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