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 | */ |
8 | |
9 | #include <linux/string.h> |
10 | #include <linux/types.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/sched.h> |
13 | #include <linux/ctype.h> |
14 | #include <linux/module.h> |
15 | |
16 | #include <asm/openprom.h> |
17 | #include <asm/oplib.h> |
18 | |
19 | extern void restore_current(void); |
20 | |
21 | static char promlib_buf[128]; |
22 | |
23 | /* Internal version of prom_getchild that does not alter return values. */ |
24 | static phandle __prom_getchild(phandle node) |
25 | { |
26 | unsigned long flags; |
27 | phandle cnode; |
28 | |
29 | spin_lock_irqsave(&prom_lock, flags); |
30 | cnode = prom_nodeops->no_child(node); |
31 | restore_current(); |
32 | spin_unlock_irqrestore(lock: &prom_lock, flags); |
33 | |
34 | return cnode; |
35 | } |
36 | |
37 | /* Return the child of node 'node' or zero if no this node has no |
38 | * direct descendent. |
39 | */ |
40 | phandle prom_getchild(phandle node) |
41 | { |
42 | phandle cnode; |
43 | |
44 | if ((s32)node == -1) |
45 | return 0; |
46 | |
47 | cnode = __prom_getchild(node); |
48 | if (cnode == 0 || (s32)cnode == -1) |
49 | return 0; |
50 | |
51 | return cnode; |
52 | } |
53 | EXPORT_SYMBOL(prom_getchild); |
54 | |
55 | /* Internal version of prom_getsibling that does not alter return values. */ |
56 | static phandle __prom_getsibling(phandle node) |
57 | { |
58 | unsigned long flags; |
59 | phandle cnode; |
60 | |
61 | spin_lock_irqsave(&prom_lock, flags); |
62 | cnode = prom_nodeops->no_nextnode(node); |
63 | restore_current(); |
64 | spin_unlock_irqrestore(lock: &prom_lock, flags); |
65 | |
66 | return cnode; |
67 | } |
68 | |
69 | /* Return the next sibling of node 'node' or zero if no more siblings |
70 | * at this level of depth in the tree. |
71 | */ |
72 | phandle prom_getsibling(phandle node) |
73 | { |
74 | phandle sibnode; |
75 | |
76 | if ((s32)node == -1) |
77 | return 0; |
78 | |
79 | sibnode = __prom_getsibling(node); |
80 | if (sibnode == 0 || (s32)sibnode == -1) |
81 | return 0; |
82 | |
83 | return sibnode; |
84 | } |
85 | EXPORT_SYMBOL(prom_getsibling); |
86 | |
87 | /* Return the length in bytes of property 'prop' at node 'node'. |
88 | * Return -1 on error. |
89 | */ |
90 | int prom_getproplen(phandle node, const char *prop) |
91 | { |
92 | int ret; |
93 | unsigned long flags; |
94 | |
95 | if((!node) || (!prop)) |
96 | return -1; |
97 | |
98 | spin_lock_irqsave(&prom_lock, flags); |
99 | ret = prom_nodeops->no_proplen(node, prop); |
100 | restore_current(); |
101 | spin_unlock_irqrestore(&prom_lock, flags); |
102 | return ret; |
103 | } |
104 | EXPORT_SYMBOL(prom_getproplen); |
105 | |
106 | /* Acquire a property 'prop' at node 'node' and place it in |
107 | * 'buffer' which has a size of 'bufsize'. If the acquisition |
108 | * was successful the length will be returned, else -1 is returned. |
109 | */ |
110 | int prom_getproperty(phandle node, const char *prop, char *buffer, int bufsize) |
111 | { |
112 | int plen, ret; |
113 | unsigned long flags; |
114 | |
115 | plen = prom_getproplen(node, prop); |
116 | if((plen > bufsize) || (plen == 0) || (plen == -1)) |
117 | return -1; |
118 | /* Ok, things seem all right. */ |
119 | spin_lock_irqsave(&prom_lock, flags); |
120 | ret = prom_nodeops->no_getprop(node, prop, buffer); |
121 | restore_current(); |
122 | spin_unlock_irqrestore(&prom_lock, flags); |
123 | return ret; |
124 | } |
125 | EXPORT_SYMBOL(prom_getproperty); |
126 | |
127 | /* Acquire an integer property and return its value. Returns -1 |
128 | * on failure. |
129 | */ |
130 | int prom_getint(phandle node, char *prop) |
131 | { |
132 | static int intprop; |
133 | |
134 | if(prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1) |
135 | return intprop; |
136 | |
137 | return -1; |
138 | } |
139 | EXPORT_SYMBOL(prom_getint); |
140 | |
141 | /* Acquire an integer property, upon error return the passed default |
142 | * integer. |
143 | */ |
144 | int prom_getintdefault(phandle node, char *property, int deflt) |
145 | { |
146 | int retval; |
147 | |
148 | retval = prom_getint(node, property); |
149 | if(retval == -1) return deflt; |
150 | |
151 | return retval; |
152 | } |
153 | EXPORT_SYMBOL(prom_getintdefault); |
154 | |
155 | /* Acquire a boolean property, 1=TRUE 0=FALSE. */ |
156 | int prom_getbool(phandle node, char *prop) |
157 | { |
158 | int retval; |
159 | |
160 | retval = prom_getproplen(node, prop); |
161 | if(retval == -1) return 0; |
162 | return 1; |
163 | } |
164 | EXPORT_SYMBOL(prom_getbool); |
165 | |
166 | /* Acquire a property whose value is a string, returns a null |
167 | * string on error. The char pointer is the user supplied string |
168 | * buffer. |
169 | */ |
170 | void prom_getstring(phandle node, char *prop, char *user_buf, int ubuf_size) |
171 | { |
172 | int len; |
173 | |
174 | len = prom_getproperty(node, prop, user_buf, ubuf_size); |
175 | if(len != -1) return; |
176 | user_buf[0] = 0; |
177 | } |
178 | EXPORT_SYMBOL(prom_getstring); |
179 | |
180 | |
181 | /* Search siblings at 'node_start' for a node with name |
182 | * 'nodename'. Return node if successful, zero if not. |
183 | */ |
184 | phandle prom_searchsiblings(phandle node_start, char *nodename) |
185 | { |
186 | |
187 | phandle thisnode; |
188 | int error; |
189 | |
190 | for(thisnode = node_start; thisnode; |
191 | thisnode=prom_getsibling(thisnode)) { |
192 | error = prom_getproperty(thisnode, "name" , promlib_buf, |
193 | sizeof(promlib_buf)); |
194 | /* Should this ever happen? */ |
195 | if(error == -1) continue; |
196 | if(strcmp(nodename, promlib_buf)==0) return thisnode; |
197 | } |
198 | |
199 | return 0; |
200 | } |
201 | EXPORT_SYMBOL(prom_searchsiblings); |
202 | |
203 | /* Interal version of nextprop that does not alter return values. */ |
204 | static char *__prom_nextprop(phandle node, char * oprop) |
205 | { |
206 | unsigned long flags; |
207 | char *prop; |
208 | |
209 | spin_lock_irqsave(&prom_lock, flags); |
210 | prop = prom_nodeops->no_nextprop(node, oprop); |
211 | restore_current(); |
212 | spin_unlock_irqrestore(&prom_lock, flags); |
213 | |
214 | return prop; |
215 | } |
216 | |
217 | /* Return the property type string after property type 'oprop' |
218 | * at node 'node' . Returns empty string if no more |
219 | * property types for this node. |
220 | */ |
221 | char *prom_nextprop(phandle node, char *oprop, char *buffer) |
222 | { |
223 | if (node == 0 || (s32)node == -1) |
224 | return "" ; |
225 | |
226 | return __prom_nextprop(node, oprop); |
227 | } |
228 | EXPORT_SYMBOL(prom_nextprop); |
229 | |
230 | phandle prom_finddevice(char *name) |
231 | { |
232 | char nbuf[128]; |
233 | char *s = name, *d; |
234 | phandle node = prom_root_node, node2; |
235 | unsigned int which_io, phys_addr; |
236 | struct linux_prom_registers reg[PROMREG_MAX]; |
237 | |
238 | while (*s++) { |
239 | if (!*s) return node; /* path '.../' is legal */ |
240 | node = prom_getchild(node); |
241 | |
242 | for (d = nbuf; *s != 0 && *s != '@' && *s != '/';) |
243 | *d++ = *s++; |
244 | *d = 0; |
245 | |
246 | node = prom_searchsiblings(node, nbuf); |
247 | if (!node) |
248 | return 0; |
249 | |
250 | if (*s == '@') { |
251 | if (isxdigit(s[1]) && s[2] == ',') { |
252 | which_io = simple_strtoul(s+1, NULL, 16); |
253 | phys_addr = simple_strtoul(s+3, &d, 16); |
254 | if (d != s + 3 && (!*d || *d == '/') |
255 | && d <= s + 3 + 8) { |
256 | node2 = node; |
257 | while (node2 && (s32)node2 != -1) { |
258 | if (prom_getproperty (node2, "reg" , (char *)reg, sizeof (reg)) > 0) { |
259 | if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) { |
260 | node = node2; |
261 | break; |
262 | } |
263 | } |
264 | node2 = prom_getsibling(node2); |
265 | if (!node2 || (s32)node2 == -1) |
266 | break; |
267 | node2 = prom_searchsiblings(prom_getsibling(node2), nbuf); |
268 | } |
269 | } |
270 | } |
271 | while (*s != 0 && *s != '/') s++; |
272 | } |
273 | } |
274 | return node; |
275 | } |
276 | EXPORT_SYMBOL(prom_finddevice); |
277 | |
278 | /* Set property 'pname' at node 'node' to value 'value' which has a length |
279 | * of 'size' bytes. Return the number of bytes the prom accepted. |
280 | */ |
281 | int prom_setprop(phandle node, const char *pname, char *value, int size) |
282 | { |
283 | unsigned long flags; |
284 | int ret; |
285 | |
286 | if (size == 0) |
287 | return 0; |
288 | if ((pname == NULL) || (value == NULL)) |
289 | return 0; |
290 | spin_lock_irqsave(&prom_lock, flags); |
291 | ret = prom_nodeops->no_setprop(node, pname, value, size); |
292 | restore_current(); |
293 | spin_unlock_irqrestore(&prom_lock, flags); |
294 | return ret; |
295 | } |
296 | EXPORT_SYMBOL(prom_setprop); |
297 | |
298 | phandle prom_inst2pkg(int inst) |
299 | { |
300 | phandle node; |
301 | unsigned long flags; |
302 | |
303 | spin_lock_irqsave(&prom_lock, flags); |
304 | node = (*romvec->pv_v2devops.v2_inst2pkg)(inst); |
305 | restore_current(); |
306 | spin_unlock_irqrestore(&prom_lock, flags); |
307 | if ((s32)node == -1) |
308 | return 0; |
309 | return node; |
310 | } |
311 | |