xref: /linux/drivers/acpi/scan.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
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 #include <acpi/acinterp.h>	/* for acpi_ex_eisa_id_to_string() */
14 
15 #define _COMPONENT		ACPI_BUS_COMPONENT
16 ACPI_MODULE_NAME("scan");
17 #define STRUCT_TO_INT(s)	(*((int*)&s))
18 extern struct acpi_device *acpi_root;
19 
20 #define ACPI_BUS_CLASS			"system_bus"
21 #define ACPI_BUS_HID			"LNXSYBUS"
22 #define ACPI_BUS_DEVICE_NAME		"System Bus"
23 
24 static LIST_HEAD(acpi_device_list);
25 static LIST_HEAD(acpi_bus_id_list);
26 DEFINE_SPINLOCK(acpi_device_lock);
27 LIST_HEAD(acpi_wakeup_device_list);
28 
29 struct acpi_device_bus_id{
30 	char bus_id[15];
31 	unsigned int instance_no;
32 	struct list_head node;
33 };
34 
35 /*
36  * Creates hid/cid(s) string needed for modalias and uevent
37  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
38  * char *modalias: "acpi:IBM0001:ACPI0001"
39 */
40 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
41 			   int size)
42 {
43 	int len;
44 	int count;
45 
46 	if (!acpi_dev->flags.hardware_id && !acpi_dev->flags.compatible_ids)
47 		return -ENODEV;
48 
49 	len = snprintf(modalias, size, "acpi:");
50 	size -= len;
51 
52 	if (acpi_dev->flags.hardware_id) {
53 		count = snprintf(&modalias[len], size, "%s:",
54 				 acpi_dev->pnp.hardware_id);
55 		if (count < 0 || count >= size)
56 			return -EINVAL;
57 		len += count;
58 		size -= count;
59 	}
60 
61 	if (acpi_dev->flags.compatible_ids) {
62 		struct acpi_compatible_id_list *cid_list;
63 		int i;
64 
65 		cid_list = acpi_dev->pnp.cid_list;
66 		for (i = 0; i < cid_list->count; i++) {
67 			count = snprintf(&modalias[len], size, "%s:",
68 					 cid_list->id[i].value);
69 			if (count < 0 || count >= size) {
70 				printk(KERN_ERR PREFIX "%s cid[%i] exceeds event buffer size",
71 				       acpi_dev->pnp.device_name, i);
72 				break;
73 			}
74 			len += count;
75 			size -= count;
76 		}
77 	}
78 
79 	modalias[len] = '\0';
80 	return len;
81 }
82 
83 static ssize_t
84 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
85 	struct acpi_device *acpi_dev = to_acpi_device(dev);
86 	int len;
87 
88 	/* Device has no HID and no CID or string is >1024 */
89 	len = create_modalias(acpi_dev, buf, 1024);
90 	if (len <= 0)
91 		return 0;
92 	buf[len++] = '\n';
93 	return len;
94 }
95 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
96 
97 static int acpi_bus_hot_remove_device(void *context)
98 {
99 	struct acpi_device *device;
100 	acpi_handle handle = context;
101 	struct acpi_object_list arg_list;
102 	union acpi_object arg;
103 	acpi_status status = AE_OK;
104 
105 	if (acpi_bus_get_device(handle, &device))
106 		return 0;
107 
108 	if (!device)
109 		return 0;
110 
111 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
112 		"Hot-removing device %s...\n", device->dev.bus_id));
113 
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 int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
363 static int acpi_start_single_object(struct acpi_device *);
364 static int acpi_device_probe(struct device * dev)
365 {
366 	struct acpi_device *acpi_dev = to_acpi_device(dev);
367 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
368 	int ret;
369 
370 	ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
371 	if (!ret) {
372 		if (acpi_dev->bus_ops.acpi_op_start)
373 			acpi_start_single_object(acpi_dev);
374 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
375 			"Found driver [%s] for device [%s]\n",
376 			acpi_drv->name, acpi_dev->pnp.bus_id));
377 		get_device(dev);
378 	}
379 	return ret;
380 }
381 
382 static int acpi_device_remove(struct device * dev)
383 {
384 	struct acpi_device *acpi_dev = to_acpi_device(dev);
385 	struct acpi_driver *acpi_drv = acpi_dev->driver;
386 
387 	if (acpi_drv) {
388 		if (acpi_drv->ops.stop)
389 			acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
390 		if (acpi_drv->ops.remove)
391 			acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
392 	}
393 	acpi_dev->driver = NULL;
394 	acpi_dev->driver_data = NULL;
395 
396 	put_device(dev);
397 	return 0;
398 }
399 
400 static void acpi_device_shutdown(struct device *dev)
401 {
402 	struct acpi_device *acpi_dev = to_acpi_device(dev);
403 	struct acpi_driver *acpi_drv = acpi_dev->driver;
404 
405 	if (acpi_drv && acpi_drv->ops.shutdown)
406 		acpi_drv->ops.shutdown(acpi_dev);
407 
408 	return ;
409 }
410 
411 struct bus_type acpi_bus_type = {
412 	.name		= "acpi",
413 	.suspend	= acpi_device_suspend,
414 	.resume		= acpi_device_resume,
415 	.shutdown	= acpi_device_shutdown,
416 	.match		= acpi_bus_match,
417 	.probe		= acpi_device_probe,
418 	.remove		= acpi_device_remove,
419 	.uevent		= acpi_device_uevent,
420 };
421 
422 static int acpi_device_register(struct acpi_device *device,
423 				 struct acpi_device *parent)
424 {
425 	int result;
426 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
427 	int found = 0;
428 	/*
429 	 * Linkage
430 	 * -------
431 	 * Link this device to its parent and siblings.
432 	 */
433 	INIT_LIST_HEAD(&device->children);
434 	INIT_LIST_HEAD(&device->node);
435 	INIT_LIST_HEAD(&device->g_list);
436 	INIT_LIST_HEAD(&device->wakeup_list);
437 
438 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
439 	if (!new_bus_id) {
440 		printk(KERN_ERR PREFIX "Memory allocation error\n");
441 		return -ENOMEM;
442 	}
443 
444 	spin_lock(&acpi_device_lock);
445 	/*
446 	 * Find suitable bus_id and instance number in acpi_bus_id_list
447 	 * If failed, create one and link it into acpi_bus_id_list
448 	 */
449 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
450 		if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
451 			acpi_device_bus_id->instance_no ++;
452 			found = 1;
453 			kfree(new_bus_id);
454 			break;
455 		}
456 	}
457 	if(!found) {
458 		acpi_device_bus_id = new_bus_id;
459 		strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
460 		acpi_device_bus_id->instance_no = 0;
461 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
462 	}
463 	sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
464 
465 	if (device->parent) {
466 		list_add_tail(&device->node, &device->parent->children);
467 		list_add_tail(&device->g_list, &device->parent->g_list);
468 	} else
469 		list_add_tail(&device->g_list, &acpi_device_list);
470 	if (device->wakeup.flags.valid)
471 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
472 	spin_unlock(&acpi_device_lock);
473 
474 	if (device->parent)
475 		device->dev.parent = &parent->dev;
476 	device->dev.bus = &acpi_bus_type;
477 	device_initialize(&device->dev);
478 	device->dev.release = &acpi_device_release;
479 	result = device_add(&device->dev);
480 	if(result) {
481 		dev_err(&device->dev, "Error adding device\n");
482 		goto end;
483 	}
484 
485 	result = acpi_device_setup_files(device);
486 	if(result)
487 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n", device->dev.bus_id);
488 
489 	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
490 	return 0;
491   end:
492 	spin_lock(&acpi_device_lock);
493 	if (device->parent) {
494 		list_del(&device->node);
495 		list_del(&device->g_list);
496 	} else
497 		list_del(&device->g_list);
498 	list_del(&device->wakeup_list);
499 	spin_unlock(&acpi_device_lock);
500 	return result;
501 }
502 
503 static void acpi_device_unregister(struct acpi_device *device, int type)
504 {
505 	spin_lock(&acpi_device_lock);
506 	if (device->parent) {
507 		list_del(&device->node);
508 		list_del(&device->g_list);
509 	} else
510 		list_del(&device->g_list);
511 
512 	list_del(&device->wakeup_list);
513 	spin_unlock(&acpi_device_lock);
514 
515 	acpi_detach_data(device->handle, acpi_bus_data_handler);
516 
517 	acpi_device_remove_files(device);
518 	device_unregister(&device->dev);
519 }
520 
521 /* --------------------------------------------------------------------------
522                                  Driver Management
523    -------------------------------------------------------------------------- */
524 /**
525  * acpi_bus_driver_init - add a device to a driver
526  * @device: the device to add and initialize
527  * @driver: driver for the device
528  *
529  * Used to initialize a device via its device driver.  Called whenever a
530  * driver is bound to a device.  Invokes the driver's add() ops.
531  */
532 static int
533 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
534 {
535 	int result = 0;
536 
537 
538 	if (!device || !driver)
539 		return -EINVAL;
540 
541 	if (!driver->ops.add)
542 		return -ENOSYS;
543 
544 	result = driver->ops.add(device);
545 	if (result) {
546 		device->driver = NULL;
547 		device->driver_data = NULL;
548 		return result;
549 	}
550 
551 	device->driver = driver;
552 
553 	/*
554 	 * TBD - Configuration Management: Assign resources to device based
555 	 * upon possible configuration and currently allocated resources.
556 	 */
557 
558 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
559 			  "Driver successfully bound to device\n"));
560 	return 0;
561 }
562 
563 static int acpi_start_single_object(struct acpi_device *device)
564 {
565 	int result = 0;
566 	struct acpi_driver *driver;
567 
568 
569 	if (!(driver = device->driver))
570 		return 0;
571 
572 	if (driver->ops.start) {
573 		result = driver->ops.start(device);
574 		if (result && driver->ops.remove)
575 			driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
576 	}
577 
578 	return result;
579 }
580 
581 /**
582  * acpi_bus_register_driver - register a driver with the ACPI bus
583  * @driver: driver being registered
584  *
585  * Registers a driver with the ACPI bus.  Searches the namespace for all
586  * devices that match the driver's criteria and binds.  Returns zero for
587  * success or a negative error status for failure.
588  */
589 int acpi_bus_register_driver(struct acpi_driver *driver)
590 {
591 	int ret;
592 
593 	if (acpi_disabled)
594 		return -ENODEV;
595 	driver->drv.name = driver->name;
596 	driver->drv.bus = &acpi_bus_type;
597 	driver->drv.owner = driver->owner;
598 
599 	ret = driver_register(&driver->drv);
600 	return ret;
601 }
602 
603 EXPORT_SYMBOL(acpi_bus_register_driver);
604 
605 /**
606  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
607  * @driver: driver to unregister
608  *
609  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
610  * devices that match the driver's criteria and unbinds.
611  */
612 void acpi_bus_unregister_driver(struct acpi_driver *driver)
613 {
614 	driver_unregister(&driver->drv);
615 }
616 
617 EXPORT_SYMBOL(acpi_bus_unregister_driver);
618 
619 /* --------------------------------------------------------------------------
620                                  Device Enumeration
621    -------------------------------------------------------------------------- */
622 acpi_status
623 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
624 {
625 	acpi_status status;
626 	acpi_handle tmp;
627 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
628 	union acpi_object *obj;
629 
630 	status = acpi_get_handle(handle, "_EJD", &tmp);
631 	if (ACPI_FAILURE(status))
632 		return status;
633 
634 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
635 	if (ACPI_SUCCESS(status)) {
636 		obj = buffer.pointer;
637 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
638 					 ejd);
639 		kfree(buffer.pointer);
640 	}
641 	return status;
642 }
643 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
644 
645 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
646 {
647 
648 	/* TBD */
649 
650 	return;
651 }
652 
653 static int acpi_bus_get_perf_flags(struct acpi_device *device)
654 {
655 	device->performance.state = ACPI_STATE_UNKNOWN;
656 	return 0;
657 }
658 
659 static acpi_status
660 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
661 					     union acpi_object *package)
662 {
663 	int i = 0;
664 	union acpi_object *element = NULL;
665 
666 	if (!device || !package || (package->package.count < 2))
667 		return AE_BAD_PARAMETER;
668 
669 	element = &(package->package.elements[0]);
670 	if (!element)
671 		return AE_BAD_PARAMETER;
672 	if (element->type == ACPI_TYPE_PACKAGE) {
673 		if ((element->package.count < 2) ||
674 		    (element->package.elements[0].type !=
675 		     ACPI_TYPE_LOCAL_REFERENCE)
676 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
677 			return AE_BAD_DATA;
678 		device->wakeup.gpe_device =
679 		    element->package.elements[0].reference.handle;
680 		device->wakeup.gpe_number =
681 		    (u32) element->package.elements[1].integer.value;
682 	} else if (element->type == ACPI_TYPE_INTEGER) {
683 		device->wakeup.gpe_number = element->integer.value;
684 	} else
685 		return AE_BAD_DATA;
686 
687 	element = &(package->package.elements[1]);
688 	if (element->type != ACPI_TYPE_INTEGER) {
689 		return AE_BAD_DATA;
690 	}
691 	device->wakeup.sleep_state = element->integer.value;
692 
693 	if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
694 		return AE_NO_MEMORY;
695 	}
696 	device->wakeup.resources.count = package->package.count - 2;
697 	for (i = 0; i < device->wakeup.resources.count; i++) {
698 		element = &(package->package.elements[i + 2]);
699 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
700 			return AE_BAD_DATA;
701 
702 		device->wakeup.resources.handles[i] = element->reference.handle;
703 	}
704 
705 	return AE_OK;
706 }
707 
708 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
709 {
710 	acpi_status status = 0;
711 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
712 	union acpi_object *package = NULL;
713 	int psw_error;
714 
715 	struct acpi_device_id button_device_ids[] = {
716 		{"PNP0C0D", 0},
717 		{"PNP0C0C", 0},
718 		{"PNP0C0E", 0},
719 		{"", 0},
720 	};
721 
722 	/* _PRW */
723 	status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
724 	if (ACPI_FAILURE(status)) {
725 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
726 		goto end;
727 	}
728 
729 	package = (union acpi_object *)buffer.pointer;
730 	status = acpi_bus_extract_wakeup_device_power_package(device, package);
731 	if (ACPI_FAILURE(status)) {
732 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
733 		goto end;
734 	}
735 
736 	kfree(buffer.pointer);
737 
738 	device->wakeup.flags.valid = 1;
739 	/* Call _PSW/_DSW object to disable its ability to wake the sleeping
740 	 * system for the ACPI device with the _PRW object.
741 	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
742 	 * So it is necessary to call _DSW object first. Only when it is not
743 	 * present will the _PSW object used.
744 	 */
745 	psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
746 	if (psw_error)
747 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
748 				"error in _DSW or _PSW evaluation\n"));
749 
750 	/* Power button, Lid switch always enable wakeup */
751 	if (!acpi_match_device_ids(device, button_device_ids))
752 		device->wakeup.flags.run_wake = 1;
753 
754 	/*
755 	 * Don't set Power button GPE as run_wake
756 	 * if Fixed Power button is used
757 	 */
758 	if (!strcmp(device->pnp.hardware_id, "PNP0C0C") &&
759 		!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
760 		device->wakeup.flags.run_wake = 0;
761 		device->wakeup.flags.valid = 0;
762 	}
763 
764       end:
765 	if (ACPI_FAILURE(status))
766 		device->flags.wake_capable = 0;
767 	return 0;
768 }
769 
770 static int acpi_bus_get_power_flags(struct acpi_device *device)
771 {
772 	acpi_status status = 0;
773 	acpi_handle handle = NULL;
774 	u32 i = 0;
775 
776 
777 	/*
778 	 * Power Management Flags
779 	 */
780 	status = acpi_get_handle(device->handle, "_PSC", &handle);
781 	if (ACPI_SUCCESS(status))
782 		device->power.flags.explicit_get = 1;
783 	status = acpi_get_handle(device->handle, "_IRC", &handle);
784 	if (ACPI_SUCCESS(status))
785 		device->power.flags.inrush_current = 1;
786 
787 	/*
788 	 * Enumerate supported power management states
789 	 */
790 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
791 		struct acpi_device_power_state *ps = &device->power.states[i];
792 		char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
793 
794 		/* Evaluate "_PRx" to se if power resources are referenced */
795 		acpi_evaluate_reference(device->handle, object_name, NULL,
796 					&ps->resources);
797 		if (ps->resources.count) {
798 			device->power.flags.power_resources = 1;
799 			ps->flags.valid = 1;
800 		}
801 
802 		/* Evaluate "_PSx" to see if we can do explicit sets */
803 		object_name[2] = 'S';
804 		status = acpi_get_handle(device->handle, object_name, &handle);
805 		if (ACPI_SUCCESS(status)) {
806 			ps->flags.explicit_set = 1;
807 			ps->flags.valid = 1;
808 		}
809 
810 		/* State is valid if we have some power control */
811 		if (ps->resources.count || ps->flags.explicit_set)
812 			ps->flags.valid = 1;
813 
814 		ps->power = -1;	/* Unknown - driver assigned */
815 		ps->latency = -1;	/* Unknown - driver assigned */
816 	}
817 
818 	/* Set defaults for D0 and D3 states (always valid) */
819 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
820 	device->power.states[ACPI_STATE_D0].power = 100;
821 	device->power.states[ACPI_STATE_D3].flags.valid = 1;
822 	device->power.states[ACPI_STATE_D3].power = 0;
823 
824 	/* TBD: System wake support and resource requirements. */
825 
826 	device->power.state = ACPI_STATE_UNKNOWN;
827 	acpi_bus_get_power(device->handle, &(device->power.state));
828 
829 	return 0;
830 }
831 
832 static int acpi_bus_get_flags(struct acpi_device *device)
833 {
834 	acpi_status status = AE_OK;
835 	acpi_handle temp = NULL;
836 
837 
838 	/* Presence of _STA indicates 'dynamic_status' */
839 	status = acpi_get_handle(device->handle, "_STA", &temp);
840 	if (ACPI_SUCCESS(status))
841 		device->flags.dynamic_status = 1;
842 
843 	/* Presence of _CID indicates 'compatible_ids' */
844 	status = acpi_get_handle(device->handle, "_CID", &temp);
845 	if (ACPI_SUCCESS(status))
846 		device->flags.compatible_ids = 1;
847 
848 	/* Presence of _RMV indicates 'removable' */
849 	status = acpi_get_handle(device->handle, "_RMV", &temp);
850 	if (ACPI_SUCCESS(status))
851 		device->flags.removable = 1;
852 
853 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
854 	status = acpi_get_handle(device->handle, "_EJD", &temp);
855 	if (ACPI_SUCCESS(status))
856 		device->flags.ejectable = 1;
857 	else {
858 		status = acpi_get_handle(device->handle, "_EJ0", &temp);
859 		if (ACPI_SUCCESS(status))
860 			device->flags.ejectable = 1;
861 	}
862 
863 	/* Presence of _LCK indicates 'lockable' */
864 	status = acpi_get_handle(device->handle, "_LCK", &temp);
865 	if (ACPI_SUCCESS(status))
866 		device->flags.lockable = 1;
867 
868 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
869 	status = acpi_get_handle(device->handle, "_PS0", &temp);
870 	if (ACPI_FAILURE(status))
871 		status = acpi_get_handle(device->handle, "_PR0", &temp);
872 	if (ACPI_SUCCESS(status))
873 		device->flags.power_manageable = 1;
874 
875 	/* Presence of _PRW indicates wake capable */
876 	status = acpi_get_handle(device->handle, "_PRW", &temp);
877 	if (ACPI_SUCCESS(status))
878 		device->flags.wake_capable = 1;
879 
880 	/* TBD: Performance management */
881 
882 	return 0;
883 }
884 
885 static void acpi_device_get_busid(struct acpi_device *device,
886 				  acpi_handle handle, int type)
887 {
888 	char bus_id[5] = { '?', 0 };
889 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
890 	int i = 0;
891 
892 	/*
893 	 * Bus ID
894 	 * ------
895 	 * The device's Bus ID is simply the object name.
896 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
897 	 */
898 	switch (type) {
899 	case ACPI_BUS_TYPE_SYSTEM:
900 		strcpy(device->pnp.bus_id, "ACPI");
901 		break;
902 	case ACPI_BUS_TYPE_POWER_BUTTON:
903 		strcpy(device->pnp.bus_id, "PWRF");
904 		break;
905 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
906 		strcpy(device->pnp.bus_id, "SLPF");
907 		break;
908 	default:
909 		acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
910 		/* Clean up trailing underscores (if any) */
911 		for (i = 3; i > 1; i--) {
912 			if (bus_id[i] == '_')
913 				bus_id[i] = '\0';
914 			else
915 				break;
916 		}
917 		strcpy(device->pnp.bus_id, bus_id);
918 		break;
919 	}
920 }
921 
922 static int
923 acpi_video_bus_match(struct acpi_device *device)
924 {
925 	acpi_handle h_dummy;
926 
927 	if (!device)
928 		return -EINVAL;
929 
930 	/* Since there is no HID, CID for ACPI Video drivers, we have
931 	 * to check well known required nodes for each feature we support.
932 	 */
933 
934 	/* Does this device able to support video switching ? */
935 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
936 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
937 		return 0;
938 
939 	/* Does this device able to retrieve a video ROM ? */
940 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
941 		return 0;
942 
943 	/* Does this device able to configure which video head to be POSTed ? */
944 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
945 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
946 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
947 		return 0;
948 
949 	return -ENODEV;
950 }
951 
952 /*
953  * acpi_bay_match - see if a device is an ejectable driver bay
954  *
955  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
956  * then we can safely call it an ejectable drive bay
957  */
958 static int acpi_bay_match(struct acpi_device *device){
959 	acpi_status status;
960 	acpi_handle handle;
961 	acpi_handle tmp;
962 	acpi_handle phandle;
963 
964 	handle = device->handle;
965 
966 	status = acpi_get_handle(handle, "_EJ0", &tmp);
967 	if (ACPI_FAILURE(status))
968 		return -ENODEV;
969 
970 	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
971 		(ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
972 		(ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
973 		(ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
974 		return 0;
975 
976 	if (acpi_get_parent(handle, &phandle))
977 		return -ENODEV;
978 
979         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
980                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
981                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
982                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
983                 return 0;
984 
985 	return -ENODEV;
986 }
987 
988 /*
989  * acpi_dock_match - see if a device has a _DCK method
990  */
991 static int acpi_dock_match(struct acpi_device *device)
992 {
993 	acpi_handle tmp;
994 	return acpi_get_handle(device->handle, "_DCK", &tmp);
995 }
996 
997 static void acpi_device_set_id(struct acpi_device *device,
998 			       struct acpi_device *parent, acpi_handle handle,
999 			       int type)
1000 {
1001 	struct acpi_device_info *info;
1002 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1003 	char *hid = NULL;
1004 	char *uid = NULL;
1005 	struct acpi_compatible_id_list *cid_list = NULL;
1006 	const char *cid_add = NULL;
1007 	acpi_status status;
1008 
1009 	switch (type) {
1010 	case ACPI_BUS_TYPE_DEVICE:
1011 		status = acpi_get_object_info(handle, &buffer);
1012 		if (ACPI_FAILURE(status)) {
1013 			printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1014 			return;
1015 		}
1016 
1017 		info = buffer.pointer;
1018 		if (info->valid & ACPI_VALID_HID)
1019 			hid = info->hardware_id.value;
1020 		if (info->valid & ACPI_VALID_UID)
1021 			uid = info->unique_id.value;
1022 		if (info->valid & ACPI_VALID_CID)
1023 			cid_list = &info->compatibility_id;
1024 		if (info->valid & ACPI_VALID_ADR) {
1025 			device->pnp.bus_address = info->address;
1026 			device->flags.bus_address = 1;
1027 		}
1028 
1029 		/* If we have a video/bay/dock device, add our selfdefined
1030 		   HID to the CID list. Like that the video/bay/dock drivers
1031 		   will get autoloaded and the device might still match
1032 		   against another driver.
1033 		*/
1034 		if (ACPI_SUCCESS(acpi_video_bus_match(device)))
1035 			cid_add = ACPI_VIDEO_HID;
1036 		else if (ACPI_SUCCESS(acpi_bay_match(device)))
1037 			cid_add = ACPI_BAY_HID;
1038 		else if (ACPI_SUCCESS(acpi_dock_match(device)))
1039 			cid_add = ACPI_DOCK_HID;
1040 
1041 		break;
1042 	case ACPI_BUS_TYPE_POWER:
1043 		hid = ACPI_POWER_HID;
1044 		break;
1045 	case ACPI_BUS_TYPE_PROCESSOR:
1046 		hid = ACPI_PROCESSOR_HID;
1047 		break;
1048 	case ACPI_BUS_TYPE_SYSTEM:
1049 		hid = ACPI_SYSTEM_HID;
1050 		break;
1051 	case ACPI_BUS_TYPE_THERMAL:
1052 		hid = ACPI_THERMAL_HID;
1053 		break;
1054 	case ACPI_BUS_TYPE_POWER_BUTTON:
1055 		hid = ACPI_BUTTON_HID_POWERF;
1056 		break;
1057 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1058 		hid = ACPI_BUTTON_HID_SLEEPF;
1059 		break;
1060 	}
1061 
1062 	/*
1063 	 * \_SB
1064 	 * ----
1065 	 * Fix for the system root bus device -- the only root-level device.
1066 	 */
1067 	if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
1068 		hid = ACPI_BUS_HID;
1069 		strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1070 		strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1071 	}
1072 
1073 	if (hid) {
1074 		strcpy(device->pnp.hardware_id, hid);
1075 		device->flags.hardware_id = 1;
1076 	}
1077 	if (uid) {
1078 		strcpy(device->pnp.unique_id, uid);
1079 		device->flags.unique_id = 1;
1080 	}
1081 	if (cid_list || cid_add) {
1082 		struct  acpi_compatible_id_list *list;
1083 		int size = 0;
1084 		int count = 0;
1085 
1086 		if (cid_list) {
1087 			size = cid_list->size;
1088 		} else if (cid_add) {
1089 			size = sizeof(struct acpi_compatible_id_list);
1090 			cid_list = ACPI_ALLOCATE_ZEROED((acpi_size) size);
1091 			if (!cid_list) {
1092 				printk(KERN_ERR "Memory allocation error\n");
1093 				kfree(buffer.pointer);
1094 				return;
1095 			} else {
1096 				cid_list->count = 0;
1097 				cid_list->size = size;
1098 			}
1099 		}
1100 		if (cid_add)
1101 			size += sizeof(struct acpi_compatible_id);
1102 		list = kmalloc(size, GFP_KERNEL);
1103 
1104 		if (list) {
1105 			if (cid_list) {
1106 				memcpy(list, cid_list, cid_list->size);
1107 				count = cid_list->count;
1108 			}
1109 			if (cid_add) {
1110 				strncpy(list->id[count].value, cid_add,
1111 					ACPI_MAX_CID_LENGTH);
1112 				count++;
1113 				device->flags.compatible_ids = 1;
1114 			}
1115 			list->size = size;
1116 			list->count = count;
1117 			device->pnp.cid_list = list;
1118 		} else
1119 			printk(KERN_ERR PREFIX "Memory allocation error\n");
1120 	}
1121 
1122 	kfree(buffer.pointer);
1123 }
1124 
1125 static int acpi_device_set_context(struct acpi_device *device, int type)
1126 {
1127 	acpi_status status = AE_OK;
1128 	int result = 0;
1129 	/*
1130 	 * Context
1131 	 * -------
1132 	 * Attach this 'struct acpi_device' to the ACPI object.  This makes
1133 	 * resolutions from handle->device very efficient.  Note that we need
1134 	 * to be careful with fixed-feature devices as they all attach to the
1135 	 * root object.
1136 	 */
1137 	if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
1138 	    type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
1139 		status = acpi_attach_data(device->handle,
1140 					  acpi_bus_data_handler, device);
1141 
1142 		if (ACPI_FAILURE(status)) {
1143 			printk(KERN_ERR PREFIX "Error attaching device data\n");
1144 			result = -ENODEV;
1145 		}
1146 	}
1147 	return result;
1148 }
1149 
1150 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1151 {
1152 	if (!dev)
1153 		return -EINVAL;
1154 
1155 	dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1156 	device_release_driver(&dev->dev);
1157 
1158 	if (!rmdevice)
1159 		return 0;
1160 
1161 	/*
1162 	 * unbind _ADR-Based Devices when hot removal
1163 	 */
1164 	if (dev->flags.bus_address) {
1165 		if ((dev->parent) && (dev->parent->ops.unbind))
1166 			dev->parent->ops.unbind(dev);
1167 	}
1168 	acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1169 
1170 	return 0;
1171 }
1172 
1173 static int
1174 acpi_add_single_object(struct acpi_device **child,
1175 		       struct acpi_device *parent, acpi_handle handle, int type,
1176 			struct acpi_bus_ops *ops)
1177 {
1178 	int result = 0;
1179 	struct acpi_device *device = NULL;
1180 
1181 
1182 	if (!child)
1183 		return -EINVAL;
1184 
1185 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1186 	if (!device) {
1187 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1188 		return -ENOMEM;
1189 	}
1190 
1191 	device->handle = handle;
1192 	device->parent = parent;
1193 	device->bus_ops = *ops; /* workround for not call .start */
1194 
1195 
1196 	acpi_device_get_busid(device, handle, type);
1197 
1198 	/*
1199 	 * Flags
1200 	 * -----
1201 	 * Get prior to calling acpi_bus_get_status() so we know whether
1202 	 * or not _STA is present.  Note that we only look for object
1203 	 * handles -- cannot evaluate objects until we know the device is
1204 	 * present and properly initialized.
1205 	 */
1206 	result = acpi_bus_get_flags(device);
1207 	if (result)
1208 		goto end;
1209 
1210 	/*
1211 	 * Status
1212 	 * ------
1213 	 * See if the device is present.  We always assume that non-Device
1214 	 * and non-Processor objects (e.g. thermal zones, power resources,
1215 	 * etc.) are present, functioning, etc. (at least when parent object
1216 	 * is present).  Note that _STA has a different meaning for some
1217 	 * objects (e.g. power resources) so we need to be careful how we use
1218 	 * it.
1219 	 */
1220 	switch (type) {
1221 	case ACPI_BUS_TYPE_PROCESSOR:
1222 	case ACPI_BUS_TYPE_DEVICE:
1223 		result = acpi_bus_get_status(device);
1224 		if (ACPI_FAILURE(result)) {
1225 			result = -ENODEV;
1226 			goto end;
1227 		}
1228 		/*
1229 		 * When the device is neither present nor functional, the
1230 		 * device should not be added to Linux ACPI device tree.
1231 		 * When the status of the device is not present but functinal,
1232 		 * it should be added to Linux ACPI tree. For example : bay
1233 		 * device , dock device.
1234 		 * In such conditions it is unncessary to check whether it is
1235 		 * bay device or dock device.
1236 		 */
1237 		if (!device->status.present && !device->status.functional) {
1238 			result = -ENODEV;
1239 			goto end;
1240 		}
1241 		break;
1242 	default:
1243 		STRUCT_TO_INT(device->status) =
1244 		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
1245 		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
1246 		break;
1247 	}
1248 
1249 	/*
1250 	 * Initialize Device
1251 	 * -----------------
1252 	 * TBD: Synch with Core's enumeration/initialization process.
1253 	 */
1254 
1255 	/*
1256 	 * Hardware ID, Unique ID, & Bus Address
1257 	 * -------------------------------------
1258 	 */
1259 	acpi_device_set_id(device, parent, handle, type);
1260 
1261 	/*
1262 	 * The ACPI device is attached to acpi handle before getting
1263 	 * the power/wakeup/peformance flags. Otherwise OS can't get
1264 	 * the corresponding ACPI device by the acpi handle in the course
1265 	 * of getting the power/wakeup/performance flags.
1266 	 */
1267 	result = acpi_device_set_context(device, type);
1268 	if (result)
1269 		goto end;
1270 
1271 	/*
1272 	 * Power Management
1273 	 * ----------------
1274 	 */
1275 	if (device->flags.power_manageable) {
1276 		result = acpi_bus_get_power_flags(device);
1277 		if (result)
1278 			goto end;
1279 	}
1280 
1281 	/*
1282 	 * Wakeup device management
1283 	 *-----------------------
1284 	 */
1285 	if (device->flags.wake_capable) {
1286 		result = acpi_bus_get_wakeup_device_flags(device);
1287 		if (result)
1288 			goto end;
1289 	}
1290 
1291 	/*
1292 	 * Performance Management
1293 	 * ----------------------
1294 	 */
1295 	if (device->flags.performance_manageable) {
1296 		result = acpi_bus_get_perf_flags(device);
1297 		if (result)
1298 			goto end;
1299 	}
1300 
1301 
1302 	result = acpi_device_register(device, parent);
1303 
1304 	/*
1305 	 * Bind _ADR-Based Devices when hot add
1306 	 */
1307 	if (device->flags.bus_address) {
1308 		if (device->parent && device->parent->ops.bind)
1309 			device->parent->ops.bind(device);
1310 	}
1311 
1312       end:
1313 	if (!result)
1314 		*child = device;
1315 	else {
1316 		kfree(device->pnp.cid_list);
1317 		kfree(device);
1318 	}
1319 
1320 	return result;
1321 }
1322 
1323 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1324 {
1325 	acpi_status status = AE_OK;
1326 	struct acpi_device *parent = NULL;
1327 	struct acpi_device *child = NULL;
1328 	acpi_handle phandle = NULL;
1329 	acpi_handle chandle = NULL;
1330 	acpi_object_type type = 0;
1331 	u32 level = 1;
1332 
1333 
1334 	if (!start)
1335 		return -EINVAL;
1336 
1337 	parent = start;
1338 	phandle = start->handle;
1339 
1340 	/*
1341 	 * Parse through the ACPI namespace, identify all 'devices', and
1342 	 * create a new 'struct acpi_device' for each.
1343 	 */
1344 	while ((level > 0) && parent) {
1345 
1346 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1347 					      chandle, &chandle);
1348 
1349 		/*
1350 		 * If this scope is exhausted then move our way back up.
1351 		 */
1352 		if (ACPI_FAILURE(status)) {
1353 			level--;
1354 			chandle = phandle;
1355 			acpi_get_parent(phandle, &phandle);
1356 			if (parent->parent)
1357 				parent = parent->parent;
1358 			continue;
1359 		}
1360 
1361 		status = acpi_get_type(chandle, &type);
1362 		if (ACPI_FAILURE(status))
1363 			continue;
1364 
1365 		/*
1366 		 * If this is a scope object then parse it (depth-first).
1367 		 */
1368 		if (type == ACPI_TYPE_LOCAL_SCOPE) {
1369 			level++;
1370 			phandle = chandle;
1371 			chandle = NULL;
1372 			continue;
1373 		}
1374 
1375 		/*
1376 		 * We're only interested in objects that we consider 'devices'.
1377 		 */
1378 		switch (type) {
1379 		case ACPI_TYPE_DEVICE:
1380 			type = ACPI_BUS_TYPE_DEVICE;
1381 			break;
1382 		case ACPI_TYPE_PROCESSOR:
1383 			type = ACPI_BUS_TYPE_PROCESSOR;
1384 			break;
1385 		case ACPI_TYPE_THERMAL:
1386 			type = ACPI_BUS_TYPE_THERMAL;
1387 			break;
1388 		case ACPI_TYPE_POWER:
1389 			type = ACPI_BUS_TYPE_POWER;
1390 			break;
1391 		default:
1392 			continue;
1393 		}
1394 
1395 		if (ops->acpi_op_add)
1396 			status = acpi_add_single_object(&child, parent,
1397 				chandle, type, ops);
1398 		else
1399 			status = acpi_bus_get_device(chandle, &child);
1400 
1401 		if (ACPI_FAILURE(status))
1402 			continue;
1403 
1404 		if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1405 			status = acpi_start_single_object(child);
1406 			if (ACPI_FAILURE(status))
1407 				continue;
1408 		}
1409 
1410 		/*
1411 		 * If the device is present, enabled, and functioning then
1412 		 * parse its scope (depth-first).  Note that we need to
1413 		 * represent absent devices to facilitate PnP notifications
1414 		 * -- but only the subtree head (not all of its children,
1415 		 * which will be enumerated when the parent is inserted).
1416 		 *
1417 		 * TBD: Need notifications and other detection mechanisms
1418 		 *      in place before we can fully implement this.
1419 		 */
1420 		 /*
1421 		 * When the device is not present but functional, it is also
1422 		 * necessary to scan the children of this device.
1423 		 */
1424 		if (child->status.present || (!child->status.present &&
1425 					child->status.functional)) {
1426 			status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1427 						      NULL, NULL);
1428 			if (ACPI_SUCCESS(status)) {
1429 				level++;
1430 				phandle = chandle;
1431 				chandle = NULL;
1432 				parent = child;
1433 			}
1434 		}
1435 	}
1436 
1437 	return 0;
1438 }
1439 
1440 int
1441 acpi_bus_add(struct acpi_device **child,
1442 	     struct acpi_device *parent, acpi_handle handle, int type)
1443 {
1444 	int result;
1445 	struct acpi_bus_ops ops;
1446 
1447 	memset(&ops, 0, sizeof(ops));
1448 	ops.acpi_op_add = 1;
1449 
1450 	result = acpi_add_single_object(child, parent, handle, type, &ops);
1451 	if (!result)
1452 		result = acpi_bus_scan(*child, &ops);
1453 
1454 	return result;
1455 }
1456 
1457 EXPORT_SYMBOL(acpi_bus_add);
1458 
1459 int acpi_bus_start(struct acpi_device *device)
1460 {
1461 	int result;
1462 	struct acpi_bus_ops ops;
1463 
1464 
1465 	if (!device)
1466 		return -EINVAL;
1467 
1468 	result = acpi_start_single_object(device);
1469 	if (!result) {
1470 		memset(&ops, 0, sizeof(ops));
1471 		ops.acpi_op_start = 1;
1472 		result = acpi_bus_scan(device, &ops);
1473 	}
1474 	return result;
1475 }
1476 
1477 EXPORT_SYMBOL(acpi_bus_start);
1478 
1479 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1480 {
1481 	acpi_status status;
1482 	struct acpi_device *parent, *child;
1483 	acpi_handle phandle, chandle;
1484 	acpi_object_type type;
1485 	u32 level = 1;
1486 	int err = 0;
1487 
1488 	parent = start;
1489 	phandle = start->handle;
1490 	child = chandle = NULL;
1491 
1492 	while ((level > 0) && parent && (!err)) {
1493 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1494 					      chandle, &chandle);
1495 
1496 		/*
1497 		 * If this scope is exhausted then move our way back up.
1498 		 */
1499 		if (ACPI_FAILURE(status)) {
1500 			level--;
1501 			chandle = phandle;
1502 			acpi_get_parent(phandle, &phandle);
1503 			child = parent;
1504 			parent = parent->parent;
1505 
1506 			if (level == 0)
1507 				err = acpi_bus_remove(child, rmdevice);
1508 			else
1509 				err = acpi_bus_remove(child, 1);
1510 
1511 			continue;
1512 		}
1513 
1514 		status = acpi_get_type(chandle, &type);
1515 		if (ACPI_FAILURE(status)) {
1516 			continue;
1517 		}
1518 		/*
1519 		 * If there is a device corresponding to chandle then
1520 		 * parse it (depth-first).
1521 		 */
1522 		if (acpi_bus_get_device(chandle, &child) == 0) {
1523 			level++;
1524 			phandle = chandle;
1525 			chandle = NULL;
1526 			parent = child;
1527 		}
1528 		continue;
1529 	}
1530 	return err;
1531 }
1532 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1533 
1534 
1535 static int acpi_bus_scan_fixed(struct acpi_device *root)
1536 {
1537 	int result = 0;
1538 	struct acpi_device *device = NULL;
1539 	struct acpi_bus_ops ops;
1540 
1541 	if (!root)
1542 		return -ENODEV;
1543 
1544 	memset(&ops, 0, sizeof(ops));
1545 	ops.acpi_op_add = 1;
1546 	ops.acpi_op_start = 1;
1547 
1548 	/*
1549 	 * Enumerate all fixed-feature devices.
1550 	 */
1551 	if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1552 		result = acpi_add_single_object(&device, acpi_root,
1553 						NULL,
1554 						ACPI_BUS_TYPE_POWER_BUTTON,
1555 						&ops);
1556 	}
1557 
1558 	if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1559 		result = acpi_add_single_object(&device, acpi_root,
1560 						NULL,
1561 						ACPI_BUS_TYPE_SLEEP_BUTTON,
1562 						&ops);
1563 	}
1564 
1565 	return result;
1566 }
1567 
1568 
1569 static int __init acpi_scan_init(void)
1570 {
1571 	int result;
1572 	struct acpi_bus_ops ops;
1573 
1574 
1575 	if (acpi_disabled)
1576 		return 0;
1577 
1578 	memset(&ops, 0, sizeof(ops));
1579 	ops.acpi_op_add = 1;
1580 	ops.acpi_op_start = 1;
1581 
1582 	result = bus_register(&acpi_bus_type);
1583 	if (result) {
1584 		/* We don't want to quit even if we failed to add suspend/resume */
1585 		printk(KERN_ERR PREFIX "Could not register bus type\n");
1586 	}
1587 
1588 	/*
1589 	 * Create the root device in the bus's device tree
1590 	 */
1591 	result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1592 					ACPI_BUS_TYPE_SYSTEM, &ops);
1593 	if (result)
1594 		goto Done;
1595 
1596 	/*
1597 	 * Enumerate devices in the ACPI namespace.
1598 	 */
1599 	result = acpi_bus_scan_fixed(acpi_root);
1600 
1601 	if (!result)
1602 		result = acpi_bus_scan(acpi_root, &ops);
1603 
1604 	if (result)
1605 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1606 
1607       Done:
1608 	return result;
1609 }
1610 
1611 subsys_initcall(acpi_scan_init);
1612