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
20static 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 */
38inline phandle __prom_getchild(phandle node)
39{
40	return prom_node_to_node("child", node);
41}
42
43phandle 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}
54EXPORT_SYMBOL(prom_getchild);
55
56inline 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 */
71inline phandle __prom_getsibling(phandle node)
72{
73	return prom_node_to_node(prom_peer_name, node);
74}
75
76phandle 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}
88EXPORT_SYMBOL(prom_getsibling);
89
90/* Return the length in bytes of property 'prop' at node 'node'.
91 * Return -1 on error.
92 */
93int 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}
111EXPORT_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 */
117int 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}
140EXPORT_SYMBOL(prom_getproperty);
141
142/* Acquire an integer property and return its value.  Returns -1
143 * on failure.
144 */
145int 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}
154EXPORT_SYMBOL(prom_getint);
155
156/* Acquire an integer property, upon error return the passed default
157 * integer.
158 */
159
160int 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}
170EXPORT_SYMBOL(prom_getintdefault);
171
172/* Acquire a boolean property, 1=TRUE 0=FALSE. */
173int 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}
182EXPORT_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 */
188void 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}
198EXPORT_SYMBOL(prom_getstring);
199
200/* Does the device at node 'node' have name 'name'?
201 * YES = 1   NO = 0
202 */
203int 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 */
215phandle 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}
232EXPORT_SYMBOL(prom_searchsiblings);
233
234static 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 */
239char *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}
259EXPORT_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 */
265char *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}
291EXPORT_SYMBOL(prom_nextprop);
292
293phandle 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}
309EXPORT_SYMBOL(prom_finddevice);
310
311int 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}
323EXPORT_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 */
328int
329prom_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 == 0) || (value == 0))
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}
357EXPORT_SYMBOL(prom_setprop);
358
359inline 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
378int 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