1/* $Id: tree.c,v 1.1.1.1 2007/08/03 18:52:18 Exp $
2 * tree.c: Basic device tree traversal/scanning for the Linux
3 *         prom library.
4 *
5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6 */
7
8#define PROMLIB_INTERNAL
9
10#include <linux/string.h>
11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <linux/ctype.h>
15
16#include <asm/openprom.h>
17#include <asm/oplib.h>
18
19extern void restore_current(void);
20
21static char promlib_buf[128];
22
23/* Internal version of prom_getchild that does not alter return values. */
24int __prom_getchild(int node)
25{
26	unsigned long flags;
27	int 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 */
40int prom_getchild(int node)
41{
42	int cnode;
43
44	if (node == -1)
45		return 0;
46
47	cnode = __prom_getchild(node);
48	if (cnode == 0 || cnode == -1)
49		return 0;
50
51	return cnode;
52}
53
54/* Internal version of prom_getsibling that does not alter return values. */
55int __prom_getsibling(int node)
56{
57	unsigned long flags;
58	int cnode;
59
60	spin_lock_irqsave(&prom_lock, flags);
61	cnode = prom_nodeops->no_nextnode(node);
62	restore_current();
63	spin_unlock_irqrestore(&prom_lock, flags);
64
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 */
71int prom_getsibling(int node)
72{
73	int sibnode;
74
75	if (node == -1)
76		return 0;
77
78	sibnode = __prom_getsibling(node);
79	if (sibnode == 0 || sibnode == -1)
80		return 0;
81
82	return sibnode;
83}
84
85/* Return the length in bytes of property 'prop' at node 'node'.
86 * Return -1 on error.
87 */
88int prom_getproplen(int node, char *prop)
89{
90	int ret;
91	unsigned long flags;
92
93	if((!node) || (!prop))
94		return -1;
95
96	spin_lock_irqsave(&prom_lock, flags);
97	ret = prom_nodeops->no_proplen(node, prop);
98	restore_current();
99	spin_unlock_irqrestore(&prom_lock, flags);
100	return ret;
101}
102
103/* Acquire a property 'prop' at node 'node' and place it in
104 * 'buffer' which has a size of 'bufsize'.  If the acquisition
105 * was successful the length will be returned, else -1 is returned.
106 */
107int prom_getproperty(int node, char *prop, char *buffer, int bufsize)
108{
109	int plen, ret;
110	unsigned long flags;
111
112	plen = prom_getproplen(node, prop);
113	if((plen > bufsize) || (plen == 0) || (plen == -1))
114		return -1;
115	/* Ok, things seem all right. */
116	spin_lock_irqsave(&prom_lock, flags);
117	ret = prom_nodeops->no_getprop(node, prop, buffer);
118	restore_current();
119	spin_unlock_irqrestore(&prom_lock, flags);
120	return ret;
121}
122
123/* Acquire an integer property and return its value.  Returns -1
124 * on failure.
125 */
126int prom_getint(int node, char *prop)
127{
128	static int intprop;
129
130	if(prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1)
131		return intprop;
132
133	return -1;
134}
135
136/* Acquire an integer property, upon error return the passed default
137 * integer.
138 */
139int prom_getintdefault(int node, char *property, int deflt)
140{
141	int retval;
142
143	retval = prom_getint(node, property);
144	if(retval == -1) return deflt;
145
146	return retval;
147}
148
149/* Acquire a boolean property, 1=TRUE 0=FALSE. */
150int prom_getbool(int node, char *prop)
151{
152	int retval;
153
154	retval = prom_getproplen(node, prop);
155	if(retval == -1) return 0;
156	return 1;
157}
158
159/* Acquire a property whose value is a string, returns a null
160 * string on error.  The char pointer is the user supplied string
161 * buffer.
162 */
163void prom_getstring(int node, char *prop, char *user_buf, int ubuf_size)
164{
165	int len;
166
167	len = prom_getproperty(node, prop, user_buf, ubuf_size);
168	if(len != -1) return;
169	user_buf[0] = 0;
170	return;
171}
172
173
174/* Does the device at node 'node' have name 'name'?
175 * YES = 1   NO = 0
176 */
177int prom_nodematch(int node, char *name)
178{
179	int error;
180
181	static char namebuf[128];
182	error = prom_getproperty(node, "name", namebuf, sizeof(namebuf));
183	if (error == -1) return 0;
184	if(strcmp(namebuf, name) == 0) return 1;
185	return 0;
186}
187
188/* Search siblings at 'node_start' for a node with name
189 * 'nodename'.  Return node if successful, zero if not.
190 */
191int prom_searchsiblings(int node_start, char *nodename)
192{
193
194	int thisnode, error;
195
196	for(thisnode = node_start; thisnode;
197	    thisnode=prom_getsibling(thisnode)) {
198		error = prom_getproperty(thisnode, "name", promlib_buf,
199					 sizeof(promlib_buf));
200		/* Should this ever happen? */
201		if(error == -1) continue;
202		if(strcmp(nodename, promlib_buf)==0) return thisnode;
203	}
204
205	return 0;
206}
207
208/* Interal version of nextprop that does not alter return values. */
209char * __prom_nextprop(int node, char * oprop)
210{
211	unsigned long flags;
212	char *prop;
213
214	spin_lock_irqsave(&prom_lock, flags);
215	prop = prom_nodeops->no_nextprop(node, oprop);
216	restore_current();
217	spin_unlock_irqrestore(&prom_lock, flags);
218
219	return prop;
220}
221
222/* Return the first property name for node 'node'. */
223/* buffer is unused argument, but as v9 uses it, we need to have the same interface */
224char * prom_firstprop(int node, char *bufer)
225{
226	if (node == 0 || node == -1)
227		return "";
228
229	return __prom_nextprop(node, "");
230}
231
232/* Return the property type string after property type 'oprop'
233 * at node 'node' .  Returns empty string if no more
234 * property types for this node.
235 */
236char * prom_nextprop(int node, char *oprop, char *buffer)
237{
238	if (node == 0 || node == -1)
239		return "";
240
241	return __prom_nextprop(node, oprop);
242}
243
244int prom_finddevice(char *name)
245{
246	char nbuf[128];
247	char *s = name, *d;
248	int node = prom_root_node, node2;
249	unsigned int which_io, phys_addr;
250	struct linux_prom_registers reg[PROMREG_MAX];
251
252	while (*s++) {
253		if (!*s) return node; /* path '.../' is legal */
254		node = prom_getchild(node);
255
256		for (d = nbuf; *s != 0 && *s != '@' && *s != '/';)
257			*d++ = *s++;
258		*d = 0;
259
260		node = prom_searchsiblings(node, nbuf);
261		if (!node)
262			return 0;
263
264		if (*s == '@') {
265			if (isxdigit(s[1]) && s[2] == ',') {
266				which_io = simple_strtoul(s+1, NULL, 16);
267				phys_addr = simple_strtoul(s+3, &d, 16);
268				if (d != s + 3 && (!*d || *d == '/')
269				    && d <= s + 3 + 8) {
270					node2 = node;
271					while (node2 && node2 != -1) {
272						if (prom_getproperty (node2, "reg", (char *)reg, sizeof (reg)) > 0) {
273							if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) {
274								node = node2;
275								break;
276							}
277						}
278						node2 = prom_getsibling(node2);
279						if (!node2 || node2 == -1)
280							break;
281						node2 = prom_searchsiblings(prom_getsibling(node2), nbuf);
282					}
283				}
284			}
285			while (*s != 0 && *s != '/') s++;
286		}
287	}
288	return node;
289}
290
291int prom_node_has_property(int node, char *prop)
292{
293	char *current_property = "";
294
295	do {
296		current_property = prom_nextprop(node, current_property, NULL);
297		if(!strcmp(current_property, prop))
298		   return 1;
299	} while (*current_property);
300	return 0;
301}
302
303/* Set property 'pname' at node 'node' to value 'value' which has a length
304 * of 'size' bytes.  Return the number of bytes the prom accepted.
305 */
306int prom_setprop(int node, char *pname, char *value, int size)
307{
308	unsigned long flags;
309	int ret;
310
311	if(size == 0) return 0;
312	if((pname == 0) || (value == 0)) return 0;
313	spin_lock_irqsave(&prom_lock, flags);
314	ret = prom_nodeops->no_setprop(node, pname, value, size);
315	restore_current();
316	spin_unlock_irqrestore(&prom_lock, flags);
317	return ret;
318}
319
320int prom_inst2pkg(int inst)
321{
322	int node;
323	unsigned long flags;
324
325	spin_lock_irqsave(&prom_lock, flags);
326	node = (*romvec->pv_v2devops.v2_inst2pkg)(inst);
327	restore_current();
328	spin_unlock_irqrestore(&prom_lock, flags);
329	if (node == -1) return 0;
330	return node;
331}
332
333int prom_pathtoinode(char *path)
334{
335	int node, inst;
336
337	inst = prom_devopen (path);
338	if (inst == -1) return 0;
339	node = prom_inst2pkg (inst);
340	prom_devclose (inst);
341	if (node == -1) return 0;
342	return node;
343}
344