1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * tree.c: Basic device tree traversal/scanning for the Linux
4 * prom library.
5 *
6 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8 */
9
10 #include <linux/string.h>
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/module.h>
15
16 #include <asm/openprom.h>
17 #include <asm/oplib.h>
18 #include <asm/ldc.h>
19
20 static phandle prom_node_to_node(const char *type, phandle node)
21 {
22 unsigned long args[5];
23
24 args[0] = (unsigned long) type;
25 args[1] = 1;
26 args[2] = 1;
27 args[3] = (unsigned int) node;
28 args[4] = (unsigned long) -1;
29
30 p1275_cmd_direct(args);
31
32 return (phandle) args[4];
33 }
34
35 /* Return the child of node 'node' or zero if no this node has no
36 * direct descendent.
37 */
38 inline phandle __prom_getchild(phandle node)
39 {
40 return prom_node_to_node("child", node);
41 }
42
43 phandle prom_getchild(phandle node)
44 {
45 phandle cnode;
46
47 if ((s32)node == -1)
48 return 0;
49 cnode = __prom_getchild(node);
50 if ((s32)cnode == -1)
51 return 0;
52 return cnode;
53 }
54 EXPORT_SYMBOL(prom_getchild);
55
56 inline phandle prom_getparent(phandle node)
57 {
58 phandle cnode;
59
60 if ((s32)node == -1)
61 return 0;
62 cnode = prom_node_to_node("parent", node);
63 if ((s32)cnode == -1)
64 return 0;
65 return cnode;
66 }
67
68 /* Return the next sibling of node 'node' or zero if no more siblings
69 * at this level of depth in the tree.
70 */
71 inline phandle __prom_getsibling(phandle node)
72 {
73 return prom_node_to_node(prom_peer_name, node);
74 }
75
76 phandle prom_getsibling(phandle node)
77 {
78 phandle sibnode;
79
80 if ((s32)node == -1)
81 return 0;
82 sibnode = __prom_getsibling(node);
83 if ((s32)sibnode == -1)
84 return 0;
85
86 return sibnode;
87 }
88 EXPORT_SYMBOL(prom_getsibling);
89
90 /* Return the length in bytes of property 'prop' at node 'node'.
91 * Return -1 on error.
92 */
93 int prom_getproplen(phandle node, const char *prop)
94 {
95 unsigned long args[6];
96
97 if (!node || !prop)
98 return -1;
99
100 args[0] = (unsigned long) "getproplen";
101 args[1] = 2;
102 args[2] = 1;
103 args[3] = (unsigned int) node;
104 args[4] = (unsigned long) prop;
105 args[5] = (unsigned long) -1;
106
107 p1275_cmd_direct(args);
108
109 return (int) args[5];
110 }
111 EXPORT_SYMBOL(prom_getproplen);
112
113 /* Acquire a property 'prop' at node 'node' and place it in
114 * 'buffer' which has a size of 'bufsize'. If the acquisition
115 * was successful the length will be returned, else -1 is returned.
116 */
117 int prom_getproperty(phandle node, const char *prop,
118 char *buffer, int bufsize)
119 {
120 unsigned long args[8];
121 int plen;
122
123 plen = prom_getproplen(node, prop);
124 if ((plen > bufsize) || (plen == 0) || (plen == -1))
125 return -1;
126
127 args[0] = (unsigned long) prom_getprop_name;
128 args[1] = 4;
129 args[2] = 1;
130 args[3] = (unsigned int) node;
131 args[4] = (unsigned long) prop;
132 args[5] = (unsigned long) buffer;
133 args[6] = bufsize;
134 args[7] = (unsigned long) -1;
135
136 p1275_cmd_direct(args);
137
138 return (int) args[7];
139 }
140 EXPORT_SYMBOL(prom_getproperty);
141
142 /* Acquire an integer property and return its value. Returns -1
143 * on failure.
144 */
145 int prom_getint(phandle node, const char *prop)
146 {
147 int intprop;
148
149 if (prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1)
150 return intprop;
151
152 return -1;
153 }
154 EXPORT_SYMBOL(prom_getint);
155
156 /* Acquire an integer property, upon error return the passed default
157 * integer.
158 */
159
160 int prom_getintdefault(phandle node, const char *property, int deflt)
161 {
162 int retval;
163
164 retval = prom_getint(node, property);
165 if (retval == -1)
166 return deflt;
167
168 return retval;
169 }
170 EXPORT_SYMBOL(prom_getintdefault);
171
172 /* Acquire a boolean property, 1=TRUE 0=FALSE. */
173 int prom_getbool(phandle node, const char *prop)
174 {
175 int retval;
176
177 retval = prom_getproplen(node, prop);
178 if (retval == -1)
179 return 0;
180 return 1;
181 }
182 EXPORT_SYMBOL(prom_getbool);
183
184 /* Acquire a property whose value is a string, returns a null
185 * string on error. The char pointer is the user supplied string
186 * buffer.
187 */
188 void prom_getstring(phandle node, const char *prop, char *user_buf,
189 int ubuf_size)
190 {
191 int len;
192
193 len = prom_getproperty(node, prop, user_buf, ubuf_size);
194 if (len != -1)
195 return;
196 user_buf[0] = 0;
197 }
198 EXPORT_SYMBOL(prom_getstring);
199
200 /* Does the device at node 'node' have name 'name'?
201 * YES = 1 NO = 0
202 */
203 int prom_nodematch(phandle node, const char *name)
204 {
205 char namebuf[128];
206 prom_getproperty(node, "name", namebuf, sizeof(namebuf));
207 if (strcmp(namebuf, name) == 0)
208 return 1;
209 return 0;
210 }
211
212 /* Search siblings at 'node_start' for a node with name
213 * 'nodename'. Return node if successful, zero if not.
214 */
215 phandle prom_searchsiblings(phandle node_start, const char *nodename)
216 {
217 phandle thisnode;
218 int error;
219 char promlib_buf[128];
220
221 for(thisnode = node_start; thisnode;
222 thisnode=prom_getsibling(thisnode)) {
223 error = prom_getproperty(thisnode, "name", promlib_buf,
224 sizeof(promlib_buf));
225 /* Should this ever happen? */
226 if(error == -1) continue;
227 if(strcmp(nodename, promlib_buf)==0) return thisnode;
228 }
229
230 return 0;
231 }
232 EXPORT_SYMBOL(prom_searchsiblings);
233
234 static const char *prom_nextprop_name = "nextprop";
235
236 /* Return the first property type for node 'node'.
237 * buffer should be at least 32B in length
238 */
239 char *prom_firstprop(phandle node, char *buffer)
240 {
241 unsigned long args[7];
242
243 *buffer = 0;
244 if ((s32)node == -1)
245 return buffer;
246
247 args[0] = (unsigned long) prom_nextprop_name;
248 args[1] = 3;
249 args[2] = 1;
250 args[3] = (unsigned int) node;
251 args[4] = 0;
252 args[5] = (unsigned long) buffer;
253 args[6] = (unsigned long) -1;
254
255 p1275_cmd_direct(args);
256
257 return buffer;
258 }
259 EXPORT_SYMBOL(prom_firstprop);
260
261 /* Return the property type string after property type 'oprop'
262 * at node 'node' . Returns NULL string if no more
263 * property types for this node.
264 */
265 char *prom_nextprop(phandle node, const char *oprop, char *buffer)
266 {
267 unsigned long args[7];
268 char buf[32];
269
270 if ((s32)node == -1) {
271 *buffer = 0;
272 return buffer;
273 }
274 if (oprop == buffer) {
275 strcpy (buf, oprop);
276 oprop = buf;
277 }
278
279 args[0] = (unsigned long) prom_nextprop_name;
280 args[1] = 3;
281 args[2] = 1;
282 args[3] = (unsigned int) node;
283 args[4] = (unsigned long) oprop;
284 args[5] = (unsigned long) buffer;
285 args[6] = (unsigned long) -1;
286
287 p1275_cmd_direct(args);
288
289 return buffer;
290 }
291 EXPORT_SYMBOL(prom_nextprop);
292
293 phandle prom_finddevice(const char *name)
294 {
295 unsigned long args[5];
296
297 if (!name)
298 return 0;
299 args[0] = (unsigned long) "finddevice";
300 args[1] = 1;
301 args[2] = 1;
302 args[3] = (unsigned long) name;
303 args[4] = (unsigned long) -1;
304
305 p1275_cmd_direct(args);
306
307 return (int) args[4];
308 }
309 EXPORT_SYMBOL(prom_finddevice);
310
311 int prom_node_has_property(phandle node, const char *prop)
312 {
313 char buf [32];
314
315 *buf = 0;
316 do {
317 prom_nextprop(node, buf, buf);
318 if (!strcmp(buf, prop))
319 return 1;
320 } while (*buf);
321 return 0;
322 }
323 EXPORT_SYMBOL(prom_node_has_property);
324
325 /* Set property 'pname' at node 'node' to value 'value' which has a length
326 * of 'size' bytes. Return the number of bytes the prom accepted.
327 */
328 int
329 prom_setprop(phandle node, const char *pname, char *value, int size)
330 {
331 unsigned long args[8];
332
333 if (size == 0)
334 return 0;
335 if ((pname == NULL) || (value == NULL))
336 return 0;
337
338 #ifdef CONFIG_SUN_LDOMS
339 if (ldom_domaining_enabled) {
340 ldom_set_var(pname, value);
341 return 0;
342 }
343 #endif
344 args[0] = (unsigned long) "setprop";
345 args[1] = 4;
346 args[2] = 1;
347 args[3] = (unsigned int) node;
348 args[4] = (unsigned long) pname;
349 args[5] = (unsigned long) value;
350 args[6] = size;
351 args[7] = (unsigned long) -1;
352
353 p1275_cmd_direct(args);
354
355 return (int) args[7];
356 }
357 EXPORT_SYMBOL(prom_setprop);
358
359 inline phandle prom_inst2pkg(int inst)
360 {
361 unsigned long args[5];
362 phandle node;
363
364 args[0] = (unsigned long) "instance-to-package";
365 args[1] = 1;
366 args[2] = 1;
367 args[3] = (unsigned int) inst;
368 args[4] = (unsigned long) -1;
369
370 p1275_cmd_direct(args);
371
372 node = (int) args[4];
373 if ((s32)node == -1)
374 return 0;
375 return node;
376 }
377
378 int prom_ihandle2path(int handle, char *buffer, int bufsize)
379 {
380 unsigned long args[7];
381
382 args[0] = (unsigned long) "instance-to-path";
383 args[1] = 3;
384 args[2] = 1;
385 args[3] = (unsigned int) handle;
386 args[4] = (unsigned long) buffer;
387 args[5] = bufsize;
388 args[6] = (unsigned long) -1;
389
390 p1275_cmd_direct(args);
391
392 return (int) args[6];
393 }
394
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