module: turn longs into ints for module sizes
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / acpi / scan.c
blobf3132aa47a69d7b0656d9fe4fa40e9c5a9f8edcf
1 /*
2 * scan.c - support for transforming the ACPI namespace into individual objects
3 */
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>
12 #include <acpi/acpi_drivers.h>
13 #include <acpi/acinterp.h> /* for acpi_ex_eisa_id_to_string() */
15 #define _COMPONENT ACPI_BUS_COMPONENT
16 ACPI_MODULE_NAME("scan");
17 #define STRUCT_TO_INT(s) (*((int*)&s))
18 extern struct acpi_device *acpi_root;
20 #define ACPI_BUS_CLASS "system_bus"
21 #define ACPI_BUS_HID "LNXSYBUS"
22 #define ACPI_BUS_DEVICE_NAME "System Bus"
24 static LIST_HEAD(acpi_device_list);
25 static LIST_HEAD(acpi_bus_id_list);
26 DEFINE_SPINLOCK(acpi_device_lock);
27 LIST_HEAD(acpi_wakeup_device_list);
29 struct acpi_device_bus_id{
30 char bus_id[15];
31 unsigned int instance_no;
32 struct list_head node;
36 * Creates hid/cid(s) string needed for modalias and uevent
37 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
38 * char *modalias: "acpi:IBM0001:ACPI0001"
40 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
41 int size)
43 int len;
44 int count;
46 if (!acpi_dev->flags.hardware_id && !acpi_dev->flags.compatible_ids)
47 return -ENODEV;
49 len = snprintf(modalias, size, "acpi:");
50 size -= len;
52 if (acpi_dev->flags.hardware_id) {
53 count = snprintf(&modalias[len], size, "%s:",
54 acpi_dev->pnp.hardware_id);
55 if (count < 0 || count >= size)
56 return -EINVAL;
57 len += count;
58 size -= count;
61 if (acpi_dev->flags.compatible_ids) {
62 struct acpi_compatible_id_list *cid_list;
63 int i;
65 cid_list = acpi_dev->pnp.cid_list;
66 for (i = 0; i < cid_list->count; i++) {
67 count = snprintf(&modalias[len], size, "%s:",
68 cid_list->id[i].value);
69 if (count < 0 || count >= size) {
70 printk(KERN_ERR PREFIX "%s cid[%i] exceeds event buffer size",
71 acpi_dev->pnp.device_name, i);
72 break;
74 len += count;
75 size -= count;
79 modalias[len] = '\0';
80 return len;
83 static ssize_t
84 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
85 struct acpi_device *acpi_dev = to_acpi_device(dev);
86 int len;
88 /* Device has no HID and no CID or string is >1024 */
89 len = create_modalias(acpi_dev, buf, 1024);
90 if (len <= 0)
91 return 0;
92 buf[len++] = '\n';
93 return len;
95 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
97 static int acpi_bus_hot_remove_device(void *context)
99 struct acpi_device *device;
100 acpi_handle handle = context;
101 struct acpi_object_list arg_list;
102 union acpi_object arg;
103 acpi_status status = AE_OK;
105 if (acpi_bus_get_device(handle, &device))
106 return 0;
108 if (!device)
109 return 0;
111 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
112 "Hot-removing device %s...\n", device->dev.bus_id));
115 if (acpi_bus_trim(device, 1)) {
116 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
117 "Removing device failed\n"));
118 return -1;
121 /* power off device */
122 status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
123 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
124 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
125 "Power-off device failed\n"));
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);
135 arg_list.count = 1;
136 arg_list.pointer = &arg;
137 arg.type = ACPI_TYPE_INTEGER;
138 arg.integer.value = 1;
141 * TBD: _EJD support.
143 status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
144 if (ACPI_FAILURE(status))
145 return -ENODEV;
147 return 0;
150 static ssize_t
151 acpi_eject_store(struct device *d, struct device_attribute *attr,
152 const char *buf, size_t count)
154 int ret = count;
155 acpi_status status;
156 acpi_object_type type = 0;
157 struct acpi_device *acpi_device = to_acpi_device(d);
158 struct task_struct *task;
160 if ((!count) || (buf[0] != '1')) {
161 return -EINVAL;
163 #ifndef FORCE_EJECT
164 if (acpi_device->driver == NULL) {
165 ret = -ENODEV;
166 goto err;
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;
175 /* remove the device in another thread to fix the deadlock issue */
176 task = kthread_run(acpi_bus_hot_remove_device,
177 acpi_device->handle, "acpi_hot_remove_device");
178 if (IS_ERR(task))
179 ret = PTR_ERR(task);
180 err:
181 return ret;
184 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
186 static ssize_t
187 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
188 struct acpi_device *acpi_dev = to_acpi_device(dev);
190 return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
192 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
194 static ssize_t
195 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
196 struct acpi_device *acpi_dev = to_acpi_device(dev);
197 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
198 int result;
200 result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
201 if(result)
202 goto end;
204 result = sprintf(buf, "%s\n", (char*)path.pointer);
205 kfree(path.pointer);
206 end:
207 return result;
209 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
211 static int acpi_device_setup_files(struct acpi_device *dev)
213 acpi_status status;
214 acpi_handle temp;
215 int result = 0;
218 * Devices gotten from FADT don't have a "path" attribute
220 if(dev->handle) {
221 result = device_create_file(&dev->dev, &dev_attr_path);
222 if(result)
223 goto end;
226 if(dev->flags.hardware_id) {
227 result = device_create_file(&dev->dev, &dev_attr_hid);
228 if(result)
229 goto end;
232 if (dev->flags.hardware_id || dev->flags.compatible_ids){
233 result = device_create_file(&dev->dev, &dev_attr_modalias);
234 if(result)
235 goto end;
239 * If device has _EJ0, 'eject' file is created that is used to trigger
240 * hot-removal function from userland.
242 status = acpi_get_handle(dev->handle, "_EJ0", &temp);
243 if (ACPI_SUCCESS(status))
244 result = device_create_file(&dev->dev, &dev_attr_eject);
245 end:
246 return result;
249 static void acpi_device_remove_files(struct acpi_device *dev)
251 acpi_status status;
252 acpi_handle temp;
255 * If device has _EJ0, 'eject' file is created that is used to trigger
256 * hot-removal function from userland.
258 status = acpi_get_handle(dev->handle, "_EJ0", &temp);
259 if (ACPI_SUCCESS(status))
260 device_remove_file(&dev->dev, &dev_attr_eject);
262 if (dev->flags.hardware_id || dev->flags.compatible_ids)
263 device_remove_file(&dev->dev, &dev_attr_modalias);
265 if(dev->flags.hardware_id)
266 device_remove_file(&dev->dev, &dev_attr_hid);
267 if(dev->handle)
268 device_remove_file(&dev->dev, &dev_attr_path);
270 /* --------------------------------------------------------------------------
271 ACPI Bus operations
272 -------------------------------------------------------------------------- */
274 int acpi_match_device_ids(struct acpi_device *device,
275 const struct acpi_device_id *ids)
277 const struct acpi_device_id *id;
279 if (device->flags.hardware_id) {
280 for (id = ids; id->id[0]; id++) {
281 if (!strcmp((char*)id->id, device->pnp.hardware_id))
282 return 0;
286 if (device->flags.compatible_ids) {
287 struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
288 int i;
290 for (id = ids; id->id[0]; id++) {
291 /* compare multiple _CID entries against driver ids */
292 for (i = 0; i < cid_list->count; i++) {
293 if (!strcmp((char*)id->id,
294 cid_list->id[i].value))
295 return 0;
300 return -ENOENT;
302 EXPORT_SYMBOL(acpi_match_device_ids);
304 static void acpi_device_release(struct device *dev)
306 struct acpi_device *acpi_dev = to_acpi_device(dev);
308 kfree(acpi_dev->pnp.cid_list);
309 kfree(acpi_dev);
312 static int acpi_device_suspend(struct device *dev, pm_message_t state)
314 struct acpi_device *acpi_dev = to_acpi_device(dev);
315 struct acpi_driver *acpi_drv = acpi_dev->driver;
317 if (acpi_drv && acpi_drv->ops.suspend)
318 return acpi_drv->ops.suspend(acpi_dev, state);
319 return 0;
322 static int acpi_device_resume(struct device *dev)
324 struct acpi_device *acpi_dev = to_acpi_device(dev);
325 struct acpi_driver *acpi_drv = acpi_dev->driver;
327 if (acpi_drv && acpi_drv->ops.resume)
328 return acpi_drv->ops.resume(acpi_dev);
329 return 0;
332 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
334 struct acpi_device *acpi_dev = to_acpi_device(dev);
335 struct acpi_driver *acpi_drv = to_acpi_driver(drv);
337 return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
340 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
342 struct acpi_device *acpi_dev = to_acpi_device(dev);
343 int len;
345 if (add_uevent_var(env, "MODALIAS="))
346 return -ENOMEM;
347 len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
348 sizeof(env->buf) - env->buflen);
349 if (len >= (sizeof(env->buf) - env->buflen))
350 return -ENOMEM;
351 env->buflen += len;
352 return 0;
355 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
356 static int acpi_start_single_object(struct acpi_device *);
357 static int acpi_device_probe(struct device * dev)
359 struct acpi_device *acpi_dev = to_acpi_device(dev);
360 struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
361 int ret;
363 ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
364 if (!ret) {
365 if (acpi_dev->bus_ops.acpi_op_start)
366 acpi_start_single_object(acpi_dev);
367 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
368 "Found driver [%s] for device [%s]\n",
369 acpi_drv->name, acpi_dev->pnp.bus_id));
370 get_device(dev);
372 return ret;
375 static int acpi_device_remove(struct device * dev)
377 struct acpi_device *acpi_dev = to_acpi_device(dev);
378 struct acpi_driver *acpi_drv = acpi_dev->driver;
380 if (acpi_drv) {
381 if (acpi_drv->ops.stop)
382 acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
383 if (acpi_drv->ops.remove)
384 acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
386 acpi_dev->driver = NULL;
387 acpi_driver_data(dev) = NULL;
389 put_device(dev);
390 return 0;
393 static void acpi_device_shutdown(struct device *dev)
395 struct acpi_device *acpi_dev = to_acpi_device(dev);
396 struct acpi_driver *acpi_drv = acpi_dev->driver;
398 if (acpi_drv && acpi_drv->ops.shutdown)
399 acpi_drv->ops.shutdown(acpi_dev);
401 return ;
404 struct bus_type acpi_bus_type = {
405 .name = "acpi",
406 .suspend = acpi_device_suspend,
407 .resume = acpi_device_resume,
408 .shutdown = acpi_device_shutdown,
409 .match = acpi_bus_match,
410 .probe = acpi_device_probe,
411 .remove = acpi_device_remove,
412 .uevent = acpi_device_uevent,
415 static int acpi_device_register(struct acpi_device *device,
416 struct acpi_device *parent)
418 int result;
419 struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
420 int found = 0;
422 * Linkage
423 * -------
424 * Link this device to its parent and siblings.
426 INIT_LIST_HEAD(&device->children);
427 INIT_LIST_HEAD(&device->node);
428 INIT_LIST_HEAD(&device->g_list);
429 INIT_LIST_HEAD(&device->wakeup_list);
431 new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
432 if (!new_bus_id) {
433 printk(KERN_ERR PREFIX "Memory allocation error\n");
434 return -ENOMEM;
437 spin_lock(&acpi_device_lock);
439 * Find suitable bus_id and instance number in acpi_bus_id_list
440 * If failed, create one and link it into acpi_bus_id_list
442 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
443 if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
444 acpi_device_bus_id->instance_no ++;
445 found = 1;
446 kfree(new_bus_id);
447 break;
450 if(!found) {
451 acpi_device_bus_id = new_bus_id;
452 strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
453 acpi_device_bus_id->instance_no = 0;
454 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
456 sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
458 if (device->parent) {
459 list_add_tail(&device->node, &device->parent->children);
460 list_add_tail(&device->g_list, &device->parent->g_list);
461 } else
462 list_add_tail(&device->g_list, &acpi_device_list);
463 if (device->wakeup.flags.valid)
464 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
465 spin_unlock(&acpi_device_lock);
467 if (device->parent)
468 device->dev.parent = &parent->dev;
469 device->dev.bus = &acpi_bus_type;
470 device_initialize(&device->dev);
471 device->dev.release = &acpi_device_release;
472 result = device_add(&device->dev);
473 if(result) {
474 printk(KERN_ERR PREFIX "Error adding device %s", device->dev.bus_id);
475 goto end;
478 result = acpi_device_setup_files(device);
479 if(result)
480 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error creating sysfs interface for device %s\n", device->dev.bus_id));
482 device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
483 return 0;
484 end:
485 spin_lock(&acpi_device_lock);
486 if (device->parent) {
487 list_del(&device->node);
488 list_del(&device->g_list);
489 } else
490 list_del(&device->g_list);
491 list_del(&device->wakeup_list);
492 spin_unlock(&acpi_device_lock);
493 return result;
496 static void acpi_device_unregister(struct acpi_device *device, int type)
498 spin_lock(&acpi_device_lock);
499 if (device->parent) {
500 list_del(&device->node);
501 list_del(&device->g_list);
502 } else
503 list_del(&device->g_list);
505 list_del(&device->wakeup_list);
506 spin_unlock(&acpi_device_lock);
508 acpi_detach_data(device->handle, acpi_bus_data_handler);
510 acpi_device_remove_files(device);
511 device_unregister(&device->dev);
514 /* --------------------------------------------------------------------------
515 Driver Management
516 -------------------------------------------------------------------------- */
518 * acpi_bus_driver_init - add a device to a driver
519 * @device: the device to add and initialize
520 * @driver: driver for the device
522 * Used to initialize a device via its device driver. Called whenever a
523 * driver is bound to a device. Invokes the driver's add() ops.
525 static int
526 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
528 int result = 0;
531 if (!device || !driver)
532 return -EINVAL;
534 if (!driver->ops.add)
535 return -ENOSYS;
537 result = driver->ops.add(device);
538 if (result) {
539 device->driver = NULL;
540 acpi_driver_data(device) = NULL;
541 return result;
544 device->driver = driver;
547 * TBD - Configuration Management: Assign resources to device based
548 * upon possible configuration and currently allocated resources.
551 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
552 "Driver successfully bound to device\n"));
553 return 0;
556 static int acpi_start_single_object(struct acpi_device *device)
558 int result = 0;
559 struct acpi_driver *driver;
562 if (!(driver = device->driver))
563 return 0;
565 if (driver->ops.start) {
566 result = driver->ops.start(device);
567 if (result && driver->ops.remove)
568 driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
571 return result;
575 * acpi_bus_register_driver - register a driver with the ACPI bus
576 * @driver: driver being registered
578 * Registers a driver with the ACPI bus. Searches the namespace for all
579 * devices that match the driver's criteria and binds. Returns zero for
580 * success or a negative error status for failure.
582 int acpi_bus_register_driver(struct acpi_driver *driver)
584 int ret;
586 if (acpi_disabled)
587 return -ENODEV;
588 driver->drv.name = driver->name;
589 driver->drv.bus = &acpi_bus_type;
590 driver->drv.owner = driver->owner;
592 ret = driver_register(&driver->drv);
593 return ret;
596 EXPORT_SYMBOL(acpi_bus_register_driver);
599 * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
600 * @driver: driver to unregister
602 * Unregisters a driver with the ACPI bus. Searches the namespace for all
603 * devices that match the driver's criteria and unbinds.
605 void acpi_bus_unregister_driver(struct acpi_driver *driver)
607 driver_unregister(&driver->drv);
610 EXPORT_SYMBOL(acpi_bus_unregister_driver);
612 /* --------------------------------------------------------------------------
613 Device Enumeration
614 -------------------------------------------------------------------------- */
615 acpi_status
616 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
618 acpi_status status;
619 acpi_handle tmp;
620 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
621 union acpi_object *obj;
623 status = acpi_get_handle(handle, "_EJD", &tmp);
624 if (ACPI_FAILURE(status))
625 return status;
627 status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
628 if (ACPI_SUCCESS(status)) {
629 obj = buffer.pointer;
630 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
631 ejd);
632 kfree(buffer.pointer);
634 return status;
636 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
638 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
641 /* TBD */
643 return;
646 static int acpi_bus_get_perf_flags(struct acpi_device *device)
648 device->performance.state = ACPI_STATE_UNKNOWN;
649 return 0;
652 static acpi_status
653 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
654 union acpi_object *package)
656 int i = 0;
657 union acpi_object *element = NULL;
659 if (!device || !package || (package->package.count < 2))
660 return AE_BAD_PARAMETER;
662 element = &(package->package.elements[0]);
663 if (!element)
664 return AE_BAD_PARAMETER;
665 if (element->type == ACPI_TYPE_PACKAGE) {
666 if ((element->package.count < 2) ||
667 (element->package.elements[0].type !=
668 ACPI_TYPE_LOCAL_REFERENCE)
669 || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
670 return AE_BAD_DATA;
671 device->wakeup.gpe_device =
672 element->package.elements[0].reference.handle;
673 device->wakeup.gpe_number =
674 (u32) element->package.elements[1].integer.value;
675 } else if (element->type == ACPI_TYPE_INTEGER) {
676 device->wakeup.gpe_number = element->integer.value;
677 } else
678 return AE_BAD_DATA;
680 element = &(package->package.elements[1]);
681 if (element->type != ACPI_TYPE_INTEGER) {
682 return AE_BAD_DATA;
684 device->wakeup.sleep_state = element->integer.value;
686 if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
687 return AE_NO_MEMORY;
689 device->wakeup.resources.count = package->package.count - 2;
690 for (i = 0; i < device->wakeup.resources.count; i++) {
691 element = &(package->package.elements[i + 2]);
692 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
693 return AE_BAD_DATA;
695 device->wakeup.resources.handles[i] = element->reference.handle;
698 return AE_OK;
701 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
703 acpi_status status = 0;
704 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
705 union acpi_object *package = NULL;
706 int psw_error;
708 struct acpi_device_id button_device_ids[] = {
709 {"PNP0C0D", 0},
710 {"PNP0C0C", 0},
711 {"PNP0C0E", 0},
712 {"", 0},
715 /* _PRW */
716 status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
717 if (ACPI_FAILURE(status)) {
718 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
719 goto end;
722 package = (union acpi_object *)buffer.pointer;
723 status = acpi_bus_extract_wakeup_device_power_package(device, package);
724 if (ACPI_FAILURE(status)) {
725 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
726 goto end;
729 kfree(buffer.pointer);
731 device->wakeup.flags.valid = 1;
732 /* Call _PSW/_DSW object to disable its ability to wake the sleeping
733 * system for the ACPI device with the _PRW object.
734 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
735 * So it is necessary to call _DSW object first. Only when it is not
736 * present will the _PSW object used.
738 psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
739 if (psw_error)
740 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
741 "error in _DSW or _PSW evaluation\n"));
743 /* Power button, Lid switch always enable wakeup */
744 if (!acpi_match_device_ids(device, button_device_ids))
745 device->wakeup.flags.run_wake = 1;
747 end:
748 if (ACPI_FAILURE(status))
749 device->flags.wake_capable = 0;
750 return 0;
753 static int acpi_bus_get_power_flags(struct acpi_device *device)
755 acpi_status status = 0;
756 acpi_handle handle = NULL;
757 u32 i = 0;
761 * Power Management Flags
763 status = acpi_get_handle(device->handle, "_PSC", &handle);
764 if (ACPI_SUCCESS(status))
765 device->power.flags.explicit_get = 1;
766 status = acpi_get_handle(device->handle, "_IRC", &handle);
767 if (ACPI_SUCCESS(status))
768 device->power.flags.inrush_current = 1;
771 * Enumerate supported power management states
773 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
774 struct acpi_device_power_state *ps = &device->power.states[i];
775 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
777 /* Evaluate "_PRx" to se if power resources are referenced */
778 acpi_evaluate_reference(device->handle, object_name, NULL,
779 &ps->resources);
780 if (ps->resources.count) {
781 device->power.flags.power_resources = 1;
782 ps->flags.valid = 1;
785 /* Evaluate "_PSx" to see if we can do explicit sets */
786 object_name[2] = 'S';
787 status = acpi_get_handle(device->handle, object_name, &handle);
788 if (ACPI_SUCCESS(status)) {
789 ps->flags.explicit_set = 1;
790 ps->flags.valid = 1;
793 /* State is valid if we have some power control */
794 if (ps->resources.count || ps->flags.explicit_set)
795 ps->flags.valid = 1;
797 ps->power = -1; /* Unknown - driver assigned */
798 ps->latency = -1; /* Unknown - driver assigned */
801 /* Set defaults for D0 and D3 states (always valid) */
802 device->power.states[ACPI_STATE_D0].flags.valid = 1;
803 device->power.states[ACPI_STATE_D0].power = 100;
804 device->power.states[ACPI_STATE_D3].flags.valid = 1;
805 device->power.states[ACPI_STATE_D3].power = 0;
807 /* TBD: System wake support and resource requirements. */
809 device->power.state = ACPI_STATE_UNKNOWN;
811 return 0;
814 static int acpi_bus_get_flags(struct acpi_device *device)
816 acpi_status status = AE_OK;
817 acpi_handle temp = NULL;
820 /* Presence of _STA indicates 'dynamic_status' */
821 status = acpi_get_handle(device->handle, "_STA", &temp);
822 if (ACPI_SUCCESS(status))
823 device->flags.dynamic_status = 1;
825 /* Presence of _CID indicates 'compatible_ids' */
826 status = acpi_get_handle(device->handle, "_CID", &temp);
827 if (ACPI_SUCCESS(status))
828 device->flags.compatible_ids = 1;
830 /* Presence of _RMV indicates 'removable' */
831 status = acpi_get_handle(device->handle, "_RMV", &temp);
832 if (ACPI_SUCCESS(status))
833 device->flags.removable = 1;
835 /* Presence of _EJD|_EJ0 indicates 'ejectable' */
836 status = acpi_get_handle(device->handle, "_EJD", &temp);
837 if (ACPI_SUCCESS(status))
838 device->flags.ejectable = 1;
839 else {
840 status = acpi_get_handle(device->handle, "_EJ0", &temp);
841 if (ACPI_SUCCESS(status))
842 device->flags.ejectable = 1;
845 /* Presence of _LCK indicates 'lockable' */
846 status = acpi_get_handle(device->handle, "_LCK", &temp);
847 if (ACPI_SUCCESS(status))
848 device->flags.lockable = 1;
850 /* Presence of _PS0|_PR0 indicates 'power manageable' */
851 status = acpi_get_handle(device->handle, "_PS0", &temp);
852 if (ACPI_FAILURE(status))
853 status = acpi_get_handle(device->handle, "_PR0", &temp);
854 if (ACPI_SUCCESS(status))
855 device->flags.power_manageable = 1;
857 /* Presence of _PRW indicates wake capable */
858 status = acpi_get_handle(device->handle, "_PRW", &temp);
859 if (ACPI_SUCCESS(status))
860 device->flags.wake_capable = 1;
862 /* TBD: Performance management */
864 return 0;
867 static void acpi_device_get_busid(struct acpi_device *device,
868 acpi_handle handle, int type)
870 char bus_id[5] = { '?', 0 };
871 struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
872 int i = 0;
875 * Bus ID
876 * ------
877 * The device's Bus ID is simply the object name.
878 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
880 switch (type) {
881 case ACPI_BUS_TYPE_SYSTEM:
882 strcpy(device->pnp.bus_id, "ACPI");
883 break;
884 case ACPI_BUS_TYPE_POWER_BUTTON:
885 strcpy(device->pnp.bus_id, "PWRF");
886 break;
887 case ACPI_BUS_TYPE_SLEEP_BUTTON:
888 strcpy(device->pnp.bus_id, "SLPF");
889 break;
890 default:
891 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
892 /* Clean up trailing underscores (if any) */
893 for (i = 3; i > 1; i--) {
894 if (bus_id[i] == '_')
895 bus_id[i] = '\0';
896 else
897 break;
899 strcpy(device->pnp.bus_id, bus_id);
900 break;
904 static int
905 acpi_video_bus_match(struct acpi_device *device)
907 acpi_handle h_dummy;
909 if (!device)
910 return -EINVAL;
912 /* Since there is no HID, CID for ACPI Video drivers, we have
913 * to check well known required nodes for each feature we support.
916 /* Does this device able to support video switching ? */
917 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
918 ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
919 return 0;
921 /* Does this device able to retrieve a video ROM ? */
922 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
923 return 0;
925 /* Does this device able to configure which video head to be POSTed ? */
926 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
927 ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
928 ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
929 return 0;
931 return -ENODEV;
935 * acpi_bay_match - see if a device is an ejectable driver bay
937 * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
938 * then we can safely call it an ejectable drive bay
940 static int acpi_bay_match(struct acpi_device *device){
941 acpi_status status;
942 acpi_handle handle;
943 acpi_handle tmp;
944 acpi_handle phandle;
946 handle = device->handle;
948 status = acpi_get_handle(handle, "_EJ0", &tmp);
949 if (ACPI_FAILURE(status))
950 return -ENODEV;
952 if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
953 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
954 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
955 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
956 return 0;
958 if (acpi_get_parent(handle, &phandle))
959 return -ENODEV;
961 if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
962 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
963 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
964 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
965 return 0;
967 return -ENODEV;
971 * acpi_dock_match - see if a device has a _DCK method
973 static int acpi_dock_match(struct acpi_device *device)
975 acpi_handle tmp;
976 return acpi_get_handle(device->handle, "_DCK", &tmp);
979 static void acpi_device_set_id(struct acpi_device *device,
980 struct acpi_device *parent, acpi_handle handle,
981 int type)
983 struct acpi_device_info *info;
984 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
985 char *hid = NULL;
986 char *uid = NULL;
987 struct acpi_compatible_id_list *cid_list = NULL;
988 const char *cid_add = NULL;
989 acpi_status status;
991 switch (type) {
992 case ACPI_BUS_TYPE_DEVICE:
993 status = acpi_get_object_info(handle, &buffer);
994 if (ACPI_FAILURE(status)) {
995 printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
996 return;
999 info = buffer.pointer;
1000 if (info->valid & ACPI_VALID_HID)
1001 hid = info->hardware_id.value;
1002 if (info->valid & ACPI_VALID_UID)
1003 uid = info->unique_id.value;
1004 if (info->valid & ACPI_VALID_CID)
1005 cid_list = &info->compatibility_id;
1006 if (info->valid & ACPI_VALID_ADR) {
1007 device->pnp.bus_address = info->address;
1008 device->flags.bus_address = 1;
1011 /* If we have a video/bay/dock device, add our selfdefined
1012 HID to the CID list. Like that the video/bay/dock drivers
1013 will get autoloaded and the device might still match
1014 against another driver.
1016 if (ACPI_SUCCESS(acpi_video_bus_match(device)))
1017 cid_add = ACPI_VIDEO_HID;
1018 else if (ACPI_SUCCESS(acpi_bay_match(device)))
1019 cid_add = ACPI_BAY_HID;
1020 else if (ACPI_SUCCESS(acpi_dock_match(device)))
1021 cid_add = ACPI_DOCK_HID;
1023 break;
1024 case ACPI_BUS_TYPE_POWER:
1025 hid = ACPI_POWER_HID;
1026 break;
1027 case ACPI_BUS_TYPE_PROCESSOR:
1028 hid = ACPI_PROCESSOR_HID;
1029 break;
1030 case ACPI_BUS_TYPE_SYSTEM:
1031 hid = ACPI_SYSTEM_HID;
1032 break;
1033 case ACPI_BUS_TYPE_THERMAL:
1034 hid = ACPI_THERMAL_HID;
1035 break;
1036 case ACPI_BUS_TYPE_POWER_BUTTON:
1037 hid = ACPI_BUTTON_HID_POWERF;
1038 break;
1039 case ACPI_BUS_TYPE_SLEEP_BUTTON:
1040 hid = ACPI_BUTTON_HID_SLEEPF;
1041 break;
1045 * \_SB
1046 * ----
1047 * Fix for the system root bus device -- the only root-level device.
1049 if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
1050 hid = ACPI_BUS_HID;
1051 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1052 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1055 if (hid) {
1056 strcpy(device->pnp.hardware_id, hid);
1057 device->flags.hardware_id = 1;
1059 if (uid) {
1060 strcpy(device->pnp.unique_id, uid);
1061 device->flags.unique_id = 1;
1063 if (cid_list || cid_add) {
1064 struct acpi_compatible_id_list *list;
1065 int size = 0;
1066 int count = 0;
1068 if (cid_list) {
1069 size = cid_list->size;
1070 } else if (cid_add) {
1071 size = sizeof(struct acpi_compatible_id_list);
1072 cid_list = ACPI_ALLOCATE_ZEROED((acpi_size) size);
1073 if (!cid_list) {
1074 printk(KERN_ERR "Memory allocation error\n");
1075 kfree(buffer.pointer);
1076 return;
1077 } else {
1078 cid_list->count = 0;
1079 cid_list->size = size;
1082 if (cid_add)
1083 size += sizeof(struct acpi_compatible_id);
1084 list = kmalloc(size, GFP_KERNEL);
1086 if (list) {
1087 if (cid_list) {
1088 memcpy(list, cid_list, cid_list->size);
1089 count = cid_list->count;
1091 if (cid_add) {
1092 strncpy(list->id[count].value, cid_add,
1093 ACPI_MAX_CID_LENGTH);
1094 count++;
1095 device->flags.compatible_ids = 1;
1097 list->size = size;
1098 list->count = count;
1099 device->pnp.cid_list = list;
1100 } else
1101 printk(KERN_ERR PREFIX "Memory allocation error\n");
1104 kfree(buffer.pointer);
1107 static int acpi_device_set_context(struct acpi_device *device, int type)
1109 acpi_status status = AE_OK;
1110 int result = 0;
1112 * Context
1113 * -------
1114 * Attach this 'struct acpi_device' to the ACPI object. This makes
1115 * resolutions from handle->device very efficient. Note that we need
1116 * to be careful with fixed-feature devices as they all attach to the
1117 * root object.
1119 if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
1120 type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
1121 status = acpi_attach_data(device->handle,
1122 acpi_bus_data_handler, device);
1124 if (ACPI_FAILURE(status)) {
1125 printk(KERN_ERR PREFIX "Error attaching device data\n");
1126 result = -ENODEV;
1129 return result;
1132 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1134 if (!dev)
1135 return -EINVAL;
1137 dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1138 device_release_driver(&dev->dev);
1140 if (!rmdevice)
1141 return 0;
1144 * unbind _ADR-Based Devices when hot removal
1146 if (dev->flags.bus_address) {
1147 if ((dev->parent) && (dev->parent->ops.unbind))
1148 dev->parent->ops.unbind(dev);
1150 acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1152 return 0;
1155 static int
1156 acpi_is_child_device(struct acpi_device *device,
1157 int (*matcher)(struct acpi_device *))
1159 int result = -ENODEV;
1161 do {
1162 if (ACPI_SUCCESS(matcher(device)))
1163 return AE_OK;
1164 } while ((device = device->parent));
1166 return result;
1169 static int
1170 acpi_add_single_object(struct acpi_device **child,
1171 struct acpi_device *parent, acpi_handle handle, int type,
1172 struct acpi_bus_ops *ops)
1174 int result = 0;
1175 struct acpi_device *device = NULL;
1178 if (!child)
1179 return -EINVAL;
1181 device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1182 if (!device) {
1183 printk(KERN_ERR PREFIX "Memory allocation error\n");
1184 return -ENOMEM;
1187 device->handle = handle;
1188 device->parent = parent;
1189 device->bus_ops = *ops; /* workround for not call .start */
1192 acpi_device_get_busid(device, handle, type);
1195 * Flags
1196 * -----
1197 * Get prior to calling acpi_bus_get_status() so we know whether
1198 * or not _STA is present. Note that we only look for object
1199 * handles -- cannot evaluate objects until we know the device is
1200 * present and properly initialized.
1202 result = acpi_bus_get_flags(device);
1203 if (result)
1204 goto end;
1207 * Status
1208 * ------
1209 * See if the device is present. We always assume that non-Device
1210 * and non-Processor objects (e.g. thermal zones, power resources,
1211 * etc.) are present, functioning, etc. (at least when parent object
1212 * is present). Note that _STA has a different meaning for some
1213 * objects (e.g. power resources) so we need to be careful how we use
1214 * it.
1216 switch (type) {
1217 case ACPI_BUS_TYPE_PROCESSOR:
1218 case ACPI_BUS_TYPE_DEVICE:
1219 result = acpi_bus_get_status(device);
1220 if (ACPI_FAILURE(result)) {
1221 result = -ENODEV;
1222 goto end;
1224 if (!device->status.present) {
1225 /* Bay and dock should be handled even if absent */
1226 if (!ACPI_SUCCESS(
1227 acpi_is_child_device(device, acpi_bay_match)) &&
1228 !ACPI_SUCCESS(
1229 acpi_is_child_device(device, acpi_dock_match))) {
1230 result = -ENODEV;
1231 goto end;
1234 break;
1235 default:
1236 STRUCT_TO_INT(device->status) =
1237 ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
1238 ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING;
1239 break;
1243 * Initialize Device
1244 * -----------------
1245 * TBD: Synch with Core's enumeration/initialization process.
1249 * Hardware ID, Unique ID, & Bus Address
1250 * -------------------------------------
1252 acpi_device_set_id(device, parent, handle, type);
1255 * Power Management
1256 * ----------------
1258 if (device->flags.power_manageable) {
1259 result = acpi_bus_get_power_flags(device);
1260 if (result)
1261 goto end;
1265 * Wakeup device management
1266 *-----------------------
1268 if (device->flags.wake_capable) {
1269 result = acpi_bus_get_wakeup_device_flags(device);
1270 if (result)
1271 goto end;
1275 * Performance Management
1276 * ----------------------
1278 if (device->flags.performance_manageable) {
1279 result = acpi_bus_get_perf_flags(device);
1280 if (result)
1281 goto end;
1284 if ((result = acpi_device_set_context(device, type)))
1285 goto end;
1287 result = acpi_device_register(device, parent);
1290 * Bind _ADR-Based Devices when hot add
1292 if (device->flags.bus_address) {
1293 if (device->parent && device->parent->ops.bind)
1294 device->parent->ops.bind(device);
1297 end:
1298 if (!result)
1299 *child = device;
1300 else {
1301 kfree(device->pnp.cid_list);
1302 kfree(device);
1305 return result;
1308 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1310 acpi_status status = AE_OK;
1311 struct acpi_device *parent = NULL;
1312 struct acpi_device *child = NULL;
1313 acpi_handle phandle = NULL;
1314 acpi_handle chandle = NULL;
1315 acpi_object_type type = 0;
1316 u32 level = 1;
1319 if (!start)
1320 return -EINVAL;
1322 parent = start;
1323 phandle = start->handle;
1326 * Parse through the ACPI namespace, identify all 'devices', and
1327 * create a new 'struct acpi_device' for each.
1329 while ((level > 0) && parent) {
1331 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1332 chandle, &chandle);
1335 * If this scope is exhausted then move our way back up.
1337 if (ACPI_FAILURE(status)) {
1338 level--;
1339 chandle = phandle;
1340 acpi_get_parent(phandle, &phandle);
1341 if (parent->parent)
1342 parent = parent->parent;
1343 continue;
1346 status = acpi_get_type(chandle, &type);
1347 if (ACPI_FAILURE(status))
1348 continue;
1351 * If this is a scope object then parse it (depth-first).
1353 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1354 level++;
1355 phandle = chandle;
1356 chandle = NULL;
1357 continue;
1361 * We're only interested in objects that we consider 'devices'.
1363 switch (type) {
1364 case ACPI_TYPE_DEVICE:
1365 type = ACPI_BUS_TYPE_DEVICE;
1366 break;
1367 case ACPI_TYPE_PROCESSOR:
1368 type = ACPI_BUS_TYPE_PROCESSOR;
1369 break;
1370 case ACPI_TYPE_THERMAL:
1371 type = ACPI_BUS_TYPE_THERMAL;
1372 break;
1373 case ACPI_TYPE_POWER:
1374 type = ACPI_BUS_TYPE_POWER;
1375 break;
1376 default:
1377 continue;
1380 if (ops->acpi_op_add)
1381 status = acpi_add_single_object(&child, parent,
1382 chandle, type, ops);
1383 else
1384 status = acpi_bus_get_device(chandle, &child);
1386 if (ACPI_FAILURE(status))
1387 continue;
1389 if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1390 status = acpi_start_single_object(child);
1391 if (ACPI_FAILURE(status))
1392 continue;
1396 * If the device is present, enabled, and functioning then
1397 * parse its scope (depth-first). Note that we need to
1398 * represent absent devices to facilitate PnP notifications
1399 * -- but only the subtree head (not all of its children,
1400 * which will be enumerated when the parent is inserted).
1402 * TBD: Need notifications and other detection mechanisms
1403 * in place before we can fully implement this.
1405 if (child->status.present) {
1406 status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1407 NULL, NULL);
1408 if (ACPI_SUCCESS(status)) {
1409 level++;
1410 phandle = chandle;
1411 chandle = NULL;
1412 parent = child;
1417 return 0;
1421 acpi_bus_add(struct acpi_device **child,
1422 struct acpi_device *parent, acpi_handle handle, int type)
1424 int result;
1425 struct acpi_bus_ops ops;
1427 memset(&ops, 0, sizeof(ops));
1428 ops.acpi_op_add = 1;
1430 result = acpi_add_single_object(child, parent, handle, type, &ops);
1431 if (!result)
1432 result = acpi_bus_scan(*child, &ops);
1434 return result;
1437 EXPORT_SYMBOL(acpi_bus_add);
1439 int acpi_bus_start(struct acpi_device *device)
1441 int result;
1442 struct acpi_bus_ops ops;
1445 if (!device)
1446 return -EINVAL;
1448 result = acpi_start_single_object(device);
1449 if (!result) {
1450 memset(&ops, 0, sizeof(ops));
1451 ops.acpi_op_start = 1;
1452 result = acpi_bus_scan(device, &ops);
1454 return result;
1457 EXPORT_SYMBOL(acpi_bus_start);
1459 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1461 acpi_status status;
1462 struct acpi_device *parent, *child;
1463 acpi_handle phandle, chandle;
1464 acpi_object_type type;
1465 u32 level = 1;
1466 int err = 0;
1468 parent = start;
1469 phandle = start->handle;
1470 child = chandle = NULL;
1472 while ((level > 0) && parent && (!err)) {
1473 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1474 chandle, &chandle);
1477 * If this scope is exhausted then move our way back up.
1479 if (ACPI_FAILURE(status)) {
1480 level--;
1481 chandle = phandle;
1482 acpi_get_parent(phandle, &phandle);
1483 child = parent;
1484 parent = parent->parent;
1486 if (level == 0)
1487 err = acpi_bus_remove(child, rmdevice);
1488 else
1489 err = acpi_bus_remove(child, 1);
1491 continue;
1494 status = acpi_get_type(chandle, &type);
1495 if (ACPI_FAILURE(status)) {
1496 continue;
1499 * If there is a device corresponding to chandle then
1500 * parse it (depth-first).
1502 if (acpi_bus_get_device(chandle, &child) == 0) {
1503 level++;
1504 phandle = chandle;
1505 chandle = NULL;
1506 parent = child;
1508 continue;
1510 return err;
1512 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1515 static int acpi_bus_scan_fixed(struct acpi_device *root)
1517 int result = 0;
1518 struct acpi_device *device = NULL;
1519 struct acpi_bus_ops ops;
1521 if (!root)
1522 return -ENODEV;
1524 memset(&ops, 0, sizeof(ops));
1525 ops.acpi_op_add = 1;
1526 ops.acpi_op_start = 1;
1529 * Enumerate all fixed-feature devices.
1531 if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1532 result = acpi_add_single_object(&device, acpi_root,
1533 NULL,
1534 ACPI_BUS_TYPE_POWER_BUTTON,
1535 &ops);
1538 if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1539 result = acpi_add_single_object(&device, acpi_root,
1540 NULL,
1541 ACPI_BUS_TYPE_SLEEP_BUTTON,
1542 &ops);
1545 return result;
1548 int __init acpi_boot_ec_enable(void);
1550 static int __init acpi_scan_init(void)
1552 int result;
1553 struct acpi_bus_ops ops;
1556 if (acpi_disabled)
1557 return 0;
1559 memset(&ops, 0, sizeof(ops));
1560 ops.acpi_op_add = 1;
1561 ops.acpi_op_start = 1;
1563 result = bus_register(&acpi_bus_type);
1564 if (result) {
1565 /* We don't want to quit even if we failed to add suspend/resume */
1566 printk(KERN_ERR PREFIX "Could not register bus type\n");
1570 * Create the root device in the bus's device tree
1572 result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1573 ACPI_BUS_TYPE_SYSTEM, &ops);
1574 if (result)
1575 goto Done;
1578 * Enumerate devices in the ACPI namespace.
1580 result = acpi_bus_scan_fixed(acpi_root);
1582 /* EC region might be needed at bus_scan, so enable it now */
1583 acpi_boot_ec_enable();
1585 if (!result)
1586 result = acpi_bus_scan(acpi_root, &ops);
1588 if (result)
1589 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1591 Done:
1592 return result;
1595 subsys_initcall(acpi_scan_init);