]>
Commit | Line | Data |
---|---|---|
35748177 GVB |
1 | /* |
2 | * libfdt - Flat Device Tree manipulation | |
3 | * Copyright (C) 2006 David Gibson, IBM Corporation. | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU Lesser General Public License | |
7 | * as published by the Free Software Foundation; either version 2.1 of | |
8 | * the License, or (at your option) any later version. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | */ | |
19 | #include "libfdt_env.h" | |
20 | ||
21 | #include <fdt.h> | |
22 | #include <libfdt.h> | |
23 | ||
24 | #include "libfdt_internal.h" | |
25 | ||
26 | #define CHECK_HEADER(fdt) \ | |
27 | { \ | |
28 | int err; \ | |
29 | if ((err = _fdt_check_header(fdt)) != 0) \ | |
30 | return err; \ | |
31 | } | |
32 | ||
33 | static int offset_streq(const void *fdt, int offset, | |
34 | const char *s, int len) | |
35 | { | |
36 | const char *p = fdt_offset_ptr(fdt, offset, len+1); | |
37 | ||
38 | if (! p) | |
39 | /* short match */ | |
40 | return 0; | |
41 | ||
42 | if (memcmp(p, s, len) != 0) | |
43 | return 0; | |
44 | ||
45 | if (p[len] != '\0') | |
46 | return 0; | |
47 | ||
48 | return 1; | |
49 | } | |
50 | ||
51 | char *fdt_string(const void *fdt, int stroffset) | |
52 | { | |
53 | return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset; | |
54 | } | |
55 | ||
56 | int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, | |
57 | const char *name, int namelen) | |
58 | { | |
59 | int level = 0; | |
60 | uint32_t tag; | |
61 | int offset, nextoffset; | |
62 | ||
63 | CHECK_HEADER(fdt); | |
64 | ||
65 | tag = _fdt_next_tag(fdt, parentoffset, &nextoffset); | |
66 | if (tag != FDT_BEGIN_NODE) | |
67 | return -FDT_ERR_BADOFFSET; | |
68 | ||
69 | do { | |
70 | offset = nextoffset; | |
71 | tag = _fdt_next_tag(fdt, offset, &nextoffset); | |
72 | ||
73 | switch (tag) { | |
74 | case FDT_END: | |
75 | return -FDT_ERR_TRUNCATED; | |
76 | ||
77 | case FDT_BEGIN_NODE: | |
78 | level++; | |
79 | if (level != 1) | |
80 | continue; | |
81 | if (offset_streq(fdt, offset+FDT_TAGSIZE, name, namelen)) | |
82 | /* Found it! */ | |
83 | return offset; | |
84 | break; | |
85 | ||
86 | case FDT_END_NODE: | |
87 | level--; | |
88 | break; | |
89 | ||
90 | case FDT_PROP: | |
91 | case FDT_NOP: | |
92 | break; | |
93 | ||
94 | default: | |
95 | return -FDT_ERR_BADSTRUCTURE; | |
96 | } | |
97 | } while (level >= 0); | |
98 | ||
99 | return -FDT_ERR_NOTFOUND; | |
100 | } | |
101 | ||
102 | int fdt_subnode_offset(const void *fdt, int parentoffset, | |
103 | const char *name) | |
104 | { | |
105 | return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name)); | |
106 | } | |
107 | ||
108 | int fdt_path_offset(const void *fdt, const char *path) | |
109 | { | |
110 | const char *end = path + strlen(path); | |
111 | const char *p = path; | |
112 | int offset = 0; | |
113 | ||
114 | CHECK_HEADER(fdt); | |
115 | ||
116 | if (*path != '/') | |
117 | return -FDT_ERR_BADPATH; | |
118 | ||
119 | while (*p) { | |
120 | const char *q; | |
121 | ||
122 | while (*p == '/') | |
123 | p++; | |
124 | if (! *p) | |
125 | return -FDT_ERR_BADPATH; | |
126 | q = strchr(p, '/'); | |
127 | if (! q) | |
128 | q = end; | |
129 | ||
130 | offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p); | |
131 | if (offset < 0) | |
132 | return offset; | |
133 | ||
134 | p = q; | |
135 | } | |
136 | ||
137 | return offset; | |
138 | } | |
139 | ||
140 | struct fdt_property *fdt_get_property(const void *fdt, | |
141 | int nodeoffset, | |
142 | const char *name, int *lenp) | |
143 | { | |
144 | int level = 0; | |
145 | uint32_t tag; | |
146 | struct fdt_property *prop; | |
147 | int namestroff; | |
148 | int offset, nextoffset; | |
149 | int err; | |
150 | ||
151 | if ((err = _fdt_check_header(fdt)) != 0) | |
152 | goto fail; | |
153 | ||
154 | err = -FDT_ERR_BADOFFSET; | |
155 | if (nodeoffset % FDT_TAGSIZE) | |
156 | goto fail; | |
157 | ||
158 | tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset); | |
159 | if (tag != FDT_BEGIN_NODE) | |
160 | goto fail; | |
161 | ||
162 | do { | |
163 | offset = nextoffset; | |
164 | ||
165 | tag = _fdt_next_tag(fdt, offset, &nextoffset); | |
166 | switch (tag) { | |
167 | case FDT_END: | |
168 | err = -FDT_ERR_TRUNCATED; | |
169 | goto fail; | |
170 | ||
171 | case FDT_BEGIN_NODE: | |
172 | level++; | |
173 | break; | |
174 | ||
175 | case FDT_END_NODE: | |
176 | level--; | |
177 | break; | |
178 | ||
179 | case FDT_PROP: | |
180 | if (level != 0) | |
181 | continue; | |
182 | ||
183 | err = -FDT_ERR_BADSTRUCTURE; | |
184 | prop = fdt_offset_ptr_typed(fdt, offset, prop); | |
185 | if (! prop) | |
186 | goto fail; | |
187 | namestroff = fdt32_to_cpu(prop->nameoff); | |
188 | if (streq(fdt_string(fdt, namestroff), name)) { | |
189 | /* Found it! */ | |
190 | int len = fdt32_to_cpu(prop->len); | |
191 | prop = fdt_offset_ptr(fdt, offset, | |
192 | sizeof(*prop)+len); | |
193 | if (! prop) | |
194 | goto fail; | |
195 | ||
196 | if (lenp) | |
197 | *lenp = len; | |
198 | ||
199 | return prop; | |
200 | } | |
201 | break; | |
202 | ||
203 | case FDT_NOP: | |
204 | break; | |
205 | ||
206 | default: | |
207 | err = -FDT_ERR_BADSTRUCTURE; | |
208 | goto fail; | |
209 | } | |
210 | } while (level >= 0); | |
211 | ||
212 | err = -FDT_ERR_NOTFOUND; | |
213 | fail: | |
214 | if (lenp) | |
215 | *lenp = err; | |
216 | return NULL; | |
217 | } | |
218 | ||
219 | void *fdt_getprop(const void *fdt, int nodeoffset, | |
220 | const char *name, int *lenp) | |
221 | { | |
222 | const struct fdt_property *prop; | |
223 | ||
224 | prop = fdt_get_property(fdt, nodeoffset, name, lenp); | |
225 | if (! prop) | |
226 | return NULL; | |
227 | ||
228 | return prop->data; | |
229 | } |