xref: /linux/drivers/acpi/scan.c (revision a0f97e06a43cf524e616f09e6af3398e1e9c1c5b)
1 /*
2  * scan.c - support for transforming the ACPI namespace into individual objects
3  */
4 
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/kernel.h>
8 #include <linux/acpi.h>
9 
10 #include <acpi/acpi_drivers.h>
11 #include <acpi/acinterp.h>	/* for acpi_ex_eisa_id_to_string() */
12 
13 #define _COMPONENT		ACPI_BUS_COMPONENT
14 ACPI_MODULE_NAME("scan");
15 #define STRUCT_TO_INT(s)	(*((int*)&s))
16 extern struct acpi_device *acpi_root;
17 
18 #define ACPI_BUS_CLASS			"system_bus"
19 #define ACPI_BUS_HID			"LNXSYBUS"
20 #define ACPI_BUS_DEVICE_NAME		"System Bus"
21 
22 static LIST_HEAD(acpi_device_list);
23 static LIST_HEAD(acpi_bus_id_list);
24 DEFINE_SPINLOCK(acpi_device_lock);
25 LIST_HEAD(acpi_wakeup_device_list);
26 
27 struct acpi_device_bus_id{
28 	char bus_id[15];
29 	unsigned int instance_no;
30 	struct list_head node;
31 };
32 
33 /*
34  * Creates hid/cid(s) string needed for modalias and uevent
35  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
36  * char *modalias: "acpi:IBM0001:ACPI0001"
37 */
38 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
39 			   int size)
40 {
41 	int len;
42 
43 	if (!acpi_dev->flags.hardware_id)
44 		return -ENODEV;
45 
46 	len = snprintf(modalias, size, "acpi:%s:",
47 		       acpi_dev->pnp.hardware_id);
48 	if (len < 0 || len >= size)
49 		return -EINVAL;
50 	size -= len;
51 
52 	if (acpi_dev->flags.compatible_ids) {
53 		struct acpi_compatible_id_list *cid_list;
54 		int i;
55 		int count;
56 
57 		cid_list = acpi_dev->pnp.cid_list;
58 		for (i = 0; i < cid_list->count; i++) {
59 			count = snprintf(&modalias[len], size, "%s:",
60 					 cid_list->id[i].value);
61 			if (count < 0 || count >= size) {
62 				printk(KERN_ERR "acpi: %s cid[%i] exceeds event buffer size",
63 				       acpi_dev->pnp.device_name, i);
64 				break;
65 			}
66 			len += count;
67 			size -= count;
68 		}
69 	}
70 
71 	modalias[len] = '\0';
72 	return len;
73 }
74 
75 static ssize_t
76 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
77 	struct acpi_device *acpi_dev = to_acpi_device(dev);
78 	int len;
79 
80 	/* Device has no HID and no CID or string is >1024 */
81 	len = create_modalias(acpi_dev, buf, 1024);
82 	if (len <= 0)
83 		return 0;
84 	buf[len++] = '\n';
85 	return len;
86 }
87 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
88 
89 static int acpi_eject_operation(acpi_handle handle, int lockable)
90 {
91 	struct acpi_object_list arg_list;
92 	union acpi_object arg;
93 	acpi_status status = AE_OK;
94 
95 	/*
96 	 * TBD: evaluate _PS3?
97 	 */
98 
99 	if (lockable) {
100 		arg_list.count = 1;
101 		arg_list.pointer = &arg;
102 		arg.type = ACPI_TYPE_INTEGER;
103 		arg.integer.value = 0;
104 		acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
105 	}
106 
107 	arg_list.count = 1;
108 	arg_list.pointer = &arg;
109 	arg.type = ACPI_TYPE_INTEGER;
110 	arg.integer.value = 1;
111 
112 	/*
113 	 * TBD: _EJD support.
114 	 */
115 
116 	status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
117 	if (ACPI_FAILURE(status)) {
118 		return (-ENODEV);
119 	}
120 
121 	return (0);
122 }
123 
124 static ssize_t
125 acpi_eject_store(struct device *d, struct device_attribute *attr,
126 		const char *buf, size_t count)
127 {
128 	int result;
129 	int ret = count;
130 	int islockable;
131 	acpi_status status;
132 	acpi_handle handle;
133 	acpi_object_type type = 0;
134 	struct acpi_device *acpi_device = to_acpi_device(d);
135 
136 	if ((!count) || (buf[0] != '1')) {
137 		return -EINVAL;
138 	}
139 #ifndef FORCE_EJECT
140 	if (acpi_device->driver == NULL) {
141 		ret = -ENODEV;
142 		goto err;
143 	}
144 #endif
145 	status = acpi_get_type(acpi_device->handle, &type);
146 	if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
147 		ret = -ENODEV;
148 		goto err;
149 	}
150 
151 	islockable = acpi_device->flags.lockable;
152 	handle = acpi_device->handle;
153 
154 	result = acpi_bus_trim(acpi_device, 1);
155 
156 	if (!result)
157 		result = acpi_eject_operation(handle, islockable);
158 
159 	if (result) {
160 		ret = -EBUSY;
161 	}
162       err:
163 	return ret;
164 }
165 
166 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
167 
168 static ssize_t
169 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
170 	struct acpi_device *acpi_dev = to_acpi_device(dev);
171 
172 	return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
173 }
174 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
175 
176 static ssize_t
177 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
178 	struct acpi_device *acpi_dev = to_acpi_device(dev);
179 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
180 	int result;
181 
182 	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
183 	if(result)
184 		goto end;
185 
186 	result = sprintf(buf, "%s\n", (char*)path.pointer);
187 	kfree(path.pointer);
188   end:
189 	return result;
190 }
191 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
192 
193 static int acpi_device_setup_files(struct acpi_device *dev)
194 {
195 	acpi_status status;
196 	acpi_handle temp;
197 	int result = 0;
198 
199 	/*
200 	 * Devices gotten from FADT don't have a "path" attribute
201 	 */
202 	if(dev->handle) {
203 		result = device_create_file(&dev->dev, &dev_attr_path);
204 		if(result)
205 			goto end;
206 	}
207 
208 	if(dev->flags.hardware_id) {
209 		result = device_create_file(&dev->dev, &dev_attr_hid);
210 		if(result)
211 			goto end;
212 	}
213 
214 	if (dev->flags.hardware_id || dev->flags.compatible_ids){
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 	if (dev->flags.hardware_id || dev->flags.compatible_ids)
245 		device_remove_file(&dev->dev, &dev_attr_modalias);
246 
247 	if(dev->flags.hardware_id)
248 		device_remove_file(&dev->dev, &dev_attr_hid);
249 	if(dev->handle)
250 		device_remove_file(&dev->dev, &dev_attr_path);
251 }
252 /* --------------------------------------------------------------------------
253 			ACPI Bus operations
254    -------------------------------------------------------------------------- */
255 
256 int acpi_match_device_ids(struct acpi_device *device,
257 			  const struct acpi_device_id *ids)
258 {
259 	const struct acpi_device_id *id;
260 
261 	if (device->flags.hardware_id) {
262 		for (id = ids; id->id[0]; id++) {
263 			if (!strcmp((char*)id->id, device->pnp.hardware_id))
264 				return 0;
265 		}
266 	}
267 
268 	if (device->flags.compatible_ids) {
269 		struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
270 		int i;
271 
272 		for (id = ids; id->id[0]; id++) {
273 			/* compare multiple _CID entries against driver ids */
274 			for (i = 0; i < cid_list->count; i++) {
275 				if (!strcmp((char*)id->id,
276 					    cid_list->id[i].value))
277 					return 0;
278 			}
279 		}
280 	}
281 
282 	return -ENOENT;
283 }
284 EXPORT_SYMBOL(acpi_match_device_ids);
285 
286 static void acpi_device_release(struct device *dev)
287 {
288 	struct acpi_device *acpi_dev = to_acpi_device(dev);
289 
290 	kfree(acpi_dev->pnp.cid_list);
291 	kfree(acpi_dev);
292 }
293 
294 static int acpi_device_suspend(struct device *dev, pm_message_t state)
295 {
296 	struct acpi_device *acpi_dev = to_acpi_device(dev);
297 	struct acpi_driver *acpi_drv = acpi_dev->driver;
298 
299 	if (acpi_drv && acpi_drv->ops.suspend)
300 		return acpi_drv->ops.suspend(acpi_dev, state);
301 	return 0;
302 }
303 
304 static int acpi_device_resume(struct device *dev)
305 {
306 	struct acpi_device *acpi_dev = to_acpi_device(dev);
307 	struct acpi_driver *acpi_drv = acpi_dev->driver;
308 
309 	if (acpi_drv && acpi_drv->ops.resume)
310 		return acpi_drv->ops.resume(acpi_dev);
311 	return 0;
312 }
313 
314 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
315 {
316 	struct acpi_device *acpi_dev = to_acpi_device(dev);
317 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
318 
319 	return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
320 }
321 
322 static int acpi_device_uevent(struct device *dev, char **envp, int num_envp,
323 			      char *buffer, int buffer_size)
324 {
325 	struct acpi_device *acpi_dev = to_acpi_device(dev);
326 
327 	strcpy(buffer, "MODALIAS=");
328 	if (create_modalias(acpi_dev, buffer + 9, buffer_size - 9) > 0) {
329 		envp[0] = buffer;
330 		envp[1] = NULL;
331 	}
332 	return 0;
333 }
334 
335 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
336 static int acpi_start_single_object(struct acpi_device *);
337 static int acpi_device_probe(struct device * dev)
338 {
339 	struct acpi_device *acpi_dev = to_acpi_device(dev);
340 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
341 	int ret;
342 
343 	ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
344 	if (!ret) {
345 		if (acpi_dev->bus_ops.acpi_op_start)
346 			acpi_start_single_object(acpi_dev);
347 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
348 			"Found driver [%s] for device [%s]\n",
349 			acpi_drv->name, acpi_dev->pnp.bus_id));
350 		get_device(dev);
351 	}
352 	return ret;
353 }
354 
355 static int acpi_device_remove(struct device * dev)
356 {
357 	struct acpi_device *acpi_dev = to_acpi_device(dev);
358 	struct acpi_driver *acpi_drv = acpi_dev->driver;
359 
360 	if (acpi_drv) {
361 		if (acpi_drv->ops.stop)
362 			acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
363 		if (acpi_drv->ops.remove)
364 			acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
365 	}
366 	acpi_dev->driver = NULL;
367 	acpi_driver_data(dev) = NULL;
368 
369 	put_device(dev);
370 	return 0;
371 }
372 
373 static void acpi_device_shutdown(struct device *dev)
374 {
375 	struct acpi_device *acpi_dev = to_acpi_device(dev);
376 	struct acpi_driver *acpi_drv = acpi_dev->driver;
377 
378 	if (acpi_drv && acpi_drv->ops.shutdown)
379 		acpi_drv->ops.shutdown(acpi_dev);
380 
381 	return ;
382 }
383 
384 struct bus_type acpi_bus_type = {
385 	.name		= "acpi",
386 	.suspend	= acpi_device_suspend,
387 	.resume		= acpi_device_resume,
388 	.shutdown	= acpi_device_shutdown,
389 	.match		= acpi_bus_match,
390 	.probe		= acpi_device_probe,
391 	.remove		= acpi_device_remove,
392 	.uevent		= acpi_device_uevent,
393 };
394 
395 static int acpi_device_register(struct acpi_device *device,
396 				 struct acpi_device *parent)
397 {
398 	int result;
399 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
400 	int found = 0;
401 	/*
402 	 * Linkage
403 	 * -------
404 	 * Link this device to its parent and siblings.
405 	 */
406 	INIT_LIST_HEAD(&device->children);
407 	INIT_LIST_HEAD(&device->node);
408 	INIT_LIST_HEAD(&device->g_list);
409 	INIT_LIST_HEAD(&device->wakeup_list);
410 
411 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
412 	if (!new_bus_id) {
413 		printk(KERN_ERR PREFIX "Memory allocation error\n");
414 		return -ENOMEM;
415 	}
416 
417 	spin_lock(&acpi_device_lock);
418 	/*
419 	 * Find suitable bus_id and instance number in acpi_bus_id_list
420 	 * If failed, create one and link it into acpi_bus_id_list
421 	 */
422 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
423 		if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
424 			acpi_device_bus_id->instance_no ++;
425 			found = 1;
426 			kfree(new_bus_id);
427 			break;
428 		}
429 	}
430 	if(!found) {
431 		acpi_device_bus_id = new_bus_id;
432 		strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
433 		acpi_device_bus_id->instance_no = 0;
434 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
435 	}
436 	sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
437 
438 	if (device->parent) {
439 		list_add_tail(&device->node, &device->parent->children);
440 		list_add_tail(&device->g_list, &device->parent->g_list);
441 	} else
442 		list_add_tail(&device->g_list, &acpi_device_list);
443 	if (device->wakeup.flags.valid)
444 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
445 	spin_unlock(&acpi_device_lock);
446 
447 	if (device->parent)
448 		device->dev.parent = &parent->dev;
449 	device->dev.bus = &acpi_bus_type;
450 	device_initialize(&device->dev);
451 	device->dev.release = &acpi_device_release;
452 	result = device_add(&device->dev);
453 	if(result) {
454 		printk("Error adding device %s", device->dev.bus_id);
455 		goto end;
456 	}
457 
458 	result = acpi_device_setup_files(device);
459 	if(result)
460 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error creating sysfs interface for device %s\n", device->dev.bus_id));
461 
462 	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
463 	return 0;
464   end:
465 	spin_lock(&acpi_device_lock);
466 	if (device->parent) {
467 		list_del(&device->node);
468 		list_del(&device->g_list);
469 	} else
470 		list_del(&device->g_list);
471 	list_del(&device->wakeup_list);
472 	spin_unlock(&acpi_device_lock);
473 	return result;
474 }
475 
476 static void acpi_device_unregister(struct acpi_device *device, int type)
477 {
478 	spin_lock(&acpi_device_lock);
479 	if (device->parent) {
480 		list_del(&device->node);
481 		list_del(&device->g_list);
482 	} else
483 		list_del(&device->g_list);
484 
485 	list_del(&device->wakeup_list);
486 	spin_unlock(&acpi_device_lock);
487 
488 	acpi_detach_data(device->handle, acpi_bus_data_handler);
489 
490 	acpi_device_remove_files(device);
491 	device_unregister(&device->dev);
492 }
493 
494 /* --------------------------------------------------------------------------
495                                  Driver Management
496    -------------------------------------------------------------------------- */
497 /**
498  * acpi_bus_driver_init - add a device to a driver
499  * @device: the device to add and initialize
500  * @driver: driver for the device
501  *
502  * Used to initialize a device via its device driver.  Called whenever a
503  * driver is bound to a device.  Invokes the driver's add() ops.
504  */
505 static int
506 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
507 {
508 	int result = 0;
509 
510 
511 	if (!device || !driver)
512 		return -EINVAL;
513 
514 	if (!driver->ops.add)
515 		return -ENOSYS;
516 
517 	result = driver->ops.add(device);
518 	if (result) {
519 		device->driver = NULL;
520 		acpi_driver_data(device) = NULL;
521 		return result;
522 	}
523 
524 	device->driver = driver;
525 
526 	/*
527 	 * TBD - Configuration Management: Assign resources to device based
528 	 * upon possible configuration and currently allocated resources.
529 	 */
530 
531 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
532 			  "Driver successfully bound to device\n"));
533 	return 0;
534 }
535 
536 static int acpi_start_single_object(struct acpi_device *device)
537 {
538 	int result = 0;
539 	struct acpi_driver *driver;
540 
541 
542 	if (!(driver = device->driver))
543 		return 0;
544 
545 	if (driver->ops.start) {
546 		result = driver->ops.start(device);
547 		if (result && driver->ops.remove)
548 			driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
549 	}
550 
551 	return result;
552 }
553 
554 /**
555  * acpi_bus_register_driver - register a driver with the ACPI bus
556  * @driver: driver being registered
557  *
558  * Registers a driver with the ACPI bus.  Searches the namespace for all
559  * devices that match the driver's criteria and binds.  Returns zero for
560  * success or a negative error status for failure.
561  */
562 int acpi_bus_register_driver(struct acpi_driver *driver)
563 {
564 	int ret;
565 
566 	if (acpi_disabled)
567 		return -ENODEV;
568 	driver->drv.name = driver->name;
569 	driver->drv.bus = &acpi_bus_type;
570 	driver->drv.owner = driver->owner;
571 
572 	ret = driver_register(&driver->drv);
573 	return ret;
574 }
575 
576 EXPORT_SYMBOL(acpi_bus_register_driver);
577 
578 /**
579  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
580  * @driver: driver to unregister
581  *
582  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
583  * devices that match the driver's criteria and unbinds.
584  */
585 void acpi_bus_unregister_driver(struct acpi_driver *driver)
586 {
587 	driver_unregister(&driver->drv);
588 }
589 
590 EXPORT_SYMBOL(acpi_bus_unregister_driver);
591 
592 /* --------------------------------------------------------------------------
593                                  Device Enumeration
594    -------------------------------------------------------------------------- */
595 acpi_status
596 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
597 {
598 	acpi_status status;
599 	acpi_handle tmp;
600 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
601 	union acpi_object *obj;
602 
603 	status = acpi_get_handle(handle, "_EJD", &tmp);
604 	if (ACPI_FAILURE(status))
605 		return status;
606 
607 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
608 	if (ACPI_SUCCESS(status)) {
609 		obj = buffer.pointer;
610 		status = acpi_get_handle(NULL, obj->string.pointer, ejd);
611 		kfree(buffer.pointer);
612 	}
613 	return status;
614 }
615 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
616 
617 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
618 {
619 
620 	/* TBD */
621 
622 	return;
623 }
624 
625 static int acpi_bus_get_perf_flags(struct acpi_device *device)
626 {
627 	device->performance.state = ACPI_STATE_UNKNOWN;
628 	return 0;
629 }
630 
631 static acpi_status
632 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
633 					     union acpi_object *package)
634 {
635 	int i = 0;
636 	union acpi_object *element = NULL;
637 
638 	if (!device || !package || (package->package.count < 2))
639 		return AE_BAD_PARAMETER;
640 
641 	element = &(package->package.elements[0]);
642 	if (!element)
643 		return AE_BAD_PARAMETER;
644 	if (element->type == ACPI_TYPE_PACKAGE) {
645 		if ((element->package.count < 2) ||
646 		    (element->package.elements[0].type !=
647 		     ACPI_TYPE_LOCAL_REFERENCE)
648 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
649 			return AE_BAD_DATA;
650 		device->wakeup.gpe_device =
651 		    element->package.elements[0].reference.handle;
652 		device->wakeup.gpe_number =
653 		    (u32) element->package.elements[1].integer.value;
654 	} else if (element->type == ACPI_TYPE_INTEGER) {
655 		device->wakeup.gpe_number = element->integer.value;
656 	} else
657 		return AE_BAD_DATA;
658 
659 	element = &(package->package.elements[1]);
660 	if (element->type != ACPI_TYPE_INTEGER) {
661 		return AE_BAD_DATA;
662 	}
663 	device->wakeup.sleep_state = element->integer.value;
664 
665 	if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
666 		return AE_NO_MEMORY;
667 	}
668 	device->wakeup.resources.count = package->package.count - 2;
669 	for (i = 0; i < device->wakeup.resources.count; i++) {
670 		element = &(package->package.elements[i + 2]);
671 		if (element->type != ACPI_TYPE_ANY) {
672 			return AE_BAD_DATA;
673 		}
674 
675 		device->wakeup.resources.handles[i] = element->reference.handle;
676 	}
677 
678 	return AE_OK;
679 }
680 
681 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
682 {
683 	acpi_status status = 0;
684 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
685 	union acpi_object *package = NULL;
686 
687 	struct acpi_device_id button_device_ids[] = {
688 		{"PNP0C0D", 0},
689 		{"PNP0C0C", 0},
690 		{"PNP0C0E", 0},
691 		{"", 0},
692 	};
693 
694 
695 	/* _PRW */
696 	status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
697 	if (ACPI_FAILURE(status)) {
698 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
699 		goto end;
700 	}
701 
702 	package = (union acpi_object *)buffer.pointer;
703 	status = acpi_bus_extract_wakeup_device_power_package(device, package);
704 	if (ACPI_FAILURE(status)) {
705 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
706 		goto end;
707 	}
708 
709 	kfree(buffer.pointer);
710 
711 	device->wakeup.flags.valid = 1;
712 	/* Power button, Lid switch always enable wakeup */
713 	if (!acpi_match_device_ids(device, button_device_ids))
714 		device->wakeup.flags.run_wake = 1;
715 
716       end:
717 	if (ACPI_FAILURE(status))
718 		device->flags.wake_capable = 0;
719 	return 0;
720 }
721 
722 static int acpi_bus_get_power_flags(struct acpi_device *device)
723 {
724 	acpi_status status = 0;
725 	acpi_handle handle = NULL;
726 	u32 i = 0;
727 
728 
729 	/*
730 	 * Power Management Flags
731 	 */
732 	status = acpi_get_handle(device->handle, "_PSC", &handle);
733 	if (ACPI_SUCCESS(status))
734 		device->power.flags.explicit_get = 1;
735 	status = acpi_get_handle(device->handle, "_IRC", &handle);
736 	if (ACPI_SUCCESS(status))
737 		device->power.flags.inrush_current = 1;
738 
739 	/*
740 	 * Enumerate supported power management states
741 	 */
742 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
743 		struct acpi_device_power_state *ps = &device->power.states[i];
744 		char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
745 
746 		/* Evaluate "_PRx" to se if power resources are referenced */
747 		acpi_evaluate_reference(device->handle, object_name, NULL,
748 					&ps->resources);
749 		if (ps->resources.count) {
750 			device->power.flags.power_resources = 1;
751 			ps->flags.valid = 1;
752 		}
753 
754 		/* Evaluate "_PSx" to see if we can do explicit sets */
755 		object_name[2] = 'S';
756 		status = acpi_get_handle(device->handle, object_name, &handle);
757 		if (ACPI_SUCCESS(status)) {
758 			ps->flags.explicit_set = 1;
759 			ps->flags.valid = 1;
760 		}
761 
762 		/* State is valid if we have some power control */
763 		if (ps->resources.count || ps->flags.explicit_set)
764 			ps->flags.valid = 1;
765 
766 		ps->power = -1;	/* Unknown - driver assigned */
767 		ps->latency = -1;	/* Unknown - driver assigned */
768 	}
769 
770 	/* Set defaults for D0 and D3 states (always valid) */
771 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
772 	device->power.states[ACPI_STATE_D0].power = 100;
773 	device->power.states[ACPI_STATE_D3].flags.valid = 1;
774 	device->power.states[ACPI_STATE_D3].power = 0;
775 
776 	/* TBD: System wake support and resource requirements. */
777 
778 	device->power.state = ACPI_STATE_UNKNOWN;
779 
780 	return 0;
781 }
782 
783 static int acpi_bus_get_flags(struct acpi_device *device)
784 {
785 	acpi_status status = AE_OK;
786 	acpi_handle temp = NULL;
787 
788 
789 	/* Presence of _STA indicates 'dynamic_status' */
790 	status = acpi_get_handle(device->handle, "_STA", &temp);
791 	if (ACPI_SUCCESS(status))
792 		device->flags.dynamic_status = 1;
793 
794 	/* Presence of _CID indicates 'compatible_ids' */
795 	status = acpi_get_handle(device->handle, "_CID", &temp);
796 	if (ACPI_SUCCESS(status))
797 		device->flags.compatible_ids = 1;
798 
799 	/* Presence of _RMV indicates 'removable' */
800 	status = acpi_get_handle(device->handle, "_RMV", &temp);
801 	if (ACPI_SUCCESS(status))
802 		device->flags.removable = 1;
803 
804 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
805 	status = acpi_get_handle(device->handle, "_EJD", &temp);
806 	if (ACPI_SUCCESS(status))
807 		device->flags.ejectable = 1;
808 	else {
809 		status = acpi_get_handle(device->handle, "_EJ0", &temp);
810 		if (ACPI_SUCCESS(status))
811 			device->flags.ejectable = 1;
812 	}
813 
814 	/* Presence of _LCK indicates 'lockable' */
815 	status = acpi_get_handle(device->handle, "_LCK", &temp);
816 	if (ACPI_SUCCESS(status))
817 		device->flags.lockable = 1;
818 
819 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
820 	status = acpi_get_handle(device->handle, "_PS0", &temp);
821 	if (ACPI_FAILURE(status))
822 		status = acpi_get_handle(device->handle, "_PR0", &temp);
823 	if (ACPI_SUCCESS(status))
824 		device->flags.power_manageable = 1;
825 
826 	/* Presence of _PRW indicates wake capable */
827 	status = acpi_get_handle(device->handle, "_PRW", &temp);
828 	if (ACPI_SUCCESS(status))
829 		device->flags.wake_capable = 1;
830 
831 	/* TBD: Peformance management */
832 
833 	return 0;
834 }
835 
836 static void acpi_device_get_busid(struct acpi_device *device,
837 				  acpi_handle handle, int type)
838 {
839 	char bus_id[5] = { '?', 0 };
840 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
841 	int i = 0;
842 
843 	/*
844 	 * Bus ID
845 	 * ------
846 	 * The device's Bus ID is simply the object name.
847 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
848 	 */
849 	switch (type) {
850 	case ACPI_BUS_TYPE_SYSTEM:
851 		strcpy(device->pnp.bus_id, "ACPI");
852 		break;
853 	case ACPI_BUS_TYPE_POWER_BUTTON:
854 		strcpy(device->pnp.bus_id, "PWRF");
855 		break;
856 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
857 		strcpy(device->pnp.bus_id, "SLPF");
858 		break;
859 	default:
860 		acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
861 		/* Clean up trailing underscores (if any) */
862 		for (i = 3; i > 1; i--) {
863 			if (bus_id[i] == '_')
864 				bus_id[i] = '\0';
865 			else
866 				break;
867 		}
868 		strcpy(device->pnp.bus_id, bus_id);
869 		break;
870 	}
871 }
872 
873 static int
874 acpi_video_bus_match(struct acpi_device *device)
875 {
876 	acpi_handle h_dummy1;
877 	acpi_handle h_dummy2;
878 	acpi_handle h_dummy3;
879 
880 
881 	if (!device)
882 		return -EINVAL;
883 
884 	/* Since there is no HID, CID for ACPI Video drivers, we have
885 	 * to check well known required nodes for each feature we support.
886 	 */
887 
888 	/* Does this device able to support video switching ? */
889 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy1)) &&
890 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy2)))
891 		return 0;
892 
893 	/* Does this device able to retrieve a video ROM ? */
894 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy1)))
895 		return 0;
896 
897 	/* Does this device able to configure which video head to be POSTed ? */
898 	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy1)) &&
899 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy2)) &&
900 	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy3)))
901 		return 0;
902 
903 	return -ENODEV;
904 }
905 
906 /*
907  * acpi_bay_match - see if a device is an ejectable driver bay
908  *
909  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
910  * then we can safely call it an ejectable drive bay
911  */
912 static int acpi_bay_match(struct acpi_device *device){
913 	acpi_status status;
914 	acpi_handle handle;
915 	acpi_handle tmp;
916 	acpi_handle phandle;
917 
918 	handle = device->handle;
919 
920 	status = acpi_get_handle(handle, "_EJ0", &tmp);
921 	if (ACPI_FAILURE(status))
922 		return -ENODEV;
923 
924 	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
925 		(ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
926 		(ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
927 		(ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
928 		return 0;
929 
930 	if (acpi_get_parent(handle, &phandle))
931 		return -ENODEV;
932 
933         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
934                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
935                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
936                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
937                 return 0;
938 
939 	return -ENODEV;
940 }
941 
942 static void acpi_device_set_id(struct acpi_device *device,
943 			       struct acpi_device *parent, acpi_handle handle,
944 			       int type)
945 {
946 	struct acpi_device_info *info;
947 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
948 	char *hid = NULL;
949 	char *uid = NULL;
950 	struct acpi_compatible_id_list *cid_list = NULL;
951 	acpi_status status;
952 
953 	switch (type) {
954 	case ACPI_BUS_TYPE_DEVICE:
955 		status = acpi_get_object_info(handle, &buffer);
956 		if (ACPI_FAILURE(status)) {
957 			printk("%s: Error reading device info\n", __FUNCTION__);
958 			return;
959 		}
960 
961 		info = buffer.pointer;
962 		if (info->valid & ACPI_VALID_HID)
963 			hid = info->hardware_id.value;
964 		if (info->valid & ACPI_VALID_UID)
965 			uid = info->unique_id.value;
966 		if (info->valid & ACPI_VALID_CID)
967 			cid_list = &info->compatibility_id;
968 		if (info->valid & ACPI_VALID_ADR) {
969 			device->pnp.bus_address = info->address;
970 			device->flags.bus_address = 1;
971 		}
972 
973 		if(!(info->valid & (ACPI_VALID_HID | ACPI_VALID_CID))){
974 			status = acpi_video_bus_match(device);
975 			if(ACPI_SUCCESS(status))
976 				hid = ACPI_VIDEO_HID;
977 
978 			status = acpi_bay_match(device);
979 			if (ACPI_SUCCESS(status))
980 				hid = ACPI_BAY_HID;
981 		}
982 		break;
983 	case ACPI_BUS_TYPE_POWER:
984 		hid = ACPI_POWER_HID;
985 		break;
986 	case ACPI_BUS_TYPE_PROCESSOR:
987 		hid = ACPI_PROCESSOR_HID;
988 		break;
989 	case ACPI_BUS_TYPE_SYSTEM:
990 		hid = ACPI_SYSTEM_HID;
991 		break;
992 	case ACPI_BUS_TYPE_THERMAL:
993 		hid = ACPI_THERMAL_HID;
994 		break;
995 	case ACPI_BUS_TYPE_POWER_BUTTON:
996 		hid = ACPI_BUTTON_HID_POWERF;
997 		break;
998 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
999 		hid = ACPI_BUTTON_HID_SLEEPF;
1000 		break;
1001 	}
1002 
1003 	/*
1004 	 * \_SB
1005 	 * ----
1006 	 * Fix for the system root bus device -- the only root-level device.
1007 	 */
1008 	if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
1009 		hid = ACPI_BUS_HID;
1010 		strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1011 		strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1012 	}
1013 
1014 	if (hid) {
1015 		strcpy(device->pnp.hardware_id, hid);
1016 		device->flags.hardware_id = 1;
1017 	}
1018 	if (uid) {
1019 		strcpy(device->pnp.unique_id, uid);
1020 		device->flags.unique_id = 1;
1021 	}
1022 	if (cid_list) {
1023 		device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL);
1024 		if (device->pnp.cid_list)
1025 			memcpy(device->pnp.cid_list, cid_list, cid_list->size);
1026 		else
1027 			printk(KERN_ERR "Memory allocation error\n");
1028 	}
1029 
1030 	kfree(buffer.pointer);
1031 }
1032 
1033 static int acpi_device_set_context(struct acpi_device *device, int type)
1034 {
1035 	acpi_status status = AE_OK;
1036 	int result = 0;
1037 	/*
1038 	 * Context
1039 	 * -------
1040 	 * Attach this 'struct acpi_device' to the ACPI object.  This makes
1041 	 * resolutions from handle->device very efficient.  Note that we need
1042 	 * to be careful with fixed-feature devices as they all attach to the
1043 	 * root object.
1044 	 */
1045 	if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
1046 	    type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
1047 		status = acpi_attach_data(device->handle,
1048 					  acpi_bus_data_handler, device);
1049 
1050 		if (ACPI_FAILURE(status)) {
1051 			printk("Error attaching device data\n");
1052 			result = -ENODEV;
1053 		}
1054 	}
1055 	return result;
1056 }
1057 
1058 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1059 {
1060 	if (!dev)
1061 		return -EINVAL;
1062 
1063 	dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1064 	device_release_driver(&dev->dev);
1065 
1066 	if (!rmdevice)
1067 		return 0;
1068 
1069 	/*
1070 	 * unbind _ADR-Based Devices when hot removal
1071 	 */
1072 	if (dev->flags.bus_address) {
1073 		if ((dev->parent) && (dev->parent->ops.unbind))
1074 			dev->parent->ops.unbind(dev);
1075 	}
1076 	acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1077 
1078 	return 0;
1079 }
1080 
1081 static int
1082 acpi_add_single_object(struct acpi_device **child,
1083 		       struct acpi_device *parent, acpi_handle handle, int type,
1084 			struct acpi_bus_ops *ops)
1085 {
1086 	int result = 0;
1087 	struct acpi_device *device = NULL;
1088 
1089 
1090 	if (!child)
1091 		return -EINVAL;
1092 
1093 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1094 	if (!device) {
1095 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1096 		return -ENOMEM;
1097 	}
1098 
1099 	device->handle = handle;
1100 	device->parent = parent;
1101 	device->bus_ops = *ops; /* workround for not call .start */
1102 
1103 
1104 	acpi_device_get_busid(device, handle, type);
1105 
1106 	/*
1107 	 * Flags
1108 	 * -----
1109 	 * Get prior to calling acpi_bus_get_status() so we know whether
1110 	 * or not _STA is present.  Note that we only look for object
1111 	 * handles -- cannot evaluate objects until we know the device is
1112 	 * present and properly initialized.
1113 	 */
1114 	result = acpi_bus_get_flags(device);
1115 	if (result)
1116 		goto end;
1117 
1118 	/*
1119 	 * Status
1120 	 * ------
1121 	 * See if the device is present.  We always assume that non-Device
1122 	 * and non-Processor objects (e.g. thermal zones, power resources,
1123 	 * etc.) are present, functioning, etc. (at least when parent object
1124 	 * is present).  Note that _STA has a different meaning for some
1125 	 * objects (e.g. power resources) so we need to be careful how we use
1126 	 * it.
1127 	 */
1128 	switch (type) {
1129 	case ACPI_BUS_TYPE_PROCESSOR:
1130 	case ACPI_BUS_TYPE_DEVICE:
1131 		result = acpi_bus_get_status(device);
1132 		if (ACPI_FAILURE(result) || !device->status.present) {
1133 			result = -ENOENT;
1134 			goto end;
1135 		}
1136 		break;
1137 	default:
1138 		STRUCT_TO_INT(device->status) =
1139 		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
1140 		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
1141 		break;
1142 	}
1143 
1144 	/*
1145 	 * Initialize Device
1146 	 * -----------------
1147 	 * TBD: Synch with Core's enumeration/initialization process.
1148 	 */
1149 
1150 	/*
1151 	 * Hardware ID, Unique ID, & Bus Address
1152 	 * -------------------------------------
1153 	 */
1154 	acpi_device_set_id(device, parent, handle, type);
1155 
1156 	/*
1157 	 * Power Management
1158 	 * ----------------
1159 	 */
1160 	if (device->flags.power_manageable) {
1161 		result = acpi_bus_get_power_flags(device);
1162 		if (result)
1163 			goto end;
1164 	}
1165 
1166 	/*
1167 	 * Wakeup device management
1168 	 *-----------------------
1169 	 */
1170 	if (device->flags.wake_capable) {
1171 		result = acpi_bus_get_wakeup_device_flags(device);
1172 		if (result)
1173 			goto end;
1174 	}
1175 
1176 	/*
1177 	 * Performance Management
1178 	 * ----------------------
1179 	 */
1180 	if (device->flags.performance_manageable) {
1181 		result = acpi_bus_get_perf_flags(device);
1182 		if (result)
1183 			goto end;
1184 	}
1185 
1186 	if ((result = acpi_device_set_context(device, type)))
1187 		goto end;
1188 
1189 	result = acpi_device_register(device, parent);
1190 
1191 	/*
1192 	 * Bind _ADR-Based Devices when hot add
1193 	 */
1194 	if (device->flags.bus_address) {
1195 		if (device->parent && device->parent->ops.bind)
1196 			device->parent->ops.bind(device);
1197 	}
1198 
1199       end:
1200 	if (!result)
1201 		*child = device;
1202 	else {
1203 		kfree(device->pnp.cid_list);
1204 		kfree(device);
1205 	}
1206 
1207 	return result;
1208 }
1209 
1210 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1211 {
1212 	acpi_status status = AE_OK;
1213 	struct acpi_device *parent = NULL;
1214 	struct acpi_device *child = NULL;
1215 	acpi_handle phandle = NULL;
1216 	acpi_handle chandle = NULL;
1217 	acpi_object_type type = 0;
1218 	u32 level = 1;
1219 
1220 
1221 	if (!start)
1222 		return -EINVAL;
1223 
1224 	parent = start;
1225 	phandle = start->handle;
1226 
1227 	/*
1228 	 * Parse through the ACPI namespace, identify all 'devices', and
1229 	 * create a new 'struct acpi_device' for each.
1230 	 */
1231 	while ((level > 0) && parent) {
1232 
1233 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1234 					      chandle, &chandle);
1235 
1236 		/*
1237 		 * If this scope is exhausted then move our way back up.
1238 		 */
1239 		if (ACPI_FAILURE(status)) {
1240 			level--;
1241 			chandle = phandle;
1242 			acpi_get_parent(phandle, &phandle);
1243 			if (parent->parent)
1244 				parent = parent->parent;
1245 			continue;
1246 		}
1247 
1248 		status = acpi_get_type(chandle, &type);
1249 		if (ACPI_FAILURE(status))
1250 			continue;
1251 
1252 		/*
1253 		 * If this is a scope object then parse it (depth-first).
1254 		 */
1255 		if (type == ACPI_TYPE_LOCAL_SCOPE) {
1256 			level++;
1257 			phandle = chandle;
1258 			chandle = NULL;
1259 			continue;
1260 		}
1261 
1262 		/*
1263 		 * We're only interested in objects that we consider 'devices'.
1264 		 */
1265 		switch (type) {
1266 		case ACPI_TYPE_DEVICE:
1267 			type = ACPI_BUS_TYPE_DEVICE;
1268 			break;
1269 		case ACPI_TYPE_PROCESSOR:
1270 			type = ACPI_BUS_TYPE_PROCESSOR;
1271 			break;
1272 		case ACPI_TYPE_THERMAL:
1273 			type = ACPI_BUS_TYPE_THERMAL;
1274 			break;
1275 		case ACPI_TYPE_POWER:
1276 			type = ACPI_BUS_TYPE_POWER;
1277 			break;
1278 		default:
1279 			continue;
1280 		}
1281 
1282 		if (ops->acpi_op_add)
1283 			status = acpi_add_single_object(&child, parent,
1284 				chandle, type, ops);
1285 		else
1286 			status = acpi_bus_get_device(chandle, &child);
1287 
1288 		if (ACPI_FAILURE(status))
1289 			continue;
1290 
1291 		if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1292 			status = acpi_start_single_object(child);
1293 			if (ACPI_FAILURE(status))
1294 				continue;
1295 		}
1296 
1297 		/*
1298 		 * If the device is present, enabled, and functioning then
1299 		 * parse its scope (depth-first).  Note that we need to
1300 		 * represent absent devices to facilitate PnP notifications
1301 		 * -- but only the subtree head (not all of its children,
1302 		 * which will be enumerated when the parent is inserted).
1303 		 *
1304 		 * TBD: Need notifications and other detection mechanisms
1305 		 *      in place before we can fully implement this.
1306 		 */
1307 		if (child->status.present) {
1308 			status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1309 						      NULL, NULL);
1310 			if (ACPI_SUCCESS(status)) {
1311 				level++;
1312 				phandle = chandle;
1313 				chandle = NULL;
1314 				parent = child;
1315 			}
1316 		}
1317 	}
1318 
1319 	return 0;
1320 }
1321 
1322 int
1323 acpi_bus_add(struct acpi_device **child,
1324 	     struct acpi_device *parent, acpi_handle handle, int type)
1325 {
1326 	int result;
1327 	struct acpi_bus_ops ops;
1328 
1329 	memset(&ops, 0, sizeof(ops));
1330 	ops.acpi_op_add = 1;
1331 
1332 	result = acpi_add_single_object(child, parent, handle, type, &ops);
1333 	if (!result)
1334 		result = acpi_bus_scan(*child, &ops);
1335 
1336 	return result;
1337 }
1338 
1339 EXPORT_SYMBOL(acpi_bus_add);
1340 
1341 int acpi_bus_start(struct acpi_device *device)
1342 {
1343 	int result;
1344 	struct acpi_bus_ops ops;
1345 
1346 
1347 	if (!device)
1348 		return -EINVAL;
1349 
1350 	result = acpi_start_single_object(device);
1351 	if (!result) {
1352 		memset(&ops, 0, sizeof(ops));
1353 		ops.acpi_op_start = 1;
1354 		result = acpi_bus_scan(device, &ops);
1355 	}
1356 	return result;
1357 }
1358 
1359 EXPORT_SYMBOL(acpi_bus_start);
1360 
1361 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1362 {
1363 	acpi_status status;
1364 	struct acpi_device *parent, *child;
1365 	acpi_handle phandle, chandle;
1366 	acpi_object_type type;
1367 	u32 level = 1;
1368 	int err = 0;
1369 
1370 	parent = start;
1371 	phandle = start->handle;
1372 	child = chandle = NULL;
1373 
1374 	while ((level > 0) && parent && (!err)) {
1375 		status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1376 					      chandle, &chandle);
1377 
1378 		/*
1379 		 * If this scope is exhausted then move our way back up.
1380 		 */
1381 		if (ACPI_FAILURE(status)) {
1382 			level--;
1383 			chandle = phandle;
1384 			acpi_get_parent(phandle, &phandle);
1385 			child = parent;
1386 			parent = parent->parent;
1387 
1388 			if (level == 0)
1389 				err = acpi_bus_remove(child, rmdevice);
1390 			else
1391 				err = acpi_bus_remove(child, 1);
1392 
1393 			continue;
1394 		}
1395 
1396 		status = acpi_get_type(chandle, &type);
1397 		if (ACPI_FAILURE(status)) {
1398 			continue;
1399 		}
1400 		/*
1401 		 * If there is a device corresponding to chandle then
1402 		 * parse it (depth-first).
1403 		 */
1404 		if (acpi_bus_get_device(chandle, &child) == 0) {
1405 			level++;
1406 			phandle = chandle;
1407 			chandle = NULL;
1408 			parent = child;
1409 		}
1410 		continue;
1411 	}
1412 	return err;
1413 }
1414 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1415 
1416 
1417 static int acpi_bus_scan_fixed(struct acpi_device *root)
1418 {
1419 	int result = 0;
1420 	struct acpi_device *device = NULL;
1421 	struct acpi_bus_ops ops;
1422 
1423 	if (!root)
1424 		return -ENODEV;
1425 
1426 	memset(&ops, 0, sizeof(ops));
1427 	ops.acpi_op_add = 1;
1428 	ops.acpi_op_start = 1;
1429 
1430 	/*
1431 	 * Enumerate all fixed-feature devices.
1432 	 */
1433 	if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1434 		result = acpi_add_single_object(&device, acpi_root,
1435 						NULL,
1436 						ACPI_BUS_TYPE_POWER_BUTTON,
1437 						&ops);
1438 	}
1439 
1440 	if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1441 		result = acpi_add_single_object(&device, acpi_root,
1442 						NULL,
1443 						ACPI_BUS_TYPE_SLEEP_BUTTON,
1444 						&ops);
1445 	}
1446 
1447 	return result;
1448 }
1449 
1450 static int __init acpi_scan_init(void)
1451 {
1452 	int result;
1453 	struct acpi_bus_ops ops;
1454 
1455 
1456 	if (acpi_disabled)
1457 		return 0;
1458 
1459 	memset(&ops, 0, sizeof(ops));
1460 	ops.acpi_op_add = 1;
1461 	ops.acpi_op_start = 1;
1462 
1463 	result = bus_register(&acpi_bus_type);
1464 	if (result) {
1465 		/* We don't want to quit even if we failed to add suspend/resume */
1466 		printk(KERN_ERR PREFIX "Could not register bus type\n");
1467 	}
1468 
1469 	/*
1470 	 * Create the root device in the bus's device tree
1471 	 */
1472 	result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1473 					ACPI_BUS_TYPE_SYSTEM, &ops);
1474 	if (result)
1475 		goto Done;
1476 
1477 	/*
1478 	 * Enumerate devices in the ACPI namespace.
1479 	 */
1480 	result = acpi_bus_scan_fixed(acpi_root);
1481 	if (!result)
1482 		result = acpi_bus_scan(acpi_root, &ops);
1483 
1484 	if (result)
1485 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1486 
1487       Done:
1488 	return result;
1489 }
1490 
1491 subsys_initcall(acpi_scan_init);
1492