xref: /openbmc/linux/arch/sparc/prom/tree_32.c (revision 2a598d0b)
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(&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(&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