18c8e3e2fbad8b7ca773686a561e22a85120b57c
[linux-2.6.git] / drivers / acpi / scan.c
1 /*
2  * scan.c - support for transforming the ACPI namespace into individual objects
3  */
4
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/acpi.h>
8
9 #include <acpi/acpi_drivers.h>
10 #include <acpi/acinterp.h>      /* for acpi_ex_eisa_id_to_string() */
11
12 #define _COMPONENT              ACPI_BUS_COMPONENT
13 ACPI_MODULE_NAME("scan")
14 #define STRUCT_TO_INT(s)        (*((int*)&s))
15 extern struct acpi_device *acpi_root;
16
17 #define ACPI_BUS_CLASS                  "system_bus"
18 #define ACPI_BUS_HID                    "ACPI_BUS"
19 #define ACPI_BUS_DRIVER_NAME            "ACPI Bus Driver"
20 #define ACPI_BUS_DEVICE_NAME            "System Bus"
21
22 static LIST_HEAD(acpi_device_list);
23 DEFINE_SPINLOCK(acpi_device_lock);
24 LIST_HEAD(acpi_wakeup_device_list);
25
26
27 static void acpi_device_release(struct kobject *kobj)
28 {
29         struct acpi_device *dev = container_of(kobj, struct acpi_device, kobj);
30         kfree(dev->pnp.cid_list);
31         kfree(dev);
32 }
33
34 struct acpi_device_attribute {
35         struct attribute attr;
36          ssize_t(*show) (struct acpi_device *, char *);
37          ssize_t(*store) (struct acpi_device *, const char *, size_t);
38 };
39
40 typedef void acpi_device_sysfs_files(struct kobject *,
41                                      const struct attribute *);
42
43 static void setup_sys_fs_device_files(struct acpi_device *dev,
44                                       acpi_device_sysfs_files * func);
45
46 #define create_sysfs_device_files(dev)  \
47         setup_sys_fs_device_files(dev, (acpi_device_sysfs_files *)&sysfs_create_file)
48 #define remove_sysfs_device_files(dev)  \
49         setup_sys_fs_device_files(dev, (acpi_device_sysfs_files *)&sysfs_remove_file)
50
51 #define to_acpi_device(n) container_of(n, struct acpi_device, kobj)
52 #define to_handle_attr(n) container_of(n, struct acpi_device_attribute, attr);
53
54 static ssize_t acpi_device_attr_show(struct kobject *kobj,
55                                      struct attribute *attr, char *buf)
56 {
57         struct acpi_device *device = to_acpi_device(kobj);
58         struct acpi_device_attribute *attribute = to_handle_attr(attr);
59         return attribute->show ? attribute->show(device, buf) : -EIO;
60 }
61 static ssize_t acpi_device_attr_store(struct kobject *kobj,
62                                       struct attribute *attr, const char *buf,
63                                       size_t len)
64 {
65         struct acpi_device *device = to_acpi_device(kobj);
66         struct acpi_device_attribute *attribute = to_handle_attr(attr);
67         return attribute->store ? attribute->store(device, buf, len) : -EIO;
68 }
69
70 static struct sysfs_ops acpi_device_sysfs_ops = {
71         .show = acpi_device_attr_show,
72         .store = acpi_device_attr_store,
73 };
74
75 static struct kobj_type ktype_acpi_ns = {
76         .sysfs_ops = &acpi_device_sysfs_ops,
77         .release = acpi_device_release,
78 };
79
80 static int namespace_uevent(struct kset *kset, struct kobject *kobj,
81                              char **envp, int num_envp, char *buffer,
82                              int buffer_size)
83 {
84         struct acpi_device *dev = to_acpi_device(kobj);
85         int i = 0;
86         int len = 0;
87
88         if (!dev->driver)
89                 return 0;
90
91         if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
92                            "PHYSDEVDRIVER=%s", dev->driver->name))
93                 return -ENOMEM;
94
95         envp[i] = NULL;
96
97         return 0;
98 }
99
100 static struct kset_uevent_ops namespace_uevent_ops = {
101         .uevent = &namespace_uevent,
102 };
103
104 static struct kset acpi_namespace_kset = {
105         .kobj = {
106                  .name = "namespace",
107                  },
108         .subsys = &acpi_subsys,
109         .ktype = &ktype_acpi_ns,
110         .uevent_ops = &namespace_uevent_ops,
111 };
112
113 static void acpi_device_register(struct acpi_device *device,
114                                  struct acpi_device *parent)
115 {
116         /*
117          * Linkage
118          * -------
119          * Link this device to its parent and siblings.
120          */
121         INIT_LIST_HEAD(&device->children);
122         INIT_LIST_HEAD(&device->node);
123         INIT_LIST_HEAD(&device->g_list);
124         INIT_LIST_HEAD(&device->wakeup_list);
125
126         spin_lock(&acpi_device_lock);
127         if (device->parent) {
128                 list_add_tail(&device->node, &device->parent->children);
129                 list_add_tail(&device->g_list, &device->parent->g_list);
130         } else
131                 list_add_tail(&device->g_list, &acpi_device_list);
132         if (device->wakeup.flags.valid)
133                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
134         spin_unlock(&acpi_device_lock);
135
136         strlcpy(device->kobj.name, device->pnp.bus_id, KOBJ_NAME_LEN);
137         if (parent)
138                 device->kobj.parent = &parent->kobj;
139         device->kobj.ktype = &ktype_acpi_ns;
140         device->kobj.kset = &acpi_namespace_kset;
141         kobject_register(&device->kobj);
142         create_sysfs_device_files(device);
143 }
144
145 static void acpi_device_unregister(struct acpi_device *device, int type)
146 {
147         spin_lock(&acpi_device_lock);
148         if (device->parent) {
149                 list_del(&device->node);
150                 list_del(&device->g_list);
151         } else
152                 list_del(&device->g_list);
153
154         list_del(&device->wakeup_list);
155
156         spin_unlock(&acpi_device_lock);
157
158         acpi_detach_data(device->handle, acpi_bus_data_handler);
159         remove_sysfs_device_files(device);
160         kobject_unregister(&device->kobj);
161 }
162
163 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
164 {
165         ACPI_FUNCTION_TRACE("acpi_bus_data_handler");
166
167         /* TBD */
168
169         return_VOID;
170 }
171
172 static int acpi_bus_get_power_flags(struct acpi_device *device)
173 {
174         acpi_status status = 0;
175         acpi_handle handle = NULL;
176         u32 i = 0;
177
178         ACPI_FUNCTION_TRACE("acpi_bus_get_power_flags");
179
180         /*
181          * Power Management Flags
182          */
183         status = acpi_get_handle(device->handle, "_PSC", &handle);
184         if (ACPI_SUCCESS(status))
185                 device->power.flags.explicit_get = 1;
186         status = acpi_get_handle(device->handle, "_IRC", &handle);
187         if (ACPI_SUCCESS(status))
188                 device->power.flags.inrush_current = 1;
189
190         /*
191          * Enumerate supported power management states
192          */
193         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
194                 struct acpi_device_power_state *ps = &device->power.states[i];
195                 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
196
197                 /* Evaluate "_PRx" to se if power resources are referenced */
198                 acpi_evaluate_reference(device->handle, object_name, NULL,
199                                         &ps->resources);
200                 if (ps->resources.count) {
201                         device->power.flags.power_resources = 1;
202                         ps->flags.valid = 1;
203                 }
204
205                 /* Evaluate "_PSx" to see if we can do explicit sets */
206                 object_name[2] = 'S';
207                 status = acpi_get_handle(device->handle, object_name, &handle);
208                 if (ACPI_SUCCESS(status)) {
209                         ps->flags.explicit_set = 1;
210                         ps->flags.valid = 1;
211                 }
212
213                 /* State is valid if we have some power control */
214                 if (ps->resources.count || ps->flags.explicit_set)
215                         ps->flags.valid = 1;
216
217                 ps->power = -1; /* Unknown - driver assigned */
218                 ps->latency = -1;       /* Unknown - driver assigned */
219         }
220
221         /* Set defaults for D0 and D3 states (always valid) */
222         device->power.states[ACPI_STATE_D0].flags.valid = 1;
223         device->power.states[ACPI_STATE_D0].power = 100;
224         device->power.states[ACPI_STATE_D3].flags.valid = 1;
225         device->power.states[ACPI_STATE_D3].power = 0;
226
227         /* TBD: System wake support and resource requirements. */
228
229         device->power.state = ACPI_STATE_UNKNOWN;
230
231         return_VALUE(0);
232 }
233
234 int acpi_match_ids(struct acpi_device *device, char *ids)
235 {
236         if (device->flags.hardware_id)
237                 if (strstr(ids, device->pnp.hardware_id))
238                         return 0;
239
240         if (device->flags.compatible_ids) {
241                 struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
242                 int i;
243
244                 /* compare multiple _CID entries against driver ids */
245                 for (i = 0; i < cid_list->count; i++) {
246                         if (strstr(ids, cid_list->id[i].value))
247                                 return 0;
248                 }
249         }
250         return -ENOENT;
251 }
252
253 static acpi_status
254 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
255                                              union acpi_object *package)
256 {
257         int i = 0;
258         union acpi_object *element = NULL;
259
260         if (!device || !package || (package->package.count < 2))
261                 return AE_BAD_PARAMETER;
262
263         element = &(package->package.elements[0]);
264         if (!element)
265                 return AE_BAD_PARAMETER;
266         if (element->type == ACPI_TYPE_PACKAGE) {
267                 if ((element->package.count < 2) ||
268                     (element->package.elements[0].type !=
269                      ACPI_TYPE_LOCAL_REFERENCE)
270                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
271                         return AE_BAD_DATA;
272                 device->wakeup.gpe_device =
273                     element->package.elements[0].reference.handle;
274                 device->wakeup.gpe_number =
275                     (u32) element->package.elements[1].integer.value;
276         } else if (element->type == ACPI_TYPE_INTEGER) {
277                 device->wakeup.gpe_number = element->integer.value;
278         } else
279                 return AE_BAD_DATA;
280
281         element = &(package->package.elements[1]);
282         if (element->type != ACPI_TYPE_INTEGER) {
283                 return AE_BAD_DATA;
284         }
285         device->wakeup.sleep_state = element->integer.value;
286
287         if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
288                 return AE_NO_MEMORY;
289         }
290         device->wakeup.resources.count = package->package.count - 2;
291         for (i = 0; i < device->wakeup.resources.count; i++) {
292                 element = &(package->package.elements[i + 2]);
293                 if (element->type != ACPI_TYPE_ANY) {
294                         return AE_BAD_DATA;
295                 }
296
297                 device->wakeup.resources.handles[i] = element->reference.handle;
298         }
299
300         return AE_OK;
301 }
302
303 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
304 {
305         acpi_status status = 0;
306         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
307         union acpi_object *package = NULL;
308
309         ACPI_FUNCTION_TRACE("acpi_bus_get_wakeup_flags");
310
311         /* _PRW */
312         status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
313         if (ACPI_FAILURE(status)) {
314                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
315                 goto end;
316         }
317
318         package = (union acpi_object *)buffer.pointer;
319         status = acpi_bus_extract_wakeup_device_power_package(device, package);
320         if (ACPI_FAILURE(status)) {
321                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
322                 goto end;
323         }
324
325         acpi_os_free(buffer.pointer);
326
327         device->wakeup.flags.valid = 1;
328         /* Power button, Lid switch always enable wakeup */
329         if (!acpi_match_ids(device, "PNP0C0D,PNP0C0C,PNP0C0E"))
330                 device->wakeup.flags.run_wake = 1;
331
332       end:
333         if (ACPI_FAILURE(status))
334                 device->flags.wake_capable = 0;
335         return_VALUE(0);
336 }
337
338 /* --------------------------------------------------------------------------
339                 ACPI sysfs device file support
340    -------------------------------------------------------------------------- */
341 static ssize_t acpi_eject_store(struct acpi_device *device,
342                                 const char *buf, size_t count);
343
344 #define ACPI_DEVICE_ATTR(_name,_mode,_show,_store) \
345 static struct acpi_device_attribute acpi_device_attr_##_name = \
346                 __ATTR(_name, _mode, _show, _store)
347
348 ACPI_DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
349
350 /**
351  * setup_sys_fs_device_files - sets up the device files under device namespace
352  * @dev:        acpi_device object
353  * @func:       function pointer to create or destroy the device file
354  */
355 static void
356 setup_sys_fs_device_files(struct acpi_device *dev,
357                           acpi_device_sysfs_files * func)
358 {
359         acpi_status status;
360         acpi_handle temp = NULL;
361
362         /*
363          * If device has _EJ0, 'eject' file is created that is used to trigger
364          * hot-removal function from userland.
365          */
366         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
367         if (ACPI_SUCCESS(status))
368                 (*(func)) (&dev->kobj, &acpi_device_attr_eject.attr);
369 }
370
371 static int acpi_eject_operation(acpi_handle handle, int lockable)
372 {
373         struct acpi_object_list arg_list;
374         union acpi_object arg;
375         acpi_status status = AE_OK;
376
377         /*
378          * TBD: evaluate _PS3?
379          */
380
381         if (lockable) {
382                 arg_list.count = 1;
383                 arg_list.pointer = &arg;
384                 arg.type = ACPI_TYPE_INTEGER;
385                 arg.integer.value = 0;
386                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
387         }
388
389         arg_list.count = 1;
390         arg_list.pointer = &arg;
391         arg.type = ACPI_TYPE_INTEGER;
392         arg.integer.value = 1;
393
394         /*
395          * TBD: _EJD support.
396          */
397
398         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
399         if (ACPI_FAILURE(status)) {
400                 return (-ENODEV);
401         }
402
403         return (0);
404 }
405
406 static ssize_t
407 acpi_eject_store(struct acpi_device *device, const char *buf, size_t count)
408 {
409         int result;
410         int ret = count;
411         int islockable;
412         acpi_status status;
413         acpi_handle handle;
414         acpi_object_type type = 0;
415
416         if ((!count) || (buf[0] != '1')) {
417                 return -EINVAL;
418         }
419 #ifndef FORCE_EJECT
420         if (device->driver == NULL) {
421                 ret = -ENODEV;
422                 goto err;
423         }
424 #endif
425         status = acpi_get_type(device->handle, &type);
426         if (ACPI_FAILURE(status) || (!device->flags.ejectable)) {
427                 ret = -ENODEV;
428                 goto err;
429         }
430
431         islockable = device->flags.lockable;
432         handle = device->handle;
433
434         result = acpi_bus_trim(device, 1);
435
436         if (!result)
437                 result = acpi_eject_operation(handle, islockable);
438
439         if (result) {
440                 ret = -EBUSY;
441         }
442       err:
443         return ret;
444 }
445
446 /* --------------------------------------------------------------------------
447                               Performance Management
448    -------------------------------------------------------------------------- */
449
450 static int acpi_bus_get_perf_flags(struct acpi_device *device)
451 {
452         device->performance.state = ACPI_STATE_UNKNOWN;
453         return 0;
454 }
455
456 /* --------------------------------------------------------------------------
457                                  Driver Management
458    -------------------------------------------------------------------------- */
459
460 static LIST_HEAD(acpi_bus_drivers);
461
462 /**
463  * acpi_bus_match - match device IDs to driver's supported IDs
464  * @device: the device that we are trying to match to a driver
465  * @driver: driver whose device id table is being checked
466  *
467  * Checks the device's hardware (_HID) or compatible (_CID) ids to see if it
468  * matches the specified driver's criteria.
469  */
470 static int
471 acpi_bus_match(struct acpi_device *device, struct acpi_driver *driver)
472 {
473         if (driver && driver->ops.match)
474                 return driver->ops.match(device, driver);
475         return acpi_match_ids(device, driver->ids);
476 }
477
478 /**
479  * acpi_bus_driver_init - add a device to a driver
480  * @device: the device to add and initialize
481  * @driver: driver for the device
482  *
483  * Used to initialize a device via its device driver.  Called whenever a 
484  * driver is bound to a device.  Invokes the driver's add() and start() ops.
485  */
486 static int
487 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
488 {
489         int result = 0;
490
491         ACPI_FUNCTION_TRACE("acpi_bus_driver_init");
492
493         if (!device || !driver)
494                 return_VALUE(-EINVAL);
495
496         if (!driver->ops.add)
497                 return_VALUE(-ENOSYS);
498
499         result = driver->ops.add(device);
500         if (result) {
501                 device->driver = NULL;
502                 acpi_driver_data(device) = NULL;
503                 return_VALUE(result);
504         }
505
506         device->driver = driver;
507
508         /*
509          * TBD - Configuration Management: Assign resources to device based
510          * upon possible configuration and currently allocated resources.
511          */
512
513         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
514                           "Driver successfully bound to device\n"));
515         return_VALUE(0);
516 }
517
518 static int acpi_start_single_object(struct acpi_device *device)
519 {
520         int result = 0;
521         struct acpi_driver *driver;
522
523         ACPI_FUNCTION_TRACE("acpi_start_single_object");
524
525         if (!(driver = device->driver))
526                 return_VALUE(0);
527
528         if (driver->ops.start) {
529                 result = driver->ops.start(device);
530                 if (result && driver->ops.remove)
531                         driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
532         }
533
534         return_VALUE(result);
535 }
536
537 static void acpi_driver_attach(struct acpi_driver *drv)
538 {
539         struct list_head *node, *next;
540
541         ACPI_FUNCTION_TRACE("acpi_driver_attach");
542
543         spin_lock(&acpi_device_lock);
544         list_for_each_safe(node, next, &acpi_device_list) {
545                 struct acpi_device *dev =
546                     container_of(node, struct acpi_device, g_list);
547
548                 if (dev->driver || !dev->status.present)
549                         continue;
550                 spin_unlock(&acpi_device_lock);
551
552                 if (!acpi_bus_match(dev, drv)) {
553                         if (!acpi_bus_driver_init(dev, drv)) {
554                                 acpi_start_single_object(dev);
555                                 atomic_inc(&drv->references);
556                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
557                                                   "Found driver [%s] for device [%s]\n",
558                                                   drv->name, dev->pnp.bus_id));
559                         }
560                 }
561                 spin_lock(&acpi_device_lock);
562         }
563         spin_unlock(&acpi_device_lock);
564 }
565
566 static void acpi_driver_detach(struct acpi_driver *drv)
567 {
568         struct list_head *node, *next;
569
570         ACPI_FUNCTION_TRACE("acpi_driver_detach");
571
572         spin_lock(&acpi_device_lock);
573         list_for_each_safe(node, next, &acpi_device_list) {
574                 struct acpi_device *dev =
575                     container_of(node, struct acpi_device, g_list);
576
577                 if (dev->driver == drv) {
578                         spin_unlock(&acpi_device_lock);
579                         if (drv->ops.remove)
580                                 drv->ops.remove(dev, ACPI_BUS_REMOVAL_NORMAL);
581                         spin_lock(&acpi_device_lock);
582                         dev->driver = NULL;
583                         dev->driver_data = NULL;
584                         atomic_dec(&drv->references);
585                 }
586         }
587         spin_unlock(&acpi_device_lock);
588 }
589
590 /**
591  * acpi_bus_register_driver - register a driver with the ACPI bus
592  * @driver: driver being registered
593  *
594  * Registers a driver with the ACPI bus.  Searches the namespace for all
595  * devices that match the driver's criteria and binds.  Returns zero for
596  * success or a negative error status for failure.
597  */
598 int acpi_bus_register_driver(struct acpi_driver *driver)
599 {
600         ACPI_FUNCTION_TRACE("acpi_bus_register_driver");
601
602         if (acpi_disabled)
603                 return_VALUE(-ENODEV);
604
605         spin_lock(&acpi_device_lock);
606         list_add_tail(&driver->node, &acpi_bus_drivers);
607         spin_unlock(&acpi_device_lock);
608         acpi_driver_attach(driver);
609
610         return_VALUE(0);
611 }
612
613 EXPORT_SYMBOL(acpi_bus_register_driver);
614
615 /**
616  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
617  * @driver: driver to unregister
618  *
619  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
620  * devices that match the driver's criteria and unbinds.
621  */
622 void acpi_bus_unregister_driver(struct acpi_driver *driver)
623 {
624         acpi_driver_detach(driver);
625
626         if (!atomic_read(&driver->references)) {
627                 spin_lock(&acpi_device_lock);
628                 list_del_init(&driver->node);
629                 spin_unlock(&acpi_device_lock);
630         }
631         return;
632 }
633
634 EXPORT_SYMBOL(acpi_bus_unregister_driver);
635
636 /**
637  * acpi_bus_find_driver - check if there is a driver installed for the device
638  * @device: device that we are trying to find a supporting driver for
639  *
640  * Parses the list of registered drivers looking for a driver applicable for
641  * the specified device.
642  */
643 static int acpi_bus_find_driver(struct acpi_device *device)
644 {
645         int result = 0;
646         struct list_head *node, *next;
647
648         ACPI_FUNCTION_TRACE("acpi_bus_find_driver");
649
650         spin_lock(&acpi_device_lock);
651         list_for_each_safe(node, next, &acpi_bus_drivers) {
652                 struct acpi_driver *driver =
653                     container_of(node, struct acpi_driver, node);
654
655                 atomic_inc(&driver->references);
656                 spin_unlock(&acpi_device_lock);
657                 if (!acpi_bus_match(device, driver)) {
658                         result = acpi_bus_driver_init(device, driver);
659                         if (!result)
660                                 goto Done;
661                 }
662                 atomic_dec(&driver->references);
663                 spin_lock(&acpi_device_lock);
664         }
665         spin_unlock(&acpi_device_lock);
666
667       Done:
668         return_VALUE(result);
669 }
670
671 /* --------------------------------------------------------------------------
672                                  Device Enumeration
673    -------------------------------------------------------------------------- */
674
675 static int acpi_bus_get_flags(struct acpi_device *device)
676 {
677         acpi_status status = AE_OK;
678         acpi_handle temp = NULL;
679
680         ACPI_FUNCTION_TRACE("acpi_bus_get_flags");
681
682         /* Presence of _STA indicates 'dynamic_status' */
683         status = acpi_get_handle(device->handle, "_STA", &temp);
684         if (ACPI_SUCCESS(status))
685                 device->flags.dynamic_status = 1;
686
687         /* Presence of _CID indicates 'compatible_ids' */
688         status = acpi_get_handle(device->handle, "_CID", &temp);
689         if (ACPI_SUCCESS(status))
690                 device->flags.compatible_ids = 1;
691
692         /* Presence of _RMV indicates 'removable' */
693         status = acpi_get_handle(device->handle, "_RMV", &temp);
694         if (ACPI_SUCCESS(status))
695                 device->flags.removable = 1;
696
697         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
698         status = acpi_get_handle(device->handle, "_EJD", &temp);
699         if (ACPI_SUCCESS(status))
700                 device->flags.ejectable = 1;
701         else {
702                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
703                 if (ACPI_SUCCESS(status))
704                         device->flags.ejectable = 1;
705         }
706
707         /* Presence of _LCK indicates 'lockable' */
708         status = acpi_get_handle(device->handle, "_LCK", &temp);
709         if (ACPI_SUCCESS(status))
710                 device->flags.lockable = 1;
711
712         /* Presence of _PS0|_PR0 indicates 'power manageable' */
713         status = acpi_get_handle(device->handle, "_PS0", &temp);
714         if (ACPI_FAILURE(status))
715                 status = acpi_get_handle(device->handle, "_PR0", &temp);
716         if (ACPI_SUCCESS(status))
717                 device->flags.power_manageable = 1;
718
719         /* Presence of _PRW indicates wake capable */
720         status = acpi_get_handle(device->handle, "_PRW", &temp);
721         if (ACPI_SUCCESS(status))
722                 device->flags.wake_capable = 1;
723
724         /* TBD: Peformance management */
725
726         return_VALUE(0);
727 }
728
729 static void acpi_device_get_busid(struct acpi_device *device,
730                                   acpi_handle handle, int type)
731 {
732         char bus_id[5] = { '?', 0 };
733         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
734         int i = 0;
735
736         /*
737          * Bus ID
738          * ------
739          * The device's Bus ID is simply the object name.
740          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
741          */
742         switch (type) {
743         case ACPI_BUS_TYPE_SYSTEM:
744                 strcpy(device->pnp.bus_id, "ACPI");
745                 break;
746         case ACPI_BUS_TYPE_POWER_BUTTON:
747                 strcpy(device->pnp.bus_id, "PWRF");
748                 break;
749         case ACPI_BUS_TYPE_SLEEP_BUTTON:
750                 strcpy(device->pnp.bus_id, "SLPF");
751                 break;
752         default:
753                 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
754                 /* Clean up trailing underscores (if any) */
755                 for (i = 3; i > 1; i--) {
756                         if (bus_id[i] == '_')
757                                 bus_id[i] = '\0';
758                         else
759                                 break;
760                 }
761                 strcpy(device->pnp.bus_id, bus_id);
762                 break;
763         }
764 }
765
766 static void acpi_device_set_id(struct acpi_device *device,
767                                struct acpi_device *parent, acpi_handle handle,
768                                int type)
769 {
770         struct acpi_device_info *info;
771         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
772         char *hid = NULL;
773         char *uid = NULL;
774         struct acpi_compatible_id_list *cid_list = NULL;
775         acpi_status status;
776
777         switch (type) {
778         case ACPI_BUS_TYPE_DEVICE:
779                 status = acpi_get_object_info(handle, &buffer);
780                 if (ACPI_FAILURE(status)) {
781                         printk("%s: Error reading device info\n", __FUNCTION__);
782                         return;
783                 }
784
785                 info = buffer.pointer;
786                 if (info->valid & ACPI_VALID_HID)
787                         hid = info->hardware_id.value;
788                 if (info->valid & ACPI_VALID_UID)
789                         uid = info->unique_id.value;
790                 if (info->valid & ACPI_VALID_CID)
791                         cid_list = &info->compatibility_id;
792                 if (info->valid & ACPI_VALID_ADR) {
793                         device->pnp.bus_address = info->address;
794                         device->flags.bus_address = 1;
795                 }
796                 break;
797         case ACPI_BUS_TYPE_POWER:
798                 hid = ACPI_POWER_HID;
799                 break;
800         case ACPI_BUS_TYPE_PROCESSOR:
801                 hid = ACPI_PROCESSOR_HID;
802                 break;
803         case ACPI_BUS_TYPE_SYSTEM:
804                 hid = ACPI_SYSTEM_HID;
805                 break;
806         case ACPI_BUS_TYPE_THERMAL:
807                 hid = ACPI_THERMAL_HID;
808                 break;
809         case ACPI_BUS_TYPE_POWER_BUTTON:
810                 hid = ACPI_BUTTON_HID_POWERF;
811                 break;
812         case ACPI_BUS_TYPE_SLEEP_BUTTON:
813                 hid = ACPI_BUTTON_HID_SLEEPF;
814                 break;
815         }
816
817         /* 
818          * \_SB
819          * ----
820          * Fix for the system root bus device -- the only root-level device.
821          */
822         if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
823                 hid = ACPI_BUS_HID;
824                 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
825                 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
826         }
827
828         if (hid) {
829                 strcpy(device->pnp.hardware_id, hid);
830                 device->flags.hardware_id = 1;
831         }
832         if (uid) {
833                 strcpy(device->pnp.unique_id, uid);
834                 device->flags.unique_id = 1;
835         }
836         if (cid_list) {
837                 device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL);
838                 if (device->pnp.cid_list)
839                         memcpy(device->pnp.cid_list, cid_list, cid_list->size);
840                 else
841                         printk(KERN_ERR "Memory allocation error\n");
842         }
843
844         acpi_os_free(buffer.pointer);
845 }
846
847 static int acpi_device_set_context(struct acpi_device *device, int type)
848 {
849         acpi_status status = AE_OK;
850         int result = 0;
851         /*
852          * Context
853          * -------
854          * Attach this 'struct acpi_device' to the ACPI object.  This makes
855          * resolutions from handle->device very efficient.  Note that we need
856          * to be careful with fixed-feature devices as they all attach to the
857          * root object.
858          */
859         if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
860             type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
861                 status = acpi_attach_data(device->handle,
862                                           acpi_bus_data_handler, device);
863
864                 if (ACPI_FAILURE(status)) {
865                         printk("Error attaching device data\n");
866                         result = -ENODEV;
867                 }
868         }
869         return result;
870 }
871
872 static void acpi_device_get_debug_info(struct acpi_device *device,
873                                        acpi_handle handle, int type)
874 {
875 #ifdef CONFIG_ACPI_DEBUG_OUTPUT
876         char *type_string = NULL;
877         char name[80] = { '?', '\0' };
878         struct acpi_buffer buffer = { sizeof(name), name };
879
880         switch (type) {
881         case ACPI_BUS_TYPE_DEVICE:
882                 type_string = "Device";
883                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
884                 break;
885         case ACPI_BUS_TYPE_POWER:
886                 type_string = "Power Resource";
887                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
888                 break;
889         case ACPI_BUS_TYPE_PROCESSOR:
890                 type_string = "Processor";
891                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
892                 break;
893         case ACPI_BUS_TYPE_SYSTEM:
894                 type_string = "System";
895                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
896                 break;
897         case ACPI_BUS_TYPE_THERMAL:
898                 type_string = "Thermal Zone";
899                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
900                 break;
901         case ACPI_BUS_TYPE_POWER_BUTTON:
902                 type_string = "Power Button";
903                 sprintf(name, "PWRB");
904                 break;
905         case ACPI_BUS_TYPE_SLEEP_BUTTON:
906                 type_string = "Sleep Button";
907                 sprintf(name, "SLPB");
908                 break;
909         }
910
911         printk(KERN_DEBUG "Found %s %s [%p]\n", type_string, name, handle);
912 #endif                          /*CONFIG_ACPI_DEBUG_OUTPUT */
913 }
914
915 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
916 {
917         int result = 0;
918         struct acpi_driver *driver;
919
920         ACPI_FUNCTION_TRACE("acpi_bus_remove");
921
922         if (!dev)
923                 return_VALUE(-EINVAL);
924
925         driver = dev->driver;
926
927         if ((driver) && (driver->ops.remove)) {
928
929                 if (driver->ops.stop) {
930                         result = driver->ops.stop(dev, ACPI_BUS_REMOVAL_EJECT);
931                         if (result)
932                                 return_VALUE(result);
933                 }
934
935                 result = dev->driver->ops.remove(dev, ACPI_BUS_REMOVAL_EJECT);
936                 if (result) {
937                         return_VALUE(result);
938                 }
939
940                 atomic_dec(&dev->driver->references);
941                 dev->driver = NULL;
942                 acpi_driver_data(dev) = NULL;
943         }
944
945         if (!rmdevice)
946                 return_VALUE(0);
947
948         if (dev->flags.bus_address) {
949                 if ((dev->parent) && (dev->parent->ops.unbind))
950                         dev->parent->ops.unbind(dev);
951         }
952
953         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
954
955         return_VALUE(0);
956 }
957
958 static int
959 acpi_add_single_object(struct acpi_device **child,
960                        struct acpi_device *parent, acpi_handle handle, int type)
961 {
962         int result = 0;
963         struct acpi_device *device = NULL;
964
965         ACPI_FUNCTION_TRACE("acpi_add_single_object");
966
967         if (!child)
968                 return_VALUE(-EINVAL);
969
970         device = kmalloc(sizeof(struct acpi_device), GFP_KERNEL);
971         if (!device) {
972                 printk(KERN_ERR PREFIX "Memory allocation error\n");
973                 return_VALUE(-ENOMEM);
974         }
975         memset(device, 0, sizeof(struct acpi_device));
976
977         device->handle = handle;
978         device->parent = parent;
979
980         acpi_device_get_busid(device, handle, type);
981
982         /*
983          * Flags
984          * -----
985          * Get prior to calling acpi_bus_get_status() so we know whether
986          * or not _STA is present.  Note that we only look for object
987          * handles -- cannot evaluate objects until we know the device is
988          * present and properly initialized.
989          */
990         result = acpi_bus_get_flags(device);
991         if (result)
992                 goto end;
993
994         /*
995          * Status
996          * ------
997          * See if the device is present.  We always assume that non-Device
998          * and non-Processor objects (e.g. thermal zones, power resources,
999          * etc.) are present, functioning, etc. (at least when parent object
1000          * is present).  Note that _STA has a different meaning for some
1001          * objects (e.g. power resources) so we need to be careful how we use
1002          * it.
1003          */
1004         switch (type) {
1005         case ACPI_BUS_TYPE_PROCESSOR:
1006         case ACPI_BUS_TYPE_DEVICE:
1007                 result = acpi_bus_get_status(device);
1008                 if (ACPI_FAILURE(result) || !device->status.present) {
1009                         result = -ENOENT;
1010                         goto end;
1011                 }
1012                 break;
1013         default:
1014                 STRUCT_TO_INT(device->status) = 0x0F;
1015                 break;
1016         }
1017
1018         /*
1019          * Initialize Device
1020          * -----------------
1021          * TBD: Synch with Core's enumeration/initialization process.
1022          */
1023
1024         /*
1025          * Hardware ID, Unique ID, & Bus Address
1026          * -------------------------------------
1027          */
1028         acpi_device_set_id(device, parent, handle, type);
1029
1030         /*
1031          * Power Management
1032          * ----------------
1033          */
1034         if (device->flags.power_manageable) {
1035                 result = acpi_bus_get_power_flags(device);
1036                 if (result)
1037                         goto end;
1038         }
1039
1040         /*
1041          * Wakeup device management
1042          *-----------------------
1043          */
1044         if (device->flags.wake_capable) {
1045                 result = acpi_bus_get_wakeup_device_flags(device);
1046                 if (result)
1047                         goto end;
1048         }
1049
1050         /*
1051          * Performance Management
1052          * ----------------------
1053          */
1054         if (device->flags.performance_manageable) {
1055                 result = acpi_bus_get_perf_flags(device);
1056                 if (result)
1057                         goto end;
1058         }
1059
1060         if ((result = acpi_device_set_context(device, type)))
1061                 goto end;
1062
1063         acpi_device_get_debug_info(device, handle, type);
1064
1065         acpi_device_register(device, parent);
1066
1067         /*
1068          * Bind _ADR-Based Devices
1069          * -----------------------
1070          * If there's a a bus address (_ADR) then we utilize the parent's 
1071          * 'bind' function (if exists) to bind the ACPI- and natively-
1072          * enumerated device representations.
1073          */
1074         if (device->flags.bus_address) {
1075                 if (device->parent && device->parent->ops.bind)
1076                         device->parent->ops.bind(device);
1077         }
1078
1079         /*
1080          * Locate & Attach Driver
1081          * ----------------------
1082          * If there's a hardware id (_HID) or compatible ids (_CID) we check
1083          * to see if there's a driver installed for this kind of device.  Note
1084          * that drivers can install before or after a device is enumerated.
1085          *
1086          * TBD: Assumes LDM provides driver hot-plug capability.
1087          */
1088         acpi_bus_find_driver(device);
1089
1090       end:
1091         if (!result)
1092                 *child = device;
1093         else {
1094                 kfree(device->pnp.cid_list);
1095                 kfree(device);
1096         }
1097
1098         return_VALUE(result);
1099 }
1100
1101 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1102 {
1103         acpi_status status = AE_OK;
1104         struct acpi_device *parent = NULL;
1105         struct acpi_device *child = NULL;
1106         acpi_handle phandle = NULL;
1107         acpi_handle chandle = NULL;
1108         acpi_object_type type = 0;
1109         u32 level = 1;
1110
1111         ACPI_FUNCTION_TRACE("acpi_bus_scan");
1112
1113         if (!start)
1114                 return_VALUE(-EINVAL);
1115
1116         parent = start;
1117         phandle = start->handle;
1118
1119         /*
1120          * Parse through the ACPI namespace, identify all 'devices', and
1121          * create a new 'struct acpi_device' for each.
1122          */
1123         while ((level > 0) && parent) {
1124
1125                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1126                                               chandle, &chandle);
1127
1128                 /*
1129                  * If this scope is exhausted then move our way back up.
1130                  */
1131                 if (ACPI_FAILURE(status)) {
1132                         level--;
1133                         chandle = phandle;
1134                         acpi_get_parent(phandle, &phandle);
1135                         if (parent->parent)
1136                                 parent = parent->parent;
1137                         continue;
1138                 }
1139
1140                 status = acpi_get_type(chandle, &type);
1141                 if (ACPI_FAILURE(status))
1142                         continue;
1143
1144                 /*
1145                  * If this is a scope object then parse it (depth-first).
1146                  */
1147                 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1148                         level++;
1149                         phandle = chandle;
1150                         chandle = NULL;
1151                         continue;
1152                 }
1153
1154                 /*
1155                  * We're only interested in objects that we consider 'devices'.
1156                  */
1157                 switch (type) {
1158                 case ACPI_TYPE_DEVICE:
1159                         type = ACPI_BUS_TYPE_DEVICE;
1160                         break;
1161                 case ACPI_TYPE_PROCESSOR:
1162                         type = ACPI_BUS_TYPE_PROCESSOR;
1163                         break;
1164                 case ACPI_TYPE_THERMAL:
1165                         type = ACPI_BUS_TYPE_THERMAL;
1166                         break;
1167                 case ACPI_TYPE_POWER:
1168                         type = ACPI_BUS_TYPE_POWER;
1169                         break;
1170                 default:
1171                         continue;
1172                 }
1173
1174                 if (ops->acpi_op_add)
1175                         status = acpi_add_single_object(&child, parent,
1176                                                         chandle, type);
1177                 else
1178                         status = acpi_bus_get_device(chandle, &child);
1179
1180                 if (ACPI_FAILURE(status))
1181                         continue;
1182
1183                 if (ops->acpi_op_start) {
1184                         status = acpi_start_single_object(child);
1185                         if (ACPI_FAILURE(status))
1186                                 continue;
1187                 }
1188
1189                 /*
1190                  * If the device is present, enabled, and functioning then
1191                  * parse its scope (depth-first).  Note that we need to
1192                  * represent absent devices to facilitate PnP notifications
1193                  * -- but only the subtree head (not all of its children,
1194                  * which will be enumerated when the parent is inserted).
1195                  *
1196                  * TBD: Need notifications and other detection mechanisms
1197                  *      in place before we can fully implement this.
1198                  */
1199                 if (child->status.present) {
1200                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1201                                                       NULL, NULL);
1202                         if (ACPI_SUCCESS(status)) {
1203                                 level++;
1204                                 phandle = chandle;
1205                                 chandle = NULL;
1206                                 parent = child;
1207                         }
1208                 }
1209         }
1210
1211         return_VALUE(0);
1212 }
1213
1214 int
1215 acpi_bus_add(struct acpi_device **child,
1216              struct acpi_device *parent, acpi_handle handle, int type)
1217 {
1218         int result;
1219         struct acpi_bus_ops ops;
1220
1221         ACPI_FUNCTION_TRACE("acpi_bus_add");
1222
1223         result = acpi_add_single_object(child, parent, handle, type);
1224         if (!result) {
1225                 memset(&ops, 0, sizeof(ops));
1226                 ops.acpi_op_add = 1;
1227                 result = acpi_bus_scan(*child, &ops);
1228         }
1229         return_VALUE(result);
1230 }
1231
1232 EXPORT_SYMBOL(acpi_bus_add);
1233
1234 int acpi_bus_start(struct acpi_device *device)
1235 {
1236         int result;
1237         struct acpi_bus_ops ops;
1238
1239         ACPI_FUNCTION_TRACE("acpi_bus_start");
1240
1241         if (!device)
1242                 return_VALUE(-EINVAL);
1243
1244         result = acpi_start_single_object(device);
1245         if (!result) {
1246                 memset(&ops, 0, sizeof(ops));
1247                 ops.acpi_op_start = 1;
1248                 result = acpi_bus_scan(device, &ops);
1249         }
1250         return_VALUE(result);
1251 }
1252
1253 EXPORT_SYMBOL(acpi_bus_start);
1254
1255 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1256 {
1257         acpi_status status;
1258         struct acpi_device *parent, *child;
1259         acpi_handle phandle, chandle;
1260         acpi_object_type type;
1261         u32 level = 1;
1262         int err = 0;
1263
1264         parent = start;
1265         phandle = start->handle;
1266         child = chandle = NULL;
1267
1268         while ((level > 0) && parent && (!err)) {
1269                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1270                                               chandle, &chandle);
1271
1272                 /*
1273                  * If this scope is exhausted then move our way back up.
1274                  */
1275                 if (ACPI_FAILURE(status)) {
1276                         level--;
1277                         chandle = phandle;
1278                         acpi_get_parent(phandle, &phandle);
1279                         child = parent;
1280                         parent = parent->parent;
1281
1282                         if (level == 0)
1283                                 err = acpi_bus_remove(child, rmdevice);
1284                         else
1285                                 err = acpi_bus_remove(child, 1);
1286
1287                         continue;
1288                 }
1289
1290                 status = acpi_get_type(chandle, &type);
1291                 if (ACPI_FAILURE(status)) {
1292                         continue;
1293                 }
1294                 /*
1295                  * If there is a device corresponding to chandle then
1296                  * parse it (depth-first).
1297                  */
1298                 if (acpi_bus_get_device(chandle, &child) == 0) {
1299                         level++;
1300                         phandle = chandle;
1301                         chandle = NULL;
1302                         parent = child;
1303                 }
1304                 continue;
1305         }
1306         return err;
1307 }
1308 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1309
1310
1311 static int acpi_bus_scan_fixed(struct acpi_device *root)
1312 {
1313         int result = 0;
1314         struct acpi_device *device = NULL;
1315
1316         ACPI_FUNCTION_TRACE("acpi_bus_scan_fixed");
1317
1318         if (!root)
1319                 return_VALUE(-ENODEV);
1320
1321         /*
1322          * Enumerate all fixed-feature devices.
1323          */
1324         if (acpi_fadt.pwr_button == 0) {
1325                 result = acpi_add_single_object(&device, acpi_root,
1326                                                 NULL,
1327                                                 ACPI_BUS_TYPE_POWER_BUTTON);
1328                 if (!result)
1329                         result = acpi_start_single_object(device);
1330         }
1331
1332         if (acpi_fadt.sleep_button == 0) {
1333                 result = acpi_add_single_object(&device, acpi_root,
1334                                                 NULL,
1335                                                 ACPI_BUS_TYPE_SLEEP_BUTTON);
1336                 if (!result)
1337                         result = acpi_start_single_object(device);
1338         }
1339
1340         return_VALUE(result);
1341 }
1342
1343
1344 static inline struct acpi_device * to_acpi_dev(struct device * dev)
1345 {
1346         return container_of(dev, struct acpi_device, dev);
1347 }
1348
1349
1350 static int root_suspend(struct acpi_device * acpi_dev, pm_message_t state)
1351 {
1352         struct acpi_device * dev, * next;
1353         int result;
1354
1355         spin_lock(&acpi_device_lock);
1356         list_for_each_entry_safe_reverse(dev, next, &acpi_device_list, g_list) {
1357                 if (dev->driver && dev->driver->ops.suspend) {
1358                         spin_unlock(&acpi_device_lock);
1359                         result = dev->driver->ops.suspend(dev, 0);
1360                         if (result) {
1361                                 printk(KERN_ERR PREFIX "[%s - %s] Suspend failed: %d\n",
1362                                        acpi_device_name(dev),
1363                                        acpi_device_bid(dev), result);
1364                         }
1365                         spin_lock(&acpi_device_lock);
1366                 }
1367         }
1368         spin_unlock(&acpi_device_lock);
1369         return 0;
1370 }
1371
1372
1373 static int acpi_device_suspend(struct device * dev, pm_message_t state)
1374 {
1375         struct acpi_device * acpi_dev = to_acpi_dev(dev);
1376
1377         /*
1378          * For now, we should only register 1 generic device -
1379          * the ACPI root device - and from there, we walk the
1380          * tree of ACPI devices to suspend each one using the
1381          * ACPI driver methods.
1382          */
1383         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
1384                 root_suspend(acpi_dev, state);
1385         return 0;
1386 }
1387
1388
1389
1390 static int root_resume(struct acpi_device * acpi_dev)
1391 {
1392         struct acpi_device * dev, * next;
1393         int result;
1394
1395         spin_lock(&acpi_device_lock);
1396         list_for_each_entry_safe(dev, next, &acpi_device_list, g_list) {
1397                 if (dev->driver && dev->driver->ops.resume) {
1398                         spin_unlock(&acpi_device_lock);
1399                         result = dev->driver->ops.resume(dev, 0);
1400                         if (result) {
1401                                 printk(KERN_ERR PREFIX "[%s - %s] resume failed: %d\n",
1402                                        acpi_device_name(dev),
1403                                        acpi_device_bid(dev), result);
1404                         }
1405                         spin_lock(&acpi_device_lock);
1406                 }
1407         }
1408         spin_unlock(&acpi_device_lock);
1409         return 0;
1410 }
1411
1412
1413 static int acpi_device_resume(struct device * dev)
1414 {
1415         struct acpi_device * acpi_dev = to_acpi_dev(dev);
1416
1417         /*
1418          * For now, we should only register 1 generic device -
1419          * the ACPI root device - and from there, we walk the
1420          * tree of ACPI devices to resume each one using the
1421          * ACPI driver methods.
1422          */
1423         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
1424                 root_resume(acpi_dev);
1425         return 0;
1426 }
1427
1428
1429 struct bus_type acpi_bus_type = {
1430         .name           = "acpi",
1431         .suspend        = acpi_device_suspend,
1432         .resume         = acpi_device_resume,
1433 };
1434
1435
1436
1437 static int __init acpi_scan_init(void)
1438 {
1439         int result;
1440         struct acpi_bus_ops ops;
1441
1442         ACPI_FUNCTION_TRACE("acpi_scan_init");
1443
1444         if (acpi_disabled)
1445                 return_VALUE(0);
1446
1447         kset_register(&acpi_namespace_kset);
1448
1449         result = bus_register(&acpi_bus_type);
1450         if (result) {
1451                 /* We don't want to quit even if we failed to add suspend/resume */
1452                 printk(KERN_ERR PREFIX "Could not register bus type\n");
1453         }
1454
1455         /*
1456          * Create the root device in the bus's device tree
1457          */
1458         result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1459                                         ACPI_BUS_TYPE_SYSTEM);
1460         if (result)
1461                 goto Done;
1462
1463         result = acpi_start_single_object(acpi_root);
1464         if (result)
1465                 goto Done;
1466
1467         acpi_root->dev.bus = &acpi_bus_type;
1468         snprintf(acpi_root->dev.bus_id, BUS_ID_SIZE, "%s", acpi_bus_type.name);
1469         result = device_register(&acpi_root->dev);
1470         if (result) {
1471                 /* We don't want to quit even if we failed to add suspend/resume */
1472                 printk(KERN_ERR PREFIX "Could not register device\n");
1473         }
1474
1475         /*
1476          * Enumerate devices in the ACPI namespace.
1477          */
1478         result = acpi_bus_scan_fixed(acpi_root);
1479         if (!result) {
1480                 memset(&ops, 0, sizeof(ops));
1481                 ops.acpi_op_add = 1;
1482                 ops.acpi_op_start = 1;
1483                 result = acpi_bus_scan(acpi_root, &ops);
1484         }
1485
1486         if (result)
1487                 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1488
1489       Done:
1490         return_VALUE(result);
1491 }
1492
1493 subsys_initcall(acpi_scan_init);