V4L/DVB (4110): Small bug in saa7127.c
[linux-2.6] / 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_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRW\n"));
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_DEBUG_PRINT((ACPI_DB_ERROR,
322                                   "Error extracting _PRW package\n"));
323                 goto end;
324         }
325
326         acpi_os_free(buffer.pointer);
327
328         device->wakeup.flags.valid = 1;
329         /* Power button, Lid switch always enable wakeup */
330         if (!acpi_match_ids(device, "PNP0C0D,PNP0C0C,PNP0C0E"))
331                 device->wakeup.flags.run_wake = 1;
332
333       end:
334         if (ACPI_FAILURE(status))
335                 device->flags.wake_capable = 0;
336         return_VALUE(0);
337 }
338
339 /* --------------------------------------------------------------------------
340                 ACPI sysfs device file support
341    -------------------------------------------------------------------------- */
342 static ssize_t acpi_eject_store(struct acpi_device *device,
343                                 const char *buf, size_t count);
344
345 #define ACPI_DEVICE_ATTR(_name,_mode,_show,_store) \
346 static struct acpi_device_attribute acpi_device_attr_##_name = \
347                 __ATTR(_name, _mode, _show, _store)
348
349 ACPI_DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
350
351 /**
352  * setup_sys_fs_device_files - sets up the device files under device namespace
353  * @dev:        acpi_device object
354  * @func:       function pointer to create or destroy the device file
355  */
356 static void
357 setup_sys_fs_device_files(struct acpi_device *dev,
358                           acpi_device_sysfs_files * func)
359 {
360         acpi_status status;
361         acpi_handle temp = NULL;
362
363         /*
364          * If device has _EJ0, 'eject' file is created that is used to trigger
365          * hot-removal function from userland.
366          */
367         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
368         if (ACPI_SUCCESS(status))
369                 (*(func)) (&dev->kobj, &acpi_device_attr_eject.attr);
370 }
371
372 static int acpi_eject_operation(acpi_handle handle, int lockable)
373 {
374         struct acpi_object_list arg_list;
375         union acpi_object arg;
376         acpi_status status = AE_OK;
377
378         /*
379          * TBD: evaluate _PS3?
380          */
381
382         if (lockable) {
383                 arg_list.count = 1;
384                 arg_list.pointer = &arg;
385                 arg.type = ACPI_TYPE_INTEGER;
386                 arg.integer.value = 0;
387                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
388         }
389
390         arg_list.count = 1;
391         arg_list.pointer = &arg;
392         arg.type = ACPI_TYPE_INTEGER;
393         arg.integer.value = 1;
394
395         /*
396          * TBD: _EJD support.
397          */
398
399         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
400         if (ACPI_FAILURE(status)) {
401                 return (-ENODEV);
402         }
403
404         return (0);
405 }
406
407 static ssize_t
408 acpi_eject_store(struct acpi_device *device, const char *buf, size_t count)
409 {
410         int result;
411         int ret = count;
412         int islockable;
413         acpi_status status;
414         acpi_handle handle;
415         acpi_object_type type = 0;
416
417         if ((!count) || (buf[0] != '1')) {
418                 return -EINVAL;
419         }
420 #ifndef FORCE_EJECT
421         if (device->driver == NULL) {
422                 ret = -ENODEV;
423                 goto err;
424         }
425 #endif
426         status = acpi_get_type(device->handle, &type);
427         if (ACPI_FAILURE(status) || (!device->flags.ejectable)) {
428                 ret = -ENODEV;
429                 goto err;
430         }
431
432         islockable = device->flags.lockable;
433         handle = device->handle;
434
435         result = acpi_bus_trim(device, 1);
436
437         if (!result)
438                 result = acpi_eject_operation(handle, islockable);
439
440         if (result) {
441                 ret = -EBUSY;
442         }
443       err:
444         return ret;
445 }
446
447 /* --------------------------------------------------------------------------
448                               Performance Management
449    -------------------------------------------------------------------------- */
450
451 static int acpi_bus_get_perf_flags(struct acpi_device *device)
452 {
453         device->performance.state = ACPI_STATE_UNKNOWN;
454         return 0;
455 }
456
457 /* --------------------------------------------------------------------------
458                                  Driver Management
459    -------------------------------------------------------------------------- */
460
461 static LIST_HEAD(acpi_bus_drivers);
462
463 /**
464  * acpi_bus_match - match device IDs to driver's supported IDs
465  * @device: the device that we are trying to match to a driver
466  * @driver: driver whose device id table is being checked
467  *
468  * Checks the device's hardware (_HID) or compatible (_CID) ids to see if it
469  * matches the specified driver's criteria.
470  */
471 static int
472 acpi_bus_match(struct acpi_device *device, struct acpi_driver *driver)
473 {
474         if (driver && driver->ops.match)
475                 return driver->ops.match(device, driver);
476         return acpi_match_ids(device, driver->ids);
477 }
478
479 /**
480  * acpi_bus_driver_init - add a device to a driver
481  * @device: the device to add and initialize
482  * @driver: driver for the device
483  *
484  * Used to initialize a device via its device driver.  Called whenever a 
485  * driver is bound to a device.  Invokes the driver's add() and start() ops.
486  */
487 static int
488 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
489 {
490         int result = 0;
491
492         ACPI_FUNCTION_TRACE("acpi_bus_driver_init");
493
494         if (!device || !driver)
495                 return_VALUE(-EINVAL);
496
497         if (!driver->ops.add)
498                 return_VALUE(-ENOSYS);
499
500         result = driver->ops.add(device);
501         if (result) {
502                 device->driver = NULL;
503                 acpi_driver_data(device) = NULL;
504                 return_VALUE(result);
505         }
506
507         device->driver = driver;
508
509         /*
510          * TBD - Configuration Management: Assign resources to device based
511          * upon possible configuration and currently allocated resources.
512          */
513
514         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
515                           "Driver successfully bound to device\n"));
516         return_VALUE(0);
517 }
518
519 static int acpi_start_single_object(struct acpi_device *device)
520 {
521         int result = 0;
522         struct acpi_driver *driver;
523
524         ACPI_FUNCTION_TRACE("acpi_start_single_object");
525
526         if (!(driver = device->driver))
527                 return_VALUE(0);
528
529         if (driver->ops.start) {
530                 result = driver->ops.start(device);
531                 if (result && driver->ops.remove)
532                         driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
533         }
534
535         return_VALUE(result);
536 }
537
538 static void acpi_driver_attach(struct acpi_driver *drv)
539 {
540         struct list_head *node, *next;
541
542         ACPI_FUNCTION_TRACE("acpi_driver_attach");
543
544         spin_lock(&acpi_device_lock);
545         list_for_each_safe(node, next, &acpi_device_list) {
546                 struct acpi_device *dev =
547                     container_of(node, struct acpi_device, g_list);
548
549                 if (dev->driver || !dev->status.present)
550                         continue;
551                 spin_unlock(&acpi_device_lock);
552
553                 if (!acpi_bus_match(dev, drv)) {
554                         if (!acpi_bus_driver_init(dev, drv)) {
555                                 acpi_start_single_object(dev);
556                                 atomic_inc(&drv->references);
557                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
558                                                   "Found driver [%s] for device [%s]\n",
559                                                   drv->name, dev->pnp.bus_id));
560                         }
561                 }
562                 spin_lock(&acpi_device_lock);
563         }
564         spin_unlock(&acpi_device_lock);
565 }
566
567 static void acpi_driver_detach(struct acpi_driver *drv)
568 {
569         struct list_head *node, *next;
570
571         ACPI_FUNCTION_TRACE("acpi_driver_detach");
572
573         spin_lock(&acpi_device_lock);
574         list_for_each_safe(node, next, &acpi_device_list) {
575                 struct acpi_device *dev =
576                     container_of(node, struct acpi_device, g_list);
577
578                 if (dev->driver == drv) {
579                         spin_unlock(&acpi_device_lock);
580                         if (drv->ops.remove)
581                                 drv->ops.remove(dev, ACPI_BUS_REMOVAL_NORMAL);
582                         spin_lock(&acpi_device_lock);
583                         dev->driver = NULL;
584                         dev->driver_data = NULL;
585                         atomic_dec(&drv->references);
586                 }
587         }
588         spin_unlock(&acpi_device_lock);
589 }
590
591 /**
592  * acpi_bus_register_driver - register a driver with the ACPI bus
593  * @driver: driver being registered
594  *
595  * Registers a driver with the ACPI bus.  Searches the namespace for all
596  * devices that match the driver's criteria and binds.  Returns zero for
597  * success or a negative error status for failure.
598  */
599 int acpi_bus_register_driver(struct acpi_driver *driver)
600 {
601         ACPI_FUNCTION_TRACE("acpi_bus_register_driver");
602
603         if (acpi_disabled)
604                 return_VALUE(-ENODEV);
605
606         spin_lock(&acpi_device_lock);
607         list_add_tail(&driver->node, &acpi_bus_drivers);
608         spin_unlock(&acpi_device_lock);
609         acpi_driver_attach(driver);
610
611         return_VALUE(0);
612 }
613
614 EXPORT_SYMBOL(acpi_bus_register_driver);
615
616 /**
617  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
618  * @driver: driver to unregister
619  *
620  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
621  * devices that match the driver's criteria and unbinds.
622  */
623 void acpi_bus_unregister_driver(struct acpi_driver *driver)
624 {
625         acpi_driver_detach(driver);
626
627         if (!atomic_read(&driver->references)) {
628                 spin_lock(&acpi_device_lock);
629                 list_del_init(&driver->node);
630                 spin_unlock(&acpi_device_lock);
631         }
632         return;
633 }
634
635 EXPORT_SYMBOL(acpi_bus_unregister_driver);
636
637 /**
638  * acpi_bus_find_driver - check if there is a driver installed for the device
639  * @device: device that we are trying to find a supporting driver for
640  *
641  * Parses the list of registered drivers looking for a driver applicable for
642  * the specified device.
643  */
644 static int acpi_bus_find_driver(struct acpi_device *device)
645 {
646         int result = 0;
647         struct list_head *node, *next;
648
649         ACPI_FUNCTION_TRACE("acpi_bus_find_driver");
650
651         spin_lock(&acpi_device_lock);
652         list_for_each_safe(node, next, &acpi_bus_drivers) {
653                 struct acpi_driver *driver =
654                     container_of(node, struct acpi_driver, node);
655
656                 atomic_inc(&driver->references);
657                 spin_unlock(&acpi_device_lock);
658                 if (!acpi_bus_match(device, driver)) {
659                         result = acpi_bus_driver_init(device, driver);
660                         if (!result)
661                                 goto Done;
662                 }
663                 atomic_dec(&driver->references);
664                 spin_lock(&acpi_device_lock);
665         }
666         spin_unlock(&acpi_device_lock);
667
668       Done:
669         return_VALUE(result);
670 }
671
672 /* --------------------------------------------------------------------------
673                                  Device Enumeration
674    -------------------------------------------------------------------------- */
675
676 static int acpi_bus_get_flags(struct acpi_device *device)
677 {
678         acpi_status status = AE_OK;
679         acpi_handle temp = NULL;
680
681         ACPI_FUNCTION_TRACE("acpi_bus_get_flags");
682
683         /* Presence of _STA indicates 'dynamic_status' */
684         status = acpi_get_handle(device->handle, "_STA", &temp);
685         if (ACPI_SUCCESS(status))
686                 device->flags.dynamic_status = 1;
687
688         /* Presence of _CID indicates 'compatible_ids' */
689         status = acpi_get_handle(device->handle, "_CID", &temp);
690         if (ACPI_SUCCESS(status))
691                 device->flags.compatible_ids = 1;
692
693         /* Presence of _RMV indicates 'removable' */
694         status = acpi_get_handle(device->handle, "_RMV", &temp);
695         if (ACPI_SUCCESS(status))
696                 device->flags.removable = 1;
697
698         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
699         status = acpi_get_handle(device->handle, "_EJD", &temp);
700         if (ACPI_SUCCESS(status))
701                 device->flags.ejectable = 1;
702         else {
703                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
704                 if (ACPI_SUCCESS(status))
705                         device->flags.ejectable = 1;
706         }
707
708         /* Presence of _LCK indicates 'lockable' */
709         status = acpi_get_handle(device->handle, "_LCK", &temp);
710         if (ACPI_SUCCESS(status))
711                 device->flags.lockable = 1;
712
713         /* Presence of _PS0|_PR0 indicates 'power manageable' */
714         status = acpi_get_handle(device->handle, "_PS0", &temp);
715         if (ACPI_FAILURE(status))
716                 status = acpi_get_handle(device->handle, "_PR0", &temp);
717         if (ACPI_SUCCESS(status))
718                 device->flags.power_manageable = 1;
719
720         /* Presence of _PRW indicates wake capable */
721         status = acpi_get_handle(device->handle, "_PRW", &temp);
722         if (ACPI_SUCCESS(status))
723                 device->flags.wake_capable = 1;
724
725         /* TBD: Peformance management */
726
727         return_VALUE(0);
728 }
729
730 static void acpi_device_get_busid(struct acpi_device *device,
731                                   acpi_handle handle, int type)
732 {
733         char bus_id[5] = { '?', 0 };
734         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
735         int i = 0;
736
737         /*
738          * Bus ID
739          * ------
740          * The device's Bus ID is simply the object name.
741          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
742          */
743         switch (type) {
744         case ACPI_BUS_TYPE_SYSTEM:
745                 strcpy(device->pnp.bus_id, "ACPI");
746                 break;
747         case ACPI_BUS_TYPE_POWER_BUTTON:
748                 strcpy(device->pnp.bus_id, "PWRF");
749                 break;
750         case ACPI_BUS_TYPE_SLEEP_BUTTON:
751                 strcpy(device->pnp.bus_id, "SLPF");
752                 break;
753         default:
754                 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
755                 /* Clean up trailing underscores (if any) */
756                 for (i = 3; i > 1; i--) {
757                         if (bus_id[i] == '_')
758                                 bus_id[i] = '\0';
759                         else
760                                 break;
761                 }
762                 strcpy(device->pnp.bus_id, bus_id);
763                 break;
764         }
765 }
766
767 static void acpi_device_set_id(struct acpi_device *device,
768                                struct acpi_device *parent, acpi_handle handle,
769                                int type)
770 {
771         struct acpi_device_info *info;
772         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
773         char *hid = NULL;
774         char *uid = NULL;
775         struct acpi_compatible_id_list *cid_list = NULL;
776         acpi_status status;
777
778         switch (type) {
779         case ACPI_BUS_TYPE_DEVICE:
780                 status = acpi_get_object_info(handle, &buffer);
781                 if (ACPI_FAILURE(status)) {
782                         printk("%s: Error reading device info\n", __FUNCTION__);
783                         return;
784                 }
785
786                 info = buffer.pointer;
787                 if (info->valid & ACPI_VALID_HID)
788                         hid = info->hardware_id.value;
789                 if (info->valid & ACPI_VALID_UID)
790                         uid = info->unique_id.value;
791                 if (info->valid & ACPI_VALID_CID)
792                         cid_list = &info->compatibility_id;
793                 if (info->valid & ACPI_VALID_ADR) {
794                         device->pnp.bus_address = info->address;
795                         device->flags.bus_address = 1;
796                 }
797                 break;
798         case ACPI_BUS_TYPE_POWER:
799                 hid = ACPI_POWER_HID;
800                 break;
801         case ACPI_BUS_TYPE_PROCESSOR:
802                 hid = ACPI_PROCESSOR_HID;
803                 break;
804         case ACPI_BUS_TYPE_SYSTEM:
805                 hid = ACPI_SYSTEM_HID;
806                 break;
807         case ACPI_BUS_TYPE_THERMAL:
808                 hid = ACPI_THERMAL_HID;
809                 break;
810         case ACPI_BUS_TYPE_POWER_BUTTON:
811                 hid = ACPI_BUTTON_HID_POWERF;
812                 break;
813         case ACPI_BUS_TYPE_SLEEP_BUTTON:
814                 hid = ACPI_BUTTON_HID_SLEEPF;
815                 break;
816         }
817
818         /* 
819          * \_SB
820          * ----
821          * Fix for the system root bus device -- the only root-level device.
822          */
823         if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
824                 hid = ACPI_BUS_HID;
825                 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
826                 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
827         }
828
829         if (hid) {
830                 strcpy(device->pnp.hardware_id, hid);
831                 device->flags.hardware_id = 1;
832         }
833         if (uid) {
834                 strcpy(device->pnp.unique_id, uid);
835                 device->flags.unique_id = 1;
836         }
837         if (cid_list) {
838                 device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL);
839                 if (device->pnp.cid_list)
840                         memcpy(device->pnp.cid_list, cid_list, cid_list->size);
841                 else
842                         printk(KERN_ERR "Memory allocation error\n");
843         }
844
845         acpi_os_free(buffer.pointer);
846 }
847
848 static int acpi_device_set_context(struct acpi_device *device, int type)
849 {
850         acpi_status status = AE_OK;
851         int result = 0;
852         /*
853          * Context
854          * -------
855          * Attach this 'struct acpi_device' to the ACPI object.  This makes
856          * resolutions from handle->device very efficient.  Note that we need
857          * to be careful with fixed-feature devices as they all attach to the
858          * root object.
859          */
860         if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
861             type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
862                 status = acpi_attach_data(device->handle,
863                                           acpi_bus_data_handler, device);
864
865                 if (ACPI_FAILURE(status)) {
866                         printk("Error attaching device data\n");
867                         result = -ENODEV;
868                 }
869         }
870         return result;
871 }
872
873 static void acpi_device_get_debug_info(struct acpi_device *device,
874                                        acpi_handle handle, int type)
875 {
876 #ifdef CONFIG_ACPI_DEBUG_OUTPUT
877         char *type_string = NULL;
878         char name[80] = { '?', '\0' };
879         struct acpi_buffer buffer = { sizeof(name), name };
880
881         switch (type) {
882         case ACPI_BUS_TYPE_DEVICE:
883                 type_string = "Device";
884                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
885                 break;
886         case ACPI_BUS_TYPE_POWER:
887                 type_string = "Power Resource";
888                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
889                 break;
890         case ACPI_BUS_TYPE_PROCESSOR:
891                 type_string = "Processor";
892                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
893                 break;
894         case ACPI_BUS_TYPE_SYSTEM:
895                 type_string = "System";
896                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
897                 break;
898         case ACPI_BUS_TYPE_THERMAL:
899                 type_string = "Thermal Zone";
900                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
901                 break;
902         case ACPI_BUS_TYPE_POWER_BUTTON:
903                 type_string = "Power Button";
904                 sprintf(name, "PWRB");
905                 break;
906         case ACPI_BUS_TYPE_SLEEP_BUTTON:
907                 type_string = "Sleep Button";
908                 sprintf(name, "SLPB");
909                 break;
910         }
911
912         printk(KERN_DEBUG "Found %s %s [%p]\n", type_string, name, handle);
913 #endif                          /*CONFIG_ACPI_DEBUG_OUTPUT */
914 }
915
916 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
917 {
918         int result = 0;
919         struct acpi_driver *driver;
920
921         ACPI_FUNCTION_TRACE("acpi_bus_remove");
922
923         if (!dev)
924                 return_VALUE(-EINVAL);
925
926         driver = dev->driver;
927
928         if ((driver) && (driver->ops.remove)) {
929
930                 if (driver->ops.stop) {
931                         result = driver->ops.stop(dev, ACPI_BUS_REMOVAL_EJECT);
932                         if (result)
933                                 return_VALUE(result);
934                 }
935
936                 result = dev->driver->ops.remove(dev, ACPI_BUS_REMOVAL_EJECT);
937                 if (result) {
938                         return_VALUE(result);
939                 }
940
941                 atomic_dec(&dev->driver->references);
942                 dev->driver = NULL;
943                 acpi_driver_data(dev) = NULL;
944         }
945
946         if (!rmdevice)
947                 return_VALUE(0);
948
949         if (dev->flags.bus_address) {
950                 if ((dev->parent) && (dev->parent->ops.unbind))
951                         dev->parent->ops.unbind(dev);
952         }
953
954         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
955
956         return_VALUE(0);
957 }
958
959 static int
960 acpi_add_single_object(struct acpi_device **child,
961                        struct acpi_device *parent, acpi_handle handle, int type)
962 {
963         int result = 0;
964         struct acpi_device *device = NULL;
965
966         ACPI_FUNCTION_TRACE("acpi_add_single_object");
967
968         if (!child)
969                 return_VALUE(-EINVAL);
970
971         device = kmalloc(sizeof(struct acpi_device), GFP_KERNEL);
972         if (!device) {
973                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Memory allocation error\n"));
974                 return_VALUE(-ENOMEM);
975         }
976         memset(device, 0, sizeof(struct acpi_device));
977
978         device->handle = handle;
979         device->parent = parent;
980
981         acpi_device_get_busid(device, handle, type);
982
983         /*
984          * Flags
985          * -----
986          * Get prior to calling acpi_bus_get_status() so we know whether
987          * or not _STA is present.  Note that we only look for object
988          * handles -- cannot evaluate objects until we know the device is
989          * present and properly initialized.
990          */
991         result = acpi_bus_get_flags(device);
992         if (result)
993                 goto end;
994
995         /*
996          * Status
997          * ------
998          * See if the device is present.  We always assume that non-Device
999          * and non-Processor objects (e.g. thermal zones, power resources,
1000          * etc.) are present, functioning, etc. (at least when parent object
1001          * is present).  Note that _STA has a different meaning for some
1002          * objects (e.g. power resources) so we need to be careful how we use
1003          * it.
1004          */
1005         switch (type) {
1006         case ACPI_BUS_TYPE_PROCESSOR:
1007         case ACPI_BUS_TYPE_DEVICE:
1008                 result = acpi_bus_get_status(device);
1009                 if (ACPI_FAILURE(result) || !device->status.present) {
1010                         result = -ENOENT;
1011                         goto end;
1012                 }
1013                 break;
1014         default:
1015                 STRUCT_TO_INT(device->status) = 0x0F;
1016                 break;
1017         }
1018
1019         /*
1020          * Initialize Device
1021          * -----------------
1022          * TBD: Synch with Core's enumeration/initialization process.
1023          */
1024
1025         /*
1026          * Hardware ID, Unique ID, & Bus Address
1027          * -------------------------------------
1028          */
1029         acpi_device_set_id(device, parent, handle, type);
1030
1031         /*
1032          * Power Management
1033          * ----------------
1034          */
1035         if (device->flags.power_manageable) {
1036                 result = acpi_bus_get_power_flags(device);
1037                 if (result)
1038                         goto end;
1039         }
1040
1041         /*
1042          * Wakeup device management
1043          *-----------------------
1044          */
1045         if (device->flags.wake_capable) {
1046                 result = acpi_bus_get_wakeup_device_flags(device);
1047                 if (result)
1048                         goto end;
1049         }
1050
1051         /*
1052          * Performance Management
1053          * ----------------------
1054          */
1055         if (device->flags.performance_manageable) {
1056                 result = acpi_bus_get_perf_flags(device);
1057                 if (result)
1058                         goto end;
1059         }
1060
1061         if ((result = acpi_device_set_context(device, type)))
1062                 goto end;
1063
1064         acpi_device_get_debug_info(device, handle, type);
1065
1066         acpi_device_register(device, parent);
1067
1068         /*
1069          * Bind _ADR-Based Devices
1070          * -----------------------
1071          * If there's a a bus address (_ADR) then we utilize the parent's 
1072          * 'bind' function (if exists) to bind the ACPI- and natively-
1073          * enumerated device representations.
1074          */
1075         if (device->flags.bus_address) {
1076                 if (device->parent && device->parent->ops.bind)
1077                         device->parent->ops.bind(device);
1078         }
1079
1080         /*
1081          * Locate & Attach Driver
1082          * ----------------------
1083          * If there's a hardware id (_HID) or compatible ids (_CID) we check
1084          * to see if there's a driver installed for this kind of device.  Note
1085          * that drivers can install before or after a device is enumerated.
1086          *
1087          * TBD: Assumes LDM provides driver hot-plug capability.
1088          */
1089         acpi_bus_find_driver(device);
1090
1091       end:
1092         if (!result)
1093                 *child = device;
1094         else {
1095                 kfree(device->pnp.cid_list);
1096                 kfree(device);
1097         }
1098
1099         return_VALUE(result);
1100 }
1101
1102 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1103 {
1104         acpi_status status = AE_OK;
1105         struct acpi_device *parent = NULL;
1106         struct acpi_device *child = NULL;
1107         acpi_handle phandle = NULL;
1108         acpi_handle chandle = NULL;
1109         acpi_object_type type = 0;
1110         u32 level = 1;
1111
1112         ACPI_FUNCTION_TRACE("acpi_bus_scan");
1113
1114         if (!start)
1115                 return_VALUE(-EINVAL);
1116
1117         parent = start;
1118         phandle = start->handle;
1119
1120         /*
1121          * Parse through the ACPI namespace, identify all 'devices', and
1122          * create a new 'struct acpi_device' for each.
1123          */
1124         while ((level > 0) && parent) {
1125
1126                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1127                                               chandle, &chandle);
1128
1129                 /*
1130                  * If this scope is exhausted then move our way back up.
1131                  */
1132                 if (ACPI_FAILURE(status)) {
1133                         level--;
1134                         chandle = phandle;
1135                         acpi_get_parent(phandle, &phandle);
1136                         if (parent->parent)
1137                                 parent = parent->parent;
1138                         continue;
1139                 }
1140
1141                 status = acpi_get_type(chandle, &type);
1142                 if (ACPI_FAILURE(status))
1143                         continue;
1144
1145                 /*
1146                  * If this is a scope object then parse it (depth-first).
1147                  */
1148                 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1149                         level++;
1150                         phandle = chandle;
1151                         chandle = NULL;
1152                         continue;
1153                 }
1154
1155                 /*
1156                  * We're only interested in objects that we consider 'devices'.
1157                  */
1158                 switch (type) {
1159                 case ACPI_TYPE_DEVICE:
1160                         type = ACPI_BUS_TYPE_DEVICE;
1161                         break;
1162                 case ACPI_TYPE_PROCESSOR:
1163                         type = ACPI_BUS_TYPE_PROCESSOR;
1164                         break;
1165                 case ACPI_TYPE_THERMAL:
1166                         type = ACPI_BUS_TYPE_THERMAL;
1167                         break;
1168                 case ACPI_TYPE_POWER:
1169                         type = ACPI_BUS_TYPE_POWER;
1170                         break;
1171                 default:
1172                         continue;
1173                 }
1174
1175                 if (ops->acpi_op_add)
1176                         status = acpi_add_single_object(&child, parent,
1177                                                         chandle, type);
1178                 else
1179                         status = acpi_bus_get_device(chandle, &child);
1180
1181                 if (ACPI_FAILURE(status))
1182                         continue;
1183
1184                 if (ops->acpi_op_start) {
1185                         status = acpi_start_single_object(child);
1186                         if (ACPI_FAILURE(status))
1187                                 continue;
1188                 }
1189
1190                 /*
1191                  * If the device is present, enabled, and functioning then
1192                  * parse its scope (depth-first).  Note that we need to
1193                  * represent absent devices to facilitate PnP notifications
1194                  * -- but only the subtree head (not all of its children,
1195                  * which will be enumerated when the parent is inserted).
1196                  *
1197                  * TBD: Need notifications and other detection mechanisms
1198                  *      in place before we can fully implement this.
1199                  */
1200                 if (child->status.present) {
1201                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1202                                                       NULL, NULL);
1203                         if (ACPI_SUCCESS(status)) {
1204                                 level++;
1205                                 phandle = chandle;
1206                                 chandle = NULL;
1207                                 parent = child;
1208                         }
1209                 }
1210         }
1211
1212         return_VALUE(0);
1213 }
1214
1215 int
1216 acpi_bus_add(struct acpi_device **child,
1217              struct acpi_device *parent, acpi_handle handle, int type)
1218 {
1219         int result;
1220         struct acpi_bus_ops ops;
1221
1222         ACPI_FUNCTION_TRACE("acpi_bus_add");
1223
1224         result = acpi_add_single_object(child, parent, handle, type);
1225         if (!result) {
1226                 memset(&ops, 0, sizeof(ops));
1227                 ops.acpi_op_add = 1;
1228                 result = acpi_bus_scan(*child, &ops);
1229         }
1230         return_VALUE(result);
1231 }
1232
1233 EXPORT_SYMBOL(acpi_bus_add);
1234
1235 int acpi_bus_start(struct acpi_device *device)
1236 {
1237         int result;
1238         struct acpi_bus_ops ops;
1239
1240         ACPI_FUNCTION_TRACE("acpi_bus_start");
1241
1242         if (!device)
1243                 return_VALUE(-EINVAL);
1244
1245         result = acpi_start_single_object(device);
1246         if (!result) {
1247                 memset(&ops, 0, sizeof(ops));
1248                 ops.acpi_op_start = 1;
1249                 result = acpi_bus_scan(device, &ops);
1250         }
1251         return_VALUE(result);
1252 }
1253
1254 EXPORT_SYMBOL(acpi_bus_start);
1255
1256 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1257 {
1258         acpi_status status;
1259         struct acpi_device *parent, *child;
1260         acpi_handle phandle, chandle;
1261         acpi_object_type type;
1262         u32 level = 1;
1263         int err = 0;
1264
1265         parent = start;
1266         phandle = start->handle;
1267         child = chandle = NULL;
1268
1269         while ((level > 0) && parent && (!err)) {
1270                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1271                                               chandle, &chandle);
1272
1273                 /*
1274                  * If this scope is exhausted then move our way back up.
1275                  */
1276                 if (ACPI_FAILURE(status)) {
1277                         level--;
1278                         chandle = phandle;
1279                         acpi_get_parent(phandle, &phandle);
1280                         child = parent;
1281                         parent = parent->parent;
1282
1283                         if (level == 0)
1284                                 err = acpi_bus_remove(child, rmdevice);
1285                         else
1286                                 err = acpi_bus_remove(child, 1);
1287
1288                         continue;
1289                 }
1290
1291                 status = acpi_get_type(chandle, &type);
1292                 if (ACPI_FAILURE(status)) {
1293                         continue;
1294                 }
1295                 /*
1296                  * If there is a device corresponding to chandle then
1297                  * parse it (depth-first).
1298                  */
1299                 if (acpi_bus_get_device(chandle, &child) == 0) {
1300                         level++;
1301                         phandle = chandle;
1302                         chandle = NULL;
1303                         parent = child;
1304                 }
1305                 continue;
1306         }
1307         return err;
1308 }
1309 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1310
1311
1312 static int acpi_bus_scan_fixed(struct acpi_device *root)
1313 {
1314         int result = 0;
1315         struct acpi_device *device = NULL;
1316
1317         ACPI_FUNCTION_TRACE("acpi_bus_scan_fixed");
1318
1319         if (!root)
1320                 return_VALUE(-ENODEV);
1321
1322         /*
1323          * Enumerate all fixed-feature devices.
1324          */
1325         if (acpi_fadt.pwr_button == 0) {
1326                 result = acpi_add_single_object(&device, acpi_root,
1327                                                 NULL,
1328                                                 ACPI_BUS_TYPE_POWER_BUTTON);
1329                 if (!result)
1330                         result = acpi_start_single_object(device);
1331         }
1332
1333         if (acpi_fadt.sleep_button == 0) {
1334                 result = acpi_add_single_object(&device, acpi_root,
1335                                                 NULL,
1336                                                 ACPI_BUS_TYPE_SLEEP_BUTTON);
1337                 if (!result)
1338                         result = acpi_start_single_object(device);
1339         }
1340
1341         return_VALUE(result);
1342 }
1343
1344
1345 static inline struct acpi_device * to_acpi_dev(struct device * dev)
1346 {
1347         return container_of(dev, struct acpi_device, dev);
1348 }
1349
1350
1351 static int root_suspend(struct acpi_device * acpi_dev, pm_message_t state)
1352 {
1353         struct acpi_device * dev, * next;
1354         int result;
1355
1356         spin_lock(&acpi_device_lock);
1357         list_for_each_entry_safe_reverse(dev, next, &acpi_device_list, g_list) {
1358                 if (dev->driver && dev->driver->ops.suspend) {
1359                         spin_unlock(&acpi_device_lock);
1360                         result = dev->driver->ops.suspend(dev, 0);
1361                         if (result) {
1362                                 printk(KERN_ERR PREFIX "[%s - %s] Suspend failed: %d\n",
1363                                        acpi_device_name(dev),
1364                                        acpi_device_bid(dev), result);
1365                         }
1366                         spin_lock(&acpi_device_lock);
1367                 }
1368         }
1369         spin_unlock(&acpi_device_lock);
1370         return 0;
1371 }
1372
1373
1374 static int acpi_device_suspend(struct device * dev, pm_message_t state)
1375 {
1376         struct acpi_device * acpi_dev = to_acpi_dev(dev);
1377
1378         /*
1379          * For now, we should only register 1 generic device -
1380          * the ACPI root device - and from there, we walk the
1381          * tree of ACPI devices to suspend each one using the
1382          * ACPI driver methods.
1383          */
1384         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
1385                 root_suspend(acpi_dev, state);
1386         return 0;
1387 }
1388
1389
1390
1391 static int root_resume(struct acpi_device * acpi_dev)
1392 {
1393         struct acpi_device * dev, * next;
1394         int result;
1395
1396         spin_lock(&acpi_device_lock);
1397         list_for_each_entry_safe(dev, next, &acpi_device_list, g_list) {
1398                 if (dev->driver && dev->driver->ops.resume) {
1399                         spin_unlock(&acpi_device_lock);
1400                         result = dev->driver->ops.resume(dev, 0);
1401                         if (result) {
1402                                 printk(KERN_ERR PREFIX "[%s - %s] resume failed: %d\n",
1403                                        acpi_device_name(dev),
1404                                        acpi_device_bid(dev), result);
1405                         }
1406                         spin_lock(&acpi_device_lock);
1407                 }
1408         }
1409         spin_unlock(&acpi_device_lock);
1410         return 0;
1411 }
1412
1413
1414 static int acpi_device_resume(struct device * dev)
1415 {
1416         struct acpi_device * acpi_dev = to_acpi_dev(dev);
1417
1418         /*
1419          * For now, we should only register 1 generic device -
1420          * the ACPI root device - and from there, we walk the
1421          * tree of ACPI devices to resume each one using the
1422          * ACPI driver methods.
1423          */
1424         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
1425                 root_resume(acpi_dev);
1426         return 0;
1427 }
1428
1429
1430 struct bus_type acpi_bus_type = {
1431         .name           = "acpi",
1432         .suspend        = acpi_device_suspend,
1433         .resume         = acpi_device_resume,
1434 };
1435
1436
1437
1438 static int __init acpi_scan_init(void)
1439 {
1440         int result;
1441         struct acpi_bus_ops ops;
1442
1443         ACPI_FUNCTION_TRACE("acpi_scan_init");
1444
1445         if (acpi_disabled)
1446                 return_VALUE(0);
1447
1448         kset_register(&acpi_namespace_kset);
1449
1450         result = bus_register(&acpi_bus_type);
1451         if (result) {
1452                 /* We don't want to quit even if we failed to add suspend/resume */
1453                 printk(KERN_ERR PREFIX "Could not register bus type\n");
1454         }
1455
1456         /*
1457          * Create the root device in the bus's device tree
1458          */
1459         result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1460                                         ACPI_BUS_TYPE_SYSTEM);
1461         if (result)
1462                 goto Done;
1463
1464         result = acpi_start_single_object(acpi_root);
1465         if (result)
1466                 goto Done;
1467
1468         acpi_root->dev.bus = &acpi_bus_type;
1469         snprintf(acpi_root->dev.bus_id, BUS_ID_SIZE, "%s", acpi_bus_type.name);
1470         result = device_register(&acpi_root->dev);
1471         if (result) {
1472                 /* We don't want to quit even if we failed to add suspend/resume */
1473                 printk(KERN_ERR PREFIX "Could not register device\n");
1474         }
1475
1476         /*
1477          * Enumerate devices in the ACPI namespace.
1478          */
1479         result = acpi_bus_scan_fixed(acpi_root);
1480         if (!result) {
1481                 memset(&ops, 0, sizeof(ops));
1482                 ops.acpi_op_add = 1;
1483                 ops.acpi_op_start = 1;
1484                 result = acpi_bus_scan(acpi_root, &ops);
1485         }
1486
1487         if (result)
1488                 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1489
1490       Done:
1491         return_VALUE(result);
1492 }
1493
1494 subsys_initcall(acpi_scan_init);