleep_state
)
357 if (!dev
|| !dev
->wakeup
.flags
.valid
)
360 mutex_lock(&acpi_device_lock
);
362 if (dev
->wakeup
.prepare_count
++)
365 /* Open power resource */
366 for (i
= 0; i
< dev
->wakeup
.resources
.count
; i
++) {
367 int ret
= acpi_power_on(dev
->wakeup
.resources
.handles
[i
], dev
);
369 printk(KERN_ERR PREFIX
"Transition power state\n");
370 dev
->wakeup
.flags
.valid
= 0;
377 * Passing 3 as the third argument below means the device may be placed
378 * in arbitrary power state afterwards.
380 err
= acpi_device_sleep_wake(dev
, 1, sleep_state
, 3);
384 dev
->wakeup
.prepare_count
= 0;
387 mutex_unlock(&acpi_device_lock
);
392 * Shutdown a wakeup device, counterpart of above method
393 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
394 * State Wake) for the device, if present
395 * 2. Shutdown down the power resources
397 int acpi_disable_wakeup_device_power(struct acpi_device
*dev
)
401 if (!dev
|| !dev
->wakeup
.flags
.valid
)
404 mutex_lock(&acpi_device_lock
);
406 if (--dev
->wakeup
.prepare_count
> 0)
410 * Executing the code below even if prepare_count is already zero when
411 * the function is called may be useful, for example for initialisation.
413 if (dev
->wakeup
.prepare_count
< 0)
414 dev
->wakeup
.prepare_count
= 0;
416 err
= acpi_device_sleep_wake(dev
, 0, 0, 0);
420 /* Close power resource */
421 for (i
= 0; i
< dev
->wakeup
.resources
.count
; i
++) {
422 int ret
= acpi_power_off_device(
423 dev
->wakeup
.resources
.handles
[i
], dev
);
425 printk(KERN_ERR PREFIX
"Transition power state\n");
426 dev
->wakeup
.flags
.valid
= 0;
433 mutex_unlock(&acpi_device_lock
);
437 /* --------------------------------------------------------------------------
438 Device Power Management
439 -------------------------------------------------------------------------- */
441 int acpi_power_get_inferred_state(struct acpi_device
*device
)
444 struct acpi_handle_list
*list
= NULL
;
452 device
->power
.state
= ACPI_STATE_UNKNOWN
;
455 * We know a device's inferred power state when all the resources
456 * required for a given D-state are 'on'.
458 for (i
= ACPI_STATE_D0
; i
< ACPI_STATE_D3
; i
++) {
459 list
= &device
->power
.states
[i
].resources
;
463 result
= acpi_power_get_list_state(list
, &list_state
);
467 if (list_state
== ACPI_POWER_RESOURCE_STATE_ON
) {
468 device
->power
.state
= i
;
473 device
->power
.state
= ACPI_STATE_D3
;
478 int acpi_power_transition(struct acpi_device
*device
, int state
)
481 struct acpi_handle_list
*cl
= NULL
; /* Current Resources */
482 struct acpi_handle_list
*tl
= NULL
; /* Target Resources */
486 if (!device
|| (state
< ACPI_STATE_D0
) || (state
> ACPI_STATE_D3
))
489 if ((device
->power
.state
< ACPI_STATE_D0
)
490 || (device
->power
.state
> ACPI_STATE_D3
))
493 cl
= &device
->power
.states
[device
->power
.state
].resources
;
494 tl
= &device
->power
.states
[state
].resources
;
496 /* TBD: Resources must be ordered. */
499 * First we reference all power resources required in the target list
500 * (e.g. so the device doesn't lose power while transitioning).
502 for (i
= 0; i
< tl
->count
; i
++) {
503 result
= acpi_power_on(tl
->handles
[i
], device
);
508 if (device
->power
.state
== state
) {
513 * Then we dereference all power resources used in the current list.
515 for (i
= 0; i
< cl
->count
; i
++) {
516 result
= acpi_power_off_device(cl
->handles
[i
], device
);
523 device
->power
.state
= ACPI_STATE_UNKNOWN
;
525 /* We shouldn't change the state till all above operations succeed */
526 device
->power
.state
= state
;
532 /* --------------------------------------------------------------------------
534 -------------------------------------------------------------------------- */
536 static int acpi_power_add(struct acpi_device
*device
)
538 int result
= 0, state
;
539 acpi_status status
= AE_OK
;
540 struct acpi_power_resource
*resource
= NULL
;
541 union acpi_object acpi_object
;
542 struct acpi_buffer buffer
= { sizeof(acpi_object
), &acpi_object
};
548 resource
= kzalloc(sizeof(struct acpi_power_resource
), GFP_KERNEL
);
552 resource
->device
= device
;
553 mutex_init(&resource
->resource_lock
);
554 INIT_LIST_HEAD(&resource
->reference
);
555 strcpy(resource
->name
, device
->pnp
.bus_id
);
556 strcpy(acpi_device_name(device
), ACPI_POWER_DEVICE_NAME
);
557 strcpy(acpi_device_class(device
), ACPI_POWER_CLASS
);
558 device
->driver_data
= resource
;
560 /* Evalute the object to get the system level and resource order. */
561 status
= acpi_evaluate_object(device
->handle
, NULL
, NULL
, &buffer
);
562 if (ACPI_FAILURE(status
)) {
566 resource
->system_level
= acpi_object
.power_resource
.system_level
;
567 resource
->order
= acpi_object
.power_resource
.resource_order
;
569 result
= acpi_power_get_state(device
->handle
, &state
);
574 case ACPI_POWER_RESOURCE_STATE_ON
:
575 device
->power
.state
= ACPI_STATE_D0
;
577 case ACPI_POWER_RESOURCE_STATE_OFF
:
578 device
->power
.state
= ACPI_STATE_D3
;
581 device
->power
.state
= ACPI_STATE_UNKNOWN
;
585 printk(KERN_INFO PREFIX
"%s [%s] (%s)\n", acpi_device_name(device
),
586 acpi_device_bid(device
), state
? "on" : "off");
595 static int acpi_power_remove(struct acpi_device
*device
, int type
)
597 struct acpi_power_resource
*resource
= NULL
;
598 struct list_head
*node
, *next
;
601 if (!device
|| !acpi_driver_data(device
))
604 resource
= acpi_driver_data(device
);
606 mutex_lock(&resource
->resource_lock
);
607 list_for_each_safe(node
, next
, &resource
->reference
) {
608 struct acpi_power_reference
*ref
= container_of(node
, struct acpi_power_reference
, node
);
609 list_del(&ref
->node
);
612 mutex_unlock(&resource
->resource_lock
);
619 static int acpi_power_resume(struct acpi_device
*device
)
621 int result
= 0, state
;
622 struct acpi_power_resource
*resource
= NULL
;
623 struct acpi_power_reference
*ref
;
625 if (!device
|| !acpi_driver_data(device
))
628 resource
= acpi_driver_data(device
);
630 result
= acpi_power_get_state(device
->handle
, &state
);
634 mutex_lock(&resource
->resource_lock
);
635 if (state
== ACPI_POWER_RESOURCE_STATE_OFF
&&
636 !list_empty(&resource
->reference
)) {
637 ref
= container_of(resource
->reference
.next
, struct acpi_power_reference
, node
);
638 mutex_unlock(&resource
->resource_lock
);
639 result
= acpi_power_on(device
->handle
, ref
->device
);
643 mutex_unlock(&resource
->resource_lock
);
647 int __init
acpi_power_init(void)
649 INIT_LIST_HEAD(&acpi_power_resource_list
);
650 return acpi_bus_register_driver(&acpi_power_driver
);