xref: /linux/drivers/acpi/scan.c (revision 704bf317fd21683e5c71a542f5fb5f65271a1582)
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/slab.h>
8 #include <linux/kernel.h>
9 #include <linux/acpi.h>
10 #include <linux/signal.h>
11 #include <linux/kthread.h>
12 #include <linux/dmi.h>
13 
14 #include <acpi/acpi_drivers.h>
15 
16 #include "internal.h"
17 
18 #define _COMPONENT		ACPI_BUS_COMPONENT
19 ACPI_MODULE_NAME("scan");
20 #define STRUCT_TO_INT(s)	(*((int*)&s))
21 extern struct acpi_device *acpi_root;
22 
23 #define ACPI_BUS_CLASS			"system_bus"
24 #define ACPI_BUS_HID			"LNXSYBUS"
25 #define ACPI_BUS_DEVICE_NAME		"System Bus"
26 
27 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
28 
29 static const char *dummy_hid = "device";
30 
31 static LIST_HEAD(acpi_device_list);
32 static LIST_HEAD(acpi_bus_id_list);
33 DEFINE_MUTEX(acpi_device_lock);
34 LIST_HEAD(acpi_wakeup_device_list);
35 
36 struct acpi_device_bus_id{
37 	char bus_id[15];
38 	unsigned int instance_no;
39 	struct list_head node;
40 };
41 
42 /*
43  * Creates hid/cid(s) string needed for modalias and uevent
44  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
45  * char *modalias: "acpi:IBM0001:ACPI0001"
46 */
47 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
48 			   int size)
49 {
50 	int len;
51 	int count;
52 	struct acpi_hardware_id *id;
53 
54 	if (list_empty(&acpi_dev->pnp.ids))
55 		return 0;
56 
57 	len = snprintf(modalias, size, "acpi:");
58 	size -= len;
59 
60 	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
61 		count = snprintf(&modalias[len], size, "%s:", id->id);
62 		if (count < 0 || count >= size)
63 			return -EINVAL;
64 		len += count;
65 		size -= count;
66 	}
67 
68 	modalias[len] = '\0';
69 	return len;
70 }
71 
72 static ssize_t
73 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
74 	struct acpi_device *acpi_dev = to_acpi_device(dev);
75 	int len;
76 
77 	/* Device has no HID and no CID or string is >1024 */
78 	len = create_modalias(acpi_dev, buf, 1024);
79 	if (len <= 0)
80 		return 0;
81 	buf[len++] = '\n';
82 	return len;
83 }
84 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
85 
86 static void acpi_bus_hot_remove_device(void *context)
87 {
88 	struct acpi_device *device;
89 	acpi_handle handle = context;
90 	struct acpi_object_list arg_list;
91 	union acpi_object arg;
92 	acpi_status status = AE_OK;
93 
94 	if (acpi_bus_get_device(handle, &device))
95 		return;
96 
97 	if (!device)
98 		return;
99 
100 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
101 		"Hot-removing device %s...\n", dev_name(&device->dev)));
102 
103 	if (acpi_bus_trim(device, 1)) {
104 		printk(KERN_ERR PREFIX
105 				"Removing device failed\n");
106 		return;
107 	}
108 
109 	/* power off device */
110 	status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
111 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
112 		printk(KERN_WARNING PREFIX
113 				"Power-off device failed\n");
114 
115 	if (device->flags.lockable) {
116 		arg_list.count = 1;
117 		arg_list.pointer = &arg;
118 		arg.type = ACPI_TYPE_INTEGER;
119 		arg.integer.value = 0;
120 		acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
121 	}
122 
123 	arg_list.count = 1;
124 	arg_list.pointer = &arg;
125 	arg.type = ACPI_TYPE_INTEGER;
126 	arg.integer.value = 1;
127 
128 	/*
129 	 * TBD: _EJD support.
130 	 */
131 	status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
132 	if (ACPI_FAILURE(status))
133 		printk(KERN_WARNING PREFIX
134 				"Eject device failed\n");
135 
136 	return;
137 }
138 
139 static ssize_t
140 acpi_eject_store(struct device *d, struct device_attribute *attr,
141 		const char *buf, size_t count)
142 {
143 	int ret = count;
144 	acpi_status status;
145 	acpi_object_type type = 0;
146 	struct acpi_device *acpi_device = to_acpi_device(d);
147 
148 	if ((!count) || (buf[0] != '1')) {
149 		return -EINVAL;
150 	}
151 #ifndef FORCE_EJECT
152 	if (acpi_device->driver == NULL) {
153 		ret = -ENODEV;
154 		goto err;
155 	}
156 #endif
157 	status = acpi_get_type(acpi_device->handle, &type);
158 	if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
159 		ret = -ENODEV;
160 		goto err;
161 	}
162 
163 	acpi_os_hotplug_execute(acpi_bus_hot_remove_device, acpi_device->handle);
164 err:
165 	return ret;
166 }
167 
168 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
169 
170 static ssize_t
171 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
172 	struct acpi_device *acpi_dev = to_acpi_device(dev);
173 
174 	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
175 }
176 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
177 
178 static ssize_t
179 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
180 	struct acpi_device *acpi_dev = to_acpi_device(dev);
181 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
182 	int result;
183 
184 	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
185 	if (result)
186 		goto end;
187 
188 	result = sprintf(buf, "%s\n", (char*)path.pointer);
189 	kfree(path.pointer);
190 end:
191 	return result;
192 }
193 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
194 
195 static int acpi_device_setup_files(struct acpi_device *dev)
196 {
197 	acpi_status status;
198 	acpi_handle temp;
199 	int result = 0;
200 
201 	/*
202 	 * Devices gotten from FADT don't have a "path" attribute
203 	 */
204 	if (dev->handle) {
205 		result = device_create_file(&dev->dev, &dev_attr_path);
206 		if (result)
207 			goto end;
208 	}
209 
210 	if (!list_empty(&dev->pnp.ids)) {
211 		result = device_create_file(&dev->dev, &dev_attr_hid);
212 		if (result)
213 			goto end;
214 
215 		result = device_create_file(&dev->dev, &dev_attr_modalias);
216 		if (result)
217 			goto end;
218 	}
219 
220         /*
221          * If device has _EJ0, 'eject' file is created that is used to trigger
222          * hot-removal function from userland.
223          */
224 	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
225 	if (ACPI_SUCCESS(status))
226 		result = device_create_file(&dev->dev, &dev_attr_eject);
227 end:
228 	return result;
229 }
230 
231 static void acpi_device_remove_files(struct acpi_device *dev)
232 {
233 	acpi_status status;
234 	acpi_handle temp;
235 
236 	/*
237 	 * If device has _EJ0, 'eject' file is created that is used to trigger
238 	 * hot-removal function from userland.
239 	 */
240 	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
241 	if (ACPI_SUCCESS(status))
242 		device_remove_file(&dev->dev, &dev_attr_eject);
243 
244 	device_remove_file(&dev->dev, &dev_attr_modalias);
245 	device_remove_file(&dev->dev, &dev_attr_hid);
246 	if (dev->handle)
247 		device_remove_file(&dev->dev, &dev_attr_path);
248 }
249 /* --------------------------------------------------------------------------
250 			ACPI Bus operations
251    -------------------------------------------------------------------------- */
252 
253 int acpi_match_device_ids(struct acpi_device *device,
254 			  const struct acpi_device_id *ids)
255 {
256 	const struct acpi_device_id *id;
257 	struct acpi_hardware_id *hwid;
258 
259 	/*
260 	 * If the device is not present, it is unnecessary to load device
261 	 * driver for it.
262 	 */
263 	if (!device->status.present)
264 		return -ENODEV;
265 
266 	for (id = ids; id->id[0]; id++)
267 		list_for_each_entry(hwid, &device->pnp.ids, list)
268 			if (!strcmp((char *) id->id, hwid->id))
269 				return 0;
270 
271 	return -ENOENT;
272 }
273 EXPORT_SYMBOL(acpi_match_device_ids);
274 
275 static void acpi_free_ids(struct acpi_device *device)
276 {
277 	struct acpi_hardware_id *id, *tmp;
278 
279 	list_for_each_entry_safe(id, tmp, &device->pnp.ids, list) {
280 		kfree(id->id);
281 		kfree(id);
282 	}
283 }
284 
285 static void acpi_device_release(struct device *dev)
286 {
287 	struct acpi_device *acpi_dev = to_acpi_device(dev);
288 
289 	acpi_free_ids(acpi_dev);
290 	kfree(acpi_dev);
291 }
292 
293 static int acpi_device_suspend(struct device *dev, pm_message_t state)
294 {
295 	struct acpi_device *acpi_dev = to_acpi_device(dev);
296 	struct acpi_driver *acpi_drv = acpi_dev->driver;
297 
298 	if (acpi_drv && acpi_drv->ops.suspend)
299 		return acpi_drv->ops.suspend(acpi_dev, state);
300 	return 0;
301 }
302 
303 static int acpi_device_resume(struct device *dev)
304 {
305 	struct acpi_device *acpi_dev = to_acpi_device(dev);
306 	struct acpi_driver *acpi_drv = acpi_dev->driver;
307 
308 	if (acpi_drv && acpi_drv->ops.resume)
309 		return acpi_drv->ops.resume(acpi_dev);
310 	return 0;
311 }
312 
313 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
314 {
315 	struct acpi_device *acpi_dev = to_acpi_device(dev);
316 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
317 
318 	return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
319 }
320 
321 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
322 {
323 	struct acpi_device *acpi_dev = to_acpi_device(dev);
324 	int len;
325 
326 	if (list_empty(&acpi_dev->pnp.ids))
327 		return 0;
328 
329 	if (add_uevent_var(env, "MODALIAS="))
330 		return -ENOMEM;
331 	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
332 			      sizeof(env->buf) - env->buflen);
333 	if (len >= (sizeof(env->buf) - env->buflen))
334 		return -ENOMEM;
335 	env->buflen += len;
336 	return 0;
337 }
338 
339 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
340 {
341 	struct acpi_device *device = data;
342 
343 	device->driver->ops.notify(device, event);
344 }
345 
346 static acpi_status acpi_device_notify_fixed(void *data)
347 {
348 	struct acpi_device *device = data;
349 
350 	/* Fixed hardware devices have no handles */
351 	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
352 	return AE_OK;
353 }
354 
355 static int acpi_device_install_notify_handler(struct acpi_device *device)
356 {
357 	acpi_status status;
358 
359 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
360 		status =
361 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
362 						     acpi_device_notify_fixed,
363 						     device);
364 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
365 		status =
366 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
367 						     acpi_device_notify_fixed,
368 						     device);
369 	else
370 		status = acpi_install_notify_handler(device->handle,
371 						     ACPI_DEVICE_NOTIFY,
372 						     acpi_device_notify,
373 						     device);
374 
375 	if (ACPI_FAILURE(status))
376 		return -EINVAL;
377 	return 0;
378 }
379 
380 static void acpi_device_remove_notify_handler(struct acpi_device *device)
381 {
382 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
383 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
384 						acpi_device_notify_fixed);
385 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
386 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
387 						acpi_device_notify_fixed);
388 	else
389 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
390 					   acpi_device_notify);
391 }
392 
393 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
394 static int acpi_start_single_object(struct acpi_device *);
395 static int acpi_device_probe(struct device * dev)
396 {
397 	struct acpi_device *acpi_dev = to_acpi_device(dev);
398 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
399 	int ret;
400 
401 	ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
402 	if (!ret) {
403 		if (acpi_dev->bus_ops.acpi_op_start)
404 			acpi_start_single_object(acpi_dev);
405 
406 		if (acpi_drv->ops.notify) {
407 			ret = acpi_device_install_notify_handler(acpi_dev);
408 			if (ret) {
409 				if (acpi_drv->ops.remove)
410 					acpi_drv->ops.remove(acpi_dev,
411 						     acpi_dev->removal_type);
412 				return ret;
413 			}
414 		}
415 
416 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
417 			"Found driver [%s] for device [%s]\n",
418 			acpi_drv->name, acpi_dev->pnp.bus_id));
419 		get_device(dev);
420 	}
421 	return ret;
422 }
423 
424 static int acpi_device_remove(struct device * dev)
425 {
426 	struct acpi_device *acpi_dev = to_acpi_device(dev);
427 	struct acpi_driver *acpi_drv = acpi_dev->driver;
428 
429 	if (acpi_drv) {
430 		if (acpi_drv->ops.notify)
431 			acpi_device_remove_notify_handler(acpi_dev);
432 		if (acpi_drv->ops.remove)
433 			acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
434 	}
435 	acpi_dev->driver = NULL;
436 	acpi_dev->driver_data = NULL;
437 
438 	put_device(dev);
439 	return 0;
440 }
441 
442 struct bus_type acpi_bus_type = {
443 	.name		= "acpi",
444 	.suspend	= acpi_device_suspend,
445 	.resume		= acpi_device_resume,
446 	.match		= acpi_bus_match,
447 	.probe		= acpi_device_probe,
448 	.remove		= acpi_device_remove,
449 	.uevent		= acpi_device_uevent,
450 };
451 
452 static int acpi_device_register(struct acpi_device *device)
453 {
454 	int result;
455 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
456 	int found = 0;
457 
458 	/*
459 	 * Linkage
460 	 * -------
461 	 * Link this device to its parent and siblings.
462 	 */
463 	INIT_LIST_HEAD(&device->children);
464 	INIT_LIST_HEAD(&device->node);
465 	INIT_LIST_HEAD(&device->wakeup_list);
466 
467 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
468 	if (!new_bus_id) {
469 		printk(KERN_ERR PREFIX "Memory allocation error\n");
470 		return -ENOMEM;
471 	}
472 
473 	mutex_lock(&acpi_device_lock);
474 	/*
475 	 * Find suitable bus_id and instance number in acpi_bus_id_list
476 	 * If failed, create one and link it into acpi_bus_id_list
477 	 */
478 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
479 		if (!strcmp(acpi_device_bus_id->bus_id,
480 			    acpi_device_hid(device))) {
481 			acpi_device_bus_id->instance_no++;
482 			found = 1;
483 			kfree(new_bus_id);
484 			break;
485 		}
486 	}
487 	if (!found) {
488 		acpi_device_bus_id = new_bus_id;
489 		strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
490 		acpi_device_bus_id->instance_no = 0;
491 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
492 	}
493 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
494 
495 	if (device->parent)
496 		list_add_tail(&device->node, &device->parent->children);
497 
498 	if (device->wakeup.flags.valid)
499 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
500 	mutex_unlock(&acpi_device_lock);
501 
502 	if (device->parent)
503 		device->dev.parent = &device->parent->dev;
504 	device->dev.bus = &acpi_bus_type;
505 	device->dev.release = &acpi_device_release;
506 	result = device_register(&device->dev);
507 	if (result) {
508 		dev_err(&device->dev, "Error registering device\n");
509 		goto end;
510 	}
511 
512 	result = acpi_device_setup_files(device);
513 	if (result)
514 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
515 		       dev_name(&device->dev));
516 
517 	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
518 	return 0;
519 end:
520 	mutex_lock(&acpi_device_lock);
521 	if (device->parent)
522 		list_del(&device->node);
523 	list_del(&device->wakeup_list);
524 	mutex_unlock(&acpi_device_lock);
525 	return result;
526 }
527 
528 static void acpi_device_unregister(struct acpi_device *device, int type)
529 {
530 	mutex_lock(&acpi_device_lock);
531 	if (device->parent)
532 		list_del(&device->node);
533 
534 	list_del(&device->wakeup_list);
535 	mutex_unlock(&acpi_device_lock);
536 
537 	acpi_detach_data(device->handle, acpi_bus_data_handler);
538 
539 	acpi_device_remove_files(device);
540 	device_unregister(&device->dev);
541 }
542 
543 /* --------------------------------------------------------------------------
544                                  Driver Management
545    -------------------------------------------------------------------------- */
546 /**
547  * acpi_bus_driver_init - add a device to a driver
548  * @device: the device to add and initialize
549  * @driver: driver for the device
550  *
551  * Used to initialize a device via its device driver.  Called whenever a
552  * driver is bound to a device.  Invokes the driver's add() ops.
553  */
554 static int
555 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
556 {
557 	int result = 0;
558 
559 	if (!device || !driver)
560 		return -EINVAL;
561 
562 	if (!driver->ops.add)
563 		return -ENOSYS;
564 
565 	result = driver->ops.add(device);
566 	if (result) {
567 		device->driver = NULL;
568 		device->driver_data = NULL;
569 		return result;
570 	}
571 
572 	device->driver = driver;
573 
574 	/*
575 	 * TBD - Configuration Management: Assign resources to device based
576 	 * upon possible configuration and currently allocated resources.
577 	 */
578 
579 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
580 			  "Driver successfully bound to device\n"));
581 	return 0;
582 }
583 
584 static int acpi_start_single_object(struct acpi_device *device)
585 {
586 	int result = 0;
587 	struct acpi_driver *driver;
588 
589 
590 	if (!(driver = device->driver))
591 		return 0;
592 
593 	if (driver->ops.start) {
594 		result = driver->ops.start(device);
595 		if (result && driver->ops.remove)
596 			driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
597 	}
598 
599 	return result;
600 }
601 
602 /**
603  * acpi_bus_register_driver - register a driver with the ACPI bus
604  * @driver: driver being registered
605  *
606  * Registers a driver with the ACPI bus.  Searches the namespace for all
607  * devices that match the driver's criteria and binds.  Returns zero for
608  * success or a negative error status for failure.
609  */
610 int acpi_bus_register_driver(struct acpi_driver *driver)
611 {
612 	int ret;
613 
614 	if (acpi_disabled)
615 		return -ENODEV;
616 	driver->drv.name = driver->name;
617 	driver->drv.bus = &acpi_bus_type;
618 	driver->drv.owner = driver->owner;
619 
620 	ret = driver_register(&driver->drv);
621 	return ret;
622 }
623 
624 EXPORT_SYMBOL(acpi_bus_register_driver);
625 
626 /**
627  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
628  * @driver: driver to unregister
629  *
630  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
631  * devices that match the driver's criteria and unbinds.
632  */
633 void acpi_bus_unregister_driver(struct acpi_driver *driver)
634 {
635 	driver_unregister(&driver->drv);
636 }
637 
638 EXPORT_SYMBOL(acpi_bus_unregister_driver);
639 
640 /* --------------------------------------------------------------------------
641                                  Device Enumeration
642    -------------------------------------------------------------------------- */
643 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
644 {
645 	acpi_status status;
646 	int ret;
647 	struct acpi_device *device;
648 
649 	/*
650 	 * Fixed hardware devices do not appear in the namespace and do not
651 	 * have handles, but we fabricate acpi_devices for them, so we have
652 	 * to deal with them specially.
653 	 */
654 	if (handle == NULL)
655 		return acpi_root;
656 
657 	do {
658 		status = acpi_get_parent(handle, &handle);
659 		if (status == AE_NULL_ENTRY)
660 			return NULL;
661 		if (ACPI_FAILURE(status))
662 			return acpi_root;
663 
664 		ret = acpi_bus_get_device(handle, &device);
665 		if (ret == 0)
666 			return device;
667 	} while (1);
668 }
669 
670 acpi_status
671 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
672 {
673 	acpi_status status;
674 	acpi_handle tmp;
675 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
676 	union acpi_object *obj;
677 
678 	status = acpi_get_handle(handle, "_EJD", &tmp);
679 	if (ACPI_FAILURE(status))
680 		return status;
681 
682 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
683 	if (ACPI_SUCCESS(status)) {
684 		obj = buffer.pointer;
685 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
686 					 ejd);
687 		kfree(buffer.pointer);
688 	}
689 	return status;
690 }
691 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
692 
693 void acpi_bus_data_handler(acpi_handle handle, void *context)
694 {
695 
696 	/* TBD */
697 
698 	return;
699 }
700 
701 static int acpi_bus_get_perf_flags(struct acpi_device *device)
702 {
703 	device->performance.state = ACPI_STATE_UNKNOWN;
704 	return 0;
705 }
706 
707 static acpi_status
708 acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
709 					     struct acpi_device_wakeup *wakeup)
710 {
711 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
712 	union acpi_object *package = NULL;
713 	union acpi_object *element = NULL;
714 	acpi_status status;
715 	int i = 0;
716 
717 	if (!wakeup)
718 		return AE_BAD_PARAMETER;
719 
720 	/* _PRW */
721 	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
722 	if (ACPI_FAILURE(status)) {
723 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
724 		return status;
725 	}
726 
727 	package = (union acpi_object *)buffer.pointer;
728 
729 	if (!package || (package->package.count < 2)) {
730 		status = AE_BAD_DATA;
731 		goto out;
732 	}
733 
734 	element = &(package->package.elements[0]);
735 	if (!element) {
736 		status = AE_BAD_DATA;
737 		goto out;
738 	}
739 	if (element->type == ACPI_TYPE_PACKAGE) {
740 		if ((element->package.count < 2) ||
741 		    (element->package.elements[0].type !=
742 		     ACPI_TYPE_LOCAL_REFERENCE)
743 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER)) {
744 			status = AE_BAD_DATA;
745 			goto out;
746 		}
747 		wakeup->gpe_device =
748 		    element->package.elements[0].reference.handle;
749 		wakeup->gpe_number =
750 		    (u32) element->package.elements[1].integer.value;
751 	} else if (element->type == ACPI_TYPE_INTEGER) {
752 		wakeup->gpe_device = NULL;
753 		wakeup->gpe_number = element->integer.value;
754 	} else {
755 		status = AE_BAD_DATA;
756 		goto out;
757 	}
758 
759 	element = &(package->package.elements[1]);
760 	if (element->type != ACPI_TYPE_INTEGER) {
761 		status = AE_BAD_DATA;
762 		goto out;
763 	}
764 	wakeup->sleep_state = element->integer.value;
765 
766 	if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
767 		status = AE_NO_MEMORY;
768 		goto out;
769 	}
770 	wakeup->resources.count = package->package.count - 2;
771 	for (i = 0; i < wakeup->resources.count; i++) {
772 		element = &(package->package.elements[i + 2]);
773 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
774 			status = AE_BAD_DATA;
775 			goto out;
776 		}
777 
778 		wakeup->resources.handles[i] = element->reference.handle;
779 	}
780 
781 	acpi_gpe_can_wake(wakeup->gpe_device, wakeup->gpe_number);
782 
783  out:
784 	kfree(buffer.pointer);
785 
786 	return status;
787 }
788 
789 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
790 {
791 	struct acpi_device_id button_device_ids[] = {
792 		{"PNP0C0D", 0},
793 		{"PNP0C0C", 0},
794 		{"PNP0C0E", 0},
795 		{"", 0},
796 	};
797 	acpi_status status;
798 	acpi_event_status event_status;
799 
800 	device->wakeup.run_wake_count = 0;
801 	device->wakeup.flags.notifier_present = 0;
802 
803 	/* Power button, Lid switch always enable wakeup */
804 	if (!acpi_match_device_ids(device, button_device_ids)) {
805 		device->wakeup.flags.run_wake = 1;
806 		device->wakeup.flags.always_enabled = 1;
807 		return;
808 	}
809 
810 	status = acpi_get_gpe_status(device->wakeup.gpe_device,
811 					device->wakeup.gpe_number,
812 						&event_status);
813 	if (status == AE_OK)
814 		device->wakeup.flags.run_wake =
815 				!!(event_status & ACPI_EVENT_FLAG_HANDLE);
816 }
817 
818 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
819 {
820 	acpi_status status = 0;
821 	int psw_error;
822 
823 	status = acpi_bus_extract_wakeup_device_power_package(device->handle,
824 							      &device->wakeup);
825 	if (ACPI_FAILURE(status)) {
826 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
827 		goto end;
828 	}
829 
830 	device->wakeup.flags.valid = 1;
831 	device->wakeup.prepare_count = 0;
832 	acpi_bus_set_run_wake_flags(device);
833 	/* Call _PSW/_DSW object to disable its ability to wake the sleeping
834 	 * system for the ACPI device with the _PRW object.
835 	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
836 	 * So it is necessary to call _DSW object first. Only when it is not
837 	 * present will the _PSW object used.
838 	 */
839 	psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
840 	if (psw_error)
841 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
842 				"error in _DSW or _PSW evaluation\n"));
843 
844 end:
845 	if (ACPI_FAILURE(status))
846 		device->flags.wake_capable = 0;
847 	return 0;
848 }
849 
850 static int acpi_bus_get_power_flags(struct acpi_device *device)
851 {
852 	acpi_status status = 0;
853 	acpi_handle handle = NULL;
854 	u32 i = 0;
855 
856 
857 	/*
858 	 * Power Management Flags
859 	 */
860 	status = acpi_get_handle(device->handle, "_PSC", &handle);
861 	if (ACPI_SUCCESS(status))
862 		device->power.flags.explicit_get = 1;
863 	status = acpi_get_handle(device->handle, "_IRC", &handle);
864 	if (ACPI_SUCCESS(status))
865 		device->power.flags.inrush_current = 1;
866 
867 	/*
868 	 * Enumerate supported power management states
869 	 */
870 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
871 		struct acpi_device_power_state *ps = &device->power.states[i];
872 		char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
873 
874 		/* Evaluate "_PRx" to se if power resources are referenced */
875 		acpi_evaluate_reference(device->handle, object_name, NULL,
876 					&ps->resources);
877 		if (ps->resources.count) {
878 			device->power.flags.power_resources = 1;
879 			ps->flags.valid = 1;
880 		}
881 
882 		/* Evaluate "_PSx" to see if we can do explicit sets */
883 		object_name[2] = 'S';
884 		status = acpi_get_handle(device->handle, object_name, &handle);
885 		if (ACPI_SUCCESS(status)) {
886 			ps->flags.explicit_set = 1;
887 			ps->flags.valid = 1;
888 		}
889 
890 		/* State is valid if we have some power control */
891 		if (ps->resources.count || ps->flags.explicit_set)
892 			ps->flags.valid = 1;
893 
894 		ps->power = -1;	/* Unknown - driver assigned */
895 		ps->latency = -1;	/* Unknown - driver assigned */
896 	}
897 
898 	/* Set defaults for D0 and D3 states (always valid) */
899 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
900 	device->power.states[ACPI_STATE_D0].power = 100;
901 	device->power.states[ACPI_STATE_D3].flags.valid = 1;
902 	device->power.states[ACPI_STATE_D3].power = 0;
903 
904 	/* TBD: System wake support and resource requirements. */
905 
906 	device->power.state = ACPI_STATE_UNKNOWN;
907 	acpi_bus_get_power(device->handle, &(device->power.state));
908 
909 	return 0;
910 }
911 
912 static int acpi_bus_get_flags(struct acpi_device *device)
913 {
914 	acpi_status status = AE_OK;
915 	acpi_handle temp = NULL;
916 
917 
918 	/* Presence of _STA indicates 'dynamic_status' */
919 	status = acpi_get_handle(device->handle, "_STA", &temp);
920 	if (ACPI_SUCCESS(status))
921 		device->flags.dynamic_status = 1;
922 
923 	/* Presence of _RMV indicates 'removable' */
924 	status = acpi_get_handle(device->handle, "_RMV", &temp);
925 	if (ACPI_SUCCESS(status))
926 		device->flags.removable = 1;
927 
928 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
929 	status = acpi_get_handle(device->handle, "_EJD", &temp);
930 	if (ACPI_SUCCESS(status))
931 		device->flags.ejectable = 1;
932 	else {
933 		status = acpi_get_handle(device->handle, "_EJ0", &temp);
934 		if (ACPI_SUCCESS(status))
935 			device->flags.ejectable = 1;
936 	}
937 
938 	/* Presence of _LCK indicates 'lockable' */
939 	status = acpi_get_handle(device->handle, "_LCK", &temp);
940 	if (ACPI_SUCCESS(status))
941 		device->flags.lockable = 1;
942 
943 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
944 	status = acpi_get_handle(device->handle, "_PS0", &temp);
945 	if (ACPI_FAILURE(status))
946 		status = acpi_get_handle(device->handle, "_PR0", &temp);
947 	if (ACPI_SUCCESS(status))
948 		device->flags.power_manageable = 1;
949 
950 	/* Presence of _PRW indicates wake capable */
951 	status = acpi_get_handle(device->handle, "_PRW", &temp);
952 	if (ACPI_SUCCESS(status))
953 		device->flags.wake_capable = 1;
954 
955 	/* TBD: Performance management */
956 
957 	return 0;
958 }
959 
960 static void acpi_device_get_busid(struct acpi_device *device)
961 {
962 	char bus_id[5] = { '?', 0 };
963 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
964 	int i = 0;
965 
966 	/*
967 	 * Bus ID
968 	 * ------
969 	 * The device's Bus ID is simply the object name.
970 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
971 	 */
972 	if (ACPI_IS_ROOT_DEVICE(device)) {
973 		strcpy(device->pnp.bus_id, "ACPI");
974 		return;
975 	}
976 
977 	switch (device->device_type) {
978 	case ACPI_BUS_TYPE_POWER_BUTTON:
979 		strcpy(device->pnp.bus_id, "PWRF");
980 		break;
981 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
982 		strcpy(device->pnp.bus_id, "SLPF");
983 		break;
984 	default:
985 		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
986 		/* Clean up trailing underscores (if any) */
987 		for (i = 3; i > 1; i--) {
988 			if (bus_id[i] == '_')
989 				bus_id[i] = '\0';
990 			else
991 				break;
992 		}
993 		strcpy(device->pnp.bus_id, bus_id);
994 		break;
995 	}
996 }
997 
998 /*
999  * acpi_bay_match - see if a device is an ejectable driver bay
1000  *
1001  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1002  * then we can safely call it an ejectable drive bay
1003  */
1004 static int acpi_bay_match(struct acpi_device *device){
1005 	acpi_status status;
1006 	acpi_handle handle;
1007 	acpi_handle tmp;
1008 	acpi_handle phandle;
1009 
1010 	handle = device->handle;
1011 
1012 	status = acpi_get_handle(handle, "_EJ0", &tmp);
1013 	if (ACPI_FAILURE(status))
1014 		return -ENODEV;
1015 
1016 	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
1017 		(ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
1018 		(ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
1019 		(ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
1020 		return 0;
1021 
1022 	if (acpi_get_parent(handle, &phandle))
1023 		return -ENODEV;
1024 
1025         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
1026                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
1027                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
1028                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
1029                 return 0;
1030 
1031 	return -ENODEV;
1032 }
1033 
1034 /*
1035  * acpi_dock_match - see if a device has a _DCK method
1036  */
1037 static int acpi_dock_match(struct acpi_device *device)
1038 {
1039 	acpi_handle tmp;
1040 	return acpi_get_handle(device->handle, "_DCK", &tmp);
1041 }
1042 
1043 const char *acpi_device_hid(struct acpi_device *device)
1044 {
1045 	struct acpi_hardware_id *hid;
1046 
1047 	if (list_empty(&device->pnp.ids))
1048 		return dummy_hid;
1049 
1050 	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1051 	return hid->id;
1052 }
1053 EXPORT_SYMBOL(acpi_device_hid);
1054 
1055 static void acpi_add_id(struct acpi_device *device, const char *dev_id)
1056 {
1057 	struct acpi_hardware_id *id;
1058 
1059 	id = kmalloc(sizeof(*id), GFP_KERNEL);
1060 	if (!id)
1061 		return;
1062 
1063 	id->id = kmalloc(strlen(dev_id) + 1, GFP_KERNEL);
1064 	if (!id->id) {
1065 		kfree(id);
1066 		return;
1067 	}
1068 
1069 	strcpy(id->id, dev_id);
1070 	list_add_tail(&id->list, &device->pnp.ids);
1071 }
1072 
1073 /*
1074  * Old IBM workstations have a DSDT bug wherein the SMBus object
1075  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1076  * prefix.  Work around this.
1077  */
1078 static int acpi_ibm_smbus_match(struct acpi_device *device)
1079 {
1080 	acpi_handle h_dummy;
1081 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
1082 	int result;
1083 
1084 	if (!dmi_name_in_vendors("IBM"))
1085 		return -ENODEV;
1086 
1087 	/* Look for SMBS object */
1088 	result = acpi_get_name(device->handle, ACPI_SINGLE_NAME, &path);
1089 	if (result)
1090 		return result;
1091 
1092 	if (strcmp("SMBS", path.pointer)) {
1093 		result = -ENODEV;
1094 		goto out;
1095 	}
1096 
1097 	/* Does it have the necessary (but misnamed) methods? */
1098 	result = -ENODEV;
1099 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "SBI", &h_dummy)) &&
1100 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "SBR", &h_dummy)) &&
1101 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "SBW", &h_dummy)))
1102 		result = 0;
1103 out:
1104 	kfree(path.pointer);
1105 	return result;
1106 }
1107 
1108 static void acpi_device_set_id(struct acpi_device *device)
1109 {
1110 	acpi_status status;
1111 	struct acpi_device_info *info;
1112 	struct acpica_device_id_list *cid_list;
1113 	int i;
1114 
1115 	switch (device->device_type) {
1116 	case ACPI_BUS_TYPE_DEVICE:
1117 		if (ACPI_IS_ROOT_DEVICE(device)) {
1118 			acpi_add_id(device, ACPI_SYSTEM_HID);
1119 			break;
1120 		}
1121 
1122 		status = acpi_get_object_info(device->handle, &info);
1123 		if (ACPI_FAILURE(status)) {
1124 			printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1125 			return;
1126 		}
1127 
1128 		if (info->valid & ACPI_VALID_HID)
1129 			acpi_add_id(device, info->hardware_id.string);
1130 		if (info->valid & ACPI_VALID_CID) {
1131 			cid_list = &info->compatible_id_list;
1132 			for (i = 0; i < cid_list->count; i++)
1133 				acpi_add_id(device, cid_list->ids[i].string);
1134 		}
1135 		if (info->valid & ACPI_VALID_ADR) {
1136 			device->pnp.bus_address = info->address;
1137 			device->flags.bus_address = 1;
1138 		}
1139 
1140 		kfree(info);
1141 
1142 		/*
1143 		 * Some devices don't reliably have _HIDs & _CIDs, so add
1144 		 * synthetic HIDs to make sure drivers can find them.
1145 		 */
1146 		if (acpi_is_video_device(device))
1147 			acpi_add_id(device, ACPI_VIDEO_HID);
1148 		else if (ACPI_SUCCESS(acpi_bay_match(device)))
1149 			acpi_add_id(device, ACPI_BAY_HID);
1150 		else if (ACPI_SUCCESS(acpi_dock_match(device)))
1151 			acpi_add_id(device, ACPI_DOCK_HID);
1152 		else if (!acpi_ibm_smbus_match(device))
1153 			acpi_add_id(device, ACPI_SMBUS_IBM_HID);
1154 		else if (!acpi_device_hid(device) &&
1155 			 ACPI_IS_ROOT_DEVICE(device->parent)) {
1156 			acpi_add_id(device, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1157 			strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1158 			strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1159 		}
1160 
1161 		break;
1162 	case ACPI_BUS_TYPE_POWER:
1163 		acpi_add_id(device, ACPI_POWER_HID);
1164 		break;
1165 	case ACPI_BUS_TYPE_PROCESSOR:
1166 		acpi_add_id(device, ACPI_PROCESSOR_OBJECT_HID);
1167 		break;
1168 	case ACPI_BUS_TYPE_THERMAL:
1169 		acpi_add_id(device, ACPI_THERMAL_HID);
1170 		break;
1171 	case ACPI_BUS_TYPE_POWER_BUTTON:
1172 		acpi_add_id(device, ACPI_BUTTON_HID_POWERF);
1173 		break;
1174 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1175 		acpi_add_id(device, ACPI_BUTTON_HID_SLEEPF);
1176 		break;
1177 	}
1178 }
1179 
1180 static int acpi_device_set_context(struct acpi_device *device)
1181 {
1182 	acpi_status status;
1183 
1184 	/*
1185 	 * Context
1186 	 * -------
1187 	 * Attach this 'struct acpi_device' to the ACPI object.  This makes
1188 	 * resolutions from handle->device very efficient.  Fixed hardware
1189 	 * devices have no handles, so we skip them.
1190 	 */
1191 	if (!device->handle)
1192 		return 0;
1193 
1194 	status = acpi_attach_data(device->handle,
1195 				  acpi_bus_data_handler, device);
1196 	if (ACPI_SUCCESS(status))
1197 		return 0;
1198 
1199 	printk(KERN_ERR PREFIX "Error attaching device data\n");
1200 	return -ENODEV;
1201 }
1202 
1203 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1204 {
1205 	if (!dev)
1206 		return -EINVAL;
1207 
1208 	dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1209 	device_release_driver(&dev->dev);
1210 
1211 	if (!rmdevice)
1212 		return 0;
1213 
1214 	/*
1215 	 * unbind _ADR-Based Devices when hot removal
1216 	 */
1217 	if (dev->flags.bus_address) {
1218 		if ((dev->parent) && (dev->parent->ops.unbind))
1219 			dev->parent->ops.unbind(dev);
1220 	}
1221 	acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1222 
1223 	return 0;
1224 }
1225 
1226 static int acpi_add_single_object(struct acpi_device **child,
1227 				  acpi_handle handle, int type,
1228 				  unsigned long long sta,
1229 				  struct acpi_bus_ops *ops)
1230 {
1231 	int result;
1232 	struct acpi_device *device;
1233 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1234 
1235 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1236 	if (!device) {
1237 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1238 		return -ENOMEM;
1239 	}
1240 
1241 	INIT_LIST_HEAD(&device->pnp.ids);
1242 	device->device_type = type;
1243 	device->handle = handle;
1244 	device->parent = acpi_bus_get_parent(handle);
1245 	device->bus_ops = *ops; /* workround for not call .start */
1246 	STRUCT_TO_INT(device->status) = sta;
1247 
1248 	acpi_device_get_busid(device);
1249 
1250 	/*
1251 	 * Flags
1252 	 * -----
1253 	 * Note that we only look for object handles -- cannot evaluate objects
1254 	 * until we know the device is present and properly initialized.
1255 	 */
1256 	result = acpi_bus_get_flags(device);
1257 	if (result)
1258 		goto end;
1259 
1260 	/*
1261 	 * Initialize Device
1262 	 * -----------------
1263 	 * TBD: Synch with Core's enumeration/initialization process.
1264 	 */
1265 	acpi_device_set_id(device);
1266 
1267 	/*
1268 	 * Power Management
1269 	 * ----------------
1270 	 */
1271 	if (device->flags.power_manageable) {
1272 		result = acpi_bus_get_power_flags(device);
1273 		if (result)
1274 			goto end;
1275 	}
1276 
1277 	/*
1278 	 * Wakeup device management
1279 	 *-----------------------
1280 	 */
1281 	if (device->flags.wake_capable) {
1282 		result = acpi_bus_get_wakeup_device_flags(device);
1283 		if (result)
1284 			goto end;
1285 	}
1286 
1287 	/*
1288 	 * Performance Management
1289 	 * ----------------------
1290 	 */
1291 	if (device->flags.performance_manageable) {
1292 		result = acpi_bus_get_perf_flags(device);
1293 		if (result)
1294 			goto end;
1295 	}
1296 
1297 	if ((result = acpi_device_set_context(device)))
1298 		goto end;
1299 
1300 	result = acpi_device_register(device);
1301 
1302 	/*
1303 	 * Bind _ADR-Based Devices when hot add
1304 	 */
1305 	if (device->flags.bus_address) {
1306 		if (device->parent && device->parent->ops.bind)
1307 			device->parent->ops.bind(device);
1308 	}
1309 
1310 end:
1311 	if (!result) {
1312 		acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1313 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1314 			"Adding %s [%s] parent %s\n", dev_name(&device->dev),
1315 			 (char *) buffer.pointer,
1316 			 device->parent ? dev_name(&device->parent->dev) :
1317 					  "(null)"));
1318 		kfree(buffer.pointer);
1319 		*child = device;
1320 	} else
1321 		acpi_device_release(&device->dev);
1322 
1323 	return result;
1324 }
1325 
1326 #define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \
1327 			  ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING)
1328 
1329 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1330 				    unsigned long long *sta)
1331 {
1332 	acpi_status status;
1333 	acpi_object_type acpi_type;
1334 
1335 	status = acpi_get_type(handle, &acpi_type);
1336 	if (ACPI_FAILURE(status))
1337 		return -ENODEV;
1338 
1339 	switch (acpi_type) {
1340 	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
1341 	case ACPI_TYPE_DEVICE:
1342 		*type = ACPI_BUS_TYPE_DEVICE;
1343 		status = acpi_bus_get_status_handle(handle, sta);
1344 		if (ACPI_FAILURE(status))
1345 			return -ENODEV;
1346 		break;
1347 	case ACPI_TYPE_PROCESSOR:
1348 		*type = ACPI_BUS_TYPE_PROCESSOR;
1349 		status = acpi_bus_get_status_handle(handle, sta);
1350 		if (ACPI_FAILURE(status))
1351 			return -ENODEV;
1352 		break;
1353 	case ACPI_TYPE_THERMAL:
1354 		*type = ACPI_BUS_TYPE_THERMAL;
1355 		*sta = ACPI_STA_DEFAULT;
1356 		break;
1357 	case ACPI_TYPE_POWER:
1358 		*type = ACPI_BUS_TYPE_POWER;
1359 		*sta = ACPI_STA_DEFAULT;
1360 		break;
1361 	default:
1362 		return -ENODEV;
1363 	}
1364 
1365 	return 0;
1366 }
1367 
1368 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
1369 				      void *context, void **return_value)
1370 {
1371 	struct acpi_bus_ops *ops = context;
1372 	int type;
1373 	unsigned long long sta;
1374 	struct acpi_device_wakeup wakeup;
1375 	struct acpi_device *device;
1376 	acpi_status status;
1377 	int result;
1378 
1379 	result = acpi_bus_type_and_status(handle, &type, &sta);
1380 	if (result)
1381 		return AE_OK;
1382 
1383 	if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1384 	    !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1385 		acpi_bus_extract_wakeup_device_power_package(handle, &wakeup);
1386 		return AE_CTRL_DEPTH;
1387 	}
1388 
1389 	/*
1390 	 * We may already have an acpi_device from a previous enumeration.  If
1391 	 * so, we needn't add it again, but we may still have to start it.
1392 	 */
1393 	device = NULL;
1394 	acpi_bus_get_device(handle, &device);
1395 	if (ops->acpi_op_add && !device)
1396 		acpi_add_single_object(&device, handle, type, sta, ops);
1397 
1398 	if (!device)
1399 		return AE_CTRL_DEPTH;
1400 
1401 	if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1402 		status = acpi_start_single_object(device);
1403 		if (ACPI_FAILURE(status))
1404 			return AE_CTRL_DEPTH;
1405 	}
1406 
1407 	if (!*return_value)
1408 		*return_value = device;
1409 	return AE_OK;
1410 }
1411 
1412 static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
1413 			 struct acpi_device **child)
1414 {
1415 	acpi_status status;
1416 	void *device = NULL;
1417 
1418 	status = acpi_bus_check_add(handle, 0, ops, &device);
1419 	if (ACPI_SUCCESS(status))
1420 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1421 				    acpi_bus_check_add, NULL, ops, &device);
1422 
1423 	if (child)
1424 		*child = device;
1425 
1426 	if (device)
1427 		return 0;
1428 	else
1429 		return -ENODEV;
1430 }
1431 
1432 /*
1433  * acpi_bus_add and acpi_bus_start
1434  *
1435  * scan a given ACPI tree and (probably recently hot-plugged)
1436  * create and add or starts found devices.
1437  *
1438  * If no devices were found -ENODEV is returned which does not
1439  * mean that this is a real error, there just have been no suitable
1440  * ACPI objects in the table trunk from which the kernel could create
1441  * a device and add/start an appropriate driver.
1442  */
1443 
1444 int
1445 acpi_bus_add(struct acpi_device **child,
1446 	     struct acpi_device *parent, acpi_handle handle, int type)
1447 {
1448 	struct acpi_bus_ops ops;
1449 
1450 	memset(&ops, 0, sizeof(ops));
1451 	ops.acpi_op_add = 1;
1452 
1453 	return acpi_bus_scan(handle, &ops, child);
1454 }
1455 EXPORT_SYMBOL(acpi_bus_add);
1456 
1457 int acpi_bus_start(struct acpi_device *device)
1458 {
1459 	struct acpi_bus_ops ops;
1460 	int result;
1461 
1462 	if (!device)
1463 		return -EINVAL;
1464 
1465 	memset(&ops, 0, sizeof(ops));
1466 	ops.acpi_op_start = 1;
1467 
1468 	result = acpi_bus_scan(device->handle, &ops, NULL);
1469 
1470 	acpi_update_gpes();
1471 
1472 	return result;
1473 }
1474 EXPORT_SYMBOL(acpi_bus_start);
1475 
1476 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1477 {
1478 	acpi_status status;
1479 	struct acpi_device *parent, *child;
1480 	acpi_handle phandle, chandle;
1481 	acpi_object_type type;
1482 	u32 level = 1;
1483 	int err = 0;
1484 
1485 	parent = start;
1486 	phandle = start->handle;
1487 	child = chandle = NULL;
1488 
1489 	while ((level > 0) && parent && (!err)) {
1490 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1491 					      chandle, &chandle);
1492 
1493 		/*
1494 		 * If this scope is exhausted then move our way back up.
1495 		 */
1496 		if (ACPI_FAILURE(status)) {
1497 			level--;
1498 			chandle = phandle;
1499 			acpi_get_parent(phandle, &phandle);
1500 			child = parent;
1501 			parent = parent->parent;
1502 
1503 			if (level == 0)
1504 				err = acpi_bus_remove(child, rmdevice);
1505 			else
1506 				err = acpi_bus_remove(child, 1);
1507 
1508 			continue;
1509 		}
1510 
1511 		status = acpi_get_type(chandle, &type);
1512 		if (ACPI_FAILURE(status)) {
1513 			continue;
1514 		}
1515 		/*
1516 		 * If there is a device corresponding to chandle then
1517 		 * parse it (depth-first).
1518 		 */
1519 		if (acpi_bus_get_device(chandle, &child) == 0) {
1520 			level++;
1521 			phandle = chandle;
1522 			chandle = NULL;
1523 			parent = child;
1524 		}
1525 		continue;
1526 	}
1527 	return err;
1528 }
1529 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1530 
1531 static int acpi_bus_scan_fixed(void)
1532 {
1533 	int result = 0;
1534 	struct acpi_device *device = NULL;
1535 	struct acpi_bus_ops ops;
1536 
1537 	memset(&ops, 0, sizeof(ops));
1538 	ops.acpi_op_add = 1;
1539 	ops.acpi_op_start = 1;
1540 
1541 	/*
1542 	 * Enumerate all fixed-feature devices.
1543 	 */
1544 	if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1545 		result = acpi_add_single_object(&device, NULL,
1546 						ACPI_BUS_TYPE_POWER_BUTTON,
1547 						ACPI_STA_DEFAULT,
1548 						&ops);
1549 	}
1550 
1551 	if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1552 		result = acpi_add_single_object(&device, NULL,
1553 						ACPI_BUS_TYPE_SLEEP_BUTTON,
1554 						ACPI_STA_DEFAULT,
1555 						&ops);
1556 	}
1557 
1558 	return result;
1559 }
1560 
1561 int __init acpi_scan_init(void)
1562 {
1563 	int result;
1564 	struct acpi_bus_ops ops;
1565 
1566 	memset(&ops, 0, sizeof(ops));
1567 	ops.acpi_op_add = 1;
1568 	ops.acpi_op_start = 1;
1569 
1570 	result = bus_register(&acpi_bus_type);
1571 	if (result) {
1572 		/* We don't want to quit even if we failed to add suspend/resume */
1573 		printk(KERN_ERR PREFIX "Could not register bus type\n");
1574 	}
1575 
1576 	/*
1577 	 * Enumerate devices in the ACPI namespace.
1578 	 */
1579 	result = acpi_bus_scan(ACPI_ROOT_OBJECT, &ops, &acpi_root);
1580 
1581 	if (!result)
1582 		result = acpi_bus_scan_fixed();
1583 
1584 	if (result)
1585 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1586 	else
1587 		acpi_update_gpes();
1588 
1589 	return result;
1590 }
1591