1 // SPDX-License-Identifier: GPL-2.0
3 * tree.c: Basic device tree traversal/scanning for the Linux
6 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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>
16 #include <asm/openprom.h>
17 #include <asm/oplib.h>
20 static phandle
prom_node_to_node(const char *type
, phandle node
)
22 unsigned long args
[5];
24 args
[0] = (unsigned long) type
;
27 args
[3] = (unsigned int) node
;
28 args
[4] = (unsigned long) -1;
30 p1275_cmd_direct(args
);
32 return (phandle
) args
[4];
35 /* Return the child of node 'node' or zero if no this node has no
38 inline phandle
__prom_getchild(phandle node
)
40 return prom_node_to_node("child", node
);
43 phandle
prom_getchild(phandle node
)
49 cnode
= __prom_getchild(node
);
54 EXPORT_SYMBOL(prom_getchild
);
56 inline phandle
prom_getparent(phandle node
)
62 cnode
= prom_node_to_node("parent", node
);
68 /* Return the next sibling of node 'node' or zero if no more siblings
69 * at this level of depth in the tree.
71 inline phandle
__prom_getsibling(phandle node
)
73 return prom_node_to_node(prom_peer_name
, node
);
76 phandle
prom_getsibling(phandle node
)
82 sibnode
= __prom_getsibling(node
);
83 if ((s32
)sibnode
== -1)
88 EXPORT_SYMBOL(prom_getsibling
);
90 /* Return the length in bytes of property 'prop' at node 'node'.
93 int prom_getproplen(phandle node
, const char *prop
)
95 unsigned long args
[6];
100 args
[0] = (unsigned long) "getproplen";
103 args
[3] = (unsigned int) node
;
104 args
[4] = (unsigned long) prop
;
105 args
[5] = (unsigned long) -1;
107 p1275_cmd_direct(args
);
109 return (int) args
[5];
111 EXPORT_SYMBOL(prom_getproplen
);
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.
117 int prom_getproperty(phandle node
, const char *prop
,
118 char *buffer
, int bufsize
)
120 unsigned long args
[8];
123 plen
= prom_getproplen(node
, prop
);
124 if ((plen
> bufsize
) || (plen
== 0) || (plen
== -1))
127 args
[0] = (unsigned long) prom_getprop_name
;
130 args
[3] = (unsigned int) node
;
131 args
[4] = (unsigned long) prop
;
132 args
[5] = (unsigned long) buffer
;
134 args
[7] = (unsigned long) -1;
136 p1275_cmd_direct(args
);
138 return (int) args
[7];
140 EXPORT_SYMBOL(prom_getproperty
);
142 /* Acquire an integer property and return its value. Returns -1
145 int prom_getint(phandle node
, const char *prop
)
149 if (prom_getproperty(node
, prop
, (char *) &intprop
, sizeof(int)) != -1)
154 EXPORT_SYMBOL(prom_getint
);
156 /* Acquire an integer property, upon error return the passed default
160 int prom_getintdefault(phandle node
, const char *property
, int deflt
)
164 retval
= prom_getint(node
, property
);
170 EXPORT_SYMBOL(prom_getintdefault
);
172 /* Acquire a boolean property, 1=TRUE 0=FALSE. */
173 int prom_getbool(phandle node
, const char *prop
)
177 retval
= prom_getproplen(node
, prop
);
182 EXPORT_SYMBOL(prom_getbool
);
184 /* Acquire a property whose value is a string, returns a null
185 * string on error. The char pointer is the user supplied string
188 void prom_getstring(phandle node
, const char *prop
, char *user_buf
,
193 len
= prom_getproperty(node
, prop
, user_buf
, ubuf_size
);
198 EXPORT_SYMBOL(prom_getstring
);
200 /* Does the device at node 'node' have name 'name'?
203 int prom_nodematch(phandle node
, const char *name
)
206 prom_getproperty(node
, "name", namebuf
, sizeof(namebuf
));
207 if (strcmp(namebuf
, name
) == 0)
212 /* Search siblings at 'node_start' for a node with name
213 * 'nodename'. Return node if successful, zero if not.
215 phandle
prom_searchsiblings(phandle node_start
, const char *nodename
)
219 char promlib_buf
[128];
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
;
232 EXPORT_SYMBOL(prom_searchsiblings
);
234 static const char *prom_nextprop_name
= "nextprop";
236 /* Return the first property type for node 'node'.
237 * buffer should be at least 32B in length
239 char *prom_firstprop(phandle node
, char *buffer
)
241 unsigned long args
[7];
247 args
[0] = (unsigned long) prom_nextprop_name
;
250 args
[3] = (unsigned int) node
;
252 args
[5] = (unsigned long) buffer
;
253 args
[6] = (unsigned long) -1;
255 p1275_cmd_direct(args
);
259 EXPORT_SYMBOL(prom_firstprop
);
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.
265 char *prom_nextprop(phandle node
, const char *oprop
, char *buffer
)
267 unsigned long args
[7];
270 if ((s32
)node
== -1) {
274 if (oprop
== buffer
) {
279 args
[0] = (unsigned long) prom_nextprop_name
;
282 args
[3] = (unsigned int) node
;
283 args
[4] = (unsigned long) oprop
;
284 args
[5] = (unsigned long) buffer
;
285 args
[6] = (unsigned long) -1;
287 p1275_cmd_direct(args
);
291 EXPORT_SYMBOL(prom_nextprop
);
293 phandle
prom_finddevice(const char *name
)
295 unsigned long args
[5];
299 args
[0] = (unsigned long) "finddevice";
302 args
[3] = (unsigned long) name
;
303 args
[4] = (unsigned long) -1;
305 p1275_cmd_direct(args
);
307 return (int) args
[4];
309 EXPORT_SYMBOL(prom_finddevice
);
311 int prom_node_has_property(phandle node
, const char *prop
)
317 prom_nextprop(node
, buf
, buf
);
318 if (!strcmp(buf
, prop
))
323 EXPORT_SYMBOL(prom_node_has_property
);
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.
329 prom_setprop(phandle node
, const char *pname
, char *value
, int size
)
331 unsigned long args
[8];
335 if ((pname
== 0) || (value
== 0))
338 #ifdef CONFIG_SUN_LDOMS
339 if (ldom_domaining_enabled
) {
340 ldom_set_var(pname
, value
);
344 args
[0] = (unsigned long) "setprop";
347 args
[3] = (unsigned int) node
;
348 args
[4] = (unsigned long) pname
;
349 args
[5] = (unsigned long) value
;
351 args
[7] = (unsigned long) -1;
353 p1275_cmd_direct(args
);
355 return (int) args
[7];
357 EXPORT_SYMBOL(prom_setprop
);
359 inline phandle
prom_inst2pkg(int inst
)
361 unsigned long args
[5];
364 args
[0] = (unsigned long) "instance-to-package";
367 args
[3] = (unsigned int) inst
;
368 args
[4] = (unsigned long) -1;
370 p1275_cmd_direct(args
);
372 node
= (int) args
[4];
378 int prom_ihandle2path(int handle
, char *buffer
, int bufsize
)
380 unsigned long args
[7];
382 args
[0] = (unsigned long) "instance-to-path";
385 args
[3] = (unsigned int) handle
;
386 args
[4] = (unsigned long) buffer
;
388 args
[6] = (unsigned long) -1;
390 p1275_cmd_direct(args
);
392 return (int) args
[6];