xref: /linux/drivers/acpi/scan.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
1 /*
2  * scan.c - support for transforming the ACPI namespace into individual objects
3  */
4 
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/kernel.h>
8 #include <linux/acpi.h>
9 #include <linux/signal.h>
10 #include <linux/kthread.h>
11 
12 #include <acpi/acpi_drivers.h>
13 
14 #include "internal.h"
15 
16 #define _COMPONENT		ACPI_BUS_COMPONENT
17 ACPI_MODULE_NAME("scan");
18 #define STRUCT_TO_INT(s)	(*((int*)&s))
19 extern struct acpi_device *acpi_root;
20 
21 #define ACPI_BUS_CLASS			"system_bus"
22 #define ACPI_BUS_HID			"LNXSYBUS"
23 #define ACPI_BUS_DEVICE_NAME		"System Bus"
24 
25 static LIST_HEAD(acpi_device_list);
26 static LIST_HEAD(acpi_bus_id_list);
27 DEFINE_MUTEX(acpi_device_lock);
28 LIST_HEAD(acpi_wakeup_device_list);
29 
30 struct acpi_device_bus_id{
31 	char bus_id[15];
32 	unsigned int instance_no;
33 	struct list_head node;
34 };
35 
36 /*
37  * Creates hid/cid(s) string needed for modalias and uevent
38  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
39  * char *modalias: "acpi:IBM0001:ACPI0001"
40 */
41 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
42 			   int size)
43 {
44 	int len;
45 	int count;
46 
47 	if (!acpi_dev->flags.hardware_id && !acpi_dev->flags.compatible_ids)
48 		return -ENODEV;
49 
50 	len = snprintf(modalias, size, "acpi:");
51 	size -= len;
52 
53 	if (acpi_dev->flags.hardware_id) {
54 		count = snprintf(&modalias[len], size, "%s:",
55 				 acpi_dev->pnp.hardware_id);
56 		if (count < 0 || count >= size)
57 			return -EINVAL;
58 		len += count;
59 		size -= count;
60 	}
61 
62 	if (acpi_dev->flags.compatible_ids) {
63 		struct acpi_compatible_id_list *cid_list;
64 		int i;
65 
66 		cid_list = acpi_dev->pnp.cid_list;
67 		for (i = 0; i < cid_list->count; i++) {
68 			count = snprintf(&modalias[len], size, "%s:",
69 					 cid_list->id[i].value);
70 			if (count < 0 || count >= size) {
71 				printk(KERN_ERR PREFIX "%s cid[%i] exceeds event buffer size",
72 				       acpi_dev->pnp.device_name, i);
73 				break;
74 			}
75 			len += count;
76 			size -= count;
77 		}
78 	}
79 
80 	modalias[len] = '\0';
81 	return len;
82 }
83 
84 static ssize_t
85 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
86 	struct acpi_device *acpi_dev = to_acpi_device(dev);
87 	int len;
88 
89 	/* Device has no HID and no CID or string is >1024 */
90 	len = create_modalias(acpi_dev, buf, 1024);
91 	if (len <= 0)
92 		return 0;
93 	buf[len++] = '\n';
94 	return len;
95 }
96 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
97 
98 static void acpi_bus_hot_remove_device(void *context)
99 {
100 	struct acpi_device *device;
101 	acpi_handle handle = context;
102 	struct acpi_object_list arg_list;
103 	union acpi_object arg;
104 	acpi_status status = AE_OK;
105 
106 	if (acpi_bus_get_device(handle, &device))
107 		return;
108 
109 	if (!device)
110 		return;
111 
112 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
113 		"Hot-removing device %s...\n", dev_name(&device->dev)));
114 
115 	if (acpi_bus_trim(device, 1)) {
116 		printk(KERN_ERR PREFIX
117 				"Removing device failed\n");
118 		return;
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 		printk(KERN_WARNING PREFIX
146 				"Eject device failed\n");
147 
148 	return;
149 }
150 
151 static ssize_t
152 acpi_eject_store(struct device *d, struct device_attribute *attr,
153 		const char *buf, size_t count)
154 {
155 	int ret = count;
156 	acpi_status status;
157 	acpi_object_type type = 0;
158 	struct acpi_device *acpi_device = to_acpi_device(d);
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 	acpi_os_hotplug_execute(acpi_bus_hot_remove_device, acpi_device->handle);
176 err:
177 	return ret;
178 }
179 
180 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
181 
182 static ssize_t
183 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
184 	struct acpi_device *acpi_dev = to_acpi_device(dev);
185 
186 	return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
187 }
188 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
189 
190 static ssize_t
191 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
192 	struct acpi_device *acpi_dev = to_acpi_device(dev);
193 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
194 	int result;
195 
196 	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
197 	if (result)
198 		goto end;
199 
200 	result = sprintf(buf, "%s\n", (char*)path.pointer);
201 	kfree(path.pointer);
202 end:
203 	return result;
204 }
205 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
206 
207 static int acpi_device_setup_files(struct acpi_device *dev)
208 {
209 	acpi_status status;
210 	acpi_handle temp;
211 	int result = 0;
212 
213 	/*
214 	 * Devices gotten from FADT don't have a "path" attribute
215 	 */
216 	if (dev->handle) {
217 		result = device_create_file(&dev->dev, &dev_attr_path);
218 		if (result)
219 			goto end;
220 	}
221 
222 	if (dev->flags.hardware_id) {
223 		result = device_create_file(&dev->dev, &dev_attr_hid);
224 		if (result)
225 			goto end;
226 	}
227 
228 	if (dev->flags.hardware_id || dev->flags.compatible_ids) {
229 		result = device_create_file(&dev->dev, &dev_attr_modalias);
230 		if (result)
231 			goto end;
232 	}
233 
234         /*
235          * If device has _EJ0, 'eject' file is created that is used to trigger
236          * hot-removal function from userland.
237          */
238 	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
239 	if (ACPI_SUCCESS(status))
240 		result = device_create_file(&dev->dev, &dev_attr_eject);
241 end:
242 	return result;
243 }
244 
245 static void acpi_device_remove_files(struct acpi_device *dev)
246 {
247 	acpi_status status;
248 	acpi_handle temp;
249 
250 	/*
251 	 * If device has _EJ0, 'eject' file is created that is used to trigger
252 	 * hot-removal function from userland.
253 	 */
254 	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
255 	if (ACPI_SUCCESS(status))
256 		device_remove_file(&dev->dev, &dev_attr_eject);
257 
258 	if (dev->flags.hardware_id || dev->flags.compatible_ids)
259 		device_remove_file(&dev->dev, &dev_attr_modalias);
260 
261 	if (dev->flags.hardware_id)
262 		device_remove_file(&dev->dev, &dev_attr_hid);
263 	if (dev->handle)
264 		device_remove_file(&dev->dev, &dev_attr_path);
265 }
266 /* --------------------------------------------------------------------------
267 			ACPI Bus operations
268    -------------------------------------------------------------------------- */
269 
270 int acpi_match_device_ids(struct acpi_device *device,
271 			  const struct acpi_device_id *ids)
272 {
273 	const struct acpi_device_id *id;
274 
275 	/*
276 	 * If the device is not present, it is unnecessary to load device
277 	 * driver for it.
278 	 */
279 	if (!device->status.present)
280 		return -ENODEV;
281 
282 	if (device->flags.hardware_id) {
283 		for (id = ids; id->id[0]; id++) {
284 			if (!strcmp((char*)id->id, device->pnp.hardware_id))
285 				return 0;
286 		}
287 	}
288 
289 	if (device->flags.compatible_ids) {
290 		struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
291 		int i;
292 
293 		for (id = ids; id->id[0]; id++) {
294 			/* compare multiple _CID entries against driver ids */
295 			for (i = 0; i < cid_list->count; i++) {
296 				if (!strcmp((char*)id->id,
297 					    cid_list->id[i].value))
298 					return 0;
299 			}
300 		}
301 	}
302 
303 	return -ENOENT;
304 }
305 EXPORT_SYMBOL(acpi_match_device_ids);
306 
307 static void acpi_device_release(struct device *dev)
308 {
309 	struct acpi_device *acpi_dev = to_acpi_device(dev);
310 
311 	kfree(acpi_dev->pnp.cid_list);
312 	kfree(acpi_dev);
313 }
314 
315 static int acpi_device_suspend(struct device *dev, pm_message_t state)
316 {
317 	struct acpi_device *acpi_dev = to_acpi_device(dev);
318 	struct acpi_driver *acpi_drv = acpi_dev->driver;
319 
320 	if (acpi_drv && acpi_drv->ops.suspend)
321 		return acpi_drv->ops.suspend(acpi_dev, state);
322 	return 0;
323 }
324 
325 static int acpi_device_resume(struct device *dev)
326 {
327 	struct acpi_device *acpi_dev = to_acpi_device(dev);
328 	struct acpi_driver *acpi_drv = acpi_dev->driver;
329 
330 	if (acpi_drv && acpi_drv->ops.resume)
331 		return acpi_drv->ops.resume(acpi_dev);
332 	return 0;
333 }
334 
335 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
336 {
337 	struct acpi_device *acpi_dev = to_acpi_device(dev);
338 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
339 
340 	return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
341 }
342 
343 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
344 {
345 	struct acpi_device *acpi_dev = to_acpi_device(dev);
346 	int len;
347 
348 	if (add_uevent_var(env, "MODALIAS="))
349 		return -ENOMEM;
350 	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
351 			      sizeof(env->buf) - env->buflen);
352 	if (len >= (sizeof(env->buf) - env->buflen))
353 		return -ENOMEM;
354 	env->buflen += len;
355 	return 0;
356 }
357 
358 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
359 {
360 	struct acpi_device *device = data;
361 
362 	device->driver->ops.notify(device, event);
363 }
364 
365 static acpi_status acpi_device_notify_fixed(void *data)
366 {
367 	struct acpi_device *device = data;
368 
369 	acpi_device_notify(device->handle, ACPI_FIXED_HARDWARE_EVENT, device);
370 	return AE_OK;
371 }
372 
373 static int acpi_device_install_notify_handler(struct acpi_device *device)
374 {
375 	acpi_status status;
376 	char *hid;
377 
378 	hid = acpi_device_hid(device);
379 	if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))
380 		status =
381 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
382 						     acpi_device_notify_fixed,
383 						     device);
384 	else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
385 		status =
386 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
387 						     acpi_device_notify_fixed,
388 						     device);
389 	else
390 		status = acpi_install_notify_handler(device->handle,
391 						     ACPI_DEVICE_NOTIFY,
392 						     acpi_device_notify,
393 						     device);
394 
395 	if (ACPI_FAILURE(status))
396 		return -EINVAL;
397 	return 0;
398 }
399 
400 static void acpi_device_remove_notify_handler(struct acpi_device *device)
401 {
402 	if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF))
403 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
404 						acpi_device_notify_fixed);
405 	else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF))
406 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
407 						acpi_device_notify_fixed);
408 	else
409 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
410 					   acpi_device_notify);
411 }
412 
413 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
414 static int acpi_start_single_object(struct acpi_device *);
415 static int acpi_device_probe(struct device * dev)
416 {
417 	struct acpi_device *acpi_dev = to_acpi_device(dev);
418 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
419 	int ret;
420 
421 	ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
422 	if (!ret) {
423 		if (acpi_dev->bus_ops.acpi_op_start)
424 			acpi_start_single_object(acpi_dev);
425 
426 		if (acpi_drv->ops.notify) {
427 			ret = acpi_device_install_notify_handler(acpi_dev);
428 			if (ret) {
429 				if (acpi_drv->ops.stop)
430 					acpi_drv->ops.stop(acpi_dev,
431 						   acpi_dev->removal_type);
432 				if (acpi_drv->ops.remove)
433 					acpi_drv->ops.remove(acpi_dev,
434 						     acpi_dev->removal_type);
435 				return ret;
436 			}
437 		}
438 
439 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
440 			"Found driver [%s] for device [%s]\n",
441 			acpi_drv->name, acpi_dev->pnp.bus_id));
442 		get_device(dev);
443 	}
444 	return ret;
445 }
446 
447 static int acpi_device_remove(struct device * dev)
448 {
449 	struct acpi_device *acpi_dev = to_acpi_device(dev);
450 	struct acpi_driver *acpi_drv = acpi_dev->driver;
451 
452 	if (acpi_drv) {
453 		if (acpi_drv->ops.notify)
454 			acpi_device_remove_notify_handler(acpi_dev);
455 		if (acpi_drv->ops.stop)
456 			acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
457 		if (acpi_drv->ops.remove)
458 			acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
459 	}
460 	acpi_dev->driver = NULL;
461 	acpi_dev->driver_data = NULL;
462 
463 	put_device(dev);
464 	return 0;
465 }
466 
467 struct bus_type acpi_bus_type = {
468 	.name		= "acpi",
469 	.suspend	= acpi_device_suspend,
470 	.resume		= acpi_device_resume,
471 	.match		= acpi_bus_match,
472 	.probe		= acpi_device_probe,
473 	.remove		= acpi_device_remove,
474 	.uevent		= acpi_device_uevent,
475 };
476 
477 static int acpi_device_register(struct acpi_device *device,
478 				 struct acpi_device *parent)
479 {
480 	int result;
481 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
482 	int found = 0;
483 	/*
484 	 * Linkage
485 	 * -------
486 	 * Link this device to its parent and siblings.
487 	 */
488 	INIT_LIST_HEAD(&device->children);
489 	INIT_LIST_HEAD(&device->node);
490 	INIT_LIST_HEAD(&device->wakeup_list);
491 
492 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
493 	if (!new_bus_id) {
494 		printk(KERN_ERR PREFIX "Memory allocation error\n");
495 		return -ENOMEM;
496 	}
497 
498 	mutex_lock(&acpi_device_lock);
499 	/*
500 	 * Find suitable bus_id and instance number in acpi_bus_id_list
501 	 * If failed, create one and link it into acpi_bus_id_list
502 	 */
503 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
504 		if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
505 			acpi_device_bus_id->instance_no ++;
506 			found = 1;
507 			kfree(new_bus_id);
508 			break;
509 		}
510 	}
511 	if (!found) {
512 		acpi_device_bus_id = new_bus_id;
513 		strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
514 		acpi_device_bus_id->instance_no = 0;
515 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
516 	}
517 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
518 
519 	if (device->parent)
520 		list_add_tail(&device->node, &device->parent->children);
521 
522 	if (device->wakeup.flags.valid)
523 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
524 	mutex_unlock(&acpi_device_lock);
525 
526 	if (device->parent)
527 		device->dev.parent = &parent->dev;
528 	device->dev.bus = &acpi_bus_type;
529 	device->dev.release = &acpi_device_release;
530 	result = device_register(&device->dev);
531 	if (result) {
532 		dev_err(&device->dev, "Error registering device\n");
533 		goto end;
534 	}
535 
536 	result = acpi_device_setup_files(device);
537 	if (result)
538 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
539 		       dev_name(&device->dev));
540 
541 	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
542 	return 0;
543 end:
544 	mutex_lock(&acpi_device_lock);
545 	if (device->parent)
546 		list_del(&device->node);
547 	list_del(&device->wakeup_list);
548 	mutex_unlock(&acpi_device_lock);
549 	return result;
550 }
551 
552 static void acpi_device_unregister(struct acpi_device *device, int type)
553 {
554 	mutex_lock(&acpi_device_lock);
555 	if (device->parent)
556 		list_del(&device->node);
557 
558 	list_del(&device->wakeup_list);
559 	mutex_unlock(&acpi_device_lock);
560 
561 	acpi_detach_data(device->handle, acpi_bus_data_handler);
562 
563 	acpi_device_remove_files(device);
564 	device_unregister(&device->dev);
565 }
566 
567 /* --------------------------------------------------------------------------
568                                  Driver Management
569    -------------------------------------------------------------------------- */
570 /**
571  * acpi_bus_driver_init - add a device to a driver
572  * @device: the device to add and initialize
573  * @driver: driver for the device
574  *
575  * Used to initialize a device via its device driver.  Called whenever a
576  * driver is bound to a device.  Invokes the driver's add() ops.
577  */
578 static int
579 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
580 {
581 	int result = 0;
582 
583 	if (!device || !driver)
584 		return -EINVAL;
585 
586 	if (!driver->ops.add)
587 		return -ENOSYS;
588 
589 	result = driver->ops.add(device);
590 	if (result) {
591 		device->driver = NULL;
592 		device->driver_data = NULL;
593 		return result;
594 	}
595 
596 	device->driver = driver;
597 
598 	/*
599 	 * TBD - Configuration Management: Assign resources to device based
600 	 * upon possible configuration and currently allocated resources.
601 	 */
602 
603 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
604 			  "Driver successfully bound to device\n"));
605 	return 0;
606 }
607 
608 static int acpi_start_single_object(struct acpi_device *device)
609 {
610 	int result = 0;
611 	struct acpi_driver *driver;
612 
613 
614 	if (!(driver = device->driver))
615 		return 0;
616 
617 	if (driver->ops.start) {
618 		result = driver->ops.start(device);
619 		if (result && driver->ops.remove)
620 			driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
621 	}
622 
623 	return result;
624 }
625 
626 /**
627  * acpi_bus_register_driver - register a driver with the ACPI bus
628  * @driver: driver being registered
629  *
630  * Registers a driver with the ACPI bus.  Searches the namespace for all
631  * devices that match the driver's criteria and binds.  Returns zero for
632  * success or a negative error status for failure.
633  */
634 int acpi_bus_register_driver(struct acpi_driver *driver)
635 {
636 	int ret;
637 
638 	if (acpi_disabled)
639 		return -ENODEV;
640 	driver->drv.name = driver->name;
641 	driver->drv.bus = &acpi_bus_type;
642 	driver->drv.owner = driver->owner;
643 
644 	ret = driver_register(&driver->drv);
645 	return ret;
646 }
647 
648 EXPORT_SYMBOL(acpi_bus_register_driver);
649 
650 /**
651  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
652  * @driver: driver to unregister
653  *
654  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
655  * devices that match the driver's criteria and unbinds.
656  */
657 void acpi_bus_unregister_driver(struct acpi_driver *driver)
658 {
659 	driver_unregister(&driver->drv);
660 }
661 
662 EXPORT_SYMBOL(acpi_bus_unregister_driver);
663 
664 /* --------------------------------------------------------------------------
665                                  Device Enumeration
666    -------------------------------------------------------------------------- */
667 acpi_status
668 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
669 {
670 	acpi_status status;
671 	acpi_handle tmp;
672 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
673 	union acpi_object *obj;
674 
675 	status = acpi_get_handle(handle, "_EJD", &tmp);
676 	if (ACPI_FAILURE(status))
677 		return status;
678 
679 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
680 	if (ACPI_SUCCESS(status)) {
681 		obj = buffer.pointer;
682 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
683 					 ejd);
684 		kfree(buffer.pointer);
685 	}
686 	return status;
687 }
688 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
689 
690 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
691 {
692 
693 	/* TBD */
694 
695 	return;
696 }
697 
698 static int acpi_bus_get_perf_flags(struct acpi_device *device)
699 {
700 	device->performance.state = ACPI_STATE_UNKNOWN;
701 	return 0;
702 }
703 
704 static acpi_status
705 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
706 					     union acpi_object *package)
707 {
708 	int i = 0;
709 	union acpi_object *element = NULL;
710 
711 	if (!device || !package || (package->package.count < 2))
712 		return AE_BAD_PARAMETER;
713 
714 	element = &(package->package.elements[0]);
715 	if (!element)
716 		return AE_BAD_PARAMETER;
717 	if (element->type == ACPI_TYPE_PACKAGE) {
718 		if ((element->package.count < 2) ||
719 		    (element->package.elements[0].type !=
720 		     ACPI_TYPE_LOCAL_REFERENCE)
721 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
722 			return AE_BAD_DATA;
723 		device->wakeup.gpe_device =
724 		    element->package.elements[0].reference.handle;
725 		device->wakeup.gpe_number =
726 		    (u32) element->package.elements[1].integer.value;
727 	} else if (element->type == ACPI_TYPE_INTEGER) {
728 		device->wakeup.gpe_number = element->integer.value;
729 	} else
730 		return AE_BAD_DATA;
731 
732 	element = &(package->package.elements[1]);
733 	if (element->type != ACPI_TYPE_INTEGER) {
734 		return AE_BAD_DATA;
735 	}
736 	device->wakeup.sleep_state = element->integer.value;
737 
738 	if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
739 		return AE_NO_MEMORY;
740 	}
741 	device->wakeup.resources.count = package->package.count - 2;
742 	for (i = 0; i < device->wakeup.resources.count; i++) {
743 		element = &(package->package.elements[i + 2]);
744 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
745 			return AE_BAD_DATA;
746 
747 		device->wakeup.resources.handles[i] = element->reference.handle;
748 	}
749 
750 	return AE_OK;
751 }
752 
753 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
754 {
755 	acpi_status status = 0;
756 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
757 	union acpi_object *package = NULL;
758 	int psw_error;
759 
760 	struct acpi_device_id button_device_ids[] = {
761 		{"PNP0C0D", 0},
762 		{"PNP0C0C", 0},
763 		{"PNP0C0E", 0},
764 		{"", 0},
765 	};
766 
767 	/* _PRW */
768 	status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
769 	if (ACPI_FAILURE(status)) {
770 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
771 		goto end;
772 	}
773 
774 	package = (union acpi_object *)buffer.pointer;
775 	status = acpi_bus_extract_wakeup_device_power_package(device, package);
776 	if (ACPI_FAILURE(status)) {
777 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
778 		goto end;
779 	}
780 
781 	kfree(buffer.pointer);
782 
783 	device->wakeup.flags.valid = 1;
784 	/* Call _PSW/_DSW object to disable its ability to wake the sleeping
785 	 * system for the ACPI device with the _PRW object.
786 	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
787 	 * So it is necessary to call _DSW object first. Only when it is not
788 	 * present will the _PSW object used.
789 	 */
790 	psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
791 	if (psw_error)
792 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
793 				"error in _DSW or _PSW evaluation\n"));
794 
795 	/* Power button, Lid switch always enable wakeup */
796 	if (!acpi_match_device_ids(device, button_device_ids))
797 		device->wakeup.flags.run_wake = 1;
798 
799 end:
800 	if (ACPI_FAILURE(status))
801 		device->flags.wake_capable = 0;
802 	return 0;
803 }
804 
805 static int acpi_bus_get_power_flags(struct acpi_device *device)
806 {
807 	acpi_status status = 0;
808 	acpi_handle handle = NULL;
809 	u32 i = 0;
810 
811 
812 	/*
813 	 * Power Management Flags
814 	 */
815 	status = acpi_get_handle(device->handle, "_PSC", &handle);
816 	if (ACPI_SUCCESS(status))
817 		device->power.flags.explicit_get = 1;
818 	status = acpi_get_handle(device->handle, "_IRC", &handle);
819 	if (ACPI_SUCCESS(status))
820 		device->power.flags.inrush_current = 1;
821 
822 	/*
823 	 * Enumerate supported power management states
824 	 */
825 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
826 		struct acpi_device_power_state *ps = &device->power.states[i];
827 		char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
828 
829 		/* Evaluate "_PRx" to se if power resources are referenced */
830 		acpi_evaluate_reference(device->handle, object_name, NULL,
831 					&ps->resources);
832 		if (ps->resources.count) {
833 			device->power.flags.power_resources = 1;
834 			ps->flags.valid = 1;
835 		}
836 
837 		/* Evaluate "_PSx" to see if we can do explicit sets */
838 		object_name[2] = 'S';
839 		status = acpi_get_handle(device->handle, object_name, &handle);
840 		if (ACPI_SUCCESS(status)) {
841 			ps->flags.explicit_set = 1;
842 			ps->flags.valid = 1;
843 		}
844 
845 		/* State is valid if we have some power control */
846 		if (ps->resources.count || ps->flags.explicit_set)
847 			ps->flags.valid = 1;
848 
849 		ps->power = -1;	/* Unknown - driver assigned */
850 		ps->latency = -1;	/* Unknown - driver assigned */
851 	}
852 
853 	/* Set defaults for D0 and D3 states (always valid) */
854 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
855 	device->power.states[ACPI_STATE_D0].power = 100;
856 	device->power.states[ACPI_STATE_D3].flags.valid = 1;
857 	device->power.states[ACPI_STATE_D3].power = 0;
858 
859 	/* TBD: System wake support and resource requirements. */
860 
861 	device->power.state = ACPI_STATE_UNKNOWN;
862 	acpi_bus_get_power(device->handle, &(device->power.state));
863 
864 	return 0;
865 }
866 
867 static int acpi_bus_get_flags(struct acpi_device *device)
868 {
869 	acpi_status status = AE_OK;
870 	acpi_handle temp = NULL;
871 
872 
873 	/* Presence of _STA indicates 'dynamic_status' */
874 	status = acpi_get_handle(device->handle, "_STA", &temp);
875 	if (ACPI_SUCCESS(status))
876 		device->flags.dynamic_status = 1;
877 
878 	/* Presence of _CID indicates 'compatible_ids' */
879 	status = acpi_get_handle(device->handle, "_CID", &temp);
880 	if (ACPI_SUCCESS(status))
881 		device->flags.compatible_ids = 1;
882 
883 	/* Presence of _RMV indicates 'removable' */
884 	status = acpi_get_handle(device->handle, "_RMV", &temp);
885 	if (ACPI_SUCCESS(status))
886 		device->flags.removable = 1;
887 
888 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
889 	status = acpi_get_handle(device->handle, "_EJD", &temp);
890 	if (ACPI_SUCCESS(status))
891 		device->flags.ejectable = 1;
892 	else {
893 		status = acpi_get_handle(device->handle, "_EJ0", &temp);
894 		if (ACPI_SUCCESS(status))
895 			device->flags.ejectable = 1;
896 	}
897 
898 	/* Presence of _LCK indicates 'lockable' */
899 	status = acpi_get_handle(device->handle, "_LCK", &temp);
900 	if (ACPI_SUCCESS(status))
901 		device->flags.lockable = 1;
902 
903 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
904 	status = acpi_get_handle(device->handle, "_PS0", &temp);
905 	if (ACPI_FAILURE(status))
906 		status = acpi_get_handle(device->handle, "_PR0", &temp);
907 	if (ACPI_SUCCESS(status))
908 		device->flags.power_manageable = 1;
909 
910 	/* Presence of _PRW indicates wake capable */
911 	status = acpi_get_handle(device->handle, "_PRW", &temp);
912 	if (ACPI_SUCCESS(status))
913 		device->flags.wake_capable = 1;
914 
915 	/* TBD: Performance management */
916 
917 	return 0;
918 }
919 
920 static void acpi_device_get_busid(struct acpi_device *device,
921 				  acpi_handle handle, int type)
922 {
923 	char bus_id[5] = { '?', 0 };
924 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
925 	int i = 0;
926 
927 	/*
928 	 * Bus ID
929 	 * ------
930 	 * The device's Bus ID is simply the object name.
931 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
932 	 */
933 	switch (type) {
934 	case ACPI_BUS_TYPE_SYSTEM:
935 		strcpy(device->pnp.bus_id, "ACPI");
936 		break;
937 	case ACPI_BUS_TYPE_POWER_BUTTON:
938 		strcpy(device->pnp.bus_id, "PWRF");
939 		break;
940 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
941 		strcpy(device->pnp.bus_id, "SLPF");
942 		break;
943 	default:
944 		acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
945 		/* Clean up trailing underscores (if any) */
946 		for (i = 3; i > 1; i--) {
947 			if (bus_id[i] == '_')
948 				bus_id[i] = '\0';
949 			else
950 				break;
951 		}
952 		strcpy(device->pnp.bus_id, bus_id);
953 		break;
954 	}
955 }
956 
957 /*
958  * acpi_bay_match - see if a device is an ejectable driver bay
959  *
960  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
961  * then we can safely call it an ejectable drive bay
962  */
963 static int acpi_bay_match(struct acpi_device *device){
964 	acpi_status status;
965 	acpi_handle handle;
966 	acpi_handle tmp;
967 	acpi_handle phandle;
968 
969 	handle = device->handle;
970 
971 	status = acpi_get_handle(handle, "_EJ0", &tmp);
972 	if (ACPI_FAILURE(status))
973 		return -ENODEV;
974 
975 	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
976 		(ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
977 		(ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
978 		(ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
979 		return 0;
980 
981 	if (acpi_get_parent(handle, &phandle))
982 		return -ENODEV;
983 
984         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
985                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
986                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
987                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
988                 return 0;
989 
990 	return -ENODEV;
991 }
992 
993 /*
994  * acpi_dock_match - see if a device has a _DCK method
995  */
996 static int acpi_dock_match(struct acpi_device *device)
997 {
998 	acpi_handle tmp;
999 	return acpi_get_handle(device->handle, "_DCK", &tmp);
1000 }
1001 
1002 static void acpi_device_set_id(struct acpi_device *device,
1003 			       struct acpi_device *parent, acpi_handle handle,
1004 			       int type)
1005 {
1006 	struct acpi_device_info *info;
1007 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1008 	char *hid = NULL;
1009 	char *uid = NULL;
1010 	struct acpi_compatible_id_list *cid_list = NULL;
1011 	const char *cid_add = NULL;
1012 	acpi_status status;
1013 
1014 	switch (type) {
1015 	case ACPI_BUS_TYPE_DEVICE:
1016 		status = acpi_get_object_info(handle, &buffer);
1017 		if (ACPI_FAILURE(status)) {
1018 			printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1019 			return;
1020 		}
1021 
1022 		info = buffer.pointer;
1023 		if (info->valid & ACPI_VALID_HID)
1024 			hid = info->hardware_id.value;
1025 		if (info->valid & ACPI_VALID_UID)
1026 			uid = info->unique_id.value;
1027 		if (info->valid & ACPI_VALID_CID)
1028 			cid_list = &info->compatibility_id;
1029 		if (info->valid & ACPI_VALID_ADR) {
1030 			device->pnp.bus_address = info->address;
1031 			device->flags.bus_address = 1;
1032 		}
1033 
1034 		/* If we have a video/bay/dock device, add our selfdefined
1035 		   HID to the CID list. Like that the video/bay/dock drivers
1036 		   will get autoloaded and the device might still match
1037 		   against another driver.
1038 		*/
1039 		if (acpi_is_video_device(device))
1040 			cid_add = ACPI_VIDEO_HID;
1041 		else if (ACPI_SUCCESS(acpi_bay_match(device)))
1042 			cid_add = ACPI_BAY_HID;
1043 		else if (ACPI_SUCCESS(acpi_dock_match(device)))
1044 			cid_add = ACPI_DOCK_HID;
1045 
1046 		break;
1047 	case ACPI_BUS_TYPE_POWER:
1048 		hid = ACPI_POWER_HID;
1049 		break;
1050 	case ACPI_BUS_TYPE_PROCESSOR:
1051 		hid = ACPI_PROCESSOR_OBJECT_HID;
1052 		break;
1053 	case ACPI_BUS_TYPE_SYSTEM:
1054 		hid = ACPI_SYSTEM_HID;
1055 		break;
1056 	case ACPI_BUS_TYPE_THERMAL:
1057 		hid = ACPI_THERMAL_HID;
1058 		break;
1059 	case ACPI_BUS_TYPE_POWER_BUTTON:
1060 		hid = ACPI_BUTTON_HID_POWERF;
1061 		break;
1062 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1063 		hid = ACPI_BUTTON_HID_SLEEPF;
1064 		break;
1065 	}
1066 
1067 	/*
1068 	 * \_SB
1069 	 * ----
1070 	 * Fix for the system root bus device -- the only root-level device.
1071 	 */
1072 	if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
1073 		hid = ACPI_BUS_HID;
1074 		strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1075 		strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1076 	}
1077 
1078 	if (hid) {
1079 		strcpy(device->pnp.hardware_id, hid);
1080 		device->flags.hardware_id = 1;
1081 	}
1082 	if (uid) {
1083 		strcpy(device->pnp.unique_id, uid);
1084 		device->flags.unique_id = 1;
1085 	}
1086 	if (cid_list || cid_add) {
1087 		struct  acpi_compatible_id_list *list;
1088 		int size = 0;
1089 		int count = 0;
1090 
1091 		if (cid_list) {
1092 			size = cid_list->size;
1093 		} else if (cid_add) {
1094 			size = sizeof(struct acpi_compatible_id_list);
1095 			cid_list = ACPI_ALLOCATE_ZEROED((acpi_size) size);
1096 			if (!cid_list) {
1097 				printk(KERN_ERR "Memory allocation error\n");
1098 				kfree(buffer.pointer);
1099 				return;
1100 			} else {
1101 				cid_list->count = 0;
1102 				cid_list->size = size;
1103 			}
1104 		}
1105 		if (cid_add)
1106 			size += sizeof(struct acpi_compatible_id);
1107 		list = kmalloc(size, GFP_KERNEL);
1108 
1109 		if (list) {
1110 			if (cid_list) {
1111 				memcpy(list, cid_list, cid_list->size);
1112 				count = cid_list->count;
1113 			}
1114 			if (cid_add) {
1115 				strncpy(list->id[count].value, cid_add,
1116 					ACPI_MAX_CID_LENGTH);
1117 				count++;
1118 				device->flags.compatible_ids = 1;
1119 			}
1120 			list->size = size;
1121 			list->count = count;
1122 			device->pnp.cid_list = list;
1123 		} else
1124 			printk(KERN_ERR PREFIX "Memory allocation error\n");
1125 	}
1126 
1127 	kfree(buffer.pointer);
1128 }
1129 
1130 static int acpi_device_set_context(struct acpi_device *device, int type)
1131 {
1132 	acpi_status status = AE_OK;
1133 	int result = 0;
1134 	/*
1135 	 * Context
1136 	 * -------
1137 	 * Attach this 'struct acpi_device' to the ACPI object.  This makes
1138 	 * resolutions from handle->device very efficient.  Note that we need
1139 	 * to be careful with fixed-feature devices as they all attach to the
1140 	 * root object.
1141 	 */
1142 	if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
1143 	    type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
1144 		status = acpi_attach_data(device->handle,
1145 					  acpi_bus_data_handler, device);
1146 
1147 		if (ACPI_FAILURE(status)) {
1148 			printk(KERN_ERR PREFIX "Error attaching device data\n");
1149 			result = -ENODEV;
1150 		}
1151 	}
1152 	return result;
1153 }
1154 
1155 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1156 {
1157 	if (!dev)
1158 		return -EINVAL;
1159 
1160 	dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1161 	device_release_driver(&dev->dev);
1162 
1163 	if (!rmdevice)
1164 		return 0;
1165 
1166 	/*
1167 	 * unbind _ADR-Based Devices when hot removal
1168 	 */
1169 	if (dev->flags.bus_address) {
1170 		if ((dev->parent) && (dev->parent->ops.unbind))
1171 			dev->parent->ops.unbind(dev);
1172 	}
1173 	acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1174 
1175 	return 0;
1176 }
1177 
1178 static int
1179 acpi_add_single_object(struct acpi_device **child,
1180 		       struct acpi_device *parent, acpi_handle handle, int type,
1181 			struct acpi_bus_ops *ops)
1182 {
1183 	int result = 0;
1184 	struct acpi_device *device = NULL;
1185 
1186 
1187 	if (!child)
1188 		return -EINVAL;
1189 
1190 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1191 	if (!device) {
1192 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1193 		return -ENOMEM;
1194 	}
1195 
1196 	device->handle = handle;
1197 	device->parent = parent;
1198 	device->bus_ops = *ops; /* workround for not call .start */
1199 
1200 
1201 	acpi_device_get_busid(device, handle, type);
1202 
1203 	/*
1204 	 * Flags
1205 	 * -----
1206 	 * Get prior to calling acpi_bus_get_status() so we know whether
1207 	 * or not _STA is present.  Note that we only look for object
1208 	 * handles -- cannot evaluate objects until we know the device is
1209 	 * present and properly initialized.
1210 	 */
1211 	result = acpi_bus_get_flags(device);
1212 	if (result)
1213 		goto end;
1214 
1215 	/*
1216 	 * Status
1217 	 * ------
1218 	 * See if the device is present.  We always assume that non-Device
1219 	 * and non-Processor objects (e.g. thermal zones, power resources,
1220 	 * etc.) are present, functioning, etc. (at least when parent object
1221 	 * is present).  Note that _STA has a different meaning for some
1222 	 * objects (e.g. power resources) so we need to be careful how we use
1223 	 * it.
1224 	 */
1225 	switch (type) {
1226 	case ACPI_BUS_TYPE_PROCESSOR:
1227 	case ACPI_BUS_TYPE_DEVICE:
1228 		result = acpi_bus_get_status(device);
1229 		if (ACPI_FAILURE(result)) {
1230 			result = -ENODEV;
1231 			goto end;
1232 		}
1233 		/*
1234 		 * When the device is neither present nor functional, the
1235 		 * device should not be added to Linux ACPI device tree.
1236 		 * When the status of the device is not present but functinal,
1237 		 * it should be added to Linux ACPI tree. For example : bay
1238 		 * device , dock device.
1239 		 * In such conditions it is unncessary to check whether it is
1240 		 * bay device or dock device.
1241 		 */
1242 		if (!device->status.present && !device->status.functional) {
1243 			result = -ENODEV;
1244 			goto end;
1245 		}
1246 		break;
1247 	default:
1248 		STRUCT_TO_INT(device->status) =
1249 		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
1250 		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
1251 		break;
1252 	}
1253 
1254 	/*
1255 	 * Initialize Device
1256 	 * -----------------
1257 	 * TBD: Synch with Core's enumeration/initialization process.
1258 	 */
1259 
1260 	/*
1261 	 * Hardware ID, Unique ID, & Bus Address
1262 	 * -------------------------------------
1263 	 */
1264 	acpi_device_set_id(device, parent, handle, type);
1265 
1266 	/*
1267 	 * The ACPI device is attached to acpi handle before getting
1268 	 * the power/wakeup/peformance flags. Otherwise OS can't get
1269 	 * the corresponding ACPI device by the acpi handle in the course
1270 	 * of getting the power/wakeup/performance flags.
1271 	 */
1272 	result = acpi_device_set_context(device, type);
1273 	if (result)
1274 		goto end;
1275 
1276 	/*
1277 	 * Power Management
1278 	 * ----------------
1279 	 */
1280 	if (device->flags.power_manageable) {
1281 		result = acpi_bus_get_power_flags(device);
1282 		if (result)
1283 			goto end;
1284 	}
1285 
1286 	/*
1287 	 * Wakeup device management
1288 	 *-----------------------
1289 	 */
1290 	if (device->flags.wake_capable) {
1291 		result = acpi_bus_get_wakeup_device_flags(device);
1292 		if (result)
1293 			goto end;
1294 	}
1295 
1296 	/*
1297 	 * Performance Management
1298 	 * ----------------------
1299 	 */
1300 	if (device->flags.performance_manageable) {
1301 		result = acpi_bus_get_perf_flags(device);
1302 		if (result)
1303 			goto end;
1304 	}
1305 
1306 
1307 	result = acpi_device_register(device, parent);
1308 
1309 	/*
1310 	 * Bind _ADR-Based Devices when hot add
1311 	 */
1312 	if (device->flags.bus_address) {
1313 		if (device->parent && device->parent->ops.bind)
1314 			device->parent->ops.bind(device);
1315 	}
1316 
1317 end:
1318 	if (!result)
1319 		*child = device;
1320 	else {
1321 		kfree(device->pnp.cid_list);
1322 		kfree(device);
1323 	}
1324 
1325 	return result;
1326 }
1327 
1328 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1329 {
1330 	acpi_status status = AE_OK;
1331 	struct acpi_device *parent = NULL;
1332 	struct acpi_device *child = NULL;
1333 	acpi_handle phandle = NULL;
1334 	acpi_handle chandle = NULL;
1335 	acpi_object_type type = 0;
1336 	u32 level = 1;
1337 
1338 
1339 	if (!start)
1340 		return -EINVAL;
1341 
1342 	parent = start;
1343 	phandle = start->handle;
1344 
1345 	/*
1346 	 * Parse through the ACPI namespace, identify all 'devices', and
1347 	 * create a new 'struct acpi_device' for each.
1348 	 */
1349 	while ((level > 0) && parent) {
1350 
1351 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1352 					      chandle, &chandle);
1353 
1354 		/*
1355 		 * If this scope is exhausted then move our way back up.
1356 		 */
1357 		if (ACPI_FAILURE(status)) {
1358 			level--;
1359 			chandle = phandle;
1360 			acpi_get_parent(phandle, &phandle);
1361 			if (parent->parent)
1362 				parent = parent->parent;
1363 			continue;
1364 		}
1365 
1366 		status = acpi_get_type(chandle, &type);
1367 		if (ACPI_FAILURE(status))
1368 			continue;
1369 
1370 		/*
1371 		 * If this is a scope object then parse it (depth-first).
1372 		 */
1373 		if (type == ACPI_TYPE_LOCAL_SCOPE) {
1374 			level++;
1375 			phandle = chandle;
1376 			chandle = NULL;
1377 			continue;
1378 		}
1379 
1380 		/*
1381 		 * We're only interested in objects that we consider 'devices'.
1382 		 */
1383 		switch (type) {
1384 		case ACPI_TYPE_DEVICE:
1385 			type = ACPI_BUS_TYPE_DEVICE;
1386 			break;
1387 		case ACPI_TYPE_PROCESSOR:
1388 			type = ACPI_BUS_TYPE_PROCESSOR;
1389 			break;
1390 		case ACPI_TYPE_THERMAL:
1391 			type = ACPI_BUS_TYPE_THERMAL;
1392 			break;
1393 		case ACPI_TYPE_POWER:
1394 			type = ACPI_BUS_TYPE_POWER;
1395 			break;
1396 		default:
1397 			continue;
1398 		}
1399 
1400 		if (ops->acpi_op_add)
1401 			status = acpi_add_single_object(&child, parent,
1402 				chandle, type, ops);
1403 		else
1404 			status = acpi_bus_get_device(chandle, &child);
1405 
1406 		if (ACPI_FAILURE(status))
1407 			continue;
1408 
1409 		if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1410 			status = acpi_start_single_object(child);
1411 			if (ACPI_FAILURE(status))
1412 				continue;
1413 		}
1414 
1415 		/*
1416 		 * If the device is present, enabled, and functioning then
1417 		 * parse its scope (depth-first).  Note that we need to
1418 		 * represent absent devices to facilitate PnP notifications
1419 		 * -- but only the subtree head (not all of its children,
1420 		 * which will be enumerated when the parent is inserted).
1421 		 *
1422 		 * TBD: Need notifications and other detection mechanisms
1423 		 *      in place before we can fully implement this.
1424 		 */
1425 		 /*
1426 		 * When the device is not present but functional, it is also
1427 		 * necessary to scan the children of this device.
1428 		 */
1429 		if (child->status.present || (!child->status.present &&
1430 					child->status.functional)) {
1431 			status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1432 						      NULL, NULL);
1433 			if (ACPI_SUCCESS(status)) {
1434 				level++;
1435 				phandle = chandle;
1436 				chandle = NULL;
1437 				parent = child;
1438 			}
1439 		}
1440 	}
1441 
1442 	return 0;
1443 }
1444 
1445 int
1446 acpi_bus_add(struct acpi_device **child,
1447 	     struct acpi_device *parent, acpi_handle handle, int type)
1448 {
1449 	int result;
1450 	struct acpi_bus_ops ops;
1451 
1452 	memset(&ops, 0, sizeof(ops));
1453 	ops.acpi_op_add = 1;
1454 
1455 	result = acpi_add_single_object(child, parent, handle, type, &ops);
1456 	if (!result)
1457 		result = acpi_bus_scan(*child, &ops);
1458 
1459 	return result;
1460 }
1461 EXPORT_SYMBOL(acpi_bus_add);
1462 
1463 int acpi_bus_start(struct acpi_device *device)
1464 {
1465 	int result;
1466 	struct acpi_bus_ops ops;
1467 
1468 
1469 	if (!device)
1470 		return -EINVAL;
1471 
1472 	result = acpi_start_single_object(device);
1473 	if (!result) {
1474 		memset(&ops, 0, sizeof(ops));
1475 		ops.acpi_op_start = 1;
1476 		result = acpi_bus_scan(device, &ops);
1477 	}
1478 	return result;
1479 }
1480 EXPORT_SYMBOL(acpi_bus_start);
1481 
1482 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1483 {
1484 	acpi_status status;
1485 	struct acpi_device *parent, *child;
1486 	acpi_handle phandle, chandle;
1487 	acpi_object_type type;
1488 	u32 level = 1;
1489 	int err = 0;
1490 
1491 	parent = start;
1492 	phandle = start->handle;
1493 	child = chandle = NULL;
1494 
1495 	while ((level > 0) && parent && (!err)) {
1496 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1497 					      chandle, &chandle);
1498 
1499 		/*
1500 		 * If this scope is exhausted then move our way back up.
1501 		 */
1502 		if (ACPI_FAILURE(status)) {
1503 			level--;
1504 			chandle = phandle;
1505 			acpi_get_parent(phandle, &phandle);
1506 			child = parent;
1507 			parent = parent->parent;
1508 
1509 			if (level == 0)
1510 				err = acpi_bus_remove(child, rmdevice);
1511 			else
1512 				err = acpi_bus_remove(child, 1);
1513 
1514 			continue;
1515 		}
1516 
1517 		status = acpi_get_type(chandle, &type);
1518 		if (ACPI_FAILURE(status)) {
1519 			continue;
1520 		}
1521 		/*
1522 		 * If there is a device corresponding to chandle then
1523 		 * parse it (depth-first).
1524 		 */
1525 		if (acpi_bus_get_device(chandle, &child) == 0) {
1526 			level++;
1527 			phandle = chandle;
1528 			chandle = NULL;
1529 			parent = child;
1530 		}
1531 		continue;
1532 	}
1533 	return err;
1534 }
1535 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1536 
1537 static int acpi_bus_scan_fixed(struct acpi_device *root)
1538 {
1539 	int result = 0;
1540 	struct acpi_device *device = NULL;
1541 	struct acpi_bus_ops ops;
1542 
1543 	if (!root)
1544 		return -ENODEV;
1545 
1546 	memset(&ops, 0, sizeof(ops));
1547 	ops.acpi_op_add = 1;
1548 	ops.acpi_op_start = 1;
1549 
1550 	/*
1551 	 * Enumerate all fixed-feature devices.
1552 	 */
1553 	if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1554 		result = acpi_add_single_object(&device, acpi_root,
1555 						NULL,
1556 						ACPI_BUS_TYPE_POWER_BUTTON,
1557 						&ops);
1558 	}
1559 
1560 	if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1561 		result = acpi_add_single_object(&device, acpi_root,
1562 						NULL,
1563 						ACPI_BUS_TYPE_SLEEP_BUTTON,
1564 						&ops);
1565 	}
1566 
1567 	return result;
1568 }
1569 
1570 int __init acpi_scan_init(void)
1571 {
1572 	int result;
1573 	struct acpi_bus_ops ops;
1574 
1575 	memset(&ops, 0, sizeof(ops));
1576 	ops.acpi_op_add = 1;
1577 	ops.acpi_op_start = 1;
1578 
1579 	result = bus_register(&acpi_bus_type);
1580 	if (result) {
1581 		/* We don't want to quit even if we failed to add suspend/resume */
1582 		printk(KERN_ERR PREFIX "Could not register bus type\n");
1583 	}
1584 
1585 	/*
1586 	 * Create the root device in the bus's device tree
1587 	 */
1588 	result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1589 					ACPI_BUS_TYPE_SYSTEM, &ops);
1590 	if (result)
1591 		goto Done;
1592 
1593 	/*
1594 	 * Enumerate devices in the ACPI namespace.
1595 	 */
1596 	result = acpi_bus_scan_fixed(acpi_root);
1597 
1598 	if (!result)
1599 		result = acpi_bus_scan(acpi_root, &ops);
1600 
1601 	if (result)
1602 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1603 
1604 Done:
1605 	return result;
1606 }
1607