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("acpi_power")
49 #define ACPI_POWER_COMPONENT 0x00800000
50 #define ACPI_POWER_CLASS "power_resource"
51 #define ACPI_POWER_DRIVER_NAME "ACPI Power Resource Driver"
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
58 static int acpi_power_add(struct acpi_device *device);
59 static int acpi_power_remove(struct acpi_device *device, int type);
60 static int acpi_power_open_fs(struct inode *inode, struct file *file);
62 static struct acpi_driver acpi_power_driver = {
63 .name = ACPI_POWER_DRIVER_NAME,
64 .class = ACPI_POWER_CLASS,
65 .ids = ACPI_POWER_HID,
67 .add = acpi_power_add,
68 .remove = acpi_power_remove,
72 struct acpi_power_resource {
74 struct acpi_device * device;
82 static struct list_head acpi_power_resource_list;
84 static struct file_operations acpi_power_fops = {
85 .open = acpi_power_open_fs,
88 .release = single_release,
91 /* --------------------------------------------------------------------------
92 Power Resource Management
93 -------------------------------------------------------------------------- */
96 acpi_power_get_context(acpi_handle handle,
97 struct acpi_power_resource **resource)
100 struct acpi_device *device = NULL;
106 result = acpi_bus_get_device(handle, &device);
108 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
112 *resource = (struct acpi_power_resource *)acpi_driver_data(device);
119 static int acpi_power_get_state(struct acpi_power_resource *resource)
121 acpi_status status = AE_OK;
122 unsigned long sta = 0;
128 status = acpi_evaluate_integer(resource->handle, "_STA", NULL, &sta);
129 if (ACPI_FAILURE(status))
133 resource->state = ACPI_POWER_RESOURCE_STATE_ON;
135 resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
137 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
138 resource->name, resource->state ? "on" : "off"));
143 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
146 struct acpi_power_resource *resource = NULL;
153 /* The state of the list is 'on' IFF all resources are 'on'. */
155 for (i = 0; i < list->count; i++) {
156 result = acpi_power_get_context(list->handles[i], &resource);
159 result = acpi_power_get_state(resource);
163 *state = resource->state;
165 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
169 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
170 *state ? "on" : "off"));
175 static int acpi_power_on(acpi_handle handle)
178 acpi_status status = AE_OK;
179 struct acpi_device *device = NULL;
180 struct acpi_power_resource *resource = NULL;
183 result = acpi_power_get_context(handle, &resource);
187 resource->references++;
189 if ((resource->references > 1)
190 || (resource->state == ACPI_POWER_RESOURCE_STATE_ON)) {
191 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
196 status = acpi_evaluate_object(resource->handle, "_ON", NULL, NULL);
197 if (ACPI_FAILURE(status))
200 result = acpi_power_get_state(resource);
203 if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
206 /* Update the power resource's _device_ power state */
207 device = resource->device;
208 resource->device->power.state = ACPI_STATE_D0;
210 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
216 static int acpi_power_off_device(acpi_handle handle)
219 acpi_status status = AE_OK;
220 struct acpi_device *device = NULL;
221 struct acpi_power_resource *resource = NULL;
224 result = acpi_power_get_context(handle, &resource);
228 if (resource->references)
229 resource->references--;
231 if (resource->references) {
232 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
233 "Resource [%s] is still in use, dereferencing\n",
234 device->pnp.bus_id));
238 if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
239 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
240 device->pnp.bus_id));
244 status = acpi_evaluate_object(resource->handle, "_OFF", NULL, NULL);
245 if (ACPI_FAILURE(status))
248 result = acpi_power_get_state(resource);
251 if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
254 /* Update the power resource's _device_ power state */
255 device = resource->device;
256 device->power.state = ACPI_STATE_D3;
258 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
265 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
266 * 1. Power on the power resources required for the wakeup device
267 * 2. Enable _PSW (power state wake) for the device if present
269 int acpi_enable_wakeup_device_power(struct acpi_device *dev)
271 union acpi_object arg = { ACPI_TYPE_INTEGER };
272 struct acpi_object_list arg_list = { 1, &arg };
273 acpi_status status = AE_OK;
277 if (!dev || !dev->wakeup.flags.valid)
280 arg.integer.value = 1;
281 /* Open power resource */
282 for (i = 0; i < dev->wakeup.resources.count; i++) {
283 ret = acpi_power_on(dev->wakeup.resources.handles[i]);
285 printk(KERN_ERR PREFIX "Transition power state\n");
286 dev->wakeup.flags.valid = 0;
292 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
293 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
294 printk(KERN_ERR PREFIX "Evaluate _PSW\n");
295 dev->wakeup.flags.valid = 0;
303 * Shutdown a wakeup device, counterpart of above method
304 * 1. Disable _PSW (power state wake)
305 * 2. Shutdown down the power resources
307 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
309 union acpi_object arg = { ACPI_TYPE_INTEGER };
310 struct acpi_object_list arg_list = { 1, &arg };
311 acpi_status status = AE_OK;
316 if (!dev || !dev->wakeup.flags.valid)
319 arg.integer.value = 0;
321 status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
322 if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
323 printk(KERN_ERR PREFIX "Evaluate _PSW\n");
324 dev->wakeup.flags.valid = 0;
328 /* Close power resource */
329 for (i = 0; i < dev->wakeup.resources.count; i++) {
330 ret = acpi_power_off_device(dev->wakeup.resources.handles[i]);
332 printk(KERN_ERR PREFIX "Transition power state\n");
333 dev->wakeup.flags.valid = 0;
341 /* --------------------------------------------------------------------------
342 Device Power Management
343 -------------------------------------------------------------------------- */
345 int acpi_power_get_inferred_state(struct acpi_device *device)
348 struct acpi_handle_list *list = NULL;
356 device->power.state = ACPI_STATE_UNKNOWN;
359 * We know a device's inferred power state when all the resources
360 * required for a given D-state are 'on'.
362 for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
363 list = &device->power.states[i].resources;
367 result = acpi_power_get_list_state(list, &list_state);
371 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
372 device->power.state = i;
377 device->power.state = ACPI_STATE_D3;
382 int acpi_power_transition(struct acpi_device *device, int state)
385 struct acpi_handle_list *cl = NULL; /* Current Resources */
386 struct acpi_handle_list *tl = NULL; /* Target Resources */
390 if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
393 if ((device->power.state < ACPI_STATE_D0)
394 || (device->power.state > ACPI_STATE_D3))
397 cl = &device->power.states[device->power.state].resources;
398 tl = &device->power.states[state].resources;
400 device->power.state = ACPI_STATE_UNKNOWN;
402 if (!cl->count && !tl->count) {
407 /* TBD: Resources must be ordered. */
410 * First we reference all power resources required in the target list
411 * (e.g. so the device doesn't lose power while transitioning).
413 for (i = 0; i < tl->count; i++) {
414 result = acpi_power_on(tl->handles[i]);
420 * Then we dereference all power resources used in the current list.
422 for (i = 0; i < cl->count; i++) {
423 result = acpi_power_off_device(cl->handles[i]);
428 /* We shouldn't change the state till all above operations succeed */
429 device->power.state = state;
432 printk(KERN_WARNING PREFIX "Transitioning device [%s] to D%d\n",
433 device->pnp.bus_id, state);
438 /* --------------------------------------------------------------------------
440 -------------------------------------------------------------------------- */
442 static struct proc_dir_entry *acpi_power_dir;
444 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
446 struct acpi_power_resource *resource = NULL;
449 resource = (struct acpi_power_resource *)seq->private;
454 seq_puts(seq, "state: ");
455 switch (resource->state) {
456 case ACPI_POWER_RESOURCE_STATE_ON:
457 seq_puts(seq, "on\n");
459 case ACPI_POWER_RESOURCE_STATE_OFF:
460 seq_puts(seq, "off\n");
463 seq_puts(seq, "unknown\n");
467 seq_printf(seq, "system level: S%d\n"
469 "reference count: %d\n",
470 resource->system_level,
471 resource->order, resource->references);
477 static int acpi_power_open_fs(struct inode *inode, struct file *file)
479 return single_open(file, acpi_power_seq_show, PDE(inode)->data);
482 static int acpi_power_add_fs(struct acpi_device *device)
484 struct proc_dir_entry *entry = NULL;
490 if (!acpi_device_dir(device)) {
491 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
493 if (!acpi_device_dir(device))
498 entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
499 S_IRUGO, acpi_device_dir(device));
503 entry->proc_fops = &acpi_power_fops;
504 entry->data = acpi_driver_data(device);
510 static int acpi_power_remove_fs(struct acpi_device *device)
513 if (acpi_device_dir(device)) {
514 remove_proc_entry(ACPI_POWER_FILE_STATUS,
515 acpi_device_dir(device));
516 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
517 acpi_device_dir(device) = NULL;
523 /* --------------------------------------------------------------------------
525 -------------------------------------------------------------------------- */
527 static int acpi_power_add(struct acpi_device *device)
530 acpi_status status = AE_OK;
531 struct acpi_power_resource *resource = NULL;
532 union acpi_object acpi_object;
533 struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
539 resource = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
542 memset(resource, 0, sizeof(struct acpi_power_resource));
544 resource->handle = device->handle;
545 resource->device = device;
546 strcpy(resource->name, device->pnp.bus_id);
547 strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
548 strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
549 acpi_driver_data(device) = resource;
551 /* Evalute the object to get the system level and resource order. */
552 status = acpi_evaluate_object(resource->handle, NULL, NULL, &buffer);
553 if (ACPI_FAILURE(status)) {
557 resource->system_level = acpi_object.power_resource.system_level;
558 resource->order = acpi_object.power_resource.resource_order;
560 result = acpi_power_get_state(resource);
564 switch (resource->state) {
565 case ACPI_POWER_RESOURCE_STATE_ON:
566 device->power.state = ACPI_STATE_D0;
568 case ACPI_POWER_RESOURCE_STATE_OFF:
569 device->power.state = ACPI_STATE_D3;
572 device->power.state = ACPI_STATE_UNKNOWN;
576 result = acpi_power_add_fs(device);
580 printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
581 acpi_device_bid(device), resource->state ? "on" : "off");
590 static int acpi_power_remove(struct acpi_device *device, int type)
592 struct acpi_power_resource *resource = NULL;
595 if (!device || !acpi_driver_data(device))
598 resource = (struct acpi_power_resource *)acpi_driver_data(device);
600 acpi_power_remove_fs(device);
607 static int __init acpi_power_init(void)
615 INIT_LIST_HEAD(&acpi_power_resource_list);
617 acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
621 result = acpi_bus_register_driver(&acpi_power_driver);
623 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
630 subsys_initcall(acpi_power_init);