Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linux
[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/kernel.h>
8 #include <linux/acpi.h>
9 #include <linux/signal.h>
10 #include <linux/kthread.h>
11
12 #include <acpi/acpi_drivers.h>
13
14 #include "internal.h"
15
16 #define _COMPONENT              ACPI_BUS_COMPONENT
17 ACPI_MODULE_NAME("scan");
18 #define STRUCT_TO_INT(s)        (*((int*)&s))
19 extern struct acpi_device *acpi_root;
20
21 #define ACPI_BUS_CLASS                  "system_bus"
22 #define ACPI_BUS_HID                    "LNXSYBUS"
23 #define ACPI_BUS_DEVICE_NAME            "System Bus"
24
25 static LIST_HEAD(acpi_device_list);
26 static LIST_HEAD(acpi_bus_id_list);
27 DEFINE_SPINLOCK(acpi_device_lock);
28 LIST_HEAD(acpi_wakeup_device_list);
29
30 struct acpi_device_bus_id{
31         char bus_id[15];
32         unsigned int instance_no;
33         struct list_head node;
34 };
35
36 /*
37  * Creates hid/cid(s) string needed for modalias and uevent
38  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
39  * char *modalias: "acpi:IBM0001:ACPI0001"
40 */
41 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
42                            int size)
43 {
44         int len;
45         int count;
46
47         if (!acpi_dev->flags.hardware_id && !acpi_dev->flags.compatible_ids)
48                 return -ENODEV;
49
50         len = snprintf(modalias, size, "acpi:");
51         size -= len;
52
53         if (acpi_dev->flags.hardware_id) {
54                 count = snprintf(&modalias[len], size, "%s:",
55                                  acpi_dev->pnp.hardware_id);
56                 if (count < 0 || count >= size)
57                         return -EINVAL;
58                 len += count;
59                 size -= count;
60         }
61
62         if (acpi_dev->flags.compatible_ids) {
63                 struct acpi_compatible_id_list *cid_list;
64                 int i;
65
66                 cid_list = acpi_dev->pnp.cid_list;
67                 for (i = 0; i < cid_list->count; i++) {
68                         count = snprintf(&modalias[len], size, "%s:",
69                                          cid_list->id[i].value);
70                         if (count < 0 || count >= size) {
71                                 printk(KERN_ERR PREFIX "%s cid[%i] exceeds event buffer size",
72                                        acpi_dev->pnp.device_name, i);
73                                 break;
74                         }
75                         len += count;
76                         size -= count;
77                 }
78         }
79
80         modalias[len] = '\0';
81         return len;
82 }
83
84 static ssize_t
85 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
86         struct acpi_device *acpi_dev = to_acpi_device(dev);
87         int len;
88
89         /* Device has no HID and no CID or string is >1024 */
90         len = create_modalias(acpi_dev, buf, 1024);
91         if (len <= 0)
92                 return 0;
93         buf[len++] = '\n';
94         return len;
95 }
96 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
97
98 static int acpi_bus_hot_remove_device(void *context)
99 {
100         struct acpi_device *device;
101         acpi_handle handle = context;
102         struct acpi_object_list arg_list;
103         union acpi_object arg;
104         acpi_status status = AE_OK;
105
106         if (acpi_bus_get_device(handle, &device))
107                 return 0;
108
109         if (!device)
110                 return 0;
111
112         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
113                 "Hot-removing device %s...\n", dev_name(&device->dev)));
114
115         if (acpi_bus_trim(device, 1)) {
116                 printk(KERN_ERR PREFIX
117                                 "Removing device failed\n");
118                 return -1;
119         }
120
121         /* power off device */
122         status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
123         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
124                 printk(KERN_WARNING PREFIX
125                                 "Power-off device failed\n");
126
127         if (device->flags.lockable) {
128                 arg_list.count = 1;
129                 arg_list.pointer = &arg;
130                 arg.type = ACPI_TYPE_INTEGER;
131                 arg.integer.value = 0;
132                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
133         }
134
135         arg_list.count = 1;
136         arg_list.pointer = &arg;
137         arg.type = ACPI_TYPE_INTEGER;
138         arg.integer.value = 1;
139
140         /*
141          * TBD: _EJD support.
142          */
143         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
144         if (ACPI_FAILURE(status))
145                 return -ENODEV;
146
147         return 0;
148 }
149
150 static ssize_t
151 acpi_eject_store(struct device *d, struct device_attribute *attr,
152                 const char *buf, size_t count)
153 {
154         int ret = count;
155         acpi_status status;
156         acpi_object_type type = 0;
157         struct acpi_device *acpi_device = to_acpi_device(d);
158         struct task_struct *task;
159
160         if ((!count) || (buf[0] != '1')) {
161                 return -EINVAL;
162         }
163 #ifndef FORCE_EJECT
164         if (acpi_device->driver == NULL) {
165                 ret = -ENODEV;
166                 goto err;
167         }
168 #endif
169         status = acpi_get_type(acpi_device->handle, &type);
170         if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
171                 ret = -ENODEV;
172                 goto err;
173         }
174
175         /* remove the device in another thread to fix the deadlock issue */
176         task = kthread_run(acpi_bus_hot_remove_device,
177                                 acpi_device->handle, "acpi_hot_remove_device");
178         if (IS_ERR(task))
179                 ret = PTR_ERR(task);
180 err:
181         return ret;
182 }
183
184 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
185
186 static ssize_t
187 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
188         struct acpi_device *acpi_dev = to_acpi_device(dev);
189
190         return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
191 }
192 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
193
194 static ssize_t
195 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
196         struct acpi_device *acpi_dev = to_acpi_device(dev);
197         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
198         int result;
199
200         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
201         if(result)
202                 goto end;
203
204         result = sprintf(buf, "%s\n", (char*)path.pointer);
205         kfree(path.pointer);
206   end:
207         return result;
208 }
209 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
210
211 static int acpi_device_setup_files(struct acpi_device *dev)
212 {
213         acpi_status status;
214         acpi_handle temp;
215         int result = 0;
216
217         /*
218          * Devices gotten from FADT don't have a "path" attribute
219          */
220         if(dev->handle) {
221                 result = device_create_file(&dev->dev, &dev_attr_path);
222                 if(result)
223                         goto end;
224         }
225
226         if(dev->flags.hardware_id) {
227                 result = device_create_file(&dev->dev, &dev_attr_hid);
228                 if(result)
229                         goto end;
230         }
231
232         if (dev->flags.hardware_id || dev->flags.compatible_ids){
233                 result = device_create_file(&dev->dev, &dev_attr_modalias);
234                 if(result)
235                         goto end;
236         }
237
238         /*
239          * If device has _EJ0, 'eject' file is created that is used to trigger
240          * hot-removal function from userland.
241          */
242         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
243         if (ACPI_SUCCESS(status))
244                 result = device_create_file(&dev->dev, &dev_attr_eject);
245   end:
246         return result;
247 }
248
249 static void acpi_device_remove_files(struct acpi_device *dev)
250 {
251         acpi_status status;
252         acpi_handle temp;
253
254         /*
255          * If device has _EJ0, 'eject' file is created that is used to trigger
256          * hot-removal function from userland.
257          */
258         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
259         if (ACPI_SUCCESS(status))
260                 device_remove_file(&dev->dev, &dev_attr_eject);
261
262         if (dev->flags.hardware_id || dev->flags.compatible_ids)
263                 device_remove_file(&dev->dev, &dev_attr_modalias);
264
265         if(dev->flags.hardware_id)
266                 device_remove_file(&dev->dev, &dev_attr_hid);
267         if(dev->handle)
268                 device_remove_file(&dev->dev, &dev_attr_path);
269 }
270 /* --------------------------------------------------------------------------
271                         ACPI Bus operations
272    -------------------------------------------------------------------------- */
273
274 int acpi_match_device_ids(struct acpi_device *device,
275                           const struct acpi_device_id *ids)
276 {
277         const struct acpi_device_id *id;
278
279         /*
280          * If the device is not present, it is unnecessary to load device
281          * driver for it.
282          */
283         if (!device->status.present)
284                 return -ENODEV;
285
286         if (device->flags.hardware_id) {
287                 for (id = ids; id->id[0]; id++) {
288                         if (!strcmp((char*)id->id, device->pnp.hardware_id))
289                                 return 0;
290                 }
291         }
292
293         if (device->flags.compatible_ids) {
294                 struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
295                 int i;
296
297                 for (id = ids; id->id[0]; id++) {
298                         /* compare multiple _CID entries against driver ids */
299                         for (i = 0; i < cid_list->count; i++) {
300                                 if (!strcmp((char*)id->id,
301                                             cid_list->id[i].value))
302                                         return 0;
303                         }
304                 }
305         }
306
307         return -ENOENT;
308 }
309 EXPORT_SYMBOL(acpi_match_device_ids);
310
311 static void acpi_device_release(struct device *dev)
312 {
313         struct acpi_device *acpi_dev = to_acpi_device(dev);
314
315         kfree(acpi_dev->pnp.cid_list);
316         kfree(acpi_dev);
317 }
318
319 static int acpi_device_suspend(struct device *dev, pm_message_t state)
320 {
321         struct acpi_device *acpi_dev = to_acpi_device(dev);
322         struct acpi_driver *acpi_drv = acpi_dev->driver;
323
324         if (acpi_drv && acpi_drv->ops.suspend)
325                 return acpi_drv->ops.suspend(acpi_dev, state);
326         return 0;
327 }
328
329 static int acpi_device_resume(struct device *dev)
330 {
331         struct acpi_device *acpi_dev = to_acpi_device(dev);
332         struct acpi_driver *acpi_drv = acpi_dev->driver;
333
334         if (acpi_drv && acpi_drv->ops.resume)
335                 return acpi_drv->ops.resume(acpi_dev);
336         return 0;
337 }
338
339 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
340 {
341         struct acpi_device *acpi_dev = to_acpi_device(dev);
342         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
343
344         return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
345 }
346
347 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
348 {
349         struct acpi_device *acpi_dev = to_acpi_device(dev);
350         int len;
351
352         if (add_uevent_var(env, "MODALIAS="))
353                 return -ENOMEM;
354         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
355                               sizeof(env->buf) - env->buflen);
356         if (len >= (sizeof(env->buf) - env->buflen))
357                 return -ENOMEM;
358         env->buflen += len;
359         return 0;
360 }
361
362 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
363 {
364         struct acpi_device *device = data;
365
366         device->driver->ops.notify(device, event);
367 }
368
369 static acpi_status acpi_device_notify_fixed(void *data)
370 {
371         struct acpi_device *device = data;
372
373         acpi_device_notify(device->handle, ACPI_FIXED_HARDWARE_EVENT, device);
374         return AE_OK;
375 }
376
377 static int acpi_device_install_notify_handler(struct acpi_device *device)
378 {
379         acpi_status status;
380         char *hid;
381
382         hid = acpi_device_hid(device);
383         if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))
384                 status =
385                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
386                                                      acpi_device_notify_fixed,
387                                                      device);
388         else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
389                 status =
390                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
391                                                      acpi_device_notify_fixed,
392                                                      device);
393         else
394                 status = acpi_install_notify_handler(device->handle,
395                                                      ACPI_DEVICE_NOTIFY,
396                                                      acpi_device_notify,
397                                                      device);
398
399         if (ACPI_FAILURE(status))
400                 return -EINVAL;
401         return 0;
402 }
403
404 static void acpi_device_remove_notify_handler(struct acpi_device *device)
405 {
406         if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF))
407                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
408                                                 acpi_device_notify_fixed);
409         else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF))
410                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
411                                                 acpi_device_notify_fixed);
412         else
413                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
414                                            acpi_device_notify);
415 }
416
417 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
418 static int acpi_start_single_object(struct acpi_device *);
419 static int acpi_device_probe(struct device * dev)
420 {
421         struct acpi_device *acpi_dev = to_acpi_device(dev);
422         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
423         int ret;
424
425         ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
426         if (!ret) {
427                 if (acpi_dev->bus_ops.acpi_op_start)
428                         acpi_start_single_object(acpi_dev);
429
430                 if (acpi_drv->ops.notify) {
431                         ret = acpi_device_install_notify_handler(acpi_dev);
432                         if (ret) {
433                                 if (acpi_drv->ops.stop)
434                                         acpi_drv->ops.stop(acpi_dev,
435                                                    acpi_dev->removal_type);
436                                 if (acpi_drv->ops.remove)
437                                         acpi_drv->ops.remove(acpi_dev,
438                                                      acpi_dev->removal_type);
439                                 return ret;
440                         }
441                 }
442
443                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
444                         "Found driver [%s] for device [%s]\n",
445                         acpi_drv->name, acpi_dev->pnp.bus_id));
446                 get_device(dev);
447         }
448         return ret;
449 }
450
451 static int acpi_device_remove(struct device * dev)
452 {
453         struct acpi_device *acpi_dev = to_acpi_device(dev);
454         struct acpi_driver *acpi_drv = acpi_dev->driver;
455
456         if (acpi_drv) {
457                 if (acpi_drv->ops.notify)
458                         acpi_device_remove_notify_handler(acpi_dev);
459                 if (acpi_drv->ops.stop)
460                         acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
461                 if (acpi_drv->ops.remove)
462                         acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
463         }
464         acpi_dev->driver = NULL;
465         acpi_dev->driver_data = NULL;
466
467         put_device(dev);
468         return 0;
469 }
470
471 struct bus_type acpi_bus_type = {
472         .name           = "acpi",
473         .suspend        = acpi_device_suspend,
474         .resume         = acpi_device_resume,
475         .match          = acpi_bus_match,
476         .probe          = acpi_device_probe,
477         .remove         = acpi_device_remove,
478         .uevent         = acpi_device_uevent,
479 };
480
481 static int acpi_device_register(struct acpi_device *device,
482                                  struct acpi_device *parent)
483 {
484         int result;
485         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
486         int found = 0;
487         /*
488          * Linkage
489          * -------
490          * Link this device to its parent and siblings.
491          */
492         INIT_LIST_HEAD(&device->children);
493         INIT_LIST_HEAD(&device->node);
494         INIT_LIST_HEAD(&device->g_list);
495         INIT_LIST_HEAD(&device->wakeup_list);
496
497         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
498         if (!new_bus_id) {
499                 printk(KERN_ERR PREFIX "Memory allocation error\n");
500                 return -ENOMEM;
501         }
502
503         spin_lock(&acpi_device_lock);
504         /*
505          * Find suitable bus_id and instance number in acpi_bus_id_list
506          * If failed, create one and link it into acpi_bus_id_list
507          */
508         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
509                 if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
510                         acpi_device_bus_id->instance_no ++;
511                         found = 1;
512                         kfree(new_bus_id);
513                         break;
514                 }
515         }
516         if(!found) {
517                 acpi_device_bus_id = new_bus_id;
518                 strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
519                 acpi_device_bus_id->instance_no = 0;
520                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
521         }
522         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
523
524         if (device->parent) {
525                 list_add_tail(&device->node, &device->parent->children);
526                 list_add_tail(&device->g_list, &device->parent->g_list);
527         } else
528                 list_add_tail(&device->g_list, &acpi_device_list);
529         if (device->wakeup.flags.valid)
530                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
531         spin_unlock(&acpi_device_lock);
532
533         if (device->parent)
534                 device->dev.parent = &parent->dev;
535         device->dev.bus = &acpi_bus_type;
536         device_initialize(&device->dev);
537         device->dev.release = &acpi_device_release;
538         result = device_add(&device->dev);
539         if(result) {
540                 dev_err(&device->dev, "Error adding device\n");
541                 goto end;
542         }
543
544         result = acpi_device_setup_files(device);
545         if(result)
546                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
547                        dev_name(&device->dev));
548
549         device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
550         return 0;
551   end:
552         spin_lock(&acpi_device_lock);
553         if (device->parent) {
554                 list_del(&device->node);
555                 list_del(&device->g_list);
556         } else
557                 list_del(&device->g_list);
558         list_del(&device->wakeup_list);
559         spin_unlock(&acpi_device_lock);
560         return result;
561 }
562
563 static void acpi_device_unregister(struct acpi_device *device, int type)
564 {
565         spin_lock(&acpi_device_lock);
566         if (device->parent) {
567                 list_del(&device->node);
568                 list_del(&device->g_list);
569         } else
570                 list_del(&device->g_list);
571
572         list_del(&device->wakeup_list);
573         spin_unlock(&acpi_device_lock);
574
575         acpi_detach_data(device->handle, acpi_bus_data_handler);
576
577         acpi_device_remove_files(device);
578         device_unregister(&device->dev);
579 }
580
581 /* --------------------------------------------------------------------------
582                                  Driver Management
583    -------------------------------------------------------------------------- */
584 /**
585  * acpi_bus_driver_init - add a device to a driver
586  * @device: the device to add and initialize
587  * @driver: driver for the device
588  *
589  * Used to initialize a device via its device driver.  Called whenever a 
590  * driver is bound to a device.  Invokes the driver's add() ops.
591  */
592 static int
593 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
594 {
595         int result = 0;
596
597
598         if (!device || !driver)
599                 return -EINVAL;
600
601         if (!driver->ops.add)
602                 return -ENOSYS;
603
604         result = driver->ops.add(device);
605         if (result) {
606                 device->driver = NULL;
607                 device->driver_data = NULL;
608                 return result;
609         }
610
611         device->driver = driver;
612
613         /*
614          * TBD - Configuration Management: Assign resources to device based
615          * upon possible configuration and currently allocated resources.
616          */
617
618         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
619                           "Driver successfully bound to device\n"));
620         return 0;
621 }
622
623 static int acpi_start_single_object(struct acpi_device *device)
624 {
625         int result = 0;
626         struct acpi_driver *driver;
627
628
629         if (!(driver = device->driver))
630                 return 0;
631
632         if (driver->ops.start) {
633                 result = driver->ops.start(device);
634                 if (result && driver->ops.remove)
635                         driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
636         }
637
638         return result;
639 }
640
641 /**
642  * acpi_bus_register_driver - register a driver with the ACPI bus
643  * @driver: driver being registered
644  *
645  * Registers a driver with the ACPI bus.  Searches the namespace for all
646  * devices that match the driver's criteria and binds.  Returns zero for
647  * success or a negative error status for failure.
648  */
649 int acpi_bus_register_driver(struct acpi_driver *driver)
650 {
651         int ret;
652
653         if (acpi_disabled)
654                 return -ENODEV;
655         driver->drv.name = driver->name;
656         driver->drv.bus = &acpi_bus_type;
657         driver->drv.owner = driver->owner;
658
659         ret = driver_register(&driver->drv);
660         return ret;
661 }
662
663 EXPORT_SYMBOL(acpi_bus_register_driver);
664
665 /**
666  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
667  * @driver: driver to unregister
668  *
669  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
670  * devices that match the driver's criteria and unbinds.
671  */
672 void acpi_bus_unregister_driver(struct acpi_driver *driver)
673 {
674         driver_unregister(&driver->drv);
675 }
676
677 EXPORT_SYMBOL(acpi_bus_unregister_driver);
678
679 /* --------------------------------------------------------------------------
680                                  Device Enumeration
681    -------------------------------------------------------------------------- */
682 acpi_status
683 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
684 {
685         acpi_status status;
686         acpi_handle tmp;
687         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
688         union acpi_object *obj;
689
690         status = acpi_get_handle(handle, "_EJD", &tmp);
691         if (ACPI_FAILURE(status))
692                 return status;
693
694         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
695         if (ACPI_SUCCESS(status)) {
696                 obj = buffer.pointer;
697                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
698                                          ejd);
699                 kfree(buffer.pointer);
700         }
701         return status;
702 }
703 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
704
705 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
706 {
707
708         /* TBD */
709
710         return;
711 }
712
713 static int acpi_bus_get_perf_flags(struct acpi_device *device)
714 {
715         device->performance.state = ACPI_STATE_UNKNOWN;
716         return 0;
717 }
718
719 static acpi_status
720 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
721                                              union acpi_object *package)
722 {
723         int i = 0;
724         union acpi_object *element = NULL;
725
726         if (!device || !package || (package->package.count < 2))
727                 return AE_BAD_PARAMETER;
728
729         element = &(package->package.elements[0]);
730         if (!element)
731                 return AE_BAD_PARAMETER;
732         if (element->type == ACPI_TYPE_PACKAGE) {
733                 if ((element->package.count < 2) ||
734                     (element->package.elements[0].type !=
735                      ACPI_TYPE_LOCAL_REFERENCE)
736                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
737                         return AE_BAD_DATA;
738                 device->wakeup.gpe_device =
739                     element->package.elements[0].reference.handle;
740                 device->wakeup.gpe_number =
741                     (u32) element->package.elements[1].integer.value;
742         } else if (element->type == ACPI_TYPE_INTEGER) {
743                 device->wakeup.gpe_number = element->integer.value;
744         } else
745                 return AE_BAD_DATA;
746
747         element = &(package->package.elements[1]);
748         if (element->type != ACPI_TYPE_INTEGER) {
749                 return AE_BAD_DATA;
750         }
751         device->wakeup.sleep_state = element->integer.value;
752
753         if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
754                 return AE_NO_MEMORY;
755         }
756         device->wakeup.resources.count = package->package.count - 2;
757         for (i = 0; i < device->wakeup.resources.count; i++) {
758                 element = &(package->package.elements[i + 2]);
759                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
760                         return AE_BAD_DATA;
761
762                 device->wakeup.resources.handles[i] = element->reference.handle;
763         }
764
765         return AE_OK;
766 }
767
768 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
769 {
770         acpi_status status = 0;
771         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
772         union acpi_object *package = NULL;
773         int psw_error;
774
775         struct acpi_device_id button_device_ids[] = {
776                 {"PNP0C0D", 0},
777                 {"PNP0C0C", 0},
778                 {"PNP0C0E", 0},
779                 {"", 0},
780         };
781
782         /* _PRW */
783         status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
784         if (ACPI_FAILURE(status)) {
785                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
786                 goto end;
787         }
788
789         package = (union acpi_object *)buffer.pointer;
790         status = acpi_bus_extract_wakeup_device_power_package(device, package);
791         if (ACPI_FAILURE(status)) {
792                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
793                 goto end;
794         }
795
796         kfree(buffer.pointer);
797
798         device->wakeup.flags.valid = 1;
799         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
800          * system for the ACPI device with the _PRW object.
801          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
802          * So it is necessary to call _DSW object first. Only when it is not
803          * present will the _PSW object used.
804          */
805         psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
806         if (psw_error)
807                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
808                                 "error in _DSW or _PSW evaluation\n"));
809
810         /* Power button, Lid switch always enable wakeup */
811         if (!acpi_match_device_ids(device, button_device_ids))
812                 device->wakeup.flags.run_wake = 1;
813
814       end:
815         if (ACPI_FAILURE(status))
816                 device->flags.wake_capable = 0;
817         return 0;
818 }
819
820 static int acpi_bus_get_power_flags(struct acpi_device *device)
821 {
822         acpi_status status = 0;
823         acpi_handle handle = NULL;
824         u32 i = 0;
825
826
827         /*
828          * Power Management Flags
829          */
830         status = acpi_get_handle(device->handle, "_PSC", &handle);
831         if (ACPI_SUCCESS(status))
832                 device->power.flags.explicit_get = 1;
833         status = acpi_get_handle(device->handle, "_IRC", &handle);
834         if (ACPI_SUCCESS(status))
835                 device->power.flags.inrush_current = 1;
836
837         /*
838          * Enumerate supported power management states
839          */
840         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
841                 struct acpi_device_power_state *ps = &device->power.states[i];
842                 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
843
844                 /* Evaluate "_PRx" to se if power resources are referenced */
845                 acpi_evaluate_reference(device->handle, object_name, NULL,
846                                         &ps->resources);
847                 if (ps->resources.count) {
848                         device->power.flags.power_resources = 1;
849                         ps->flags.valid = 1;
850                 }
851
852                 /* Evaluate "_PSx" to see if we can do explicit sets */
853                 object_name[2] = 'S';
854                 status = acpi_get_handle(device->handle, object_name, &handle);
855                 if (ACPI_SUCCESS(status)) {
856                         ps->flags.explicit_set = 1;
857                         ps->flags.valid = 1;
858                 }
859
860                 /* State is valid if we have some power control */
861                 if (ps->resources.count || ps->flags.explicit_set)
862                         ps->flags.valid = 1;
863
864                 ps->power = -1; /* Unknown - driver assigned */
865                 ps->latency = -1;       /* Unknown - driver assigned */
866         }
867
868         /* Set defaults for D0 and D3 states (always valid) */
869         device->power.states[ACPI_STATE_D0].flags.valid = 1;
870         device->power.states[ACPI_STATE_D0].power = 100;
871         device->power.states[ACPI_STATE_D3].flags.valid = 1;
872         device->power.states[ACPI_STATE_D3].power = 0;
873
874         /* TBD: System wake support and resource requirements. */
875
876         device->power.state = ACPI_STATE_UNKNOWN;
877         acpi_bus_get_power(device->handle, &(device->power.state));
878
879         return 0;
880 }
881
882 static int acpi_bus_get_flags(struct acpi_device *device)
883 {
884         acpi_status status = AE_OK;
885         acpi_handle temp = NULL;
886
887
888         /* Presence of _STA indicates 'dynamic_status' */
889         status = acpi_get_handle(device->handle, "_STA", &temp);
890         if (ACPI_SUCCESS(status))
891                 device->flags.dynamic_status = 1;
892
893         /* Presence of _CID indicates 'compatible_ids' */
894         status = acpi_get_handle(device->handle, "_CID", &temp);
895         if (ACPI_SUCCESS(status))
896                 device->flags.compatible_ids = 1;
897
898         /* Presence of _RMV indicates 'removable' */
899         status = acpi_get_handle(device->handle, "_RMV", &temp);
900         if (ACPI_SUCCESS(status))
901                 device->flags.removable = 1;
902
903         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
904         status = acpi_get_handle(device->handle, "_EJD", &temp);
905         if (ACPI_SUCCESS(status))
906                 device->flags.ejectable = 1;
907         else {
908                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
909                 if (ACPI_SUCCESS(status))
910                         device->flags.ejectable = 1;
911         }
912
913         /* Presence of _LCK indicates 'lockable' */
914         status = acpi_get_handle(device->handle, "_LCK", &temp);
915         if (ACPI_SUCCESS(status))
916                 device->flags.lockable = 1;
917
918         /* Presence of _PS0|_PR0 indicates 'power manageable' */
919         status = acpi_get_handle(device->handle, "_PS0", &temp);
920         if (ACPI_FAILURE(status))
921                 status = acpi_get_handle(device->handle, "_PR0", &temp);
922         if (ACPI_SUCCESS(status))
923                 device->flags.power_manageable = 1;
924
925         /* Presence of _PRW indicates wake capable */
926         status = acpi_get_handle(device->handle, "_PRW", &temp);
927         if (ACPI_SUCCESS(status))
928                 device->flags.wake_capable = 1;
929
930         /* TBD: Performance management */
931
932         return 0;
933 }
934
935 static void acpi_device_get_busid(struct acpi_device *device,
936                                   acpi_handle handle, int type)
937 {
938         char bus_id[5] = { '?', 0 };
939         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
940         int i = 0;
941
942         /*
943          * Bus ID
944          * ------
945          * The device's Bus ID is simply the object name.
946          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
947          */
948         switch (type) {
949         case ACPI_BUS_TYPE_SYSTEM:
950                 strcpy(device->pnp.bus_id, "ACPI");
951                 break;
952         case ACPI_BUS_TYPE_POWER_BUTTON:
953                 strcpy(device->pnp.bus_id, "PWRF");
954                 break;
955         case ACPI_BUS_TYPE_SLEEP_BUTTON:
956                 strcpy(device->pnp.bus_id, "SLPF");
957                 break;
958         default:
959                 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
960                 /* Clean up trailing underscores (if any) */
961                 for (i = 3; i > 1; i--) {
962                         if (bus_id[i] == '_')
963                                 bus_id[i] = '\0';
964                         else
965                                 break;
966                 }
967                 strcpy(device->pnp.bus_id, bus_id);
968                 break;
969         }
970 }
971
972 /*
973  * acpi_bay_match - see if a device is an ejectable driver bay
974  *
975  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
976  * then we can safely call it an ejectable drive bay
977  */
978 static int acpi_bay_match(struct acpi_device *device){
979         acpi_status status;
980         acpi_handle handle;
981         acpi_handle tmp;
982         acpi_handle phandle;
983
984         handle = device->handle;
985
986         status = acpi_get_handle(handle, "_EJ0", &tmp);
987         if (ACPI_FAILURE(status))
988                 return -ENODEV;
989
990         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
991                 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
992                 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
993                 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
994                 return 0;
995
996         if (acpi_get_parent(handle, &phandle))
997                 return -ENODEV;
998
999         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
1000                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
1001                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
1002                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
1003                 return 0;
1004
1005         return -ENODEV;
1006 }
1007
1008 /*
1009  * acpi_dock_match - see if a device has a _DCK method
1010  */
1011 static int acpi_dock_match(struct acpi_device *device)
1012 {
1013         acpi_handle tmp;
1014         return acpi_get_handle(device->handle, "_DCK", &tmp);
1015 }
1016
1017 static void acpi_device_set_id(struct acpi_device *device,
1018                                struct acpi_device *parent, acpi_handle handle,
1019                                int type)
1020 {
1021         struct acpi_device_info *info;
1022         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1023         char *hid = NULL;
1024         char *uid = NULL;
1025         struct acpi_compatible_id_list *cid_list = NULL;
1026         const char *cid_add = NULL;
1027         acpi_status status;
1028
1029         switch (type) {
1030         case ACPI_BUS_TYPE_DEVICE:
1031                 status = acpi_get_object_info(handle, &buffer);
1032                 if (ACPI_FAILURE(status)) {
1033                         printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1034                         return;
1035                 }
1036
1037                 info = buffer.pointer;
1038                 if (info->valid & ACPI_VALID_HID)
1039                         hid = info->hardware_id.value;
1040                 if (info->valid & ACPI_VALID_UID)
1041                         uid = info->unique_id.value;
1042                 if (info->valid & ACPI_VALID_CID)
1043                         cid_list = &info->compatibility_id;
1044                 if (info->valid & ACPI_VALID_ADR) {
1045                         device->pnp.bus_address = info->address;
1046                         device->flags.bus_address = 1;
1047                 }
1048
1049                 /* If we have a video/bay/dock device, add our selfdefined
1050                    HID to the CID list. Like that the video/bay/dock drivers
1051                    will get autoloaded and the device might still match
1052                    against another driver.
1053                 */
1054                 if (acpi_is_video_device(device))
1055                         cid_add = ACPI_VIDEO_HID;
1056                 else if (ACPI_SUCCESS(acpi_bay_match(device)))
1057                         cid_add = ACPI_BAY_HID;
1058                 else if (ACPI_SUCCESS(acpi_dock_match(device)))
1059                         cid_add = ACPI_DOCK_HID;
1060
1061                 break;
1062         case ACPI_BUS_TYPE_POWER:
1063                 hid = ACPI_POWER_HID;
1064                 break;
1065         case ACPI_BUS_TYPE_PROCESSOR:
1066                 hid = ACPI_PROCESSOR_OBJECT_HID;
1067                 break;
1068         case ACPI_BUS_TYPE_SYSTEM:
1069                 hid = ACPI_SYSTEM_HID;
1070                 break;
1071         case ACPI_BUS_TYPE_THERMAL:
1072                 hid = ACPI_THERMAL_HID;
1073                 break;
1074         case ACPI_BUS_TYPE_POWER_BUTTON:
1075                 hid = ACPI_BUTTON_HID_POWERF;
1076                 break;
1077         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1078                 hid = ACPI_BUTTON_HID_SLEEPF;
1079                 break;
1080         }
1081
1082         /* 
1083          * \_SB
1084          * ----
1085          * Fix for the system root bus device -- the only root-level device.
1086          */
1087         if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
1088                 hid = ACPI_BUS_HID;
1089                 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1090                 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1091         }
1092
1093         if (hid) {
1094                 strcpy(device->pnp.hardware_id, hid);
1095                 device->flags.hardware_id = 1;
1096         }
1097         if (uid) {
1098                 strcpy(device->pnp.unique_id, uid);
1099                 device->flags.unique_id = 1;
1100         }
1101         if (cid_list || cid_add) {
1102                 struct  acpi_compatible_id_list *list;
1103                 int size = 0;
1104                 int count = 0;
1105
1106                 if (cid_list) {
1107                         size = cid_list->size;
1108                 } else if (cid_add) {
1109                         size = sizeof(struct acpi_compatible_id_list);
1110                         cid_list = ACPI_ALLOCATE_ZEROED((acpi_size) size);
1111                         if (!cid_list) {
1112                                 printk(KERN_ERR "Memory allocation error\n");
1113                                 kfree(buffer.pointer);
1114                                 return;
1115                         } else {
1116                                 cid_list->count = 0;
1117                                 cid_list->size = size;
1118                         }
1119                 }
1120                 if (cid_add)
1121                         size += sizeof(struct acpi_compatible_id);
1122                 list = kmalloc(size, GFP_KERNEL);
1123
1124                 if (list) {
1125                         if (cid_list) {
1126                                 memcpy(list, cid_list, cid_list->size);
1127                                 count = cid_list->count;
1128                         }
1129                         if (cid_add) {
1130                                 strncpy(list->id[count].value, cid_add,
1131                                         ACPI_MAX_CID_LENGTH);
1132                                 count++;
1133                                 device->flags.compatible_ids = 1;
1134                         }
1135                         list->size = size;
1136                         list->count = count;
1137                         device->pnp.cid_list = list;
1138                 } else
1139                         printk(KERN_ERR PREFIX "Memory allocation error\n");
1140         }
1141
1142         kfree(buffer.pointer);
1143 }
1144
1145 static int acpi_device_set_context(struct acpi_device *device, int type)
1146 {
1147         acpi_status status = AE_OK;
1148         int result = 0;
1149         /*
1150          * Context
1151          * -------
1152          * Attach this 'struct acpi_device' to the ACPI object.  This makes
1153          * resolutions from handle->device very efficient.  Note that we need
1154          * to be careful with fixed-feature devices as they all attach to the
1155          * root object.
1156          */
1157         if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
1158             type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
1159                 status = acpi_attach_data(device->handle,
1160                                           acpi_bus_data_handler, device);
1161
1162                 if (ACPI_FAILURE(status)) {
1163                         printk(KERN_ERR PREFIX "Error attaching device data\n");
1164                         result = -ENODEV;
1165                 }
1166         }
1167         return result;
1168 }
1169
1170 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1171 {
1172         if (!dev)
1173                 return -EINVAL;
1174
1175         dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1176         device_release_driver(&dev->dev);
1177
1178         if (!rmdevice)
1179                 return 0;
1180
1181         /*
1182          * unbind _ADR-Based Devices when hot removal
1183          */
1184         if (dev->flags.bus_address) {
1185                 if ((dev->parent) && (dev->parent->ops.unbind))
1186                         dev->parent->ops.unbind(dev);
1187         }
1188         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1189
1190         return 0;
1191 }
1192
1193 static int
1194 acpi_add_single_object(struct acpi_device **child,
1195                        struct acpi_device *parent, acpi_handle handle, int type,
1196                         struct acpi_bus_ops *ops)
1197 {
1198         int result = 0;
1199         struct acpi_device *device = NULL;
1200
1201
1202         if (!child)
1203                 return -EINVAL;
1204
1205         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1206         if (!device) {
1207                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1208                 return -ENOMEM;
1209         }
1210
1211         device->handle = handle;
1212         device->parent = parent;
1213         device->bus_ops = *ops; /* workround for not call .start */
1214
1215
1216         acpi_device_get_busid(device, handle, type);
1217
1218         /*
1219          * Flags
1220          * -----
1221          * Get prior to calling acpi_bus_get_status() so we know whether
1222          * or not _STA is present.  Note that we only look for object
1223          * handles -- cannot evaluate objects until we know the device is
1224          * present and properly initialized.
1225          */
1226         result = acpi_bus_get_flags(device);
1227         if (result)
1228                 goto end;
1229
1230         /*
1231          * Status
1232          * ------
1233          * See if the device is present.  We always assume that non-Device
1234          * and non-Processor objects (e.g. thermal zones, power resources,
1235          * etc.) are present, functioning, etc. (at least when parent object
1236          * is present).  Note that _STA has a different meaning for some
1237          * objects (e.g. power resources) so we need to be careful how we use
1238          * it.
1239          */
1240         switch (type) {
1241         case ACPI_BUS_TYPE_PROCESSOR:
1242         case ACPI_BUS_TYPE_DEVICE:
1243                 result = acpi_bus_get_status(device);
1244                 if (ACPI_FAILURE(result)) {
1245                         result = -ENODEV;
1246                         goto end;
1247                 }
1248                 /*
1249                  * When the device is neither present nor functional, the
1250                  * device should not be added to Linux ACPI device tree.
1251                  * When the status of the device is not present but functinal,
1252                  * it should be added to Linux ACPI tree. For example : bay
1253                  * device , dock device.
1254                  * In such conditions it is unncessary to check whether it is
1255                  * bay device or dock device.
1256                  */
1257                 if (!device->status.present && !device->status.functional) {
1258                         result = -ENODEV;
1259                         goto end;
1260                 }
1261                 break;
1262         default:
1263                 STRUCT_TO_INT(device->status) =
1264                     ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
1265                     ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
1266                 break;
1267         }
1268
1269         /*
1270          * Initialize Device
1271          * -----------------
1272          * TBD: Synch with Core's enumeration/initialization process.
1273          */
1274
1275         /*
1276          * Hardware ID, Unique ID, & Bus Address
1277          * -------------------------------------
1278          */
1279         acpi_device_set_id(device, parent, handle, type);
1280
1281         /*
1282          * The ACPI device is attached to acpi handle before getting
1283          * the power/wakeup/peformance flags. Otherwise OS can't get
1284          * the corresponding ACPI device by the acpi handle in the course
1285          * of getting the power/wakeup/performance flags.
1286          */
1287         result = acpi_device_set_context(device, type);
1288         if (result)
1289                 goto end;
1290
1291         /*
1292          * Power Management
1293          * ----------------
1294          */
1295         if (device->flags.power_manageable) {
1296                 result = acpi_bus_get_power_flags(device);
1297                 if (result)
1298                         goto end;
1299         }
1300
1301         /*
1302          * Wakeup device management
1303          *-----------------------
1304          */
1305         if (device->flags.wake_capable) {
1306                 result = acpi_bus_get_wakeup_device_flags(device);
1307                 if (result)
1308                         goto end;
1309         }
1310
1311         /*
1312          * Performance Management
1313          * ----------------------
1314          */
1315         if (device->flags.performance_manageable) {
1316                 result = acpi_bus_get_perf_flags(device);
1317                 if (result)
1318                         goto end;
1319         }
1320
1321
1322         result = acpi_device_register(device, parent);
1323
1324         /*
1325          * Bind _ADR-Based Devices when hot add
1326          */
1327         if (device->flags.bus_address) {
1328                 if (device->parent && device->parent->ops.bind)
1329                         device->parent->ops.bind(device);
1330         }
1331
1332       end:
1333         if (!result)
1334                 *child = device;
1335         else {
1336                 kfree(device->pnp.cid_list);
1337                 kfree(device);
1338         }
1339
1340         return result;
1341 }
1342
1343 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1344 {
1345         acpi_status status = AE_OK;
1346         struct acpi_device *parent = NULL;
1347         struct acpi_device *child = NULL;
1348         acpi_handle phandle = NULL;
1349         acpi_handle chandle = NULL;
1350         acpi_object_type type = 0;
1351         u32 level = 1;
1352
1353
1354         if (!start)
1355                 return -EINVAL;
1356
1357         parent = start;
1358         phandle = start->handle;
1359
1360         /*
1361          * Parse through the ACPI namespace, identify all 'devices', and
1362          * create a new 'struct acpi_device' for each.
1363          */
1364         while ((level > 0) && parent) {
1365
1366                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1367                                               chandle, &chandle);
1368
1369                 /*
1370                  * If this scope is exhausted then move our way back up.
1371                  */
1372                 if (ACPI_FAILURE(status)) {
1373                         level--;
1374                         chandle = phandle;
1375                         acpi_get_parent(phandle, &phandle);
1376                         if (parent->parent)
1377                                 parent = parent->parent;
1378                         continue;
1379                 }
1380
1381                 status = acpi_get_type(chandle, &type);
1382                 if (ACPI_FAILURE(status))
1383                         continue;
1384
1385                 /*
1386                  * If this is a scope object then parse it (depth-first).
1387                  */
1388                 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1389                         level++;
1390                         phandle = chandle;
1391                         chandle = NULL;
1392                         continue;
1393                 }
1394
1395                 /*
1396                  * We're only interested in objects that we consider 'devices'.
1397                  */
1398                 switch (type) {
1399                 case ACPI_TYPE_DEVICE:
1400                         type = ACPI_BUS_TYPE_DEVICE;
1401                         break;
1402                 case ACPI_TYPE_PROCESSOR:
1403                         type = ACPI_BUS_TYPE_PROCESSOR;
1404                         break;
1405                 case ACPI_TYPE_THERMAL:
1406                         type = ACPI_BUS_TYPE_THERMAL;
1407                         break;
1408                 case ACPI_TYPE_POWER:
1409                         type = ACPI_BUS_TYPE_POWER;
1410                         break;
1411                 default:
1412                         continue;
1413                 }
1414
1415                 if (ops->acpi_op_add)
1416                         status = acpi_add_single_object(&child, parent,
1417                                 chandle, type, ops);
1418                 else
1419                         status = acpi_bus_get_device(chandle, &child);
1420
1421                 if (ACPI_FAILURE(status))
1422                         continue;
1423
1424                 if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1425                         status = acpi_start_single_object(child);
1426                         if (ACPI_FAILURE(status))
1427                                 continue;
1428                 }
1429
1430                 /*
1431                  * If the device is present, enabled, and functioning then
1432                  * parse its scope (depth-first).  Note that we need to
1433                  * represent absent devices to facilitate PnP notifications
1434                  * -- but only the subtree head (not all of its children,
1435                  * which will be enumerated when the parent is inserted).
1436                  *
1437                  * TBD: Need notifications and other detection mechanisms
1438                  *      in place before we can fully implement this.
1439                  */
1440                  /*
1441                  * When the device is not present but functional, it is also
1442                  * necessary to scan the children of this device.
1443                  */
1444                 if (child->status.present || (!child->status.present &&
1445                                         child->status.functional)) {
1446                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1447                                                       NULL, NULL);
1448                         if (ACPI_SUCCESS(status)) {
1449                                 level++;
1450                                 phandle = chandle;
1451                                 chandle = NULL;
1452                                 parent = child;
1453                         }
1454                 }
1455         }
1456
1457         return 0;
1458 }
1459
1460 int
1461 acpi_bus_add(struct acpi_device **child,
1462              struct acpi_device *parent, acpi_handle handle, int type)
1463 {
1464         int result;
1465         struct acpi_bus_ops ops;
1466
1467         memset(&ops, 0, sizeof(ops));
1468         ops.acpi_op_add = 1;
1469
1470         result = acpi_add_single_object(child, parent, handle, type, &ops);
1471         if (!result)
1472                 result = acpi_bus_scan(*child, &ops);
1473
1474         return result;
1475 }
1476
1477 EXPORT_SYMBOL(acpi_bus_add);
1478
1479 int acpi_bus_start(struct acpi_device *device)
1480 {
1481         int result;
1482         struct acpi_bus_ops ops;
1483
1484
1485         if (!device)
1486                 return -EINVAL;
1487
1488         result = acpi_start_single_object(device);
1489         if (!result) {
1490                 memset(&ops, 0, sizeof(ops));
1491                 ops.acpi_op_start = 1;
1492                 result = acpi_bus_scan(device, &ops);
1493         }
1494         return result;
1495 }
1496
1497 EXPORT_SYMBOL(acpi_bus_start);
1498
1499 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1500 {
1501         acpi_status status;
1502         struct acpi_device *parent, *child;
1503         acpi_handle phandle, chandle;
1504         acpi_object_type type;
1505         u32 level = 1;
1506         int err = 0;
1507
1508         parent = start;
1509         phandle = start->handle;
1510         child = chandle = NULL;
1511
1512         while ((level > 0) && parent && (!err)) {
1513                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1514                                               chandle, &chandle);
1515
1516                 /*
1517                  * If this scope is exhausted then move our way back up.
1518                  */
1519                 if (ACPI_FAILURE(status)) {
1520                         level--;
1521                         chandle = phandle;
1522                         acpi_get_parent(phandle, &phandle);
1523                         child = parent;
1524                         parent = parent->parent;
1525
1526                         if (level == 0)
1527                                 err = acpi_bus_remove(child, rmdevice);
1528                         else
1529                                 err = acpi_bus_remove(child, 1);
1530
1531                         continue;
1532                 }
1533
1534                 status = acpi_get_type(chandle, &type);
1535                 if (ACPI_FAILURE(status)) {
1536                         continue;
1537                 }
1538                 /*
1539                  * If there is a device corresponding to chandle then
1540                  * parse it (depth-first).
1541                  */
1542                 if (acpi_bus_get_device(chandle, &child) == 0) {
1543                         level++;
1544                         phandle = chandle;
1545                         chandle = NULL;
1546                         parent = child;
1547                 }
1548                 continue;
1549         }
1550         return err;
1551 }
1552 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1553
1554
1555 static int acpi_bus_scan_fixed(struct acpi_device *root)
1556 {
1557         int result = 0;
1558         struct acpi_device *device = NULL;
1559         struct acpi_bus_ops ops;
1560
1561         if (!root)
1562                 return -ENODEV;
1563
1564         memset(&ops, 0, sizeof(ops));
1565         ops.acpi_op_add = 1;
1566         ops.acpi_op_start = 1;
1567
1568         /*
1569          * Enumerate all fixed-feature devices.
1570          */
1571         if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1572                 result = acpi_add_single_object(&device, acpi_root,
1573                                                 NULL,
1574                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1575                                                 &ops);
1576         }
1577
1578         if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1579                 result = acpi_add_single_object(&device, acpi_root,
1580                                                 NULL,
1581                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
1582                                                 &ops);
1583         }
1584
1585         return result;
1586 }
1587
1588 int __init acpi_scan_init(void)
1589 {
1590         int result;
1591         struct acpi_bus_ops ops;
1592
1593         memset(&ops, 0, sizeof(ops));
1594         ops.acpi_op_add = 1;
1595         ops.acpi_op_start = 1;
1596
1597         result = bus_register(&acpi_bus_type);
1598         if (result) {
1599                 /* We don't want to quit even if we failed to add suspend/resume */
1600                 printk(KERN_ERR PREFIX "Could not register bus type\n");
1601         }
1602
1603         /*
1604          * Create the root device in the bus's device tree
1605          */
1606         result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1607                                         ACPI_BUS_TYPE_SYSTEM, &ops);
1608         if (result)
1609                 goto Done;
1610
1611         /*
1612          * Enumerate devices in the ACPI namespace.
1613          */
1614         result = acpi_bus_scan_fixed(acpi_root);
1615
1616         if (!result)
1617                 result = acpi_bus_scan(acpi_root, &ops);
1618
1619         if (result)
1620                 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1621
1622       Done:
1623         return result;
1624 }