2 * scan.c - support for transforming the ACPI namespace into individual objects
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/kernel.h>
9 #include <linux/acpi.h>
10 #include <linux/signal.h>
11 #include <linux/kthread.h>
12 #include <linux/dmi.h>
13 #include <linux/nls.h>
15 #include <acpi/acpi_drivers.h>
19 #define _COMPONENT ACPI_BUS_COMPONENT
20 ACPI_MODULE_NAME("scan");
21 #define STRUCT_TO_INT(s) (*((int*)&s))
22 extern struct acpi_device *acpi_root;
24 #define ACPI_BUS_CLASS "system_bus"
25 #define ACPI_BUS_HID "LNXSYBUS"
26 #define ACPI_BUS_DEVICE_NAME "System Bus"
28 #define ACPI_IS_ROOT_DEVICE(device) (!(device)->parent)
30 static const char *dummy_hid = "device";
33 * The following ACPI IDs are known to be suitable for representing as
36 static const struct acpi_device_id acpi_platform_device_ids[] = {
40 /* Haswell LPSS devices */
53 static LIST_HEAD(acpi_device_list);
54 static LIST_HEAD(acpi_bus_id_list);
55 DEFINE_MUTEX(acpi_device_lock);
56 LIST_HEAD(acpi_wakeup_device_list);
58 struct acpi_device_bus_id{
60 unsigned int instance_no;
61 struct list_head node;
65 * Creates hid/cid(s) string needed for modalias and uevent
66 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
67 * char *modalias: "acpi:IBM0001:ACPI0001"
69 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
74 struct acpi_hardware_id *id;
76 if (list_empty(&acpi_dev->pnp.ids))
79 len = snprintf(modalias, size, "acpi:");
82 list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
83 count = snprintf(&modalias[len], size, "%s:", id->id);
84 if (count < 0 || count >= size)
95 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
96 struct acpi_device *acpi_dev = to_acpi_device(dev);
99 /* Device has no HID and no CID or string is >1024 */
100 len = create_modalias(acpi_dev, buf, 1024);
106 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
109 * acpi_bus_hot_remove_device: hot-remove a device and its children
110 * @context: struct acpi_eject_event pointer (freed in this func)
112 * Hot-remove a device and its children. This function frees up the
113 * memory space passed by arg context, so that the caller may call
114 * this function asynchronously through acpi_os_hotplug_execute().
116 void acpi_bus_hot_remove_device(void *context)
118 struct acpi_eject_event *ej_event = (struct acpi_eject_event *) context;
119 struct acpi_device *device = ej_event->device;
120 acpi_handle handle = device->handle;
122 struct acpi_object_list arg_list;
123 union acpi_object arg;
124 acpi_status status = AE_OK;
125 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
127 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
128 "Hot-removing device %s...\n", dev_name(&device->dev)));
130 if (acpi_bus_trim(device)) {
131 printk(KERN_ERR PREFIX
132 "Removing device failed\n");
136 /* device has been freed */
139 /* power off device */
140 status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
141 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
142 printk(KERN_WARNING PREFIX
143 "Power-off device failed\n");
145 if (ACPI_SUCCESS(acpi_get_handle(handle, "_LCK", &temp))) {
147 arg_list.pointer = &arg;
148 arg.type = ACPI_TYPE_INTEGER;
149 arg.integer.value = 0;
150 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
154 arg_list.pointer = &arg;
155 arg.type = ACPI_TYPE_INTEGER;
156 arg.integer.value = 1;
161 status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
162 if (ACPI_FAILURE(status)) {
163 if (status != AE_NOT_FOUND)
164 printk(KERN_WARNING PREFIX
165 "Eject device failed\n");
173 /* Inform firmware the hot-remove operation has completed w/ error */
174 (void) acpi_evaluate_hotplug_ost(handle,
175 ej_event->event, ost_code, NULL);
179 EXPORT_SYMBOL(acpi_bus_hot_remove_device);
182 acpi_eject_store(struct device *d, struct device_attribute *attr,
183 const char *buf, size_t count)
187 acpi_object_type type = 0;
188 struct acpi_device *acpi_device = to_acpi_device(d);
189 struct acpi_eject_event *ej_event;
191 if ((!count) || (buf[0] != '1')) {
195 if (acpi_device->driver == NULL) {
200 status = acpi_get_type(acpi_device->handle, &type);
201 if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
206 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
212 ej_event->device = acpi_device;
213 if (acpi_device->flags.eject_pending) {
214 /* event originated from ACPI eject notification */
215 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
216 acpi_device->flags.eject_pending = 0;
218 /* event originated from user */
219 ej_event->event = ACPI_OST_EC_OSPM_EJECT;
220 (void) acpi_evaluate_hotplug_ost(acpi_device->handle,
221 ej_event->event, ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
224 acpi_os_hotplug_execute(acpi_bus_hot_remove_device, (void *)ej_event);
229 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
232 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
233 struct acpi_device *acpi_dev = to_acpi_device(dev);
235 return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
237 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
239 static ssize_t acpi_device_uid_show(struct device *dev,
240 struct device_attribute *attr, char *buf)
242 struct acpi_device *acpi_dev = to_acpi_device(dev);
244 return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
246 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
248 static ssize_t acpi_device_adr_show(struct device *dev,
249 struct device_attribute *attr, char *buf)
251 struct acpi_device *acpi_dev = to_acpi_device(dev);
253 return sprintf(buf, "0x%08x\n",
254 (unsigned int)(acpi_dev->pnp.bus_address));
256 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
259 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
260 struct acpi_device *acpi_dev = to_acpi_device(dev);
261 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
264 result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
268 result = sprintf(buf, "%s\n", (char*)path.pointer);
273 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
275 /* sysfs file that shows description text from the ACPI _STR method */
276 static ssize_t description_show(struct device *dev,
277 struct device_attribute *attr,
279 struct acpi_device *acpi_dev = to_acpi_device(dev);
282 if (acpi_dev->pnp.str_obj == NULL)
286 * The _STR object contains a Unicode identifier for a device.
287 * We need to convert to utf-8 so it can be displayed.
289 result = utf16s_to_utf8s(
290 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
291 acpi_dev->pnp.str_obj->buffer.length,
292 UTF16_LITTLE_ENDIAN, buf,
295 buf[result++] = '\n';
299 static DEVICE_ATTR(description, 0444, description_show, NULL);
302 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
304 struct acpi_device *acpi_dev = to_acpi_device(dev);
306 return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
308 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
310 static int acpi_device_setup_files(struct acpi_device *dev)
312 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
315 unsigned long long sun;
319 * Devices gotten from FADT don't have a "path" attribute
322 result = device_create_file(&dev->dev, &dev_attr_path);
327 if (!list_empty(&dev->pnp.ids)) {
328 result = device_create_file(&dev->dev, &dev_attr_hid);
332 result = device_create_file(&dev->dev, &dev_attr_modalias);
338 * If device has _STR, 'description' file is created
340 status = acpi_get_handle(dev->handle, "_STR", &temp);
341 if (ACPI_SUCCESS(status)) {
342 status = acpi_evaluate_object(dev->handle, "_STR",
344 if (ACPI_FAILURE(status))
345 buffer.pointer = NULL;
346 dev->pnp.str_obj = buffer.pointer;
347 result = device_create_file(&dev->dev, &dev_attr_description);
352 if (dev->flags.bus_address)
353 result = device_create_file(&dev->dev, &dev_attr_adr);
354 if (dev->pnp.unique_id)
355 result = device_create_file(&dev->dev, &dev_attr_uid);
357 status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
358 if (ACPI_SUCCESS(status)) {
359 dev->pnp.sun = (unsigned long)sun;
360 result = device_create_file(&dev->dev, &dev_attr_sun);
364 dev->pnp.sun = (unsigned long)-1;
368 * If device has _EJ0, 'eject' file is created that is used to trigger
369 * hot-removal function from userland.
371 status = acpi_get_handle(dev->handle, "_EJ0", &temp);
372 if (ACPI_SUCCESS(status))
373 result = device_create_file(&dev->dev, &dev_attr_eject);
378 static void acpi_device_remove_files(struct acpi_device *dev)
384 * If device has _STR, remove 'description' file
386 status = acpi_get_handle(dev->handle, "_STR", &temp);
387 if (ACPI_SUCCESS(status)) {
388 kfree(dev->pnp.str_obj);
389 device_remove_file(&dev->dev, &dev_attr_description);
392 * If device has _EJ0, remove 'eject' file.
394 status = acpi_get_handle(dev->handle, "_EJ0", &temp);
395 if (ACPI_SUCCESS(status))
396 device_remove_file(&dev->dev, &dev_attr_eject);
398 status = acpi_get_handle(dev->handle, "_SUN", &temp);
399 if (ACPI_SUCCESS(status))
400 device_remove_file(&dev->dev, &dev_attr_sun);
402 if (dev->pnp.unique_id)
403 device_remove_file(&dev->dev, &dev_attr_uid);
404 if (dev->flags.bus_address)
405 device_remove_file(&dev->dev, &dev_attr_adr);
406 device_remove_file(&dev->dev, &dev_attr_modalias);
407 device_remove_file(&dev->dev, &dev_attr_hid);
409 device_remove_file(&dev->dev, &dev_attr_path);
411 /* --------------------------------------------------------------------------
413 -------------------------------------------------------------------------- */
415 static const struct acpi_device_id *__acpi_match_device(
416 struct acpi_device *device, const struct acpi_device_id *ids)
418 const struct acpi_device_id *id;
419 struct acpi_hardware_id *hwid;
422 * If the device is not present, it is unnecessary to load device
425 if (!device->status.present)
428 for (id = ids; id->id[0]; id++)
429 list_for_each_entry(hwid, &device->pnp.ids, list)
430 if (!strcmp((char *) id->id, hwid->id))
437 * acpi_match_device - Match a struct device against a given list of ACPI IDs
438 * @ids: Array of struct acpi_device_id object to match against.
439 * @dev: The device structure to match.
441 * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
442 * object for that handle and use that object to match against a given list of
445 * Return a pointer to the first matching ID on success or %NULL on failure.
447 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
448 const struct device *dev)
450 struct acpi_device *adev;
452 if (!ids || !ACPI_HANDLE(dev)
453 || ACPI_FAILURE(acpi_bus_get_device(ACPI_HANDLE(dev), &adev)))
456 return __acpi_match_device(adev, ids);
458 EXPORT_SYMBOL_GPL(acpi_match_device);
460 int acpi_match_device_ids(struct acpi_device *device,
461 const struct acpi_device_id *ids)
463 return __acpi_match_device(device, ids) ? 0 : -ENOENT;
465 EXPORT_SYMBOL(acpi_match_device_ids);
467 void acpi_free_ids(struct acpi_device *device)
469 struct acpi_hardware_id *id, *tmp;
471 list_for_each_entry_safe(id, tmp, &device->pnp.ids, list) {
475 kfree(device->pnp.unique_id);
478 static void acpi_free_power_resources_lists(struct acpi_device *device)
482 if (device->wakeup.flags.valid)
483 acpi_power_resources_list_free(&device->wakeup.resources);
485 if (!device->flags.power_manageable)
488 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
489 struct acpi_device_power_state *ps = &device->power.states[i];
490 acpi_power_resources_list_free(&ps->resources);
494 static void acpi_device_release(struct device *dev)
496 struct acpi_device *acpi_dev = to_acpi_device(dev);
498 acpi_free_ids(acpi_dev);
499 acpi_free_power_resources_lists(acpi_dev);
503 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
505 struct acpi_device *acpi_dev = to_acpi_device(dev);
506 struct acpi_driver *acpi_drv = to_acpi_driver(drv);
508 return acpi_dev->flags.match_driver
509 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
512 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
514 struct acpi_device *acpi_dev = to_acpi_device(dev);
517 if (list_empty(&acpi_dev->pnp.ids))
520 if (add_uevent_var(env, "MODALIAS="))
522 len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
523 sizeof(env->buf) - env->buflen);
524 if (len >= (sizeof(env->buf) - env->buflen))
530 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
532 struct acpi_device *device = data;
534 device->driver->ops.notify(device, event);
537 static acpi_status acpi_device_notify_fixed(void *data)
539 struct acpi_device *device = data;
541 /* Fixed hardware devices have no handles */
542 acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
546 static int acpi_device_install_notify_handler(struct acpi_device *device)
550 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
552 acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
553 acpi_device_notify_fixed,
555 else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
557 acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
558 acpi_device_notify_fixed,
561 status = acpi_install_notify_handler(device->handle,
566 if (ACPI_FAILURE(status))
571 static void acpi_device_remove_notify_handler(struct acpi_device *device)
573 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
574 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
575 acpi_device_notify_fixed);
576 else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
577 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
578 acpi_device_notify_fixed);
580 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
584 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
585 static int acpi_device_probe(struct device * dev)
587 struct acpi_device *acpi_dev = to_acpi_device(dev);
588 struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
591 ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
593 if (acpi_drv->ops.notify) {
594 ret = acpi_device_install_notify_handler(acpi_dev);
596 if (acpi_drv->ops.remove)
597 acpi_drv->ops.remove(acpi_dev,
598 acpi_dev->removal_type);
603 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
604 "Found driver [%s] for device [%s]\n",
605 acpi_drv->name, acpi_dev->pnp.bus_id));
611 static int acpi_device_remove(struct device * dev)
613 struct acpi_device *acpi_dev = to_acpi_device(dev);
614 struct acpi_driver *acpi_drv = acpi_dev->driver;
617 if (acpi_drv->ops.notify)
618 acpi_device_remove_notify_handler(acpi_dev);
619 if (acpi_drv->ops.remove)
620 acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
622 acpi_dev->driver = NULL;
623 acpi_dev->driver_data = NULL;
629 struct bus_type acpi_bus_type = {
631 .match = acpi_bus_match,
632 .probe = acpi_device_probe,
633 .remove = acpi_device_remove,
634 .uevent = acpi_device_uevent,
637 int acpi_device_add(struct acpi_device *device,
638 void (*release)(struct device *))
641 struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
644 if (device->handle) {
647 status = acpi_attach_data(device->handle, acpi_bus_data_handler,
649 if (ACPI_FAILURE(status)) {
650 acpi_handle_err(device->handle,
651 "Unable to attach device data\n");
659 * Link this device to its parent and siblings.
661 INIT_LIST_HEAD(&device->children);
662 INIT_LIST_HEAD(&device->node);
663 INIT_LIST_HEAD(&device->wakeup_list);
664 INIT_LIST_HEAD(&device->physical_node_list);
665 mutex_init(&device->physical_node_lock);
666 INIT_LIST_HEAD(&device->power_dependent);
668 new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
670 pr_err(PREFIX "Memory allocation error\n");
675 mutex_lock(&acpi_device_lock);
677 * Find suitable bus_id and instance number in acpi_bus_id_list
678 * If failed, create one and link it into acpi_bus_id_list
680 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
681 if (!strcmp(acpi_device_bus_id->bus_id,
682 acpi_device_hid(device))) {
683 acpi_device_bus_id->instance_no++;
690 acpi_device_bus_id = new_bus_id;
691 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
692 acpi_device_bus_id->instance_no = 0;
693 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
695 dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
698 list_add_tail(&device->node, &device->parent->children);
700 if (device->wakeup.flags.valid)
701 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
702 mutex_unlock(&acpi_device_lock);
705 device->dev.parent = &device->parent->dev;
706 device->dev.bus = &acpi_bus_type;
707 device->dev.release = release;
708 result = device_add(&device->dev);
710 dev_err(&device->dev, "Error registering device\n");
714 result = acpi_device_setup_files(device);
716 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
717 dev_name(&device->dev));
719 device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
723 mutex_lock(&acpi_device_lock);
725 list_del(&device->node);
726 list_del(&device->wakeup_list);
727 mutex_unlock(&acpi_device_lock);
730 acpi_detach_data(device->handle, acpi_bus_data_handler);
734 static void acpi_device_unregister(struct acpi_device *device)
736 mutex_lock(&acpi_device_lock);
738 list_del(&device->node);
740 list_del(&device->wakeup_list);
741 mutex_unlock(&acpi_device_lock);
743 acpi_detach_data(device->handle, acpi_bus_data_handler);
745 acpi_power_add_remove_device(device, false);
746 acpi_device_remove_files(device);
747 device_del(&device->dev);
749 * Drop the reference counts of all power resources the device depends
750 * on and turn off the ones that have no more references.
752 acpi_power_transition(device, ACPI_STATE_D3_COLD);
753 put_device(&device->dev);
756 /* --------------------------------------------------------------------------
758 -------------------------------------------------------------------------- */
760 * acpi_bus_driver_init - add a device to a driver
761 * @device: the device to add and initialize
762 * @driver: driver for the device
764 * Used to initialize a device via its device driver. Called whenever a
765 * driver is bound to a device. Invokes the driver's add() ops.
768 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
772 if (!device || !driver)
775 if (!driver->ops.add)
778 result = driver->ops.add(device);
780 device->driver = NULL;
781 device->driver_data = NULL;
785 device->driver = driver;
788 * TBD - Configuration Management: Assign resources to device based
789 * upon possible configuration and currently allocated resources.
792 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
793 "Driver successfully bound to device\n"));
798 * acpi_bus_register_driver - register a driver with the ACPI bus
799 * @driver: driver being registered
801 * Registers a driver with the ACPI bus. Searches the namespace for all
802 * devices that match the driver's criteria and binds. Returns zero for
803 * success or a negative error status for failure.
805 int acpi_bus_register_driver(struct acpi_driver *driver)
811 driver->drv.name = driver->name;
812 driver->drv.bus = &acpi_bus_type;
813 driver->drv.owner = driver->owner;
815 ret = driver_register(&driver->drv);
819 EXPORT_SYMBOL(acpi_bus_register_driver);
822 * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
823 * @driver: driver to unregister
825 * Unregisters a driver with the ACPI bus. Searches the namespace for all
826 * devices that match the driver's criteria and unbinds.
828 void acpi_bus_unregister_driver(struct acpi_driver *driver)
830 driver_unregister(&driver->drv);
833 EXPORT_SYMBOL(acpi_bus_unregister_driver);
835 /* --------------------------------------------------------------------------
837 -------------------------------------------------------------------------- */
838 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
842 struct acpi_device *device;
845 * Fixed hardware devices do not appear in the namespace and do not
846 * have handles, but we fabricate acpi_devices for them, so we have
847 * to deal with them specially.
853 status = acpi_get_parent(handle, &handle);
854 if (status == AE_NULL_ENTRY)
856 if (ACPI_FAILURE(status))
859 ret = acpi_bus_get_device(handle, &device);
866 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
870 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
871 union acpi_object *obj;
873 status = acpi_get_handle(handle, "_EJD", &tmp);
874 if (ACPI_FAILURE(status))
877 status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
878 if (ACPI_SUCCESS(status)) {
879 obj = buffer.pointer;
880 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
882 kfree(buffer.pointer);
886 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
888 void acpi_bus_data_handler(acpi_handle handle, void *context)
896 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
897 struct acpi_device_wakeup *wakeup)
899 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
900 union acpi_object *package = NULL;
901 union acpi_object *element = NULL;
908 INIT_LIST_HEAD(&wakeup->resources);
911 status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
912 if (ACPI_FAILURE(status)) {
913 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
917 package = (union acpi_object *)buffer.pointer;
919 if (!package || package->package.count < 2)
922 element = &(package->package.elements[0]);
926 if (element->type == ACPI_TYPE_PACKAGE) {
927 if ((element->package.count < 2) ||
928 (element->package.elements[0].type !=
929 ACPI_TYPE_LOCAL_REFERENCE)
930 || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
934 element->package.elements[0].reference.handle;
936 (u32) element->package.elements[1].integer.value;
937 } else if (element->type == ACPI_TYPE_INTEGER) {
938 wakeup->gpe_device = NULL;
939 wakeup->gpe_number = element->integer.value;
944 element = &(package->package.elements[1]);
945 if (element->type != ACPI_TYPE_INTEGER)
948 wakeup->sleep_state = element->integer.value;
950 err = acpi_extract_power_resources(package, 2, &wakeup->resources);
954 if (!list_empty(&wakeup->resources)) {
957 sleep_state = acpi_power_min_system_level(&wakeup->resources);
958 if (sleep_state < wakeup->sleep_state) {
959 acpi_handle_warn(handle, "Overriding _PRW sleep state "
960 "(S%d) by S%d from power resources\n",
961 (int)wakeup->sleep_state, sleep_state);
962 wakeup->sleep_state = sleep_state;
965 acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
968 kfree(buffer.pointer);
972 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
974 struct acpi_device_id button_device_ids[] = {
981 acpi_event_status event_status;
983 device->wakeup.flags.notifier_present = 0;
985 /* Power button, Lid switch always enable wakeup */
986 if (!acpi_match_device_ids(device, button_device_ids)) {
987 device->wakeup.flags.run_wake = 1;
988 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
989 /* Do not use Lid/sleep button for S5 wakeup */
990 if (device->wakeup.sleep_state == ACPI_STATE_S5)
991 device->wakeup.sleep_state = ACPI_STATE_S4;
993 device_set_wakeup_capable(&device->dev, true);
997 status = acpi_get_gpe_status(device->wakeup.gpe_device,
998 device->wakeup.gpe_number,
1000 if (status == AE_OK)
1001 device->wakeup.flags.run_wake =
1002 !!(event_status & ACPI_EVENT_FLAG_HANDLE);
1005 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1008 acpi_status status = 0;
1011 /* Presence of _PRW indicates wake capable */
1012 status = acpi_get_handle(device->handle, "_PRW", &temp);
1013 if (ACPI_FAILURE(status))
1016 err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1019 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1023 device->wakeup.flags.valid = 1;
1024 device->wakeup.prepare_count = 0;
1025 acpi_bus_set_run_wake_flags(device);
1026 /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1027 * system for the ACPI device with the _PRW object.
1028 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1029 * So it is necessary to call _DSW object first. Only when it is not
1030 * present will the _PSW object used.
1032 err = acpi_device_sleep_wake(device, 0, 0, 0);
1034 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1035 "error in _DSW or _PSW evaluation\n"));
1038 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1040 struct acpi_device_power_state *ps = &device->power.states[state];
1041 char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1042 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1046 INIT_LIST_HEAD(&ps->resources);
1048 /* Evaluate "_PRx" to get referenced power resources */
1049 status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1050 if (ACPI_SUCCESS(status)) {
1051 union acpi_object *package = buffer.pointer;
1053 if (buffer.length && package
1054 && package->type == ACPI_TYPE_PACKAGE
1055 && package->package.count) {
1056 int err = acpi_extract_power_resources(package, 0,
1059 device->power.flags.power_resources = 1;
1061 ACPI_FREE(buffer.pointer);
1064 /* Evaluate "_PSx" to see if we can do explicit sets */
1066 status = acpi_get_handle(device->handle, pathname, &handle);
1067 if (ACPI_SUCCESS(status))
1068 ps->flags.explicit_set = 1;
1071 * State is valid if there are means to put the device into it.
1072 * D3hot is only valid if _PR3 present.
1074 if (!list_empty(&ps->resources)
1075 || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1076 ps->flags.valid = 1;
1077 ps->flags.os_accessible = 1;
1080 ps->power = -1; /* Unknown - driver assigned */
1081 ps->latency = -1; /* Unknown - driver assigned */
1084 static void acpi_bus_get_power_flags(struct acpi_device *device)
1090 /* Presence of _PS0|_PR0 indicates 'power manageable' */
1091 status = acpi_get_handle(device->handle, "_PS0", &handle);
1092 if (ACPI_FAILURE(status)) {
1093 status = acpi_get_handle(device->handle, "_PR0", &handle);
1094 if (ACPI_FAILURE(status))
1098 device->flags.power_manageable = 1;
1101 * Power Management Flags
1103 status = acpi_get_handle(device->handle, "_PSC", &handle);
1104 if (ACPI_SUCCESS(status))
1105 device->power.flags.explicit_get = 1;
1106 status = acpi_get_handle(device->handle, "_IRC", &handle);
1107 if (ACPI_SUCCESS(status))
1108 device->power.flags.inrush_current = 1;
1111 * Enumerate supported power management states
1113 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1114 acpi_bus_init_power_state(device, i);
1116 INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1118 /* Set defaults for D0 and D3 states (always valid) */
1119 device->power.states[ACPI_STATE_D0].flags.valid = 1;
1120 device->power.states[ACPI_STATE_D0].power = 100;
1121 device->power.states[ACPI_STATE_D3].flags.valid = 1;
1122 device->power.states[ACPI_STATE_D3].power = 0;
1124 /* Set D3cold's explicit_set flag if _PS3 exists. */
1125 if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1126 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1128 /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1129 if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1130 device->power.flags.power_resources)
1131 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1133 acpi_bus_init_power(device);
1136 static void acpi_bus_get_flags(struct acpi_device *device)
1138 acpi_status status = AE_OK;
1139 acpi_handle temp = NULL;
1141 /* Presence of _STA indicates 'dynamic_status' */
1142 status = acpi_get_handle(device->handle, "_STA", &temp);
1143 if (ACPI_SUCCESS(status))
1144 device->flags.dynamic_status = 1;
1146 /* Presence of _RMV indicates 'removable' */
1147 status = acpi_get_handle(device->handle, "_RMV", &temp);
1148 if (ACPI_SUCCESS(status))
1149 device->flags.removable = 1;
1151 /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1152 status = acpi_get_handle(device->handle, "_EJD", &temp);
1153 if (ACPI_SUCCESS(status))
1154 device->flags.ejectable = 1;
1156 status = acpi_get_handle(device->handle, "_EJ0", &temp);
1157 if (ACPI_SUCCESS(status))
1158 device->flags.ejectable = 1;
1162 static void acpi_device_get_busid(struct acpi_device *device)
1164 char bus_id[5] = { '?', 0 };
1165 struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1171 * The device's Bus ID is simply the object name.
1172 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1174 if (ACPI_IS_ROOT_DEVICE(device)) {
1175 strcpy(device->pnp.bus_id, "ACPI");
1179 switch (device->device_type) {
1180 case ACPI_BUS_TYPE_POWER_BUTTON:
1181 strcpy(device->pnp.bus_id, "PWRF");
1183 case ACPI_BUS_TYPE_SLEEP_BUTTON:
1184 strcpy(device->pnp.bus_id, "SLPF");
1187 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1188 /* Clean up trailing underscores (if any) */
1189 for (i = 3; i > 1; i--) {
1190 if (bus_id[i] == '_')
1195 strcpy(device->pnp.bus_id, bus_id);
1201 * acpi_bay_match - see if a device is an ejectable driver bay
1203 * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1204 * then we can safely call it an ejectable drive bay
1206 static int acpi_bay_match(struct acpi_device *device){
1210 acpi_handle phandle;
1212 handle = device->handle;
1214 status = acpi_get_handle(handle, "_EJ0", &tmp);
1215 if (ACPI_FAILURE(status))
1218 if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
1219 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
1220 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
1221 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
1224 if (acpi_get_parent(handle, &phandle))
1227 if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
1228 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
1229 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
1230 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
1237 * acpi_dock_match - see if a device has a _DCK method
1239 static int acpi_dock_match(struct acpi_device *device)
1242 return acpi_get_handle(device->handle, "_DCK", &tmp);
1245 const char *acpi_device_hid(struct acpi_device *device)
1247 struct acpi_hardware_id *hid;
1249 if (list_empty(&device->pnp.ids))
1252 hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1255 EXPORT_SYMBOL(acpi_device_hid);
1257 static void acpi_add_id(struct acpi_device *device, const char *dev_id)
1259 struct acpi_hardware_id *id;
1261 id = kmalloc(sizeof(*id), GFP_KERNEL);
1265 id->id = kstrdup(dev_id, GFP_KERNEL);
1271 list_add_tail(&id->list, &device->pnp.ids);
1275 * Old IBM workstations have a DSDT bug wherein the SMBus object
1276 * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1277 * prefix. Work around this.
1279 static int acpi_ibm_smbus_match(struct acpi_device *device)
1281 acpi_handle h_dummy;
1282 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
1285 if (!dmi_name_in_vendors("IBM"))
1288 /* Look for SMBS object */
1289 result = acpi_get_name(device->handle, ACPI_SINGLE_NAME, &path);
1293 if (strcmp("SMBS", path.pointer)) {
1298 /* Does it have the necessary (but misnamed) methods? */
1300 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "SBI", &h_dummy)) &&
1301 ACPI_SUCCESS(acpi_get_handle(device->handle, "SBR", &h_dummy)) &&
1302 ACPI_SUCCESS(acpi_get_handle(device->handle, "SBW", &h_dummy)))
1305 kfree(path.pointer);
1309 static void acpi_device_set_id(struct acpi_device *device)
1312 struct acpi_device_info *info;
1313 struct acpi_pnp_device_id_list *cid_list;
1316 switch (device->device_type) {
1317 case ACPI_BUS_TYPE_DEVICE:
1318 if (ACPI_IS_ROOT_DEVICE(device)) {
1319 acpi_add_id(device, ACPI_SYSTEM_HID);
1323 status = acpi_get_object_info(device->handle, &info);
1324 if (ACPI_FAILURE(status)) {
1325 printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1329 if (info->valid & ACPI_VALID_HID)
1330 acpi_add_id(device, info->hardware_id.string);
1331 if (info->valid & ACPI_VALID_CID) {
1332 cid_list = &info->compatible_id_list;
1333 for (i = 0; i < cid_list->count; i++)
1334 acpi_add_id(device, cid_list->ids[i].string);
1336 if (info->valid & ACPI_VALID_ADR) {
1337 device->pnp.bus_address = info->address;
1338 device->flags.bus_address = 1;
1340 if (info->valid & ACPI_VALID_UID)
1341 device->pnp.unique_id = kstrdup(info->unique_id.string,
1347 * Some devices don't reliably have _HIDs & _CIDs, so add
1348 * synthetic HIDs to make sure drivers can find them.
1350 if (acpi_is_video_device(device))
1351 acpi_add_id(device, ACPI_VIDEO_HID);
1352 else if (ACPI_SUCCESS(acpi_bay_match(device)))
1353 acpi_add_id(device, ACPI_BAY_HID);
1354 else if (ACPI_SUCCESS(acpi_dock_match(device)))
1355 acpi_add_id(device, ACPI_DOCK_HID);
1356 else if (!acpi_ibm_smbus_match(device))
1357 acpi_add_id(device, ACPI_SMBUS_IBM_HID);
1358 else if (list_empty(&device->pnp.ids) &&
1359 ACPI_IS_ROOT_DEVICE(device->parent)) {
1360 acpi_add_id(device, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1361 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1362 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1366 case ACPI_BUS_TYPE_POWER:
1367 acpi_add_id(device, ACPI_POWER_HID);
1369 case ACPI_BUS_TYPE_PROCESSOR:
1370 acpi_add_id(device, ACPI_PROCESSOR_OBJECT_HID);
1372 case ACPI_BUS_TYPE_THERMAL:
1373 acpi_add_id(device, ACPI_THERMAL_HID);
1375 case ACPI_BUS_TYPE_POWER_BUTTON:
1376 acpi_add_id(device, ACPI_BUTTON_HID_POWERF);
1378 case ACPI_BUS_TYPE_SLEEP_BUTTON:
1379 acpi_add_id(device, ACPI_BUTTON_HID_SLEEPF);
1384 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1385 int type, unsigned long long sta)
1387 INIT_LIST_HEAD(&device->pnp.ids);
1388 device->device_type = type;
1389 device->handle = handle;
1390 device->parent = acpi_bus_get_parent(handle);
1391 STRUCT_TO_INT(device->status) = sta;
1392 acpi_device_get_busid(device);
1393 acpi_device_set_id(device);
1394 acpi_bus_get_flags(device);
1395 device_initialize(&device->dev);
1396 dev_set_uevent_suppress(&device->dev, true);
1399 void acpi_device_add_finalize(struct acpi_device *device)
1401 dev_set_uevent_suppress(&device->dev, false);
1402 kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1405 static int acpi_add_single_object(struct acpi_device **child,
1406 acpi_handle handle, int type,
1407 unsigned long long sta, bool match_driver)
1410 struct acpi_device *device;
1411 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1413 device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1415 printk(KERN_ERR PREFIX "Memory allocation error\n");
1419 acpi_init_device_object(device, handle, type, sta);
1420 acpi_bus_get_power_flags(device);
1421 acpi_bus_get_wakeup_device_flags(device);
1423 device->flags.match_driver = match_driver;
1424 result = acpi_device_add(device, acpi_device_release);
1426 acpi_device_release(&device->dev);
1430 acpi_power_add_remove_device(device, true);
1431 acpi_device_add_finalize(device);
1432 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1433 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1434 dev_name(&device->dev), (char *) buffer.pointer,
1435 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1436 kfree(buffer.pointer);
1441 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1442 unsigned long long *sta)
1445 acpi_object_type acpi_type;
1447 status = acpi_get_type(handle, &acpi_type);
1448 if (ACPI_FAILURE(status))
1451 switch (acpi_type) {
1452 case ACPI_TYPE_ANY: /* for ACPI_ROOT_OBJECT */
1453 case ACPI_TYPE_DEVICE:
1454 *type = ACPI_BUS_TYPE_DEVICE;
1455 status = acpi_bus_get_status_handle(handle, sta);
1456 if (ACPI_FAILURE(status))
1459 case ACPI_TYPE_PROCESSOR:
1460 *type = ACPI_BUS_TYPE_PROCESSOR;
1461 status = acpi_bus_get_status_handle(handle, sta);
1462 if (ACPI_FAILURE(status))
1465 case ACPI_TYPE_THERMAL:
1466 *type = ACPI_BUS_TYPE_THERMAL;
1467 *sta = ACPI_STA_DEFAULT;
1469 case ACPI_TYPE_POWER:
1470 *type = ACPI_BUS_TYPE_POWER;
1471 *sta = ACPI_STA_DEFAULT;
1480 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1481 void *not_used, void **return_value)
1483 struct acpi_device *device = NULL;
1485 unsigned long long sta;
1489 acpi_bus_get_device(handle, &device);
1493 result = acpi_bus_type_and_status(handle, &type, &sta);
1497 if (type == ACPI_BUS_TYPE_POWER) {
1498 acpi_add_power_resource(handle);
1502 if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1503 !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1504 struct acpi_device_wakeup wakeup;
1507 status = acpi_get_handle(handle, "_PRW", &temp);
1508 if (ACPI_SUCCESS(status)) {
1509 acpi_bus_extract_wakeup_device_power_package(handle,
1511 acpi_power_resources_list_free(&wakeup.resources);
1513 return AE_CTRL_DEPTH;
1516 acpi_add_single_object(&device, handle, type, sta, false);
1518 return AE_CTRL_DEPTH;
1520 device->flags.match_driver = true;
1524 *return_value = device;
1529 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
1530 void *not_used, void **ret_not_used)
1532 acpi_status status = AE_OK;
1533 struct acpi_device *device;
1534 unsigned long long sta_not_used;
1538 * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
1539 * namespace walks prematurely.
1541 if (acpi_bus_type_and_status(handle, &type_not_used, &sta_not_used))
1544 if (acpi_bus_get_device(handle, &device))
1545 return AE_CTRL_DEPTH;
1547 if (!acpi_match_device_ids(device, acpi_platform_device_ids)) {
1548 /* This is a known good platform device. */
1549 acpi_create_platform_device(device);
1550 } else if (device_attach(&device->dev) < 0) {
1551 status = AE_CTRL_DEPTH;
1556 static int acpi_bus_scan(acpi_handle handle)
1558 void *device = NULL;
1560 if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1561 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1562 acpi_bus_check_add, NULL, NULL, &device);
1567 if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
1568 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1569 acpi_bus_device_attach, NULL, NULL, NULL);
1575 * acpi_bus_add - Add ACPI device node objects in a given namespace scope.
1576 * @handle: Root of the namespace scope to scan.
1578 * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1581 * If no devices were found, -ENODEV is returned, but it does not mean that
1582 * there has been a real error. There just have been no suitable ACPI objects
1583 * in the table trunk from which the kernel could create a device and add an
1584 * appropriate driver.
1586 int acpi_bus_add(acpi_handle handle)
1590 err = acpi_bus_scan(handle);
1594 acpi_update_all_gpes();
1597 EXPORT_SYMBOL(acpi_bus_add);
1599 static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
1600 void *not_used, void **ret_not_used)
1602 struct acpi_device *device = NULL;
1604 if (!acpi_bus_get_device(handle, &device)) {
1605 device->removal_type = ACPI_BUS_REMOVAL_EJECT;
1606 device_release_driver(&device->dev);
1611 static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
1612 void *not_used, void **ret_not_used)
1614 struct acpi_device *device = NULL;
1616 if (!acpi_bus_get_device(handle, &device))
1617 acpi_device_unregister(device);
1622 int acpi_bus_trim(struct acpi_device *start)
1625 * Execute acpi_bus_device_detach() as a post-order callback to detach
1626 * all ACPI drivers from the device nodes being removed.
1628 acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1629 acpi_bus_device_detach, NULL, NULL);
1630 acpi_bus_device_detach(start->handle, 0, NULL, NULL);
1632 * Execute acpi_bus_remove() as a post-order callback to remove device
1633 * nodes in the given namespace scope.
1635 acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1636 acpi_bus_remove, NULL, NULL);
1637 acpi_bus_remove(start->handle, 0, NULL, NULL);
1640 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1642 static int acpi_bus_scan_fixed(void)
1645 struct acpi_device *device = NULL;
1648 * Enumerate all fixed-feature devices.
1650 if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1651 result = acpi_add_single_object(&device, NULL,
1652 ACPI_BUS_TYPE_POWER_BUTTON,
1653 ACPI_STA_DEFAULT, true);
1654 device_init_wakeup(&device->dev, true);
1657 if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1658 result = acpi_add_single_object(&device, NULL,
1659 ACPI_BUS_TYPE_SLEEP_BUTTON,
1660 ACPI_STA_DEFAULT, true);
1666 int __init acpi_scan_init(void)
1670 result = bus_register(&acpi_bus_type);
1672 /* We don't want to quit even if we failed to add suspend/resume */
1673 printk(KERN_ERR PREFIX "Could not register bus type\n");
1676 acpi_pci_root_init();
1679 * Enumerate devices in the ACPI namespace.
1681 result = acpi_bus_scan(ACPI_ROOT_OBJECT);
1685 result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
1687 result = acpi_bus_scan_fixed();
1690 acpi_device_unregister(acpi_root);
1692 acpi_update_all_gpes();