ACPI: clean up scan.c
[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/kernel.h>
8 #include <linux/acpi.h>
9
10 #include <acpi/acpi_drivers.h>
11 #include <acpi/acinterp.h>      /* for acpi_ex_eisa_id_to_string() */
12
13 #define _COMPONENT              ACPI_BUS_COMPONENT
14 ACPI_MODULE_NAME("scan")
15 #define STRUCT_TO_INT(s)        (*((int*)&s))
16 extern struct acpi_device *acpi_root;
17
18 #define ACPI_BUS_CLASS                  "system_bus"
19 #define ACPI_BUS_HID                    "ACPI_BUS"
20 #define ACPI_BUS_DRIVER_NAME            "ACPI Bus Driver"
21 #define ACPI_BUS_DEVICE_NAME            "System Bus"
22
23 static LIST_HEAD(acpi_device_list);
24 DEFINE_SPINLOCK(acpi_device_lock);
25 LIST_HEAD(acpi_wakeup_device_list);
26
27
28 static void acpi_device_release(struct kobject *kobj)
29 {
30         struct acpi_device *dev = container_of(kobj, struct acpi_device, kobj);
31         kfree(dev->pnp.cid_list);
32         kfree(dev);
33 }
34
35 struct acpi_device_attribute {
36         struct attribute attr;
37          ssize_t(*show) (struct acpi_device *, char *);
38          ssize_t(*store) (struct acpi_device *, const char *, size_t);
39 };
40
41 typedef void acpi_device_sysfs_files(struct kobject *,
42                                      const struct attribute *);
43
44 static void setup_sys_fs_device_files(struct acpi_device *dev,
45                                       acpi_device_sysfs_files * func);
46
47 #define create_sysfs_device_files(dev)  \
48         setup_sys_fs_device_files(dev, (acpi_device_sysfs_files *)&sysfs_create_file)
49 #define remove_sysfs_device_files(dev)  \
50         setup_sys_fs_device_files(dev, (acpi_device_sysfs_files *)&sysfs_remove_file)
51
52 #define to_acpi_device(n) container_of(n, struct acpi_device, kobj)
53 #define to_handle_attr(n) container_of(n, struct acpi_device_attribute, attr);
54
55 static ssize_t acpi_device_attr_show(struct kobject *kobj,
56                                      struct attribute *attr, char *buf)
57 {
58         struct acpi_device *device = to_acpi_device(kobj);
59         struct acpi_device_attribute *attribute = to_handle_attr(attr);
60         return attribute->show ? attribute->show(device, buf) : -EIO;
61 }
62 static ssize_t acpi_device_attr_store(struct kobject *kobj,
63                                       struct attribute *attr, const char *buf,
64                                       size_t len)
65 {
66         struct acpi_device *device = to_acpi_device(kobj);
67         struct acpi_device_attribute *attribute = to_handle_attr(attr);
68         return attribute->store ? attribute->store(device, buf, len) : -EIO;
69 }
70
71 static struct sysfs_ops acpi_device_sysfs_ops = {
72         .show = acpi_device_attr_show,
73         .store = acpi_device_attr_store,
74 };
75
76 static struct kobj_type ktype_acpi_ns = {
77         .sysfs_ops = &acpi_device_sysfs_ops,
78         .release = acpi_device_release,
79 };
80
81 static int namespace_uevent(struct kset *kset, struct kobject *kobj,
82                              char **envp, int num_envp, char *buffer,
83                              int buffer_size)
84 {
85         struct acpi_device *dev = to_acpi_device(kobj);
86         int i = 0;
87         int len = 0;
88
89         if (!dev->driver)
90                 return 0;
91
92         if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
93                            "PHYSDEVDRIVER=%s", dev->driver->name))
94                 return -ENOMEM;
95
96         envp[i] = NULL;
97
98         return 0;
99 }
100
101 static struct kset_uevent_ops namespace_uevent_ops = {
102         .uevent = &namespace_uevent,
103 };
104
105 static struct kset acpi_namespace_kset = {
106         .kobj = {
107                  .name = "namespace",
108                  },
109         .subsys = &acpi_subsys,
110         .ktype = &ktype_acpi_ns,
111         .uevent_ops = &namespace_uevent_ops,
112 };
113
114 /* --------------------------------------------------------------------------
115                 ACPI sysfs device file support
116    -------------------------------------------------------------------------- */
117 static ssize_t acpi_eject_store(struct acpi_device *device,
118                                 const char *buf, size_t count);
119
120 #define ACPI_DEVICE_ATTR(_name,_mode,_show,_store) \
121 static struct acpi_device_attribute acpi_device_attr_##_name = \
122                 __ATTR(_name, _mode, _show, _store)
123
124 ACPI_DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
125
126 /**
127  * setup_sys_fs_device_files - sets up the device files under device namespace
128  * @dev:        acpi_device object
129  * @func:       function pointer to create or destroy the device file
130  */
131 static void
132 setup_sys_fs_device_files(struct acpi_device *dev,
133                           acpi_device_sysfs_files * func)
134 {
135         acpi_status status;
136         acpi_handle temp = NULL;
137
138         /*
139          * If device has _EJ0, 'eject' file is created that is used to trigger
140          * hot-removal function from userland.
141          */
142         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
143         if (ACPI_SUCCESS(status))
144                 (*(func)) (&dev->kobj, &acpi_device_attr_eject.attr);
145 }
146
147 static int acpi_eject_operation(acpi_handle handle, int lockable)
148 {
149         struct acpi_object_list arg_list;
150         union acpi_object arg;
151         acpi_status status = AE_OK;
152
153         /*
154          * TBD: evaluate _PS3?
155          */
156
157         if (lockable) {
158                 arg_list.count = 1;
159                 arg_list.pointer = &arg;
160                 arg.type = ACPI_TYPE_INTEGER;
161                 arg.integer.value = 0;
162                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
163         }
164
165         arg_list.count = 1;
166         arg_list.pointer = &arg;
167         arg.type = ACPI_TYPE_INTEGER;
168         arg.integer.value = 1;
169
170         /*
171          * TBD: _EJD support.
172          */
173
174         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
175         if (ACPI_FAILURE(status)) {
176                 return (-ENODEV);
177         }
178
179         return (0);
180 }
181
182 static ssize_t
183 acpi_eject_store(struct acpi_device *device, const char *buf, size_t count)
184 {
185         int result;
186         int ret = count;
187         int islockable;
188         acpi_status status;
189         acpi_handle handle;
190         acpi_object_type type = 0;
191
192         if ((!count) || (buf[0] != '1')) {
193                 return -EINVAL;
194         }
195 #ifndef FORCE_EJECT
196         if (device->driver == NULL) {
197                 ret = -ENODEV;
198                 goto err;
199         }
200 #endif
201         status = acpi_get_type(device->handle, &type);
202         if (ACPI_FAILURE(status) || (!device->flags.ejectable)) {
203                 ret = -ENODEV;
204                 goto err;
205         }
206
207         islockable = device->flags.lockable;
208         handle = device->handle;
209
210         result = acpi_bus_trim(device, 1);
211
212         if (!result)
213                 result = acpi_eject_operation(handle, islockable);
214
215         if (result) {
216                 ret = -EBUSY;
217         }
218       err:
219         return ret;
220 }
221
222 /* --------------------------------------------------------------------------
223                         ACPI Bus operations
224    -------------------------------------------------------------------------- */
225 static inline struct acpi_device * to_acpi_dev(struct device * dev)
226 {
227         return container_of(dev, struct acpi_device, dev);
228 }
229
230 static int root_suspend(struct acpi_device * acpi_dev, pm_message_t state)
231 {
232         struct acpi_device * dev, * next;
233         int result;
234
235         spin_lock(&acpi_device_lock);
236         list_for_each_entry_safe_reverse(dev, next, &acpi_device_list, g_list) {
237                 if (dev->driver && dev->driver->ops.suspend) {
238                         spin_unlock(&acpi_device_lock);
239                         result = dev->driver->ops.suspend(dev, 0);
240                         if (result) {
241                                 printk(KERN_ERR PREFIX "[%s - %s] Suspend failed: %d\n",
242                                        acpi_device_name(dev),
243                                        acpi_device_bid(dev), result);
244                         }
245                         spin_lock(&acpi_device_lock);
246                 }
247         }
248         spin_unlock(&acpi_device_lock);
249         return 0;
250 }
251
252 static int acpi_device_suspend(struct device * dev, pm_message_t state)
253 {
254         struct acpi_device * acpi_dev = to_acpi_dev(dev);
255
256         /*
257          * For now, we should only register 1 generic device -
258          * the ACPI root device - and from there, we walk the
259          * tree of ACPI devices to suspend each one using the
260          * ACPI driver methods.
261          */
262         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
263                 root_suspend(acpi_dev, state);
264         return 0;
265 }
266
267 static int root_resume(struct acpi_device * acpi_dev)
268 {
269         struct acpi_device * dev, * next;
270         int result;
271
272         spin_lock(&acpi_device_lock);
273         list_for_each_entry_safe(dev, next, &acpi_device_list, g_list) {
274                 if (dev->driver && dev->driver->ops.resume) {
275                         spin_unlock(&acpi_device_lock);
276                         result = dev->driver->ops.resume(dev, 0);
277                         if (result) {
278                                 printk(KERN_ERR PREFIX "[%s - %s] resume failed: %d\n",
279                                        acpi_device_name(dev),
280                                        acpi_device_bid(dev), result);
281                         }
282                         spin_lock(&acpi_device_lock);
283                 }
284         }
285         spin_unlock(&acpi_device_lock);
286         return 0;
287 }
288
289 static int acpi_device_resume(struct device * dev)
290 {
291         struct acpi_device * acpi_dev = to_acpi_dev(dev);
292
293         /*
294          * For now, we should only register 1 generic device -
295          * the ACPI root device - and from there, we walk the
296          * tree of ACPI devices to resume each one using the
297          * ACPI driver methods.
298          */
299         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
300                 root_resume(acpi_dev);
301         return 0;
302 }
303
304 /**
305  * acpi_bus_match - match device IDs to driver's supported IDs
306  * @device: the device that we are trying to match to a driver
307  * @driver: driver whose device id table is being checked
308  *
309  * Checks the device's hardware (_HID) or compatible (_CID) ids to see if it
310  * matches the specified driver's criteria.
311  */
312 static int
313 acpi_bus_match(struct acpi_device *device, struct acpi_driver *driver)
314 {
315         if (driver && driver->ops.match)
316                 return driver->ops.match(device, driver);
317         return acpi_match_ids(device, driver->ids);
318 }
319
320 static struct bus_type acpi_bus_type = {
321         .name           = "acpi",
322         .suspend        = acpi_device_suspend,
323         .resume         = acpi_device_resume,
324 };
325
326 static void acpi_device_register(struct acpi_device *device,
327                                  struct acpi_device *parent)
328 {
329         int err;
330
331         /*
332          * Linkage
333          * -------
334          * Link this device to its parent and siblings.
335          */
336         INIT_LIST_HEAD(&device->children);
337         INIT_LIST_HEAD(&device->node);
338         INIT_LIST_HEAD(&device->g_list);
339         INIT_LIST_HEAD(&device->wakeup_list);
340
341         spin_lock(&acpi_device_lock);
342         if (device->parent) {
343                 list_add_tail(&device->node, &device->parent->children);
344                 list_add_tail(&device->g_list, &device->parent->g_list);
345         } else
346                 list_add_tail(&device->g_list, &acpi_device_list);
347         if (device->wakeup.flags.valid)
348                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
349         spin_unlock(&acpi_device_lock);
350
351         strlcpy(device->kobj.name, device->pnp.bus_id, KOBJ_NAME_LEN);
352         if (parent)
353                 device->kobj.parent = &parent->kobj;
354         device->kobj.ktype = &ktype_acpi_ns;
355         device->kobj.kset = &acpi_namespace_kset;
356         err = kobject_register(&device->kobj);
357         if (err < 0)
358                 printk(KERN_WARNING "%s: kobject_register error: %d\n",
359                         __FUNCTION__, err);
360         create_sysfs_device_files(device);
361 }
362
363 static void acpi_device_unregister(struct acpi_device *device, int type)
364 {
365         spin_lock(&acpi_device_lock);
366         if (device->parent) {
367                 list_del(&device->node);
368                 list_del(&device->g_list);
369         } else
370                 list_del(&device->g_list);
371
372         list_del(&device->wakeup_list);
373
374         spin_unlock(&acpi_device_lock);
375
376         acpi_detach_data(device->handle, acpi_bus_data_handler);
377         remove_sysfs_device_files(device);
378         kobject_unregister(&device->kobj);
379 }
380
381 /* --------------------------------------------------------------------------
382                                  Driver Management
383    -------------------------------------------------------------------------- */
384 static LIST_HEAD(acpi_bus_drivers);
385
386 /**
387  * acpi_bus_driver_init - add a device to a driver
388  * @device: the device to add and initialize
389  * @driver: driver for the device
390  *
391  * Used to initialize a device via its device driver.  Called whenever a 
392  * driver is bound to a device.  Invokes the driver's add() and start() ops.
393  */
394 static int
395 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
396 {
397         int result = 0;
398
399
400         if (!device || !driver)
401                 return -EINVAL;
402
403         if (!driver->ops.add)
404                 return -ENOSYS;
405
406         result = driver->ops.add(device);
407         if (result) {
408                 device->driver = NULL;
409                 acpi_driver_data(device) = NULL;
410                 return result;
411         }
412
413         device->driver = driver;
414
415         /*
416          * TBD - Configuration Management: Assign resources to device based
417          * upon possible configuration and currently allocated resources.
418          */
419
420         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
421                           "Driver successfully bound to device\n"));
422         return 0;
423 }
424
425 static int acpi_start_single_object(struct acpi_device *device)
426 {
427         int result = 0;
428         struct acpi_driver *driver;
429
430
431         if (!(driver = device->driver))
432                 return 0;
433
434         if (driver->ops.start) {
435                 result = driver->ops.start(device);
436                 if (result && driver->ops.remove)
437                         driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
438         }
439
440         return result;
441 }
442
443 static void acpi_driver_attach(struct acpi_driver *drv)
444 {
445         struct list_head *node, *next;
446
447
448         spin_lock(&acpi_device_lock);
449         list_for_each_safe(node, next, &acpi_device_list) {
450                 struct acpi_device *dev =
451                     container_of(node, struct acpi_device, g_list);
452
453                 if (dev->driver || !dev->status.present)
454                         continue;
455                 spin_unlock(&acpi_device_lock);
456
457                 if (!acpi_bus_match(dev, drv)) {
458                         if (!acpi_bus_driver_init(dev, drv)) {
459                                 acpi_start_single_object(dev);
460                                 atomic_inc(&drv->references);
461                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
462                                                   "Found driver [%s] for device [%s]\n",
463                                                   drv->name, dev->pnp.bus_id));
464                         }
465                 }
466                 spin_lock(&acpi_device_lock);
467         }
468         spin_unlock(&acpi_device_lock);
469 }
470
471 static void acpi_driver_detach(struct acpi_driver *drv)
472 {
473         struct list_head *node, *next;
474
475
476         spin_lock(&acpi_device_lock);
477         list_for_each_safe(node, next, &acpi_device_list) {
478                 struct acpi_device *dev =
479                     container_of(node, struct acpi_device, g_list);
480
481                 if (dev->driver == drv) {
482                         spin_unlock(&acpi_device_lock);
483                         if (drv->ops.remove)
484                                 drv->ops.remove(dev, ACPI_BUS_REMOVAL_NORMAL);
485                         spin_lock(&acpi_device_lock);
486                         dev->driver = NULL;
487                         dev->driver_data = NULL;
488                         atomic_dec(&drv->references);
489                 }
490         }
491         spin_unlock(&acpi_device_lock);
492 }
493
494 /**
495  * acpi_bus_register_driver - register a driver with the ACPI bus
496  * @driver: driver being registered
497  *
498  * Registers a driver with the ACPI bus.  Searches the namespace for all
499  * devices that match the driver's criteria and binds.  Returns zero for
500  * success or a negative error status for failure.
501  */
502 int acpi_bus_register_driver(struct acpi_driver *driver)
503 {
504
505         if (acpi_disabled)
506                 return -ENODEV;
507
508         spin_lock(&acpi_device_lock);
509         list_add_tail(&driver->node, &acpi_bus_drivers);
510         spin_unlock(&acpi_device_lock);
511         acpi_driver_attach(driver);
512
513         return 0;
514 }
515
516 EXPORT_SYMBOL(acpi_bus_register_driver);
517
518 /**
519  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
520  * @driver: driver to unregister
521  *
522  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
523  * devices that match the driver's criteria and unbinds.
524  */
525 void acpi_bus_unregister_driver(struct acpi_driver *driver)
526 {
527         acpi_driver_detach(driver);
528
529         if (!atomic_read(&driver->references)) {
530                 spin_lock(&acpi_device_lock);
531                 list_del_init(&driver->node);
532                 spin_unlock(&acpi_device_lock);
533         }
534         return;
535 }
536
537 EXPORT_SYMBOL(acpi_bus_unregister_driver);
538
539 /**
540  * acpi_bus_find_driver - check if there is a driver installed for the device
541  * @device: device that we are trying to find a supporting driver for
542  *
543  * Parses the list of registered drivers looking for a driver applicable for
544  * the specified device.
545  */
546 static int acpi_bus_find_driver(struct acpi_device *device)
547 {
548         int result = 0;
549         struct list_head *node, *next;
550
551
552         spin_lock(&acpi_device_lock);
553         list_for_each_safe(node, next, &acpi_bus_drivers) {
554                 struct acpi_driver *driver =
555                     container_of(node, struct acpi_driver, node);
556
557                 atomic_inc(&driver->references);
558                 spin_unlock(&acpi_device_lock);
559                 if (!acpi_bus_match(device, driver)) {
560                         result = acpi_bus_driver_init(device, driver);
561                         if (!result)
562                                 goto Done;
563                 }
564                 atomic_dec(&driver->references);
565                 spin_lock(&acpi_device_lock);
566         }
567         spin_unlock(&acpi_device_lock);
568
569       Done:
570         return result;
571 }
572
573 /* --------------------------------------------------------------------------
574                                  Device Enumeration
575    -------------------------------------------------------------------------- */
576 acpi_status
577 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
578 {
579         acpi_status status;
580         acpi_handle tmp;
581         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
582         union acpi_object *obj;
583
584         status = acpi_get_handle(handle, "_EJD", &tmp);
585         if (ACPI_FAILURE(status))
586                 return status;
587
588         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
589         if (ACPI_SUCCESS(status)) {
590                 obj = buffer.pointer;
591                 status = acpi_get_handle(NULL, obj->string.pointer, ejd);
592                 kfree(buffer.pointer);
593         }
594         return status;
595 }
596 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
597
598 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
599 {
600
601         /* TBD */
602
603         return;
604 }
605
606 int acpi_match_ids(struct acpi_device *device, char *ids)
607 {
608         if (device->flags.hardware_id)
609                 if (strstr(ids, device->pnp.hardware_id))
610                         return 0;
611
612         if (device->flags.compatible_ids) {
613                 struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
614                 int i;
615
616                 /* compare multiple _CID entries against driver ids */
617                 for (i = 0; i < cid_list->count; i++) {
618                         if (strstr(ids, cid_list->id[i].value))
619                                 return 0;
620                 }
621         }
622         return -ENOENT;
623 }
624
625 static int acpi_bus_get_perf_flags(struct acpi_device *device)
626 {
627         device->performance.state = ACPI_STATE_UNKNOWN;
628         return 0;
629 }
630
631 static acpi_status
632 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
633                                              union acpi_object *package)
634 {
635         int i = 0;
636         union acpi_object *element = NULL;
637
638         if (!device || !package || (package->package.count < 2))
639                 return AE_BAD_PARAMETER;
640
641         element = &(package->package.elements[0]);
642         if (!element)
643                 return AE_BAD_PARAMETER;
644         if (element->type == ACPI_TYPE_PACKAGE) {
645                 if ((element->package.count < 2) ||
646                     (element->package.elements[0].type !=
647                      ACPI_TYPE_LOCAL_REFERENCE)
648                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
649                         return AE_BAD_DATA;
650                 device->wakeup.gpe_device =
651                     element->package.elements[0].reference.handle;
652                 device->wakeup.gpe_number =
653                     (u32) element->package.elements[1].integer.value;
654         } else if (element->type == ACPI_TYPE_INTEGER) {
655                 device->wakeup.gpe_number = element->integer.value;
656         } else
657                 return AE_BAD_DATA;
658
659         element = &(package->package.elements[1]);
660         if (element->type != ACPI_TYPE_INTEGER) {
661                 return AE_BAD_DATA;
662         }
663         device->wakeup.sleep_state = element->integer.value;
664
665         if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
666                 return AE_NO_MEMORY;
667         }
668         device->wakeup.resources.count = package->package.count - 2;
669         for (i = 0; i < device->wakeup.resources.count; i++) {
670                 element = &(package->package.elements[i + 2]);
671                 if (element->type != ACPI_TYPE_ANY) {
672                         return AE_BAD_DATA;
673                 }
674
675                 device->wakeup.resources.handles[i] = element->reference.handle;
676         }
677
678         return AE_OK;
679 }
680
681 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
682 {
683         acpi_status status = 0;
684         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
685         union acpi_object *package = NULL;
686
687
688         /* _PRW */
689         status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
690         if (ACPI_FAILURE(status)) {
691                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
692                 goto end;
693         }
694
695         package = (union acpi_object *)buffer.pointer;
696         status = acpi_bus_extract_wakeup_device_power_package(device, package);
697         if (ACPI_FAILURE(status)) {
698                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
699                 goto end;
700         }
701
702         kfree(buffer.pointer);
703
704         device->wakeup.flags.valid = 1;
705         /* Power button, Lid switch always enable wakeup */
706         if (!acpi_match_ids(device, "PNP0C0D,PNP0C0C,PNP0C0E"))
707                 device->wakeup.flags.run_wake = 1;
708
709       end:
710         if (ACPI_FAILURE(status))
711                 device->flags.wake_capable = 0;
712         return 0;
713 }
714
715 static int acpi_bus_get_power_flags(struct acpi_device *device)
716 {
717         acpi_status status = 0;
718         acpi_handle handle = NULL;
719         u32 i = 0;
720
721
722         /*
723          * Power Management Flags
724          */
725         status = acpi_get_handle(device->handle, "_PSC", &handle);
726         if (ACPI_SUCCESS(status))
727                 device->power.flags.explicit_get = 1;
728         status = acpi_get_handle(device->handle, "_IRC", &handle);
729         if (ACPI_SUCCESS(status))
730                 device->power.flags.inrush_current = 1;
731
732         /*
733          * Enumerate supported power management states
734          */
735         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
736                 struct acpi_device_power_state *ps = &device->power.states[i];
737                 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
738
739                 /* Evaluate "_PRx" to se if power resources are referenced */
740                 acpi_evaluate_reference(device->handle, object_name, NULL,
741                                         &ps->resources);
742                 if (ps->resources.count) {
743                         device->power.flags.power_resources = 1;
744                         ps->flags.valid = 1;
745                 }
746
747                 /* Evaluate "_PSx" to see if we can do explicit sets */
748                 object_name[2] = 'S';
749                 status = acpi_get_handle(device->handle, object_name, &handle);
750                 if (ACPI_SUCCESS(status)) {
751                         ps->flags.explicit_set = 1;
752                         ps->flags.valid = 1;
753                 }
754
755                 /* State is valid if we have some power control */
756                 if (ps->resources.count || ps->flags.explicit_set)
757                         ps->flags.valid = 1;
758
759                 ps->power = -1; /* Unknown - driver assigned */
760                 ps->latency = -1;       /* Unknown - driver assigned */
761         }
762
763         /* Set defaults for D0 and D3 states (always valid) */
764         device->power.states[ACPI_STATE_D0].flags.valid = 1;
765         device->power.states[ACPI_STATE_D0].power = 100;
766         device->power.states[ACPI_STATE_D3].flags.valid = 1;
767         device->power.states[ACPI_STATE_D3].power = 0;
768
769         /* TBD: System wake support and resource requirements. */
770
771         device->power.state = ACPI_STATE_UNKNOWN;
772
773         return 0;
774 }
775
776 static int acpi_bus_get_flags(struct acpi_device *device)
777 {
778         acpi_status status = AE_OK;
779         acpi_handle temp = NULL;
780
781
782         /* Presence of _STA indicates 'dynamic_status' */
783         status = acpi_get_handle(device->handle, "_STA", &temp);
784         if (ACPI_SUCCESS(status))
785                 device->flags.dynamic_status = 1;
786
787         /* Presence of _CID indicates 'compatible_ids' */
788         status = acpi_get_handle(device->handle, "_CID", &temp);
789         if (ACPI_SUCCESS(status))
790                 device->flags.compatible_ids = 1;
791
792         /* Presence of _RMV indicates 'removable' */
793         status = acpi_get_handle(device->handle, "_RMV", &temp);
794         if (ACPI_SUCCESS(status))
795                 device->flags.removable = 1;
796
797         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
798         status = acpi_get_handle(device->handle, "_EJD", &temp);
799         if (ACPI_SUCCESS(status))
800                 device->flags.ejectable = 1;
801         else {
802                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
803                 if (ACPI_SUCCESS(status))
804                         device->flags.ejectable = 1;
805         }
806
807         /* Presence of _LCK indicates 'lockable' */
808         status = acpi_get_handle(device->handle, "_LCK", &temp);
809         if (ACPI_SUCCESS(status))
810                 device->flags.lockable = 1;
811
812         /* Presence of _PS0|_PR0 indicates 'power manageable' */
813         status = acpi_get_handle(device->handle, "_PS0", &temp);
814         if (ACPI_FAILURE(status))
815                 status = acpi_get_handle(device->handle, "_PR0", &temp);
816         if (ACPI_SUCCESS(status))
817                 device->flags.power_manageable = 1;
818
819         /* Presence of _PRW indicates wake capable */
820         status = acpi_get_handle(device->handle, "_PRW", &temp);
821         if (ACPI_SUCCESS(status))
822                 device->flags.wake_capable = 1;
823
824         /* TBD: Peformance management */
825
826         return 0;
827 }
828
829 static void acpi_device_get_busid(struct acpi_device *device,
830                                   acpi_handle handle, int type)
831 {
832         char bus_id[5] = { '?', 0 };
833         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
834         int i = 0;
835
836         /*
837          * Bus ID
838          * ------
839          * The device's Bus ID is simply the object name.
840          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
841          */
842         switch (type) {
843         case ACPI_BUS_TYPE_SYSTEM:
844                 strcpy(device->pnp.bus_id, "ACPI");
845                 break;
846         case ACPI_BUS_TYPE_POWER_BUTTON:
847                 strcpy(device->pnp.bus_id, "PWRF");
848                 break;
849         case ACPI_BUS_TYPE_SLEEP_BUTTON:
850                 strcpy(device->pnp.bus_id, "SLPF");
851                 break;
852         default:
853                 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
854                 /* Clean up trailing underscores (if any) */
855                 for (i = 3; i > 1; i--) {
856                         if (bus_id[i] == '_')
857                                 bus_id[i] = '\0';
858                         else
859                                 break;
860                 }
861                 strcpy(device->pnp.bus_id, bus_id);
862                 break;
863         }
864 }
865
866 static void acpi_device_set_id(struct acpi_device *device,
867                                struct acpi_device *parent, acpi_handle handle,
868                                int type)
869 {
870         struct acpi_device_info *info;
871         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
872         char *hid = NULL;
873         char *uid = NULL;
874         struct acpi_compatible_id_list *cid_list = NULL;
875         acpi_status status;
876
877         switch (type) {
878         case ACPI_BUS_TYPE_DEVICE:
879                 status = acpi_get_object_info(handle, &buffer);
880                 if (ACPI_FAILURE(status)) {
881                         printk("%s: Error reading device info\n", __FUNCTION__);
882                         return;
883                 }
884
885                 info = buffer.pointer;
886                 if (info->valid & ACPI_VALID_HID)
887                         hid = info->hardware_id.value;
888                 if (info->valid & ACPI_VALID_UID)
889                         uid = info->unique_id.value;
890                 if (info->valid & ACPI_VALID_CID)
891                         cid_list = &info->compatibility_id;
892                 if (info->valid & ACPI_VALID_ADR) {
893                         device->pnp.bus_address = info->address;
894                         device->flags.bus_address = 1;
895                 }
896                 break;
897         case ACPI_BUS_TYPE_POWER:
898                 hid = ACPI_POWER_HID;
899                 break;
900         case ACPI_BUS_TYPE_PROCESSOR:
901                 hid = ACPI_PROCESSOR_HID;
902                 break;
903         case ACPI_BUS_TYPE_SYSTEM:
904                 hid = ACPI_SYSTEM_HID;
905                 break;
906         case ACPI_BUS_TYPE_THERMAL:
907                 hid = ACPI_THERMAL_HID;
908                 break;
909         case ACPI_BUS_TYPE_POWER_BUTTON:
910                 hid = ACPI_BUTTON_HID_POWERF;
911                 break;
912         case ACPI_BUS_TYPE_SLEEP_BUTTON:
913                 hid = ACPI_BUTTON_HID_SLEEPF;
914                 break;
915         }
916
917         /* 
918          * \_SB
919          * ----
920          * Fix for the system root bus device -- the only root-level device.
921          */
922         if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
923                 hid = ACPI_BUS_HID;
924                 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
925                 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
926         }
927
928         if (hid) {
929                 strcpy(device->pnp.hardware_id, hid);
930                 device->flags.hardware_id = 1;
931         }
932         if (uid) {
933                 strcpy(device->pnp.unique_id, uid);
934                 device->flags.unique_id = 1;
935         }
936         if (cid_list) {
937                 device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL);
938                 if (device->pnp.cid_list)
939                         memcpy(device->pnp.cid_list, cid_list, cid_list->size);
940                 else
941                         printk(KERN_ERR "Memory allocation error\n");
942         }
943
944         kfree(buffer.pointer);
945 }
946
947 static int acpi_device_set_context(struct acpi_device *device, int type)
948 {
949         acpi_status status = AE_OK;
950         int result = 0;
951         /*
952          * Context
953          * -------
954          * Attach this 'struct acpi_device' to the ACPI object.  This makes
955          * resolutions from handle->device very efficient.  Note that we need
956          * to be careful with fixed-feature devices as they all attach to the
957          * root object.
958          */
959         if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
960             type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
961                 status = acpi_attach_data(device->handle,
962                                           acpi_bus_data_handler, device);
963
964                 if (ACPI_FAILURE(status)) {
965                         printk("Error attaching device data\n");
966                         result = -ENODEV;
967                 }
968         }
969         return result;
970 }
971
972 static void acpi_device_get_debug_info(struct acpi_device *device,
973                                        acpi_handle handle, int type)
974 {
975 #ifdef CONFIG_ACPI_DEBUG_OUTPUT
976         char *type_string = NULL;
977         char name[80] = { '?', '\0' };
978         struct acpi_buffer buffer = { sizeof(name), name };
979
980         switch (type) {
981         case ACPI_BUS_TYPE_DEVICE:
982                 type_string = "Device";
983                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
984                 break;
985         case ACPI_BUS_TYPE_POWER:
986                 type_string = "Power Resource";
987                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
988                 break;
989         case ACPI_BUS_TYPE_PROCESSOR:
990                 type_string = "Processor";
991                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
992                 break;
993         case ACPI_BUS_TYPE_SYSTEM:
994                 type_string = "System";
995                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
996                 break;
997         case ACPI_BUS_TYPE_THERMAL:
998                 type_string = "Thermal Zone";
999                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1000                 break;
1001         case ACPI_BUS_TYPE_POWER_BUTTON:
1002                 type_string = "Power Button";
1003                 sprintf(name, "PWRB");
1004                 break;
1005         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1006                 type_string = "Sleep Button";
1007                 sprintf(name, "SLPB");
1008                 break;
1009         }
1010
1011         printk(KERN_DEBUG "Found %s %s [%p]\n", type_string, name, handle);
1012 #endif                          /*CONFIG_ACPI_DEBUG_OUTPUT */
1013 }
1014
1015 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1016 {
1017         int result = 0;
1018         struct acpi_driver *driver;
1019
1020
1021         if (!dev)
1022                 return -EINVAL;
1023
1024         driver = dev->driver;
1025
1026         if ((driver) && (driver->ops.remove)) {
1027
1028                 if (driver->ops.stop) {
1029                         result = driver->ops.stop(dev, ACPI_BUS_REMOVAL_EJECT);
1030                         if (result)
1031                                 return result;
1032                 }
1033
1034                 result = dev->driver->ops.remove(dev, ACPI_BUS_REMOVAL_EJECT);
1035                 if (result) {
1036                         return result;
1037                 }
1038
1039                 atomic_dec(&dev->driver->references);
1040                 dev->driver = NULL;
1041                 acpi_driver_data(dev) = NULL;
1042         }
1043
1044         if (!rmdevice)
1045                 return 0;
1046
1047         if (dev->flags.bus_address) {
1048                 if ((dev->parent) && (dev->parent->ops.unbind))
1049                         dev->parent->ops.unbind(dev);
1050         }
1051
1052         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1053
1054         return 0;
1055 }
1056
1057 static int
1058 acpi_add_single_object(struct acpi_device **child,
1059                        struct acpi_device *parent, acpi_handle handle, int type)
1060 {
1061         int result = 0;
1062         struct acpi_device *device = NULL;
1063
1064
1065         if (!child)
1066                 return -EINVAL;
1067
1068         device = kmalloc(sizeof(struct acpi_device), GFP_KERNEL);
1069         if (!device) {
1070                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1071                 return -ENOMEM;
1072         }
1073         memset(device, 0, sizeof(struct acpi_device));
1074
1075         device->handle = handle;
1076         device->parent = parent;
1077
1078         acpi_device_get_busid(device, handle, type);
1079
1080         /*
1081          * Flags
1082          * -----
1083          * Get prior to calling acpi_bus_get_status() so we know whether
1084          * or not _STA is present.  Note that we only look for object
1085          * handles -- cannot evaluate objects until we know the device is
1086          * present and properly initialized.
1087          */
1088         result = acpi_bus_get_flags(device);
1089         if (result)
1090                 goto end;
1091
1092         /*
1093          * Status
1094          * ------
1095          * See if the device is present.  We always assume that non-Device
1096          * and non-Processor objects (e.g. thermal zones, power resources,
1097          * etc.) are present, functioning, etc. (at least when parent object
1098          * is present).  Note that _STA has a different meaning for some
1099          * objects (e.g. power resources) so we need to be careful how we use
1100          * it.
1101          */
1102         switch (type) {
1103         case ACPI_BUS_TYPE_PROCESSOR:
1104         case ACPI_BUS_TYPE_DEVICE:
1105                 result = acpi_bus_get_status(device);
1106                 if (ACPI_FAILURE(result) || !device->status.present) {
1107                         result = -ENOENT;
1108                         goto end;
1109                 }
1110                 break;
1111         default:
1112                 STRUCT_TO_INT(device->status) = 0x0F;
1113                 break;
1114         }
1115
1116         /*
1117          * Initialize Device
1118          * -----------------
1119          * TBD: Synch with Core's enumeration/initialization process.
1120          */
1121
1122         /*
1123          * Hardware ID, Unique ID, & Bus Address
1124          * -------------------------------------
1125          */
1126         acpi_device_set_id(device, parent, handle, type);
1127
1128         /*
1129          * Power Management
1130          * ----------------
1131          */
1132         if (device->flags.power_manageable) {
1133                 result = acpi_bus_get_power_flags(device);
1134                 if (result)
1135                         goto end;
1136         }
1137
1138         /*
1139          * Wakeup device management
1140          *-----------------------
1141          */
1142         if (device->flags.wake_capable) {
1143                 result = acpi_bus_get_wakeup_device_flags(device);
1144                 if (result)
1145                         goto end;
1146         }
1147
1148         /*
1149          * Performance Management
1150          * ----------------------
1151          */
1152         if (device->flags.performance_manageable) {
1153                 result = acpi_bus_get_perf_flags(device);
1154                 if (result)
1155                         goto end;
1156         }
1157
1158         if ((result = acpi_device_set_context(device, type)))
1159                 goto end;
1160
1161         acpi_device_get_debug_info(device, handle, type);
1162
1163         acpi_device_register(device, parent);
1164
1165         /*
1166          * Bind _ADR-Based Devices
1167          * -----------------------
1168          * If there's a a bus address (_ADR) then we utilize the parent's 
1169          * 'bind' function (if exists) to bind the ACPI- and natively-
1170          * enumerated device representations.
1171          */
1172         if (device->flags.bus_address) {
1173                 if (device->parent && device->parent->ops.bind)
1174                         device->parent->ops.bind(device);
1175         }
1176
1177         /*
1178          * Locate & Attach Driver
1179          * ----------------------
1180          * If there's a hardware id (_HID) or compatible ids (_CID) we check
1181          * to see if there's a driver installed for this kind of device.  Note
1182          * that drivers can install before or after a device is enumerated.
1183          *
1184          * TBD: Assumes LDM provides driver hot-plug capability.
1185          */
1186         acpi_bus_find_driver(device);
1187
1188       end:
1189         if (!result)
1190                 *child = device;
1191         else {
1192                 kfree(device->pnp.cid_list);
1193                 kfree(device);
1194         }
1195
1196         return result;
1197 }
1198
1199 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1200 {
1201         acpi_status status = AE_OK;
1202         struct acpi_device *parent = NULL;
1203         struct acpi_device *child = NULL;
1204         acpi_handle phandle = NULL;
1205         acpi_handle chandle = NULL;
1206         acpi_object_type type = 0;
1207         u32 level = 1;
1208
1209
1210         if (!start)
1211                 return -EINVAL;
1212
1213         parent = start;
1214         phandle = start->handle;
1215
1216         /*
1217          * Parse through the ACPI namespace, identify all 'devices', and
1218          * create a new 'struct acpi_device' for each.
1219          */
1220         while ((level > 0) && parent) {
1221
1222                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1223                                               chandle, &chandle);
1224
1225                 /*
1226                  * If this scope is exhausted then move our way back up.
1227                  */
1228                 if (ACPI_FAILURE(status)) {
1229                         level--;
1230                         chandle = phandle;
1231                         acpi_get_parent(phandle, &phandle);
1232                         if (parent->parent)
1233                                 parent = parent->parent;
1234                         continue;
1235                 }
1236
1237                 status = acpi_get_type(chandle, &type);
1238                 if (ACPI_FAILURE(status))
1239                         continue;
1240
1241                 /*
1242                  * If this is a scope object then parse it (depth-first).
1243                  */
1244                 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1245                         level++;
1246                         phandle = chandle;
1247                         chandle = NULL;
1248                         continue;
1249                 }
1250
1251                 /*
1252                  * We're only interested in objects that we consider 'devices'.
1253                  */
1254                 switch (type) {
1255                 case ACPI_TYPE_DEVICE:
1256                         type = ACPI_BUS_TYPE_DEVICE;
1257                         break;
1258                 case ACPI_TYPE_PROCESSOR:
1259                         type = ACPI_BUS_TYPE_PROCESSOR;
1260                         break;
1261                 case ACPI_TYPE_THERMAL:
1262                         type = ACPI_BUS_TYPE_THERMAL;
1263                         break;
1264                 case ACPI_TYPE_POWER:
1265                         type = ACPI_BUS_TYPE_POWER;
1266                         break;
1267                 default:
1268                         continue;
1269                 }
1270
1271                 if (ops->acpi_op_add)
1272                         status = acpi_add_single_object(&child, parent,
1273                                                         chandle, type);
1274                 else
1275                         status = acpi_bus_get_device(chandle, &child);
1276
1277                 if (ACPI_FAILURE(status))
1278                         continue;
1279
1280                 if (ops->acpi_op_start) {
1281                         status = acpi_start_single_object(child);
1282                         if (ACPI_FAILURE(status))
1283                                 continue;
1284                 }
1285
1286                 /*
1287                  * If the device is present, enabled, and functioning then
1288                  * parse its scope (depth-first).  Note that we need to
1289                  * represent absent devices to facilitate PnP notifications
1290                  * -- but only the subtree head (not all of its children,
1291                  * which will be enumerated when the parent is inserted).
1292                  *
1293                  * TBD: Need notifications and other detection mechanisms
1294                  *      in place before we can fully implement this.
1295                  */
1296                 if (child->status.present) {
1297                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1298                                                       NULL, NULL);
1299                         if (ACPI_SUCCESS(status)) {
1300                                 level++;
1301                                 phandle = chandle;
1302                                 chandle = NULL;
1303                                 parent = child;
1304                         }
1305                 }
1306         }
1307
1308         return 0;
1309 }
1310
1311 int
1312 acpi_bus_add(struct acpi_device **child,
1313              struct acpi_device *parent, acpi_handle handle, int type)
1314 {
1315         int result;
1316         struct acpi_bus_ops ops;
1317
1318
1319         result = acpi_add_single_object(child, parent, handle, type);
1320         if (!result) {
1321                 memset(&ops, 0, sizeof(ops));
1322                 ops.acpi_op_add = 1;
1323                 result = acpi_bus_scan(*child, &ops);
1324         }
1325         return result;
1326 }
1327
1328 EXPORT_SYMBOL(acpi_bus_add);
1329
1330 int acpi_bus_start(struct acpi_device *device)
1331 {
1332         int result;
1333         struct acpi_bus_ops ops;
1334
1335
1336         if (!device)
1337                 return -EINVAL;
1338
1339         result = acpi_start_single_object(device);
1340         if (!result) {
1341                 memset(&ops, 0, sizeof(ops));
1342                 ops.acpi_op_start = 1;
1343                 result = acpi_bus_scan(device, &ops);
1344         }
1345         return result;
1346 }
1347
1348 EXPORT_SYMBOL(acpi_bus_start);
1349
1350 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1351 {
1352         acpi_status status;
1353         struct acpi_device *parent, *child;
1354         acpi_handle phandle, chandle;
1355         acpi_object_type type;
1356         u32 level = 1;
1357         int err = 0;
1358
1359         parent = start;
1360         phandle = start->handle;
1361         child = chandle = NULL;
1362
1363         while ((level > 0) && parent && (!err)) {
1364                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1365                                               chandle, &chandle);
1366
1367                 /*
1368                  * If this scope is exhausted then move our way back up.
1369                  */
1370                 if (ACPI_FAILURE(status)) {
1371                         level--;
1372                         chandle = phandle;
1373                         acpi_get_parent(phandle, &phandle);
1374                         child = parent;
1375                         parent = parent->parent;
1376
1377                         if (level == 0)
1378                                 err = acpi_bus_remove(child, rmdevice);
1379                         else
1380                                 err = acpi_bus_remove(child, 1);
1381
1382                         continue;
1383                 }
1384
1385                 status = acpi_get_type(chandle, &type);
1386                 if (ACPI_FAILURE(status)) {
1387                         continue;
1388                 }
1389                 /*
1390                  * If there is a device corresponding to chandle then
1391                  * parse it (depth-first).
1392                  */
1393                 if (acpi_bus_get_device(chandle, &child) == 0) {
1394                         level++;
1395                         phandle = chandle;
1396                         chandle = NULL;
1397                         parent = child;
1398                 }
1399                 continue;
1400         }
1401         return err;
1402 }
1403 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1404
1405
1406 static int acpi_bus_scan_fixed(struct acpi_device *root)
1407 {
1408         int result = 0;
1409         struct acpi_device *device = NULL;
1410
1411
1412         if (!root)
1413                 return -ENODEV;
1414
1415         /*
1416          * Enumerate all fixed-feature devices.
1417          */
1418         if (acpi_fadt.pwr_button == 0) {
1419                 result = acpi_add_single_object(&device, acpi_root,
1420                                                 NULL,
1421                                                 ACPI_BUS_TYPE_POWER_BUTTON);
1422                 if (!result)
1423                         result = acpi_start_single_object(device);
1424         }
1425
1426         if (acpi_fadt.sleep_button == 0) {
1427                 result = acpi_add_single_object(&device, acpi_root,
1428                                                 NULL,
1429                                                 ACPI_BUS_TYPE_SLEEP_BUTTON);
1430                 if (!result)
1431                         result = acpi_start_single_object(device);
1432         }
1433
1434         return result;
1435 }
1436
1437 static int __init acpi_scan_init(void)
1438 {
1439         int result;
1440         struct acpi_bus_ops ops;
1441
1442
1443         if (acpi_disabled)
1444                 return 0;
1445
1446         result = kset_register(&acpi_namespace_kset);
1447         if (result < 0)
1448                 printk(KERN_ERR PREFIX "kset_register error: %d\n", result);
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 result;
1492 }
1493
1494 subsys_initcall(acpi_scan_init);