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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Link physical devices with ACPI devices support
4 *
5 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
6 * Copyright (c) 2005 Intel Corp.
7 */
8
9#define pr_fmt(fmt) "ACPI: " fmt
10
11#include <linux/acpi_iort.h>
12#include <linux/export.h>
13#include <linux/init.h>
14#include <linux/list.h>
15#include <linux/device.h>
16#include <linux/slab.h>
17#include <linux/rwsem.h>
18#include <linux/acpi.h>
19#include <linux/dma-mapping.h>
20#include <linux/pci.h>
21#include <linux/pci-acpi.h>
22#include <linux/platform_device.h>
23
24#include "internal.h"
25
26static LIST_HEAD(bus_type_list);
27static DECLARE_RWSEM(bus_type_sem);
28
29#define PHYSICAL_NODE_STRING "physical_node"
30#define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
31
32int register_acpi_bus_type(struct acpi_bus_type *type)
33{
34 if (acpi_disabled)
35 return -ENODEV;
36 if (type && type->match && type->find_companion) {
37 down_write(&bus_type_sem);
38 list_add_tail(&type->list, &bus_type_list);
39 up_write(&bus_type_sem);
40 pr_info("bus type %s registered\n", type->name);
41 return 0;
42 }
43 return -ENODEV;
44}
45EXPORT_SYMBOL_GPL(register_acpi_bus_type);
46
47int unregister_acpi_bus_type(struct acpi_bus_type *type)
48{
49 if (acpi_disabled)
50 return 0;
51 if (type) {
52 down_write(&bus_type_sem);
53 list_del_init(&type->list);
54 up_write(&bus_type_sem);
55 pr_info("bus type %s unregistered\n", type->name);
56 return 0;
57 }
58 return -ENODEV;
59}
60EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
61
62static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
63{
64 struct acpi_bus_type *tmp, *ret = NULL;
65
66 down_read(&bus_type_sem);
67 list_for_each_entry(tmp, &bus_type_list, list) {
68 if (tmp->match(dev)) {
69 ret = tmp;
70 break;
71 }
72 }
73 up_read(&bus_type_sem);
74 return ret;
75}
76
77#define FIND_CHILD_MIN_SCORE 1
78#define FIND_CHILD_MID_SCORE 2
79#define FIND_CHILD_MAX_SCORE 3
80
81static int match_any(struct acpi_device *adev, void *not_used)
82{
83 return 1;
84}
85
86static bool acpi_dev_has_children(struct acpi_device *adev)
87{
88 return acpi_dev_for_each_child(adev, match_any, NULL) > 0;
89}
90
91static int find_child_checks(struct acpi_device *adev, bool check_children)
92{
93 unsigned long long sta;
94 acpi_status status;
95
96 if (check_children && !acpi_dev_has_children(adev))
97 return -ENODEV;
98
99 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
100 if (status == AE_NOT_FOUND) {
101 /*
102 * Special case: backlight device objects without _STA are
103 * preferred to other objects with the same _ADR value, because
104 * it is more likely that they are actually useful.
105 */
106 if (adev->pnp.type.backlight)
107 return FIND_CHILD_MID_SCORE;
108
109 return FIND_CHILD_MIN_SCORE;
110 }
111
112 if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
113 return -ENODEV;
114
115 /*
116 * If the device has a _HID returning a valid ACPI/PNP device ID, it is
117 * better to make it look less attractive here, so that the other device
118 * with the same _ADR value (that may not have a valid device ID) can be
119 * matched going forward. [This means a second spec violation in a row,
120 * so whatever we do here is best effort anyway.]
121 */
122 if (adev->pnp.type.platform_id)
123 return FIND_CHILD_MIN_SCORE;
124
125 return FIND_CHILD_MAX_SCORE;
126}
127
128struct find_child_walk_data {
129 struct acpi_device *adev;
130 u64 address;
131 int score;
132 bool check_sta;
133 bool check_children;
134};
135
136static int check_one_child(struct acpi_device *adev, void *data)
137{
138 struct find_child_walk_data *wd = data;
139 int score;
140
141 if (!adev->pnp.type.bus_address || acpi_device_adr(adev) != wd->address)
142 return 0;
143
144 if (!wd->adev) {
145 /*
146 * This is the first matching object, so save it. If it is not
147 * necessary to look for any other matching objects, stop the
148 * search.
149 */
150 wd->adev = adev;
151 return !(wd->check_sta || wd->check_children);
152 }
153
154 /*
155 * There is more than one matching device object with the same _ADR
156 * value. That really is unexpected, so we are kind of beyond the scope
157 * of the spec here. We have to choose which one to return, though.
158 *
159 * First, get the score for the previously found object and terminate
160 * the walk if it is maximum.
161 */
162 if (!wd->score) {
163 score = find_child_checks(wd->adev, wd->check_children);
164 if (score == FIND_CHILD_MAX_SCORE)
165 return 1;
166
167 wd->score = score;
168 }
169 /*
170 * Second, if the object that has just been found has a better score,
171 * replace the previously found one with it and terminate the walk if
172 * the new score is maximum.
173 */
174 score = find_child_checks(adev, wd->check_children);
175 if (score > wd->score) {
176 wd->adev = adev;
177 if (score == FIND_CHILD_MAX_SCORE)
178 return 1;
179
180 wd->score = score;
181 }
182
183 /* Continue, because there may be better matches. */
184 return 0;
185}
186
187static struct acpi_device *acpi_find_child(struct acpi_device *parent,
188 u64 address, bool check_children,
189 bool check_sta)
190{
191 struct find_child_walk_data wd = {
192 .address = address,
193 .check_children = check_children,
194 .check_sta = check_sta,
195 .adev = NULL,
196 .score = 0,
197 };
198
199 if (parent)
200 acpi_dev_for_each_child(parent, check_one_child, &wd);
201
202 return wd.adev;
203}
204
205struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
206 u64 address, bool check_children)
207{
208 return acpi_find_child(parent, address, check_children, true);
209}
210EXPORT_SYMBOL_GPL(acpi_find_child_device);
211
212struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev,
213 acpi_bus_address adr)
214{
215 return acpi_find_child(adev, adr, false, false);
216}
217EXPORT_SYMBOL_GPL(acpi_find_child_by_adr);
218
219static void acpi_physnode_link_name(char *buf, unsigned int node_id)
220{
221 if (node_id > 0)
222 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
223 PHYSICAL_NODE_STRING "%u", node_id);
224 else
225 strcpy(buf, PHYSICAL_NODE_STRING);
226}
227
228int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
229{
230 struct acpi_device_physical_node *physical_node, *pn;
231 char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
232 struct list_head *physnode_list;
233 unsigned int node_id;
234 int retval = -EINVAL;
235
236 if (has_acpi_companion(dev)) {
237 if (acpi_dev) {
238 dev_warn(dev, "ACPI companion already set\n");
239 return -EINVAL;
240 } else {
241 acpi_dev = ACPI_COMPANION(dev);
242 }
243 }
244 if (!acpi_dev)
245 return -EINVAL;
246
247 acpi_dev_get(acpi_dev);
248 get_device(dev);
249 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
250 if (!physical_node) {
251 retval = -ENOMEM;
252 goto err;
253 }
254
255 mutex_lock(&acpi_dev->physical_node_lock);
256
257 /*
258 * Keep the list sorted by node_id so that the IDs of removed nodes can
259 * be recycled easily.
260 */
261 physnode_list = &acpi_dev->physical_node_list;
262 node_id = 0;
263 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
264 /* Sanity check. */
265 if (pn->dev == dev) {
266 mutex_unlock(&acpi_dev->physical_node_lock);
267
268 dev_warn(dev, "Already associated with ACPI node\n");
269 kfree(physical_node);
270 if (ACPI_COMPANION(dev) != acpi_dev)
271 goto err;
272
273 put_device(dev);
274 acpi_dev_put(acpi_dev);
275 return 0;
276 }
277 if (pn->node_id == node_id) {
278 physnode_list = &pn->node;
279 node_id++;
280 }
281 }
282
283 physical_node->node_id = node_id;
284 physical_node->dev = dev;
285 list_add(&physical_node->node, physnode_list);
286 acpi_dev->physical_node_count++;
287
288 if (!has_acpi_companion(dev))
289 ACPI_COMPANION_SET(dev, acpi_dev);
290
291 acpi_physnode_link_name(physical_node_name, node_id);
292 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
293 physical_node_name);
294 if (retval)
295 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
296 physical_node_name, retval);
297
298 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
299 "firmware_node");
300 if (retval)
301 dev_err(dev, "Failed to create link firmware_node (%d)\n",
302 retval);
303
304 mutex_unlock(&acpi_dev->physical_node_lock);
305
306 if (acpi_dev->wakeup.flags.valid)
307 device_set_wakeup_capable(dev, true);
308
309 return 0;
310
311 err:
312 ACPI_COMPANION_SET(dev, NULL);
313 put_device(dev);
314 acpi_dev_put(acpi_dev);
315 return retval;
316}
317EXPORT_SYMBOL_GPL(acpi_bind_one);
318
319int acpi_unbind_one(struct device *dev)
320{
321 struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
322 struct acpi_device_physical_node *entry;
323
324 if (!acpi_dev)
325 return 0;
326
327 mutex_lock(&acpi_dev->physical_node_lock);
328
329 list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
330 if (entry->dev == dev) {
331 char physnode_name[PHYSICAL_NODE_NAME_SIZE];
332
333 list_del(&entry->node);
334 acpi_dev->physical_node_count--;
335
336 acpi_physnode_link_name(physnode_name, entry->node_id);
337 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
338 sysfs_remove_link(&dev->kobj, "firmware_node");
339 ACPI_COMPANION_SET(dev, NULL);
340 /* Drop references taken by acpi_bind_one(). */
341 put_device(dev);
342 acpi_dev_put(acpi_dev);
343 kfree(entry);
344 break;
345 }
346
347 mutex_unlock(&acpi_dev->physical_node_lock);
348 return 0;
349}
350EXPORT_SYMBOL_GPL(acpi_unbind_one);
351
352void acpi_device_notify(struct device *dev)
353{
354 struct acpi_device *adev;
355 int ret;
356
357 ret = acpi_bind_one(dev, NULL);
358 if (ret) {
359 struct acpi_bus_type *type = acpi_get_bus_type(dev);
360
361 if (!type)
362 goto err;
363
364 adev = type->find_companion(dev);
365 if (!adev) {
366 dev_dbg(dev, "ACPI companion not found\n");
367 goto err;
368 }
369 ret = acpi_bind_one(dev, adev);
370 if (ret)
371 goto err;
372
373 if (type->setup) {
374 type->setup(dev);
375 goto done;
376 }
377 } else {
378 adev = ACPI_COMPANION(dev);
379
380 if (dev_is_pci(dev)) {
381 pci_acpi_setup(dev, adev);
382 goto done;
383 } else if (dev_is_platform(dev)) {
384 acpi_configure_pmsi_domain(dev);
385 }
386 }
387
388 if (adev->handler && adev->handler->bind)
389 adev->handler->bind(dev);
390
391done:
392 acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n",
393 dev_name(dev));
394
395 return;
396
397err:
398 dev_dbg(dev, "No ACPI support\n");
399}
400
401void acpi_device_notify_remove(struct device *dev)
402{
403 struct acpi_device *adev = ACPI_COMPANION(dev);
404
405 if (!adev)
406 return;
407
408 if (dev_is_pci(dev))
409 pci_acpi_cleanup(dev, adev);
410 else if (adev->handler && adev->handler->unbind)
411 adev->handler->unbind(dev);
412
413 acpi_unbind_one(dev);
414}
1/*
2 * Link physical devices with ACPI devices support
3 *
4 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
5 * Copyright (c) 2005 Intel Corp.
6 *
7 * This file is released under the GPLv2.
8 */
9#include <linux/export.h>
10#include <linux/init.h>
11#include <linux/list.h>
12#include <linux/device.h>
13#include <linux/slab.h>
14#include <linux/rwsem.h>
15#include <linux/acpi.h>
16#include <linux/dma-mapping.h>
17
18#include "internal.h"
19
20#define ACPI_GLUE_DEBUG 0
21#if ACPI_GLUE_DEBUG
22#define DBG(fmt, ...) \
23 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
24#else
25#define DBG(fmt, ...) \
26do { \
27 if (0) \
28 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__); \
29} while (0)
30#endif
31static LIST_HEAD(bus_type_list);
32static DECLARE_RWSEM(bus_type_sem);
33
34#define PHYSICAL_NODE_STRING "physical_node"
35#define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
36
37int register_acpi_bus_type(struct acpi_bus_type *type)
38{
39 if (acpi_disabled)
40 return -ENODEV;
41 if (type && type->match && type->find_companion) {
42 down_write(&bus_type_sem);
43 list_add_tail(&type->list, &bus_type_list);
44 up_write(&bus_type_sem);
45 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
46 return 0;
47 }
48 return -ENODEV;
49}
50EXPORT_SYMBOL_GPL(register_acpi_bus_type);
51
52int unregister_acpi_bus_type(struct acpi_bus_type *type)
53{
54 if (acpi_disabled)
55 return 0;
56 if (type) {
57 down_write(&bus_type_sem);
58 list_del_init(&type->list);
59 up_write(&bus_type_sem);
60 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
61 type->name);
62 return 0;
63 }
64 return -ENODEV;
65}
66EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
67
68static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
69{
70 struct acpi_bus_type *tmp, *ret = NULL;
71
72 down_read(&bus_type_sem);
73 list_for_each_entry(tmp, &bus_type_list, list) {
74 if (tmp->match(dev)) {
75 ret = tmp;
76 break;
77 }
78 }
79 up_read(&bus_type_sem);
80 return ret;
81}
82
83#define FIND_CHILD_MIN_SCORE 1
84#define FIND_CHILD_MAX_SCORE 2
85
86static int find_child_checks(struct acpi_device *adev, bool check_children)
87{
88 bool sta_present = true;
89 unsigned long long sta;
90 acpi_status status;
91
92 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
93 if (status == AE_NOT_FOUND)
94 sta_present = false;
95 else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
96 return -ENODEV;
97
98 if (check_children && list_empty(&adev->children))
99 return -ENODEV;
100
101 return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
102}
103
104struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
105 u64 address, bool check_children)
106{
107 struct acpi_device *adev, *ret = NULL;
108 int ret_score = 0;
109
110 if (!parent)
111 return NULL;
112
113 list_for_each_entry(adev, &parent->children, node) {
114 unsigned long long addr;
115 acpi_status status;
116 int score;
117
118 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
119 NULL, &addr);
120 if (ACPI_FAILURE(status) || addr != address)
121 continue;
122
123 if (!ret) {
124 /* This is the first matching object. Save it. */
125 ret = adev;
126 continue;
127 }
128 /*
129 * There is more than one matching device object with the same
130 * _ADR value. That really is unexpected, so we are kind of
131 * beyond the scope of the spec here. We have to choose which
132 * one to return, though.
133 *
134 * First, check if the previously found object is good enough
135 * and return it if so. Second, do the same for the object that
136 * we've just found.
137 */
138 if (!ret_score) {
139 ret_score = find_child_checks(ret, check_children);
140 if (ret_score == FIND_CHILD_MAX_SCORE)
141 return ret;
142 }
143 score = find_child_checks(adev, check_children);
144 if (score == FIND_CHILD_MAX_SCORE) {
145 return adev;
146 } else if (score > ret_score) {
147 ret = adev;
148 ret_score = score;
149 }
150 }
151 return ret;
152}
153EXPORT_SYMBOL_GPL(acpi_find_child_device);
154
155static void acpi_physnode_link_name(char *buf, unsigned int node_id)
156{
157 if (node_id > 0)
158 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
159 PHYSICAL_NODE_STRING "%u", node_id);
160 else
161 strcpy(buf, PHYSICAL_NODE_STRING);
162}
163
164int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
165{
166 struct acpi_device_physical_node *physical_node, *pn;
167 char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
168 struct list_head *physnode_list;
169 unsigned int node_id;
170 int retval = -EINVAL;
171 enum dev_dma_attr attr;
172
173 if (has_acpi_companion(dev)) {
174 if (acpi_dev) {
175 dev_warn(dev, "ACPI companion already set\n");
176 return -EINVAL;
177 } else {
178 acpi_dev = ACPI_COMPANION(dev);
179 }
180 }
181 if (!acpi_dev)
182 return -EINVAL;
183
184 get_device(&acpi_dev->dev);
185 get_device(dev);
186 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
187 if (!physical_node) {
188 retval = -ENOMEM;
189 goto err;
190 }
191
192 mutex_lock(&acpi_dev->physical_node_lock);
193
194 /*
195 * Keep the list sorted by node_id so that the IDs of removed nodes can
196 * be recycled easily.
197 */
198 physnode_list = &acpi_dev->physical_node_list;
199 node_id = 0;
200 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
201 /* Sanity check. */
202 if (pn->dev == dev) {
203 mutex_unlock(&acpi_dev->physical_node_lock);
204
205 dev_warn(dev, "Already associated with ACPI node\n");
206 kfree(physical_node);
207 if (ACPI_COMPANION(dev) != acpi_dev)
208 goto err;
209
210 put_device(dev);
211 put_device(&acpi_dev->dev);
212 return 0;
213 }
214 if (pn->node_id == node_id) {
215 physnode_list = &pn->node;
216 node_id++;
217 }
218 }
219
220 physical_node->node_id = node_id;
221 physical_node->dev = dev;
222 list_add(&physical_node->node, physnode_list);
223 acpi_dev->physical_node_count++;
224
225 if (!has_acpi_companion(dev))
226 ACPI_COMPANION_SET(dev, acpi_dev);
227
228 attr = acpi_get_dma_attr(acpi_dev);
229 if (attr != DEV_DMA_NOT_SUPPORTED)
230 arch_setup_dma_ops(dev, 0, 0, NULL,
231 attr == DEV_DMA_COHERENT);
232
233 acpi_physnode_link_name(physical_node_name, node_id);
234 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
235 physical_node_name);
236 if (retval)
237 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
238 physical_node_name, retval);
239
240 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
241 "firmware_node");
242 if (retval)
243 dev_err(dev, "Failed to create link firmware_node (%d)\n",
244 retval);
245
246 mutex_unlock(&acpi_dev->physical_node_lock);
247
248 if (acpi_dev->wakeup.flags.valid)
249 device_set_wakeup_capable(dev, true);
250
251 return 0;
252
253 err:
254 ACPI_COMPANION_SET(dev, NULL);
255 put_device(dev);
256 put_device(&acpi_dev->dev);
257 return retval;
258}
259EXPORT_SYMBOL_GPL(acpi_bind_one);
260
261int acpi_unbind_one(struct device *dev)
262{
263 struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
264 struct acpi_device_physical_node *entry;
265
266 if (!acpi_dev)
267 return 0;
268
269 mutex_lock(&acpi_dev->physical_node_lock);
270
271 list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
272 if (entry->dev == dev) {
273 char physnode_name[PHYSICAL_NODE_NAME_SIZE];
274
275 list_del(&entry->node);
276 acpi_dev->physical_node_count--;
277
278 acpi_physnode_link_name(physnode_name, entry->node_id);
279 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
280 sysfs_remove_link(&dev->kobj, "firmware_node");
281 ACPI_COMPANION_SET(dev, NULL);
282 /* Drop references taken by acpi_bind_one(). */
283 put_device(dev);
284 put_device(&acpi_dev->dev);
285 kfree(entry);
286 break;
287 }
288
289 mutex_unlock(&acpi_dev->physical_node_lock);
290 return 0;
291}
292EXPORT_SYMBOL_GPL(acpi_unbind_one);
293
294static int acpi_platform_notify(struct device *dev)
295{
296 struct acpi_bus_type *type = acpi_get_bus_type(dev);
297 struct acpi_device *adev;
298 int ret;
299
300 ret = acpi_bind_one(dev, NULL);
301 if (ret && type) {
302 struct acpi_device *adev;
303
304 adev = type->find_companion(dev);
305 if (!adev) {
306 DBG("Unable to get handle for %s\n", dev_name(dev));
307 ret = -ENODEV;
308 goto out;
309 }
310 ret = acpi_bind_one(dev, adev);
311 if (ret)
312 goto out;
313 }
314 adev = ACPI_COMPANION(dev);
315 if (!adev)
316 goto out;
317
318 if (type && type->setup)
319 type->setup(dev);
320 else if (adev->handler && adev->handler->bind)
321 adev->handler->bind(dev);
322
323 out:
324#if ACPI_GLUE_DEBUG
325 if (!ret) {
326 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
327
328 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
329 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
330 kfree(buffer.pointer);
331 } else
332 DBG("Device %s -> No ACPI support\n", dev_name(dev));
333#endif
334
335 return ret;
336}
337
338static int acpi_platform_notify_remove(struct device *dev)
339{
340 struct acpi_device *adev = ACPI_COMPANION(dev);
341 struct acpi_bus_type *type;
342
343 if (!adev)
344 return 0;
345
346 type = acpi_get_bus_type(dev);
347 if (type && type->cleanup)
348 type->cleanup(dev);
349 else if (adev->handler && adev->handler->unbind)
350 adev->handler->unbind(dev);
351
352 acpi_unbind_one(dev);
353 return 0;
354}
355
356void __init init_acpi_device_notify(void)
357{
358 if (platform_notify || platform_notify_remove) {
359 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
360 return;
361 }
362 platform_notify = acpi_platform_notify;
363 platform_notify_remove = acpi_platform_notify_remove;
364}