Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/drivers/acpi/scan.c

  1 /*
  2  * scan.c - support for transforming the ACPI namespace into individual objects
  3  */
  4 
  5 #include <linux/module.h>
  6 #include <linux/init.h>
  7 #include <linux/slab.h>
  8 #include <linux/kernel.h>
  9 #include <linux/acpi.h>
 10 #include <linux/signal.h>
 11 #include <linux/kthread.h>
 12 #include <linux/dmi.h>
 13 #include <linux/nls.h>
 14 
 15 #include <asm/pgtable.h>
 16 
 17 #include "internal.h"
 18 
 19 #define _COMPONENT              ACPI_BUS_COMPONENT
 20 ACPI_MODULE_NAME("scan");
 21 extern struct acpi_device *acpi_root;
 22 
 23 #define ACPI_BUS_CLASS                  "system_bus"
 24 #define ACPI_BUS_HID                    "LNXSYBUS"
 25 #define ACPI_BUS_DEVICE_NAME            "System Bus"
 26 
 27 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
 28 
 29 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
 30 
 31 /*
 32  * If set, devices will be hot-removed even if they cannot be put offline
 33  * gracefully (from the kernel's standpoint).
 34  */
 35 bool acpi_force_hot_remove;
 36 
 37 static const char *dummy_hid = "device";
 38 
 39 static LIST_HEAD(acpi_bus_id_list);
 40 static DEFINE_MUTEX(acpi_scan_lock);
 41 static LIST_HEAD(acpi_scan_handlers_list);
 42 DEFINE_MUTEX(acpi_device_lock);
 43 LIST_HEAD(acpi_wakeup_device_list);
 44 static DEFINE_MUTEX(acpi_hp_context_lock);
 45 
 46 struct acpi_device_bus_id{
 47         char bus_id[15];
 48         unsigned int instance_no;
 49         struct list_head node;
 50 };
 51 
 52 void acpi_scan_lock_acquire(void)
 53 {
 54         mutex_lock(&acpi_scan_lock);
 55 }
 56 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
 57 
 58 void acpi_scan_lock_release(void)
 59 {
 60         mutex_unlock(&acpi_scan_lock);
 61 }
 62 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
 63 
 64 void acpi_lock_hp_context(void)
 65 {
 66         mutex_lock(&acpi_hp_context_lock);
 67 }
 68 
 69 void acpi_unlock_hp_context(void)
 70 {
 71         mutex_unlock(&acpi_hp_context_lock);
 72 }
 73 
 74 void acpi_initialize_hp_context(struct acpi_device *adev,
 75                                 struct acpi_hotplug_context *hp,
 76                                 int (*notify)(struct acpi_device *, u32),
 77                                 void (*uevent)(struct acpi_device *, u32))
 78 {
 79         acpi_lock_hp_context();
 80         hp->notify = notify;
 81         hp->uevent = uevent;
 82         acpi_set_hp_context(adev, hp);
 83         acpi_unlock_hp_context();
 84 }
 85 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
 86 
 87 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
 88 {
 89         if (!handler)
 90                 return -EINVAL;
 91 
 92         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
 93         return 0;
 94 }
 95 
 96 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
 97                                        const char *hotplug_profile_name)
 98 {
 99         int error;
100 
101         error = acpi_scan_add_handler(handler);
102         if (error)
103                 return error;
104 
105         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
106         return 0;
107 }
108 
109 /*
110  * Creates hid/cid(s) string needed for modalias and uevent
111  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
112  * char *modalias: "acpi:IBM0001:ACPI0001"
113  * Return: 0: no _HID and no _CID
114  *         -EINVAL: output error
115  *         -ENOMEM: output is truncated
116 */
117 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
118                            int size)
119 {
120         int len;
121         int count;
122         struct acpi_hardware_id *id;
123 
124         if (list_empty(&acpi_dev->pnp.ids))
125                 return 0;
126 
127         len = snprintf(modalias, size, "acpi:");
128         size -= len;
129 
130         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
131                 count = snprintf(&modalias[len], size, "%s:", id->id);
132                 if (count < 0)
133                         return -EINVAL;
134                 if (count >= size)
135                         return -ENOMEM;
136                 len += count;
137                 size -= count;
138         }
139 
140         modalias[len] = '\0';
141         return len;
142 }
143 
144 /*
145  * acpi_companion_match() - Can we match via ACPI companion device
146  * @dev: Device in question
147  *
148  * Check if the given device has an ACPI companion and if that companion has
149  * a valid list of PNP IDs, and if the device is the first (primary) physical
150  * device associated with it.
151  *
152  * If multiple physical devices are attached to a single ACPI companion, we need
153  * to be careful.  The usage scenario for this kind of relationship is that all
154  * of the physical devices in question use resources provided by the ACPI
155  * companion.  A typical case is an MFD device where all the sub-devices share
156  * the parent's ACPI companion.  In such cases we can only allow the primary
157  * (first) physical device to be matched with the help of the companion's PNP
158  * IDs.
159  *
160  * Additional physical devices sharing the ACPI companion can still use
161  * resources available from it but they will be matched normally using functions
162  * provided by their bus types (and analogously for their modalias).
163  */
164 static bool acpi_companion_match(const struct device *dev)
165 {
166         struct acpi_device *adev;
167         bool ret;
168 
169         adev = ACPI_COMPANION(dev);
170         if (!adev)
171                 return false;
172 
173         if (list_empty(&adev->pnp.ids))
174                 return false;
175 
176         mutex_lock(&adev->physical_node_lock);
177         if (list_empty(&adev->physical_node_list)) {
178                 ret = false;
179         } else {
180                 const struct acpi_device_physical_node *node;
181 
182                 node = list_first_entry(&adev->physical_node_list,
183                                         struct acpi_device_physical_node, node);
184                 ret = node->dev == dev;
185         }
186         mutex_unlock(&adev->physical_node_lock);
187 
188         return ret;
189 }
190 
191 /*
192  * Creates uevent modalias field for ACPI enumerated devices.
193  * Because the other buses does not support ACPI HIDs & CIDs.
194  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
195  * "acpi:IBM0001:ACPI0001"
196  */
197 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
198 {
199         int len;
200 
201         if (!acpi_companion_match(dev))
202                 return -ENODEV;
203 
204         if (add_uevent_var(env, "MODALIAS="))
205                 return -ENOMEM;
206         len = create_modalias(ACPI_COMPANION(dev), &env->buf[env->buflen - 1],
207                                 sizeof(env->buf) - env->buflen);
208         if (len <= 0)
209                 return len;
210         env->buflen += len;
211         return 0;
212 }
213 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
214 
215 /*
216  * Creates modalias sysfs attribute for ACPI enumerated devices.
217  * Because the other buses does not support ACPI HIDs & CIDs.
218  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
219  * "acpi:IBM0001:ACPI0001"
220  */
221 int acpi_device_modalias(struct device *dev, char *buf, int size)
222 {
223         int len;
224 
225         if (!acpi_companion_match(dev))
226                 return -ENODEV;
227 
228         len = create_modalias(ACPI_COMPANION(dev), buf, size -1);
229         if (len <= 0)
230                 return len;
231         buf[len++] = '\n';
232         return len;
233 }
234 EXPORT_SYMBOL_GPL(acpi_device_modalias);
235 
236 static ssize_t
237 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
238         struct acpi_device *acpi_dev = to_acpi_device(dev);
239         int len;
240 
241         len = create_modalias(acpi_dev, buf, 1024);
242         if (len <= 0)
243                 return len;
244         buf[len++] = '\n';
245         return len;
246 }
247 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
248 
249 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
250 {
251         struct acpi_device_physical_node *pn;
252         bool offline = true;
253 
254         mutex_lock(&adev->physical_node_lock);
255 
256         list_for_each_entry(pn, &adev->physical_node_list, node)
257                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
258                         if (uevent)
259                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
260 
261                         offline = false;
262                         break;
263                 }
264 
265         mutex_unlock(&adev->physical_node_lock);
266         return offline;
267 }
268 
269 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
270                                     void **ret_p)
271 {
272         struct acpi_device *device = NULL;
273         struct acpi_device_physical_node *pn;
274         bool second_pass = (bool)data;
275         acpi_status status = AE_OK;
276 
277         if (acpi_bus_get_device(handle, &device))
278                 return AE_OK;
279 
280         if (device->handler && !device->handler->hotplug.enabled) {
281                 *ret_p = &device->dev;
282                 return AE_SUPPORT;
283         }
284 
285         mutex_lock(&device->physical_node_lock);
286 
287         list_for_each_entry(pn, &device->physical_node_list, node) {
288                 int ret;
289 
290                 if (second_pass) {
291                         /* Skip devices offlined by the first pass. */
292                         if (pn->put_online)
293                                 continue;
294                 } else {
295                         pn->put_online = false;
296                 }
297                 ret = device_offline(pn->dev);
298                 if (acpi_force_hot_remove)
299                         continue;
300 
301                 if (ret >= 0) {
302                         pn->put_online = !ret;
303                 } else {
304                         *ret_p = pn->dev;
305                         if (second_pass) {
306                                 status = AE_ERROR;
307                                 break;
308                         }
309                 }
310         }
311 
312         mutex_unlock(&device->physical_node_lock);
313 
314         return status;
315 }
316 
317 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
318                                    void **ret_p)
319 {
320         struct acpi_device *device = NULL;
321         struct acpi_device_physical_node *pn;
322 
323         if (acpi_bus_get_device(handle, &device))
324                 return AE_OK;
325 
326         mutex_lock(&device->physical_node_lock);
327 
328         list_for_each_entry(pn, &device->physical_node_list, node)
329                 if (pn->put_online) {
330                         device_online(pn->dev);
331                         pn->put_online = false;
332                 }
333 
334         mutex_unlock(&device->physical_node_lock);
335 
336         return AE_OK;
337 }
338 
339 static int acpi_scan_try_to_offline(struct acpi_device *device)
340 {
341         acpi_handle handle = device->handle;
342         struct device *errdev = NULL;
343         acpi_status status;
344 
345         /*
346          * Carry out two passes here and ignore errors in the first pass,
347          * because if the devices in question are memory blocks and
348          * CONFIG_MEMCG is set, one of the blocks may hold data structures
349          * that the other blocks depend on, but it is not known in advance which
350          * block holds them.
351          *
352          * If the first pass is successful, the second one isn't needed, though.
353          */
354         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
355                                      NULL, acpi_bus_offline, (void *)false,
356                                      (void **)&errdev);
357         if (status == AE_SUPPORT) {
358                 dev_warn(errdev, "Offline disabled.\n");
359                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
360                                     acpi_bus_online, NULL, NULL, NULL);
361                 return -EPERM;
362         }
363         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
364         if (errdev) {
365                 errdev = NULL;
366                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
367                                     NULL, acpi_bus_offline, (void *)true,
368                                     (void **)&errdev);
369                 if (!errdev || acpi_force_hot_remove)
370                         acpi_bus_offline(handle, 0, (void *)true,
371                                          (void **)&errdev);
372 
373                 if (errdev && !acpi_force_hot_remove) {
374                         dev_warn(errdev, "Offline failed.\n");
375                         acpi_bus_online(handle, 0, NULL, NULL);
376                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
377                                             ACPI_UINT32_MAX, acpi_bus_online,
378                                             NULL, NULL, NULL);
379                         return -EBUSY;
380                 }
381         }
382         return 0;
383 }
384 
385 static int acpi_scan_hot_remove(struct acpi_device *device)
386 {
387         acpi_handle handle = device->handle;
388         unsigned long long sta;
389         acpi_status status;
390 
391         if (device->handler && device->handler->hotplug.demand_offline
392             && !acpi_force_hot_remove) {
393                 if (!acpi_scan_is_offline(device, true))
394                         return -EBUSY;
395         } else {
396                 int error = acpi_scan_try_to_offline(device);
397                 if (error)
398                         return error;
399         }
400 
401         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
402                 "Hot-removing device %s...\n", dev_name(&device->dev)));
403 
404         acpi_bus_trim(device);
405 
406         acpi_evaluate_lck(handle, 0);
407         /*
408          * TBD: _EJD support.
409          */
410         status = acpi_evaluate_ej0(handle);
411         if (status == AE_NOT_FOUND)
412                 return -ENODEV;
413         else if (ACPI_FAILURE(status))
414                 return -EIO;
415 
416         /*
417          * Verify if eject was indeed successful.  If not, log an error
418          * message.  No need to call _OST since _EJ0 call was made OK.
419          */
420         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
421         if (ACPI_FAILURE(status)) {
422                 acpi_handle_warn(handle,
423                         "Status check after eject failed (0x%x)\n", status);
424         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
425                 acpi_handle_warn(handle,
426                         "Eject incomplete - status 0x%llx\n", sta);
427         }
428 
429         return 0;
430 }
431 
432 static int acpi_scan_device_not_present(struct acpi_device *adev)
433 {
434         if (!acpi_device_enumerated(adev)) {
435                 dev_warn(&adev->dev, "Still not present\n");
436                 return -EALREADY;
437         }
438         acpi_bus_trim(adev);
439         return 0;
440 }
441 
442 static int acpi_scan_device_check(struct acpi_device *adev)
443 {
444         int error;
445 
446         acpi_bus_get_status(adev);
447         if (adev->status.present || adev->status.functional) {
448                 /*
449                  * This function is only called for device objects for which
450                  * matching scan handlers exist.  The only situation in which
451                  * the scan handler is not attached to this device object yet
452                  * is when the device has just appeared (either it wasn't
453                  * present at all before or it was removed and then added
454                  * again).
455                  */
456                 if (adev->handler) {
457                         dev_warn(&adev->dev, "Already enumerated\n");
458                         return -EALREADY;
459                 }
460                 error = acpi_bus_scan(adev->handle);
461                 if (error) {
462                         dev_warn(&adev->dev, "Namespace scan failure\n");
463                         return error;
464                 }
465                 if (!adev->handler) {
466                         dev_warn(&adev->dev, "Enumeration failure\n");
467                         error = -ENODEV;
468                 }
469         } else {
470                 error = acpi_scan_device_not_present(adev);
471         }
472         return error;
473 }
474 
475 static int acpi_scan_bus_check(struct acpi_device *adev)
476 {
477         struct acpi_scan_handler *handler = adev->handler;
478         struct acpi_device *child;
479         int error;
480 
481         acpi_bus_get_status(adev);
482         if (!(adev->status.present || adev->status.functional)) {
483                 acpi_scan_device_not_present(adev);
484                 return 0;
485         }
486         if (handler && handler->hotplug.scan_dependent)
487                 return handler->hotplug.scan_dependent(adev);
488 
489         error = acpi_bus_scan(adev->handle);
490         if (error) {
491                 dev_warn(&adev->dev, "Namespace scan failure\n");
492                 return error;
493         }
494         list_for_each_entry(child, &adev->children, node) {
495                 error = acpi_scan_bus_check(child);
496                 if (error)
497                         return error;
498         }
499         return 0;
500 }
501 
502 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
503 {
504         switch (type) {
505         case ACPI_NOTIFY_BUS_CHECK:
506                 return acpi_scan_bus_check(adev);
507         case ACPI_NOTIFY_DEVICE_CHECK:
508                 return acpi_scan_device_check(adev);
509         case ACPI_NOTIFY_EJECT_REQUEST:
510         case ACPI_OST_EC_OSPM_EJECT:
511                 if (adev->handler && !adev->handler->hotplug.enabled) {
512                         dev_info(&adev->dev, "Eject disabled\n");
513                         return -EPERM;
514                 }
515                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
516                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
517                 return acpi_scan_hot_remove(adev);
518         }
519         return -EINVAL;
520 }
521 
522 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
523 {
524         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
525         int error = -ENODEV;
526 
527         lock_device_hotplug();
528         mutex_lock(&acpi_scan_lock);
529 
530         /*
531          * The device object's ACPI handle cannot become invalid as long as we
532          * are holding acpi_scan_lock, but it might have become invalid before
533          * that lock was acquired.
534          */
535         if (adev->handle == INVALID_ACPI_HANDLE)
536                 goto err_out;
537 
538         if (adev->flags.is_dock_station) {
539                 error = dock_notify(adev, src);
540         } else if (adev->flags.hotplug_notify) {
541                 error = acpi_generic_hotplug_event(adev, src);
542                 if (error == -EPERM) {
543                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
544                         goto err_out;
545                 }
546         } else {
547                 int (*notify)(struct acpi_device *, u32);
548 
549                 acpi_lock_hp_context();
550                 notify = adev->hp ? adev->hp->notify : NULL;
551                 acpi_unlock_hp_context();
552                 /*
553                  * There may be additional notify handlers for device objects
554                  * without the .event() callback, so ignore them here.
555                  */
556                 if (notify)
557                         error = notify(adev, src);
558                 else
559                         goto out;
560         }
561         if (!error)
562                 ost_code = ACPI_OST_SC_SUCCESS;
563 
564  err_out:
565         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
566 
567  out:
568         acpi_bus_put_acpi_device(adev);
569         mutex_unlock(&acpi_scan_lock);
570         unlock_device_hotplug();
571 }
572 
573 static ssize_t real_power_state_show(struct device *dev,
574                                      struct device_attribute *attr, char *buf)
575 {
576         struct acpi_device *adev = to_acpi_device(dev);
577         int state;
578         int ret;
579 
580         ret = acpi_device_get_power(adev, &state);
581         if (ret)
582                 return ret;
583 
584         return sprintf(buf, "%s\n", acpi_power_state_string(state));
585 }
586 
587 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
588 
589 static ssize_t power_state_show(struct device *dev,
590                                 struct device_attribute *attr, char *buf)
591 {
592         struct acpi_device *adev = to_acpi_device(dev);
593 
594         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
595 }
596 
597 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
598 
599 static ssize_t
600 acpi_eject_store(struct device *d, struct device_attribute *attr,
601                 const char *buf, size_t count)
602 {
603         struct acpi_device *acpi_device = to_acpi_device(d);
604         acpi_object_type not_used;
605         acpi_status status;
606 
607         if (!count || buf[0] != '1')
608                 return -EINVAL;
609 
610         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
611             && !acpi_device->driver)
612                 return -ENODEV;
613 
614         status = acpi_get_type(acpi_device->handle, &not_used);
615         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
616                 return -ENODEV;
617 
618         get_device(&acpi_device->dev);
619         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
620         if (ACPI_SUCCESS(status))
621                 return count;
622 
623         put_device(&acpi_device->dev);
624         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
625                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
626         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
627 }
628 
629 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
630 
631 static ssize_t
632 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
633         struct acpi_device *acpi_dev = to_acpi_device(dev);
634 
635         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
636 }
637 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
638 
639 static ssize_t acpi_device_uid_show(struct device *dev,
640                                     struct device_attribute *attr, char *buf)
641 {
642         struct acpi_device *acpi_dev = to_acpi_device(dev);
643 
644         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
645 }
646 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
647 
648 static ssize_t acpi_device_adr_show(struct device *dev,
649                                     struct device_attribute *attr, char *buf)
650 {
651         struct acpi_device *acpi_dev = to_acpi_device(dev);
652 
653         return sprintf(buf, "0x%08x\n",
654                        (unsigned int)(acpi_dev->pnp.bus_address));
655 }
656 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
657 
658 static ssize_t
659 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
660         struct acpi_device *acpi_dev = to_acpi_device(dev);
661         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
662         int result;
663 
664         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
665         if (result)
666                 goto end;
667 
668         result = sprintf(buf, "%s\n", (char*)path.pointer);
669         kfree(path.pointer);
670 end:
671         return result;
672 }
673 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
674 
675 /* sysfs file that shows description text from the ACPI _STR method */
676 static ssize_t description_show(struct device *dev,
677                                 struct device_attribute *attr,
678                                 char *buf) {
679         struct acpi_device *acpi_dev = to_acpi_device(dev);
680         int result;
681 
682         if (acpi_dev->pnp.str_obj == NULL)
683                 return 0;
684 
685         /*
686          * The _STR object contains a Unicode identifier for a device.
687          * We need to convert to utf-8 so it can be displayed.
688          */
689         result = utf16s_to_utf8s(
690                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
691                 acpi_dev->pnp.str_obj->buffer.length,
692                 UTF16_LITTLE_ENDIAN, buf,
693                 PAGE_SIZE);
694 
695         buf[result++] = '\n';
696 
697         return result;
698 }
699 static DEVICE_ATTR(description, 0444, description_show, NULL);
700 
701 static ssize_t
702 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
703                      char *buf) {
704         struct acpi_device *acpi_dev = to_acpi_device(dev);
705         acpi_status status;
706         unsigned long long sun;
707 
708         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
709         if (ACPI_FAILURE(status))
710                 return -ENODEV;
711 
712         return sprintf(buf, "%llu\n", sun);
713 }
714 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
715 
716 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
717                                 char *buf) {
718         struct acpi_device *acpi_dev = to_acpi_device(dev);
719         acpi_status status;
720         unsigned long long sta;
721 
722         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
723         if (ACPI_FAILURE(status))
724                 return -ENODEV;
725 
726         return sprintf(buf, "%llu\n", sta);
727 }
728 static DEVICE_ATTR_RO(status);
729 
730 static int acpi_device_setup_files(struct acpi_device *dev)
731 {
732         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
733         acpi_status status;
734         int result = 0;
735 
736         /*
737          * Devices gotten from FADT don't have a "path" attribute
738          */
739         if (dev->handle) {
740                 result = device_create_file(&dev->dev, &dev_attr_path);
741                 if (result)
742                         goto end;
743         }
744 
745         if (!list_empty(&dev->pnp.ids)) {
746                 result = device_create_file(&dev->dev, &dev_attr_hid);
747                 if (result)
748                         goto end;
749 
750                 result = device_create_file(&dev->dev, &dev_attr_modalias);
751                 if (result)
752                         goto end;
753         }
754 
755         /*
756          * If device has _STR, 'description' file is created
757          */
758         if (acpi_has_method(dev->handle, "_STR")) {
759                 status = acpi_evaluate_object(dev->handle, "_STR",
760                                         NULL, &buffer);
761                 if (ACPI_FAILURE(status))
762                         buffer.pointer = NULL;
763                 dev->pnp.str_obj = buffer.pointer;
764                 result = device_create_file(&dev->dev, &dev_attr_description);
765                 if (result)
766                         goto end;
767         }
768 
769         if (dev->pnp.type.bus_address)
770                 result = device_create_file(&dev->dev, &dev_attr_adr);
771         if (dev->pnp.unique_id)
772                 result = device_create_file(&dev->dev, &dev_attr_uid);
773 
774         if (acpi_has_method(dev->handle, "_SUN")) {
775                 result = device_create_file(&dev->dev, &dev_attr_sun);
776                 if (result)
777                         goto end;
778         }
779 
780         if (acpi_has_method(dev->handle, "_STA")) {
781                 result = device_create_file(&dev->dev, &dev_attr_status);
782                 if (result)
783                         goto end;
784         }
785 
786         /*
787          * If device has _EJ0, 'eject' file is created that is used to trigger
788          * hot-removal function from userland.
789          */
790         if (acpi_has_method(dev->handle, "_EJ0")) {
791                 result = device_create_file(&dev->dev, &dev_attr_eject);
792                 if (result)
793                         return result;
794         }
795 
796         if (dev->flags.power_manageable) {
797                 result = device_create_file(&dev->dev, &dev_attr_power_state);
798                 if (result)
799                         return result;
800 
801                 if (dev->power.flags.power_resources)
802                         result = device_create_file(&dev->dev,
803                                                     &dev_attr_real_power_state);
804         }
805 
806 end:
807         return result;
808 }
809 
810 static void acpi_device_remove_files(struct acpi_device *dev)
811 {
812         if (dev->flags.power_manageable) {
813                 device_remove_file(&dev->dev, &dev_attr_power_state);
814                 if (dev->power.flags.power_resources)
815                         device_remove_file(&dev->dev,
816                                            &dev_attr_real_power_state);
817         }
818 
819         /*
820          * If device has _STR, remove 'description' file
821          */
822         if (acpi_has_method(dev->handle, "_STR")) {
823                 kfree(dev->pnp.str_obj);
824                 device_remove_file(&dev->dev, &dev_attr_description);
825         }
826         /*
827          * If device has _EJ0, remove 'eject' file.
828          */
829         if (acpi_has_method(dev->handle, "_EJ0"))
830                 device_remove_file(&dev->dev, &dev_attr_eject);
831 
832         if (acpi_has_method(dev->handle, "_SUN"))
833                 device_remove_file(&dev->dev, &dev_attr_sun);
834 
835         if (dev->pnp.unique_id)
836                 device_remove_file(&dev->dev, &dev_attr_uid);
837         if (dev->pnp.type.bus_address)
838                 device_remove_file(&dev->dev, &dev_attr_adr);
839         device_remove_file(&dev->dev, &dev_attr_modalias);
840         device_remove_file(&dev->dev, &dev_attr_hid);
841         if (acpi_has_method(dev->handle, "_STA"))
842                 device_remove_file(&dev->dev, &dev_attr_status);
843         if (dev->handle)
844                 device_remove_file(&dev->dev, &dev_attr_path);
845 }
846 /* --------------------------------------------------------------------------
847                         ACPI Bus operations
848    -------------------------------------------------------------------------- */
849 
850 static const struct acpi_device_id *__acpi_match_device(
851         struct acpi_device *device, const struct acpi_device_id *ids)
852 {
853         const struct acpi_device_id *id;
854         struct acpi_hardware_id *hwid;
855 
856         /*
857          * If the device is not present, it is unnecessary to load device
858          * driver for it.
859          */
860         if (!device->status.present)
861                 return NULL;
862 
863         for (id = ids; id->id[0]; id++)
864                 list_for_each_entry(hwid, &device->pnp.ids, list)
865                         if (!strcmp((char *) id->id, hwid->id))
866                                 return id;
867 
868         return NULL;
869 }
870 
871 /**
872  * acpi_match_device - Match a struct device against a given list of ACPI IDs
873  * @ids: Array of struct acpi_device_id object to match against.
874  * @dev: The device structure to match.
875  *
876  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
877  * object for that handle and use that object to match against a given list of
878  * device IDs.
879  *
880  * Return a pointer to the first matching ID on success or %NULL on failure.
881  */
882 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
883                                                const struct device *dev)
884 {
885         struct acpi_device *adev;
886         acpi_handle handle = ACPI_HANDLE(dev);
887 
888         if (!ids || !handle || acpi_bus_get_device(handle, &adev))
889                 return NULL;
890 
891         if (!acpi_companion_match(dev))
892                 return NULL;
893 
894         return __acpi_match_device(adev, ids);
895 }
896 EXPORT_SYMBOL_GPL(acpi_match_device);
897 
898 int acpi_match_device_ids(struct acpi_device *device,
899                           const struct acpi_device_id *ids)
900 {
901         return __acpi_match_device(device, ids) ? 0 : -ENOENT;
902 }
903 EXPORT_SYMBOL(acpi_match_device_ids);
904 
905 static void acpi_free_power_resources_lists(struct acpi_device *device)
906 {
907         int i;
908 
909         if (device->wakeup.flags.valid)
910                 acpi_power_resources_list_free(&device->wakeup.resources);
911 
912         if (!device->flags.power_manageable)
913                 return;
914 
915         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
916                 struct acpi_device_power_state *ps = &device->power.states[i];
917                 acpi_power_resources_list_free(&ps->resources);
918         }
919 }
920 
921 static void acpi_device_release(struct device *dev)
922 {
923         struct acpi_device *acpi_dev = to_acpi_device(dev);
924 
925         acpi_free_pnp_ids(&acpi_dev->pnp);
926         acpi_free_power_resources_lists(acpi_dev);
927         kfree(acpi_dev);
928 }
929 
930 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
931 {
932         struct acpi_device *acpi_dev = to_acpi_device(dev);
933         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
934 
935         return acpi_dev->flags.match_driver
936                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
937 }
938 
939 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
940 {
941         struct acpi_device *acpi_dev = to_acpi_device(dev);
942         int len;
943 
944         if (list_empty(&acpi_dev->pnp.ids))
945                 return 0;
946 
947         if (add_uevent_var(env, "MODALIAS="))
948                 return -ENOMEM;
949         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
950                               sizeof(env->buf) - env->buflen);
951         if (len <= 0)
952                 return len;
953         env->buflen += len;
954         return 0;
955 }
956 
957 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
958 {
959         struct acpi_device *device = data;
960 
961         device->driver->ops.notify(device, event);
962 }
963 
964 static void acpi_device_notify_fixed(void *data)
965 {
966         struct acpi_device *device = data;
967 
968         /* Fixed hardware devices have no handles */
969         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
970 }
971 
972 static acpi_status acpi_device_fixed_event(void *data)
973 {
974         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
975         return AE_OK;
976 }
977 
978 static int acpi_device_install_notify_handler(struct acpi_device *device)
979 {
980         acpi_status status;
981 
982         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
983                 status =
984                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
985                                                      acpi_device_fixed_event,
986                                                      device);
987         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
988                 status =
989                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
990                                                      acpi_device_fixed_event,
991                                                      device);
992         else
993                 status = acpi_install_notify_handler(device->handle,
994                                                      ACPI_DEVICE_NOTIFY,
995                                                      acpi_device_notify,
996                                                      device);
997 
998         if (ACPI_FAILURE(status))
999                 return -EINVAL;
1000         return 0;
1001 }
1002 
1003 static void acpi_device_remove_notify_handler(struct acpi_device *device)
1004 {
1005         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1006                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1007                                                 acpi_device_fixed_event);
1008         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1009                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1010                                                 acpi_device_fixed_event);
1011         else
1012                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
1013                                            acpi_device_notify);
1014 }
1015 
1016 static int acpi_device_probe(struct device *dev)
1017 {
1018         struct acpi_device *acpi_dev = to_acpi_device(dev);
1019         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1020         int ret;
1021 
1022         if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1023                 return -EINVAL;
1024 
1025         if (!acpi_drv->ops.add)
1026                 return -ENOSYS;
1027 
1028         ret = acpi_drv->ops.add(acpi_dev);
1029         if (ret)
1030                 return ret;
1031 
1032         acpi_dev->driver = acpi_drv;
1033         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1034                           "Driver [%s] successfully bound to device [%s]\n",
1035                           acpi_drv->name, acpi_dev->pnp.bus_id));
1036 
1037         if (acpi_drv->ops.notify) {
1038                 ret = acpi_device_install_notify_handler(acpi_dev);
1039                 if (ret) {
1040                         if (acpi_drv->ops.remove)
1041                                 acpi_drv->ops.remove(acpi_dev);
1042 
1043                         acpi_dev->driver = NULL;
1044                         acpi_dev->driver_data = NULL;
1045                         return ret;
1046                 }
1047         }
1048 
1049         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
1050                           acpi_drv->name, acpi_dev->pnp.bus_id));
1051         get_device(dev);
1052         return 0;
1053 }
1054 
1055 static int acpi_device_remove(struct device * dev)
1056 {
1057         struct acpi_device *acpi_dev = to_acpi_device(dev);
1058         struct acpi_driver *acpi_drv = acpi_dev->driver;
1059 
1060         if (acpi_drv) {
1061                 if (acpi_drv->ops.notify)
1062                         acpi_device_remove_notify_handler(acpi_dev);
1063                 if (acpi_drv->ops.remove)
1064                         acpi_drv->ops.remove(acpi_dev);
1065         }
1066         acpi_dev->driver = NULL;
1067         acpi_dev->driver_data = NULL;
1068 
1069         put_device(dev);
1070         return 0;
1071 }
1072 
1073 struct bus_type acpi_bus_type = {
1074         .name           = "acpi",
1075         .match          = acpi_bus_match,
1076         .probe          = acpi_device_probe,
1077         .remove         = acpi_device_remove,
1078         .uevent         = acpi_device_uevent,
1079 };
1080 
1081 static void acpi_device_del(struct acpi_device *device)
1082 {
1083         mutex_lock(&acpi_device_lock);
1084         if (device->parent)
1085                 list_del(&device->node);
1086 
1087         list_del(&device->wakeup_list);
1088         mutex_unlock(&acpi_device_lock);
1089 
1090         acpi_power_add_remove_device(device, false);
1091         acpi_device_remove_files(device);
1092         if (device->remove)
1093                 device->remove(device);
1094 
1095         device_del(&device->dev);
1096 }
1097 
1098 static LIST_HEAD(acpi_device_del_list);
1099 static DEFINE_MUTEX(acpi_device_del_lock);
1100 
1101 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
1102 {
1103         for (;;) {
1104                 struct acpi_device *adev;
1105 
1106                 mutex_lock(&acpi_device_del_lock);
1107 
1108                 if (list_empty(&acpi_device_del_list)) {
1109                         mutex_unlock(&acpi_device_del_lock);
1110                         break;
1111                 }
1112                 adev = list_first_entry(&acpi_device_del_list,
1113                                         struct acpi_device, del_list);
1114                 list_del(&adev->del_list);
1115 
1116                 mutex_unlock(&acpi_device_del_lock);
1117 
1118                 acpi_device_del(adev);
1119                 /*
1120                  * Drop references to all power resources that might have been
1121                  * used by the device.
1122                  */
1123                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
1124                 put_device(&adev->dev);
1125         }
1126 }
1127 
1128 /**
1129  * acpi_scan_drop_device - Drop an ACPI device object.
1130  * @handle: Handle of an ACPI namespace node, not used.
1131  * @context: Address of the ACPI device object to drop.
1132  *
1133  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
1134  * namespace node the device object pointed to by @context is attached to.
1135  *
1136  * The unregistration is carried out asynchronously to avoid running
1137  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
1138  * ensure the correct ordering (the device objects must be unregistered in the
1139  * same order in which the corresponding namespace nodes are deleted).
1140  */
1141 static void acpi_scan_drop_device(acpi_handle handle, void *context)
1142 {
1143         static DECLARE_WORK(work, acpi_device_del_work_fn);
1144         struct acpi_device *adev = context;
1145 
1146         mutex_lock(&acpi_device_del_lock);
1147 
1148         /*
1149          * Use the ACPI hotplug workqueue which is ordered, so this work item
1150          * won't run after any hotplug work items submitted subsequently.  That
1151          * prevents attempts to register device objects identical to those being
1152          * deleted from happening concurrently (such attempts result from
1153          * hotplug events handled via the ACPI hotplug workqueue).  It also will
1154          * run after all of the work items submitted previosuly, which helps
1155          * those work items to ensure that they are not accessing stale device
1156          * objects.
1157          */
1158         if (list_empty(&acpi_device_del_list))
1159                 acpi_queue_hotplug_work(&work);
1160 
1161         list_add_tail(&adev->del_list, &acpi_device_del_list);
1162         /* Make acpi_ns_validate_handle() return NULL for this handle. */
1163         adev->handle = INVALID_ACPI_HANDLE;
1164 
1165         mutex_unlock(&acpi_device_del_lock);
1166 }
1167 
1168 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
1169                                 void (*callback)(void *))
1170 {
1171         acpi_status status;
1172 
1173         if (!device)
1174                 return -EINVAL;
1175 
1176         status = acpi_get_data_full(handle, acpi_scan_drop_device,
1177                                     (void **)device, callback);
1178         if (ACPI_FAILURE(status) || !*device) {
1179                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1180                                   handle));
1181                 return -ENODEV;
1182         }
1183         return 0;
1184 }
1185 
1186 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1187 {
1188         return acpi_get_device_data(handle, device, NULL);
1189 }
1190 EXPORT_SYMBOL(acpi_bus_get_device);
1191 
1192 static void get_acpi_device(void *dev)
1193 {
1194         if (dev)
1195                 get_device(&((struct acpi_device *)dev)->dev);
1196 }
1197 
1198 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
1199 {
1200         struct acpi_device *adev = NULL;
1201 
1202         acpi_get_device_data(handle, &adev, get_acpi_device);
1203         return adev;
1204 }
1205 
1206 void acpi_bus_put_acpi_device(struct acpi_device *adev)
1207 {
1208         put_device(&adev->dev);
1209 }
1210 
1211 int acpi_device_add(struct acpi_device *device,
1212                     void (*release)(struct device *))
1213 {
1214         int result;
1215         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1216         int found = 0;
1217 
1218         if (device->handle) {
1219                 acpi_status status;
1220 
1221                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1222                                           device);
1223                 if (ACPI_FAILURE(status)) {
1224                         acpi_handle_err(device->handle,
1225                                         "Unable to attach device data\n");
1226                         return -ENODEV;
1227                 }
1228         }
1229 
1230         /*
1231          * Linkage
1232          * -------
1233          * Link this device to its parent and siblings.
1234          */
1235         INIT_LIST_HEAD(&device->children);
1236         INIT_LIST_HEAD(&device->node);
1237         INIT_LIST_HEAD(&device->wakeup_list);
1238         INIT_LIST_HEAD(&device->physical_node_list);
1239         INIT_LIST_HEAD(&device->del_list);
1240         mutex_init(&device->physical_node_lock);
1241 
1242         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1243         if (!new_bus_id) {
1244                 pr_err(PREFIX "Memory allocation error\n");
1245                 result = -ENOMEM;
1246                 goto err_detach;
1247         }
1248 
1249         mutex_lock(&acpi_device_lock);
1250         /*
1251          * Find suitable bus_id and instance number in acpi_bus_id_list
1252          * If failed, create one and link it into acpi_bus_id_list
1253          */
1254         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1255                 if (!strcmp(acpi_device_bus_id->bus_id,
1256                             acpi_device_hid(device))) {
1257                         acpi_device_bus_id->instance_no++;
1258                         found = 1;
1259                         kfree(new_bus_id);
1260                         break;
1261                 }
1262         }
1263         if (!found) {
1264                 acpi_device_bus_id = new_bus_id;
1265                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1266                 acpi_device_bus_id->instance_no = 0;
1267                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1268         }
1269         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1270 
1271         if (device->parent)
1272                 list_add_tail(&device->node, &device->parent->children);
1273 
1274         if (device->wakeup.flags.valid)
1275                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1276         mutex_unlock(&acpi_device_lock);
1277 
1278         if (device->parent)
1279                 device->dev.parent = &device->parent->dev;
1280         device->dev.bus = &acpi_bus_type;
1281         device->dev.release = release;
1282         result = device_add(&device->dev);
1283         if (result) {
1284                 dev_err(&device->dev, "Error registering device\n");
1285                 goto err;
1286         }
1287 
1288         result = acpi_device_setup_files(device);
1289         if (result)
1290                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1291                        dev_name(&device->dev));
1292 
1293         return 0;
1294 
1295  err:
1296         mutex_lock(&acpi_device_lock);
1297         if (device->parent)
1298                 list_del(&device->node);
1299         list_del(&device->wakeup_list);
1300         mutex_unlock(&acpi_device_lock);
1301 
1302  err_detach:
1303         acpi_detach_data(device->handle, acpi_scan_drop_device);
1304         return result;
1305 }
1306 
1307 /* --------------------------------------------------------------------------
1308                                  Driver Management
1309    -------------------------------------------------------------------------- */
1310 /**
1311  * acpi_bus_register_driver - register a driver with the ACPI bus
1312  * @driver: driver being registered
1313  *
1314  * Registers a driver with the ACPI bus.  Searches the namespace for all
1315  * devices that match the driver's criteria and binds.  Returns zero for
1316  * success or a negative error status for failure.
1317  */
1318 int acpi_bus_register_driver(struct acpi_driver *driver)
1319 {
1320         int ret;
1321 
1322         if (acpi_disabled)
1323                 return -ENODEV;
1324         driver->drv.name = driver->name;
1325         driver->drv.bus = &acpi_bus_type;
1326         driver->drv.owner = driver->owner;
1327 
1328         ret = driver_register(&driver->drv);
1329         return ret;
1330 }
1331 
1332 EXPORT_SYMBOL(acpi_bus_register_driver);
1333 
1334 /**
1335  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1336  * @driver: driver to unregister
1337  *
1338  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1339  * devices that match the driver's criteria and unbinds.
1340  */
1341 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1342 {
1343         driver_unregister(&driver->drv);
1344 }
1345 
1346 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1347 
1348 /* --------------------------------------------------------------------------
1349                                  Device Enumeration
1350    -------------------------------------------------------------------------- */
1351 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1352 {
1353         struct acpi_device *device = NULL;
1354         acpi_status status;
1355 
1356         /*
1357          * Fixed hardware devices do not appear in the namespace and do not
1358          * have handles, but we fabricate acpi_devices for them, so we have
1359          * to deal with them specially.
1360          */
1361         if (!handle)
1362                 return acpi_root;
1363 
1364         do {
1365                 status = acpi_get_parent(handle, &handle);
1366                 if (ACPI_FAILURE(status))
1367                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1368         } while (acpi_bus_get_device(handle, &device));
1369         return device;
1370 }
1371 
1372 acpi_status
1373 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1374 {
1375         acpi_status status;
1376         acpi_handle tmp;
1377         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1378         union acpi_object *obj;
1379 
1380         status = acpi_get_handle(handle, "_EJD", &tmp);
1381         if (ACPI_FAILURE(status))
1382                 return status;
1383 
1384         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1385         if (ACPI_SUCCESS(status)) {
1386                 obj = buffer.pointer;
1387                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1388                                          ejd);
1389                 kfree(buffer.pointer);
1390         }
1391         return status;
1392 }
1393 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1394 
1395 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1396                                         struct acpi_device_wakeup *wakeup)
1397 {
1398         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1399         union acpi_object *package = NULL;
1400         union acpi_object *element = NULL;
1401         acpi_status status;
1402         int err = -ENODATA;
1403 
1404         if (!wakeup)
1405                 return -EINVAL;
1406 
1407         INIT_LIST_HEAD(&wakeup->resources);
1408 
1409         /* _PRW */
1410         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1411         if (ACPI_FAILURE(status)) {
1412                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1413                 return err;
1414         }
1415 
1416         package = (union acpi_object *)buffer.pointer;
1417 
1418         if (!package || package->package.count < 2)
1419                 goto out;
1420 
1421         element = &(package->package.elements[0]);
1422         if (!element)
1423                 goto out;
1424 
1425         if (element->type == ACPI_TYPE_PACKAGE) {
1426                 if ((element->package.count < 2) ||
1427                     (element->package.elements[0].type !=
1428                      ACPI_TYPE_LOCAL_REFERENCE)
1429                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1430                         goto out;
1431 
1432                 wakeup->gpe_device =
1433                     element->package.elements[0].reference.handle;
1434                 wakeup->gpe_number =
1435                     (u32) element->package.elements[1].integer.value;
1436         } else if (element->type == ACPI_TYPE_INTEGER) {
1437                 wakeup->gpe_device = NULL;
1438                 wakeup->gpe_number = element->integer.value;
1439         } else {
1440                 goto out;
1441         }
1442 
1443         element = &(package->package.elements[1]);
1444         if (element->type != ACPI_TYPE_INTEGER)
1445                 goto out;
1446 
1447         wakeup->sleep_state = element->integer.value;
1448 
1449         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1450         if (err)
1451                 goto out;
1452 
1453         if (!list_empty(&wakeup->resources)) {
1454                 int sleep_state;
1455 
1456                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1457                                                   &sleep_state);
1458                 if (err) {
1459                         acpi_handle_warn(handle, "Retrieving current states "
1460                                          "of wakeup power resources failed\n");
1461                         acpi_power_resources_list_free(&wakeup->resources);
1462                         goto out;
1463                 }
1464                 if (sleep_state < wakeup->sleep_state) {
1465                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1466                                          "(S%d) by S%d from power resources\n",
1467                                          (int)wakeup->sleep_state, sleep_state);
1468                         wakeup->sleep_state = sleep_state;
1469                 }
1470         }
1471 
1472  out:
1473         kfree(buffer.pointer);
1474         return err;
1475 }
1476 
1477 static void acpi_wakeup_gpe_init(struct acpi_device *device)
1478 {
1479         struct acpi_device_id button_device_ids[] = {
1480                 {"PNP0C0C", 0},
1481                 {"PNP0C0D", 0},
1482                 {"PNP0C0E", 0},
1483                 {"", 0},
1484         };
1485         struct acpi_device_wakeup *wakeup = &device->wakeup;
1486         acpi_status status;
1487         acpi_event_status event_status;
1488 
1489         wakeup->flags.notifier_present = 0;
1490 
1491         /* Power button, Lid switch always enable wakeup */
1492         if (!acpi_match_device_ids(device, button_device_ids)) {
1493                 wakeup->flags.run_wake = 1;
1494                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1495                         /* Do not use Lid/sleep button for S5 wakeup */
1496                         if (wakeup->sleep_state == ACPI_STATE_S5)
1497                                 wakeup->sleep_state = ACPI_STATE_S4;
1498                 }
1499                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
1500                 device_set_wakeup_capable(&device->dev, true);
1501                 return;
1502         }
1503 
1504         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
1505                                 wakeup->gpe_number);
1506         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
1507                                      &event_status);
1508         if (ACPI_FAILURE(status))
1509                 return;
1510 
1511         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
1512 }
1513 
1514 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1515 {
1516         int err;
1517 
1518         /* Presence of _PRW indicates wake capable */
1519         if (!acpi_has_method(device->handle, "_PRW"))
1520                 return;
1521 
1522         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1523                                                            &device->wakeup);
1524         if (err) {
1525                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1526                 return;
1527         }
1528 
1529         device->wakeup.flags.valid = 1;
1530         device->wakeup.prepare_count = 0;
1531         acpi_wakeup_gpe_init(device);
1532         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1533          * system for the ACPI device with the _PRW object.
1534          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1535          * So it is necessary to call _DSW object first. Only when it is not
1536          * present will the _PSW object used.
1537          */
1538         err = acpi_device_sleep_wake(device, 0, 0, 0);
1539         if (err)
1540                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1541                                 "error in _DSW or _PSW evaluation\n"));
1542 }
1543 
1544 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1545 {
1546         struct acpi_device_power_state *ps = &device->power.states[state];
1547         char pathname[5] = { '_', 'P', 'R', '' + state, '\0' };
1548         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1549         acpi_status status;
1550 
1551         INIT_LIST_HEAD(&ps->resources);
1552 
1553         /* Evaluate "_PRx" to get referenced power resources */
1554         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1555         if (ACPI_SUCCESS(status)) {
1556                 union acpi_object *package = buffer.pointer;
1557 
1558                 if (buffer.length && package
1559                     && package->type == ACPI_TYPE_PACKAGE
1560                     && package->package.count) {
1561                         int err = acpi_extract_power_resources(package, 0,
1562                                                                &ps->resources);
1563                         if (!err)
1564                                 device->power.flags.power_resources = 1;
1565                 }
1566                 ACPI_FREE(buffer.pointer);
1567         }
1568 
1569         /* Evaluate "_PSx" to see if we can do explicit sets */
1570         pathname[2] = 'S';
1571         if (acpi_has_method(device->handle, pathname))
1572                 ps->flags.explicit_set = 1;
1573 
1574         /*
1575          * State is valid if there are means to put the device into it.
1576          * D3hot is only valid if _PR3 present.
1577          */
1578         if (!list_empty(&ps->resources)
1579             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1580                 ps->flags.valid = 1;
1581                 ps->flags.os_accessible = 1;
1582         }
1583 
1584         ps->power = -1;         /* Unknown - driver assigned */
1585         ps->latency = -1;       /* Unknown - driver assigned */
1586 }
1587 
1588 static void acpi_bus_get_power_flags(struct acpi_device *device)
1589 {
1590         u32 i;
1591 
1592         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1593         if (!acpi_has_method(device->handle, "_PS0") &&
1594             !acpi_has_method(device->handle, "_PR0"))
1595                 return;
1596 
1597         device->flags.power_manageable = 1;
1598 
1599         /*
1600          * Power Management Flags
1601          */
1602         if (acpi_has_method(device->handle, "_PSC"))
1603                 device->power.flags.explicit_get = 1;
1604 
1605         if (acpi_has_method(device->handle, "_IRC"))
1606                 device->power.flags.inrush_current = 1;
1607 
1608         if (acpi_has_method(device->handle, "_DSW"))
1609                 device->power.flags.dsw_present = 1;
1610 
1611         /*
1612          * Enumerate supported power management states
1613          */
1614         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1615                 acpi_bus_init_power_state(device, i);
1616 
1617         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1618 
1619         /* Set defaults for D0 and D3 states (always valid) */
1620         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1621         device->power.states[ACPI_STATE_D0].power = 100;
1622         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1623         device->power.states[ACPI_STATE_D3_COLD].power = 0;
1624 
1625         /* Set D3cold's explicit_set flag if _PS3 exists. */
1626         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1627                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1628 
1629         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1630         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1631                         device->power.flags.power_resources)
1632                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1633 
1634         if (acpi_bus_init_power(device)) {
1635                 acpi_free_power_resources_lists(device);
1636                 device->flags.power_manageable = 0;
1637         }
1638 }
1639 
1640 static void acpi_bus_get_flags(struct acpi_device *device)
1641 {
1642         /* Presence of _STA indicates 'dynamic_status' */
1643         if (acpi_has_method(device->handle, "_STA"))
1644                 device->flags.dynamic_status = 1;
1645 
1646         /* Presence of _RMV indicates 'removable' */
1647         if (acpi_has_method(device->handle, "_RMV"))
1648                 device->flags.removable = 1;
1649 
1650         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1651         if (acpi_has_method(device->handle, "_EJD") ||
1652             acpi_has_method(device->handle, "_EJ0"))
1653                 device->flags.ejectable = 1;
1654 }
1655 
1656 static void acpi_device_get_busid(struct acpi_device *device)
1657 {
1658         char bus_id[5] = { '?', 0 };
1659         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1660         int i = 0;
1661 
1662         /*
1663          * Bus ID
1664          * ------
1665          * The device's Bus ID is simply the object name.
1666          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1667          */
1668         if (ACPI_IS_ROOT_DEVICE(device)) {
1669                 strcpy(device->pnp.bus_id, "ACPI");
1670                 return;
1671         }
1672 
1673         switch (device->device_type) {
1674         case ACPI_BUS_TYPE_POWER_BUTTON:
1675                 strcpy(device->pnp.bus_id, "PWRF");
1676                 break;
1677         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1678                 strcpy(device->pnp.bus_id, "SLPF");
1679                 break;
1680         default:
1681                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1682                 /* Clean up trailing underscores (if any) */
1683                 for (i = 3; i > 1; i--) {
1684                         if (bus_id[i] == '_')
1685                                 bus_id[i] = '\0';
1686                         else
1687                                 break;
1688                 }
1689                 strcpy(device->pnp.bus_id, bus_id);
1690                 break;
1691         }
1692 }
1693 
1694 /*
1695  * acpi_ata_match - see if an acpi object is an ATA device
1696  *
1697  * If an acpi object has one of the ACPI ATA methods defined,
1698  * then we can safely call it an ATA device.
1699  */
1700 bool acpi_ata_match(acpi_handle handle)
1701 {
1702         return acpi_has_method(handle, "_GTF") ||
1703                acpi_has_method(handle, "_GTM") ||
1704                acpi_has_method(handle, "_STM") ||
1705                acpi_has_method(handle, "_SDD");
1706 }
1707 
1708 /*
1709  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1710  *
1711  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1712  * then we can safely call it an ejectable drive bay
1713  */
1714 bool acpi_bay_match(acpi_handle handle)
1715 {
1716         acpi_handle phandle;
1717 
1718         if (!acpi_has_method(handle, "_EJ0"))
1719                 return false;
1720         if (acpi_ata_match(handle))
1721                 return true;
1722         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1723                 return false;
1724 
1725         return acpi_ata_match(phandle);
1726 }
1727 
1728 bool acpi_device_is_battery(struct acpi_device *adev)
1729 {
1730         struct acpi_hardware_id *hwid;
1731 
1732         list_for_each_entry(hwid, &adev->pnp.ids, list)
1733                 if (!strcmp("PNP0C0A", hwid->id))
1734                         return true;
1735 
1736         return false;
1737 }
1738 
1739 static bool is_ejectable_bay(struct acpi_device *adev)
1740 {
1741         acpi_handle handle = adev->handle;
1742 
1743         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1744                 return true;
1745 
1746         return acpi_bay_match(handle);
1747 }
1748 
1749 /*
1750  * acpi_dock_match - see if an acpi object has a _DCK method
1751  */
1752 bool acpi_dock_match(acpi_handle handle)
1753 {
1754         return acpi_has_method(handle, "_DCK");
1755 }
1756 
1757 const char *acpi_device_hid(struct acpi_device *device)
1758 {
1759         struct acpi_hardware_id *hid;
1760 
1761         if (list_empty(&device->pnp.ids))
1762                 return dummy_hid;
1763 
1764         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1765         return hid->id;
1766 }
1767 EXPORT_SYMBOL(acpi_device_hid);
1768 
1769 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1770 {
1771         struct acpi_hardware_id *id;
1772 
1773         id = kmalloc(sizeof(*id), GFP_KERNEL);
1774         if (!id)
1775                 return;
1776 
1777         id->id = kstrdup(dev_id, GFP_KERNEL);
1778         if (!id->id) {
1779                 kfree(id);
1780                 return;
1781         }
1782 
1783         list_add_tail(&id->list, &pnp->ids);
1784         pnp->type.hardware_id = 1;
1785 }
1786 
1787 /*
1788  * Old IBM workstations have a DSDT bug wherein the SMBus object
1789  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1790  * prefix.  Work around this.
1791  */
1792 static bool acpi_ibm_smbus_match(acpi_handle handle)
1793 {
1794         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1795         struct acpi_buffer path = { sizeof(node_name), node_name };
1796 
1797         if (!dmi_name_in_vendors("IBM"))
1798                 return false;
1799 
1800         /* Look for SMBS object */
1801         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1802             strcmp("SMBS", path.pointer))
1803                 return false;
1804 
1805         /* Does it have the necessary (but misnamed) methods? */
1806         if (acpi_has_method(handle, "SBI") &&
1807             acpi_has_method(handle, "SBR") &&
1808             acpi_has_method(handle, "SBW"))
1809                 return true;
1810 
1811         return false;
1812 }
1813 
1814 static bool acpi_object_is_system_bus(acpi_handle handle)
1815 {
1816         acpi_handle tmp;
1817 
1818         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1819             tmp == handle)
1820                 return true;
1821         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1822             tmp == handle)
1823                 return true;
1824 
1825         return false;
1826 }
1827 
1828 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1829                                 int device_type)
1830 {
1831         acpi_status status;
1832         struct acpi_device_info *info;
1833         struct acpi_pnp_device_id_list *cid_list;
1834         int i;
1835 
1836         switch (device_type) {
1837         case ACPI_BUS_TYPE_DEVICE:
1838                 if (handle == ACPI_ROOT_OBJECT) {
1839                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1840                         break;
1841                 }
1842 
1843                 status = acpi_get_object_info(handle, &info);
1844                 if (ACPI_FAILURE(status)) {
1845                         pr_err(PREFIX "%s: Error reading device info\n",
1846                                         __func__);
1847                         return;
1848                 }
1849 
1850                 if (info->valid & ACPI_VALID_HID) {
1851                         acpi_add_id(pnp, info->hardware_id.string);
1852                         pnp->type.platform_id = 1;
1853                 }
1854                 if (info->valid & ACPI_VALID_CID) {
1855                         cid_list = &info->compatible_id_list;
1856                         for (i = 0; i < cid_list->count; i++)
1857                                 acpi_add_id(pnp, cid_list->ids[i].string);
1858                 }
1859                 if (info->valid & ACPI_VALID_ADR) {
1860                         pnp->bus_address = info->address;
1861                         pnp->type.bus_address = 1;
1862                 }
1863                 if (info->valid & ACPI_VALID_UID)
1864                         pnp->unique_id = kstrdup(info->unique_id.string,
1865                                                         GFP_KERNEL);
1866 
1867                 kfree(info);
1868 
1869                 /*
1870                  * Some devices don't reliably have _HIDs & _CIDs, so add
1871                  * synthetic HIDs to make sure drivers can find them.
1872                  */
1873                 if (acpi_is_video_device(handle))
1874                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1875                 else if (acpi_bay_match(handle))
1876                         acpi_add_id(pnp, ACPI_BAY_HID);
1877                 else if (acpi_dock_match(handle))
1878                         acpi_add_id(pnp, ACPI_DOCK_HID);
1879                 else if (acpi_ibm_smbus_match(handle))
1880                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1881                 else if (list_empty(&pnp->ids) &&
1882                          acpi_object_is_system_bus(handle)) {
1883                         /* \_SB, \_TZ, LNXSYBUS */
1884                         acpi_add_id(pnp, ACPI_BUS_HID);
1885                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1886                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1887                 }
1888 
1889                 break;
1890         case ACPI_BUS_TYPE_POWER:
1891                 acpi_add_id(pnp, ACPI_POWER_HID);
1892                 break;
1893         case ACPI_BUS_TYPE_PROCESSOR:
1894                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1895                 break;
1896         case ACPI_BUS_TYPE_THERMAL:
1897                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1898                 break;
1899         case ACPI_BUS_TYPE_POWER_BUTTON:
1900                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1901                 break;
1902         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1903                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1904                 break;
1905         }
1906 }
1907 
1908 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1909 {
1910         struct acpi_hardware_id *id, *tmp;
1911 
1912         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1913                 kfree(id->id);
1914                 kfree(id);
1915         }
1916         kfree(pnp->unique_id);
1917 }
1918 
1919 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1920                              int type, unsigned long long sta)
1921 {
1922         INIT_LIST_HEAD(&device->pnp.ids);
1923         device->device_type = type;
1924         device->handle = handle;
1925         device->parent = acpi_bus_get_parent(handle);
1926         acpi_set_device_status(device, sta);
1927         acpi_device_get_busid(device);
1928         acpi_set_pnp_ids(handle, &device->pnp, type);
1929         acpi_bus_get_flags(device);
1930         device->flags.match_driver = false;
1931         device->flags.initialized = true;
1932         device->flags.visited = false;
1933         device_initialize(&device->dev);
1934         dev_set_uevent_suppress(&device->dev, true);
1935 }
1936 
1937 void acpi_device_add_finalize(struct acpi_device *device)
1938 {
1939         dev_set_uevent_suppress(&device->dev, false);
1940         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1941 }
1942 
1943 static int acpi_add_single_object(struct acpi_device **child,
1944                                   acpi_handle handle, int type,
1945                                   unsigned long long sta)
1946 {
1947         int result;
1948         struct acpi_device *device;
1949         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1950 
1951         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1952         if (!device) {
1953                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1954                 return -ENOMEM;
1955         }
1956 
1957         acpi_init_device_object(device, handle, type, sta);
1958         acpi_bus_get_power_flags(device);
1959         acpi_bus_get_wakeup_device_flags(device);
1960 
1961         result = acpi_device_add(device, acpi_device_release);
1962         if (result) {
1963                 acpi_device_release(&device->dev);
1964                 return result;
1965         }
1966 
1967         acpi_power_add_remove_device(device, true);
1968         acpi_device_add_finalize(device);
1969         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1970         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1971                 dev_name(&device->dev), (char *) buffer.pointer,
1972                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1973         kfree(buffer.pointer);
1974         *child = device;
1975         return 0;
1976 }
1977 
1978 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1979                                     unsigned long long *sta)
1980 {
1981         acpi_status status;
1982         acpi_object_type acpi_type;
1983 
1984         status = acpi_get_type(handle, &acpi_type);
1985         if (ACPI_FAILURE(status))
1986                 return -ENODEV;
1987 
1988         switch (acpi_type) {
1989         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1990         case ACPI_TYPE_DEVICE:
1991                 *type = ACPI_BUS_TYPE_DEVICE;
1992                 status = acpi_bus_get_status_handle(handle, sta);
1993                 if (ACPI_FAILURE(status))
1994                         return -ENODEV;
1995                 break;
1996         case ACPI_TYPE_PROCESSOR:
1997                 *type = ACPI_BUS_TYPE_PROCESSOR;
1998                 status = acpi_bus_get_status_handle(handle, sta);
1999                 if (ACPI_FAILURE(status))
2000                         return -ENODEV;
2001                 break;
2002         case ACPI_TYPE_THERMAL:
2003                 *type = ACPI_BUS_TYPE_THERMAL;
2004                 *sta = ACPI_STA_DEFAULT;
2005                 break;
2006         case ACPI_TYPE_POWER:
2007                 *type = ACPI_BUS_TYPE_POWER;
2008                 *sta = ACPI_STA_DEFAULT;
2009                 break;
2010         default:
2011                 return -ENODEV;
2012         }
2013 
2014         return 0;
2015 }
2016 
2017 bool acpi_device_is_present(struct acpi_device *adev)
2018 {
2019         if (adev->status.present || adev->status.functional)
2020                 return true;
2021 
2022         adev->flags.initialized = false;
2023         return false;
2024 }
2025 
2026 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
2027                                        char *idstr,
2028                                        const struct acpi_device_id **matchid)
2029 {
2030         const struct acpi_device_id *devid;
2031 
2032         if (handler->match)
2033                 return handler->match(idstr, matchid);
2034 
2035         for (devid = handler->ids; devid->id[0]; devid++)
2036                 if (!strcmp((char *)devid->id, idstr)) {
2037                         if (matchid)
2038                                 *matchid = devid;
2039 
2040                         return true;
2041                 }
2042 
2043         return false;
2044 }
2045 
2046 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
2047                                         const struct acpi_device_id **matchid)
2048 {
2049         struct acpi_scan_handler *handler;
2050 
2051         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
2052                 if (acpi_scan_handler_matching(handler, idstr, matchid))
2053                         return handler;
2054 
2055         return NULL;
2056 }
2057 
2058 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
2059 {
2060         if (!!hotplug->enabled == !!val)
2061                 return;
2062 
2063         mutex_lock(&acpi_scan_lock);
2064 
2065         hotplug->enabled = val;
2066 
2067         mutex_unlock(&acpi_scan_lock);
2068 }
2069 
2070 static void acpi_scan_init_hotplug(struct acpi_device *adev)
2071 {
2072         struct acpi_hardware_id *hwid;
2073 
2074         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
2075                 acpi_dock_add(adev);
2076                 return;
2077         }
2078         list_for_each_entry(hwid, &adev->pnp.ids, list) {
2079                 struct acpi_scan_handler *handler;
2080 
2081                 handler = acpi_scan_match_handler(hwid->id, NULL);
2082                 if (handler) {
2083                         adev->flags.hotplug_notify = true;
2084                         break;
2085                 }
2086         }
2087 }
2088 
2089 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
2090                                       void *not_used, void **return_value)
2091 {
2092         struct acpi_device *device = NULL;
2093         int type;
2094         unsigned long long sta;
2095         int result;
2096 
2097         acpi_bus_get_device(handle, &device);
2098         if (device)
2099                 goto out;
2100 
2101         result = acpi_bus_type_and_status(handle, &type, &sta);
2102         if (result)
2103                 return AE_OK;
2104 
2105         if (type == ACPI_BUS_TYPE_POWER) {
2106                 acpi_add_power_resource(handle);
2107                 return AE_OK;
2108         }
2109 
2110         acpi_add_single_object(&device, handle, type, sta);
2111         if (!device)
2112                 return AE_CTRL_DEPTH;
2113 
2114         acpi_scan_init_hotplug(device);
2115 
2116  out:
2117         if (!*return_value)
2118                 *return_value = device;
2119 
2120         return AE_OK;
2121 }
2122 
2123 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
2124 {
2125         bool *is_spi_i2c_slave_p = data;
2126 
2127         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2128                 return 1;
2129 
2130         /*
2131          * devices that are connected to UART still need to be enumerated to
2132          * platform bus
2133          */
2134         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
2135                 *is_spi_i2c_slave_p = true;
2136 
2137          /* no need to do more checking */
2138         return -1;
2139 }
2140 
2141 static void acpi_default_enumeration(struct acpi_device *device)
2142 {
2143         struct list_head resource_list;
2144         bool is_spi_i2c_slave = false;
2145 
2146         if (!device->pnp.type.platform_id || device->handler)
2147                 return;
2148 
2149         /*
2150          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
2151          * respective parents.
2152          */
2153         INIT_LIST_HEAD(&resource_list);
2154         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
2155                                &is_spi_i2c_slave);
2156         acpi_dev_free_resource_list(&resource_list);
2157         if (!is_spi_i2c_slave)
2158                 acpi_create_platform_device(device);
2159 }
2160 
2161 static int acpi_scan_attach_handler(struct acpi_device *device)
2162 {
2163         struct acpi_hardware_id *hwid;
2164         int ret = 0;
2165 
2166         list_for_each_entry(hwid, &device->pnp.ids, list) {
2167                 const struct acpi_device_id *devid;
2168                 struct acpi_scan_handler *handler;
2169 
2170                 handler = acpi_scan_match_handler(hwid->id, &devid);
2171                 if (handler) {
2172                         if (!handler->attach) {
2173                                 device->pnp.type.platform_id = 0;
2174                                 continue;
2175                         }
2176                         device->handler = handler;
2177                         ret = handler->attach(device, devid);
2178                         if (ret > 0)
2179                                 break;
2180 
2181                         device->handler = NULL;
2182                         if (ret < 0)
2183                                 break;
2184                 }
2185         }
2186         if (!ret)
2187                 acpi_default_enumeration(device);
2188 
2189         return ret;
2190 }
2191 
2192 static void acpi_bus_attach(struct acpi_device *device)
2193 {
2194         struct acpi_device *child;
2195         acpi_handle ejd;
2196         int ret;
2197 
2198         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2199                 register_dock_dependent_device(device, ejd);
2200 
2201         acpi_bus_get_status(device);
2202         /* Skip devices that are not present. */
2203         if (!acpi_device_is_present(device)) {
2204                 device->flags.visited = false;
2205                 return;
2206         }
2207         if (device->handler)
2208                 goto ok;
2209 
2210         if (!device->flags.initialized) {
2211                 acpi_bus_update_power(device, NULL);
2212                 device->flags.initialized = true;
2213         }
2214         device->flags.visited = false;
2215         ret = acpi_scan_attach_handler(device);
2216         if (ret < 0)
2217                 return;
2218 
2219         device->flags.match_driver = true;
2220         if (!ret) {
2221                 ret = device_attach(&device->dev);
2222                 if (ret < 0)
2223                         return;
2224         }
2225         device->flags.visited = true;
2226 
2227  ok:
2228         list_for_each_entry(child, &device->children, node)
2229                 acpi_bus_attach(child);
2230 
2231         if (device->handler && device->handler->hotplug.notify_online)
2232                 device->handler->hotplug.notify_online(device);
2233 }
2234 
2235 /**
2236  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2237  * @handle: Root of the namespace scope to scan.
2238  *
2239  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2240  * found devices.
2241  *
2242  * If no devices were found, -ENODEV is returned, but it does not mean that
2243  * there has been a real error.  There just have been no suitable ACPI objects
2244  * in the table trunk from which the kernel could create a device and add an
2245  * appropriate driver.
2246  *
2247  * Must be called under acpi_scan_lock.
2248  */
2249 int acpi_bus_scan(acpi_handle handle)
2250 {
2251         void *device = NULL;
2252 
2253         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2254                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2255                                     acpi_bus_check_add, NULL, NULL, &device);
2256 
2257         if (device) {
2258                 acpi_bus_attach(device);
2259                 return 0;
2260         }
2261         return -ENODEV;
2262 }
2263 EXPORT_SYMBOL(acpi_bus_scan);
2264 
2265 /**
2266  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2267  * @adev: Root of the ACPI namespace scope to walk.
2268  *
2269  * Must be called under acpi_scan_lock.
2270  */
2271 void acpi_bus_trim(struct acpi_device *adev)
2272 {
2273         struct acpi_scan_handler *handler = adev->handler;
2274         struct acpi_device *child;
2275 
2276         list_for_each_entry_reverse(child, &adev->children, node)
2277                 acpi_bus_trim(child);
2278 
2279         adev->flags.match_driver = false;
2280         if (handler) {
2281                 if (handler->detach)
2282                         handler->detach(adev);
2283 
2284                 adev->handler = NULL;
2285         } else {
2286                 device_release_driver(&adev->dev);
2287         }
2288         /*
2289          * Most likely, the device is going away, so put it into D3cold before
2290          * that.
2291          */
2292         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2293         adev->flags.initialized = false;
2294         adev->flags.visited = false;
2295 }
2296 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2297 
2298 static int acpi_bus_scan_fixed(void)
2299 {
2300         int result = 0;
2301 
2302         /*
2303          * Enumerate all fixed-feature devices.
2304          */
2305         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2306                 struct acpi_device *device = NULL;
2307 
2308                 result = acpi_add_single_object(&device, NULL,
2309                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2310                                                 ACPI_STA_DEFAULT);
2311                 if (result)
2312                         return result;
2313 
2314                 device->flags.match_driver = true;
2315                 result = device_attach(&device->dev);
2316                 if (result < 0)
2317                         return result;
2318 
2319                 device_init_wakeup(&device->dev, true);
2320         }
2321 
2322         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2323                 struct acpi_device *device = NULL;
2324 
2325                 result = acpi_add_single_object(&device, NULL,
2326                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2327                                                 ACPI_STA_DEFAULT);
2328                 if (result)
2329                         return result;
2330 
2331                 device->flags.match_driver = true;
2332                 result = device_attach(&device->dev);
2333         }
2334 
2335         return result < 0 ? result : 0;
2336 }
2337 
2338 int __init acpi_scan_init(void)
2339 {
2340         int result;
2341 
2342         result = bus_register(&acpi_bus_type);
2343         if (result) {
2344                 /* We don't want to quit even if we failed to add suspend/resume */
2345                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2346         }
2347 
2348         acpi_pci_root_init();
2349         acpi_pci_link_init();
2350         acpi_processor_init();
2351         acpi_lpss_init();
2352         acpi_cmos_rtc_init();
2353         acpi_container_init();
2354         acpi_memory_hotplug_init();
2355         acpi_pnp_init();
2356         acpi_int340x_thermal_init();
2357 
2358         mutex_lock(&acpi_scan_lock);
2359         /*
2360          * Enumerate devices in the ACPI namespace.
2361          */
2362         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2363         if (result)
2364                 goto out;
2365 
2366         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2367         if (result)
2368                 goto out;
2369 
2370         /* Fixed feature devices do not exist on HW-reduced platform */
2371         if (!acpi_gbl_reduced_hardware) {
2372                 result = acpi_bus_scan_fixed();
2373                 if (result) {
2374                         acpi_detach_data(acpi_root->handle,
2375                                          acpi_scan_drop_device);
2376                         acpi_device_del(acpi_root);
2377                         put_device(&acpi_root->dev);
2378                         goto out;
2379                 }
2380         }
2381 
2382         acpi_update_all_gpes();
2383 
2384  out:
2385         mutex_unlock(&acpi_scan_lock);
2386         return result;
2387 }
2388 

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