Merge master.kernel.org:/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / drivers / acpi / namespace / nswalk.c
1 /******************************************************************************
2  *
3  * Module Name: nswalk - Functions for walking the ACPI namespace
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2005, R. Byron Moore
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44
45 #include <acpi/acpi.h>
46 #include <acpi/acnamesp.h>
47
48
49 #define _COMPONENT          ACPI_NAMESPACE
50          ACPI_MODULE_NAME    ("nswalk")
51
52
53 /*******************************************************************************
54  *
55  * FUNCTION:    acpi_ns_get_next_node
56  *
57  * PARAMETERS:  Type                - Type of node to be searched for
58  *              parent_node         - Parent node whose children we are
59  *                                    getting
60  *              child_node          - Previous child that was found.
61  *                                    The NEXT child will be returned
62  *
63  * RETURN:      struct acpi_namespace_node - Pointer to the NEXT child or NULL if
64  *                                    none is found.
65  *
66  * DESCRIPTION: Return the next peer node within the namespace.  If Handle
67  *              is valid, Scope is ignored.  Otherwise, the first node
68  *              within Scope is returned.
69  *
70  ******************************************************************************/
71
72 struct acpi_namespace_node *
73 acpi_ns_get_next_node (
74         acpi_object_type                type,
75         struct acpi_namespace_node      *parent_node,
76         struct acpi_namespace_node      *child_node)
77 {
78         struct acpi_namespace_node      *next_node = NULL;
79
80
81         ACPI_FUNCTION_ENTRY ();
82
83
84         if (!child_node) {
85                 /* It's really the parent's _scope_ that we want */
86
87                 if (parent_node->child) {
88                         next_node = parent_node->child;
89                 }
90         }
91
92         else {
93                 /* Start search at the NEXT node */
94
95                 next_node = acpi_ns_get_next_valid_node (child_node);
96         }
97
98         /* If any type is OK, we are done */
99
100         if (type == ACPI_TYPE_ANY) {
101                 /* next_node is NULL if we are at the end-of-list */
102
103                 return (next_node);
104         }
105
106         /* Must search for the node -- but within this scope only */
107
108         while (next_node) {
109                 /* If type matches, we are done */
110
111                 if (next_node->type == type) {
112                         return (next_node);
113                 }
114
115                 /* Otherwise, move on to the next node */
116
117                 next_node = acpi_ns_get_next_valid_node (next_node);
118         }
119
120         /* Not found */
121
122         return (NULL);
123 }
124
125
126 /*******************************************************************************
127  *
128  * FUNCTION:    acpi_ns_walk_namespace
129  *
130  * PARAMETERS:  Type                - acpi_object_type to search for
131  *              start_node          - Handle in namespace where search begins
132  *              max_depth           - Depth to which search is to reach
133  *              unlock_before_callback- Whether to unlock the NS before invoking
134  *                                    the callback routine
135  *              user_function       - Called when an object of "Type" is found
136  *              Context             - Passed to user function
137  *              return_value        - from the user_function if terminated early.
138  *                                    Otherwise, returns NULL.
139  * RETURNS:     Status
140  *
141  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
142  *              starting (and ending) at the node specified by start_handle.
143  *              The user_function is called whenever a node that matches
144  *              the type parameter is found.  If the user function returns
145  *              a non-zero value, the search is terminated immediately and this
146  *              value is returned to the caller.
147  *
148  *              The point of this procedure is to provide a generic namespace
149  *              walk routine that can be called from multiple places to
150  *              provide multiple services;  the User Function can be tailored
151  *              to each task, whether it is a print function, a compare
152  *              function, etc.
153  *
154  ******************************************************************************/
155
156 acpi_status
157 acpi_ns_walk_namespace (
158         acpi_object_type                type,
159         acpi_handle                     start_node,
160         u32                             max_depth,
161         u8                              unlock_before_callback,
162         acpi_walk_callback              user_function,
163         void                            *context,
164         void                            **return_value)
165 {
166         acpi_status                     status;
167         acpi_status                     mutex_status;
168         struct acpi_namespace_node      *child_node;
169         struct acpi_namespace_node      *parent_node;
170         acpi_object_type                child_type;
171         u32                             level;
172
173
174         ACPI_FUNCTION_TRACE ("ns_walk_namespace");
175
176
177         /* Special case for the namespace Root Node */
178
179         if (start_node == ACPI_ROOT_OBJECT) {
180                 start_node = acpi_gbl_root_node;
181         }
182
183         /* Null child means "get first node" */
184
185         parent_node = start_node;
186         child_node  = NULL;
187         child_type  = ACPI_TYPE_ANY;
188         level       = 1;
189
190         /*
191          * Traverse the tree of nodes until we bubble back up to where we
192          * started. When Level is zero, the loop is done because we have
193          * bubbled up to (and passed) the original parent handle (start_entry)
194          */
195         while (level > 0) {
196                 /* Get the next node in this scope.  Null if not found */
197
198                 status = AE_OK;
199                 child_node = acpi_ns_get_next_node (ACPI_TYPE_ANY, parent_node, child_node);
200                 if (child_node) {
201                         /*
202                          * Found node, Get the type if we are not
203                          * searching for ANY
204                          */
205                         if (type != ACPI_TYPE_ANY) {
206                                 child_type = child_node->type;
207                         }
208
209                         if (child_type == type) {
210                                 /*
211                                  * Found a matching node, invoke the user
212                                  * callback function
213                                  */
214                                 if (unlock_before_callback) {
215                                         mutex_status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
216                                         if (ACPI_FAILURE (mutex_status)) {
217                                                 return_ACPI_STATUS (mutex_status);
218                                         }
219                                 }
220
221                                 status = user_function (child_node, level,
222                                                  context, return_value);
223
224                                 if (unlock_before_callback) {
225                                         mutex_status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
226                                         if (ACPI_FAILURE (mutex_status)) {
227                                                 return_ACPI_STATUS (mutex_status);
228                                         }
229                                 }
230
231                                 switch (status) {
232                                 case AE_OK:
233                                 case AE_CTRL_DEPTH:
234
235                                         /* Just keep going */
236                                         break;
237
238                                 case AE_CTRL_TERMINATE:
239
240                                         /* Exit now, with OK status */
241
242                                         return_ACPI_STATUS (AE_OK);
243
244                                 default:
245
246                                         /* All others are valid exceptions */
247
248                                         return_ACPI_STATUS (status);
249                                 }
250                         }
251
252                         /*
253                          * Depth first search:
254                          * Attempt to go down another level in the namespace
255                          * if we are allowed to.  Don't go any further if we
256                          * have reached the caller specified maximum depth
257                          * or if the user function has specified that the
258                          * maximum depth has been reached.
259                          */
260                         if ((level < max_depth) && (status != AE_CTRL_DEPTH)) {
261                                 if (acpi_ns_get_next_node (ACPI_TYPE_ANY, child_node, NULL)) {
262                                         /*
263                                          * There is at least one child of this
264                                          * node, visit the onde
265                                          */
266                                         level++;
267                                         parent_node = child_node;
268                                         child_node = NULL;
269                                 }
270                         }
271                 }
272                 else {
273                         /*
274                          * No more children of this node (acpi_ns_get_next_node
275                          * failed), go back upwards in the namespace tree to
276                          * the node's parent.
277                          */
278                         level--;
279                         child_node = parent_node;
280                         parent_node = acpi_ns_get_parent_node (parent_node);
281                 }
282         }
283
284         /* Complete walk, not terminated by user function */
285
286         return_ACPI_STATUS (AE_OK);
287 }
288
289