xref: /openbmc/linux/drivers/of/pdt.c (revision 8ac727c1)
1 /* pdt.c: OF PROM device tree support code.
2  *
3  * Paul Mackerras	August 1996.
4  * Copyright (C) 1996-2005 Paul Mackerras.
5  *
6  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
7  *    {engebret|bergner}@us.ibm.com
8  *
9  *  Adapted for sparc by David S. Miller davem@davemloft.net
10  *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
11  *
12  *      This program is free software; you can redistribute it and/or
13  *      modify it under the terms of the GNU General Public License
14  *      as published by the Free Software Foundation; either version
15  *      2 of the License, or (at your option) any later version.
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/errno.h>
21 #include <linux/mutex.h>
22 #include <linux/slab.h>
23 #include <linux/of.h>
24 #include <linux/of_pdt.h>
25 #include <asm/prom.h>
26 
27 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
28 
29 void __initdata (*of_pdt_build_more)(struct device_node *dp,
30 		struct device_node ***nextp);
31 
32 #if defined(CONFIG_SPARC)
33 unsigned int of_pdt_unique_id __initdata;
34 
35 #define of_pdt_incr_unique_id(p) do { \
36 	(p)->unique_id = of_pdt_unique_id++; \
37 } while (0)
38 
39 static char * __init of_pdt_build_full_name(struct device_node *dp)
40 {
41 	int len, ourlen, plen;
42 	char *n;
43 
44 	dp->path_component_name = build_path_component(dp);
45 
46 	plen = strlen(dp->parent->full_name);
47 	ourlen = strlen(dp->path_component_name);
48 	len = ourlen + plen + 2;
49 
50 	n = prom_early_alloc(len);
51 	strcpy(n, dp->parent->full_name);
52 	if (!of_node_is_root(dp->parent)) {
53 		strcpy(n + plen, "/");
54 		plen++;
55 	}
56 	strcpy(n + plen, dp->path_component_name);
57 
58 	return n;
59 }
60 
61 #else /* CONFIG_SPARC */
62 
63 static inline void of_pdt_incr_unique_id(void *p) { }
64 static inline void irq_trans_init(struct device_node *dp) { }
65 
66 static char * __init of_pdt_build_full_name(struct device_node *dp)
67 {
68 	static int failsafe_id = 0; /* for generating unique names on failure */
69 	char *buf;
70 	int len;
71 
72 	if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
73 		goto failsafe;
74 
75 	buf = prom_early_alloc(len + 1);
76 	if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
77 		goto failsafe;
78 	return buf;
79 
80  failsafe:
81 	buf = prom_early_alloc(strlen(dp->parent->full_name) +
82 			       strlen(dp->name) + 16);
83 	sprintf(buf, "%s/%s@unknown%i",
84 		of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
85 		dp->name, failsafe_id++);
86 	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
87 	return buf;
88 }
89 
90 #endif /* !CONFIG_SPARC */
91 
92 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
93 					       char *special_name,
94 					       void *special_val,
95 					       int special_len)
96 {
97 	static struct property *tmp = NULL;
98 	struct property *p;
99 	int err;
100 
101 	if (tmp) {
102 		p = tmp;
103 		memset(p, 0, sizeof(*p) + 32);
104 		tmp = NULL;
105 	} else {
106 		p = prom_early_alloc(sizeof(struct property) + 32);
107 		of_pdt_incr_unique_id(p);
108 	}
109 
110 	p->name = (char *) (p + 1);
111 	if (special_name) {
112 		strcpy(p->name, special_name);
113 		p->length = special_len;
114 		p->value = prom_early_alloc(special_len);
115 		memcpy(p->value, special_val, special_len);
116 	} else {
117 		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
118 		if (err) {
119 			tmp = p;
120 			return NULL;
121 		}
122 		p->length = of_pdt_prom_ops->getproplen(node, p->name);
123 		if (p->length <= 0) {
124 			p->length = 0;
125 		} else {
126 			int len;
127 
128 			p->value = prom_early_alloc(p->length + 1);
129 			len = of_pdt_prom_ops->getproperty(node, p->name,
130 					p->value, p->length);
131 			if (len <= 0)
132 				p->length = 0;
133 			((unsigned char *)p->value)[p->length] = '\0';
134 		}
135 	}
136 	return p;
137 }
138 
139 static struct property * __init of_pdt_build_prop_list(phandle node)
140 {
141 	struct property *head, *tail;
142 
143 	head = tail = of_pdt_build_one_prop(node, NULL,
144 				     ".node", &node, sizeof(node));
145 
146 	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
147 	tail = tail->next;
148 	while(tail) {
149 		tail->next = of_pdt_build_one_prop(node, tail->name,
150 					    NULL, NULL, 0);
151 		tail = tail->next;
152 	}
153 
154 	return head;
155 }
156 
157 static char * __init of_pdt_get_one_property(phandle node, const char *name)
158 {
159 	char *buf = "<NULL>";
160 	int len;
161 
162 	len = of_pdt_prom_ops->getproplen(node, name);
163 	if (len > 0) {
164 		buf = prom_early_alloc(len);
165 		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
166 	}
167 
168 	return buf;
169 }
170 
171 static struct device_node * __init of_pdt_create_node(phandle node,
172 						    struct device_node *parent)
173 {
174 	struct device_node *dp;
175 
176 	if (!node)
177 		return NULL;
178 
179 	dp = prom_early_alloc(sizeof(*dp));
180 	of_pdt_incr_unique_id(dp);
181 	dp->parent = parent;
182 
183 	kref_init(&dp->kref);
184 
185 	dp->name = of_pdt_get_one_property(node, "name");
186 	dp->type = of_pdt_get_one_property(node, "device_type");
187 	dp->phandle = node;
188 
189 	dp->properties = of_pdt_build_prop_list(node);
190 
191 	irq_trans_init(dp);
192 
193 	return dp;
194 }
195 
196 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
197 						   phandle node,
198 						   struct device_node ***nextp)
199 {
200 	struct device_node *ret = NULL, *prev_sibling = NULL;
201 	struct device_node *dp;
202 
203 	while (1) {
204 		dp = of_pdt_create_node(node, parent);
205 		if (!dp)
206 			break;
207 
208 		if (prev_sibling)
209 			prev_sibling->sibling = dp;
210 
211 		if (!ret)
212 			ret = dp;
213 		prev_sibling = dp;
214 
215 		*(*nextp) = dp;
216 		*nextp = &dp->allnext;
217 
218 		dp->full_name = of_pdt_build_full_name(dp);
219 
220 		dp->child = of_pdt_build_tree(dp,
221 				of_pdt_prom_ops->getchild(node), nextp);
222 
223 		if (of_pdt_build_more)
224 			of_pdt_build_more(dp, nextp);
225 
226 		node = of_pdt_prom_ops->getsibling(node);
227 	}
228 
229 	return ret;
230 }
231 
232 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
233 {
234 	struct device_node **nextp;
235 
236 	BUG_ON(!ops);
237 	of_pdt_prom_ops = ops;
238 
239 	allnodes = of_pdt_create_node(root_node, NULL);
240 #if defined(CONFIG_SPARC)
241 	allnodes->path_component_name = "";
242 #endif
243 	allnodes->full_name = "/";
244 
245 	nextp = &allnodes->allnext;
246 	allnodes->child = of_pdt_build_tree(allnodes,
247 			of_pdt_prom_ops->getchild(allnodes->phandle), &nextp);
248 }
249