xref: /linux/drivers/of/pdt.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 
26 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
27 
28 void __initdata (*of_pdt_build_more)(struct device_node *dp);
29 
30 #if defined(CONFIG_SPARC)
31 unsigned int of_pdt_unique_id __initdata;
32 
33 #define of_pdt_incr_unique_id(p) do { \
34 	(p)->unique_id = of_pdt_unique_id++; \
35 } while (0)
36 
37 static char * __init of_pdt_build_full_name(struct device_node *dp)
38 {
39 	int len, ourlen, plen;
40 	char *n;
41 
42 	dp->path_component_name = build_path_component(dp);
43 
44 	plen = strlen(dp->parent->full_name);
45 	ourlen = strlen(dp->path_component_name);
46 	len = ourlen + plen + 2;
47 
48 	n = prom_early_alloc(len);
49 	strcpy(n, dp->parent->full_name);
50 	if (!of_node_is_root(dp->parent)) {
51 		strcpy(n + plen, "/");
52 		plen++;
53 	}
54 	strcpy(n + plen, dp->path_component_name);
55 
56 	return n;
57 }
58 
59 #else /* CONFIG_SPARC */
60 
61 static inline void of_pdt_incr_unique_id(void *p) { }
62 static inline void irq_trans_init(struct device_node *dp) { }
63 
64 static char * __init of_pdt_build_full_name(struct device_node *dp)
65 {
66 	static int failsafe_id = 0; /* for generating unique names on failure */
67 	char *buf;
68 	int len;
69 
70 	if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
71 		goto failsafe;
72 
73 	buf = prom_early_alloc(len + 1);
74 	if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
75 		goto failsafe;
76 	return buf;
77 
78  failsafe:
79 	buf = prom_early_alloc(strlen(dp->parent->full_name) +
80 			       strlen(dp->name) + 16);
81 	sprintf(buf, "%s/%s@unknown%i",
82 		of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
83 		dp->name, failsafe_id++);
84 	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
85 	return buf;
86 }
87 
88 #endif /* !CONFIG_SPARC */
89 
90 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
91 					       char *special_name,
92 					       void *special_val,
93 					       int special_len)
94 {
95 	static struct property *tmp = NULL;
96 	struct property *p;
97 	int err;
98 
99 	if (tmp) {
100 		p = tmp;
101 		memset(p, 0, sizeof(*p) + 32);
102 		tmp = NULL;
103 	} else {
104 		p = prom_early_alloc(sizeof(struct property) + 32);
105 		of_pdt_incr_unique_id(p);
106 	}
107 
108 	p->name = (char *) (p + 1);
109 	if (special_name) {
110 		strcpy(p->name, special_name);
111 		p->length = special_len;
112 		p->value = prom_early_alloc(special_len);
113 		memcpy(p->value, special_val, special_len);
114 	} else {
115 		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
116 		if (err) {
117 			tmp = p;
118 			return NULL;
119 		}
120 		p->length = of_pdt_prom_ops->getproplen(node, p->name);
121 		if (p->length <= 0) {
122 			p->length = 0;
123 		} else {
124 			int len;
125 
126 			p->value = prom_early_alloc(p->length + 1);
127 			len = of_pdt_prom_ops->getproperty(node, p->name,
128 					p->value, p->length);
129 			if (len <= 0)
130 				p->length = 0;
131 			((unsigned char *)p->value)[p->length] = '\0';
132 		}
133 	}
134 	return p;
135 }
136 
137 static struct property * __init of_pdt_build_prop_list(phandle node)
138 {
139 	struct property *head, *tail;
140 
141 	head = tail = of_pdt_build_one_prop(node, NULL,
142 				     ".node", &node, sizeof(node));
143 
144 	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
145 	tail = tail->next;
146 	while(tail) {
147 		tail->next = of_pdt_build_one_prop(node, tail->name,
148 					    NULL, NULL, 0);
149 		tail = tail->next;
150 	}
151 
152 	return head;
153 }
154 
155 static char * __init of_pdt_get_one_property(phandle node, const char *name)
156 {
157 	char *buf = "<NULL>";
158 	int len;
159 
160 	len = of_pdt_prom_ops->getproplen(node, name);
161 	if (len > 0) {
162 		buf = prom_early_alloc(len);
163 		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
164 	}
165 
166 	return buf;
167 }
168 
169 static struct device_node * __init of_pdt_create_node(phandle node,
170 						    struct device_node *parent)
171 {
172 	struct device_node *dp;
173 
174 	if (!node)
175 		return NULL;
176 
177 	dp = prom_early_alloc(sizeof(*dp));
178 	of_node_init(dp);
179 	of_pdt_incr_unique_id(dp);
180 	dp->parent = parent;
181 
182 	dp->name = of_pdt_get_one_property(node, "name");
183 	dp->type = of_pdt_get_one_property(node, "device_type");
184 	dp->phandle = node;
185 
186 	dp->properties = of_pdt_build_prop_list(node);
187 
188 	irq_trans_init(dp);
189 
190 	return dp;
191 }
192 
193 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
194 						   phandle node)
195 {
196 	struct device_node *ret = NULL, *prev_sibling = NULL;
197 	struct device_node *dp;
198 
199 	while (1) {
200 		dp = of_pdt_create_node(node, parent);
201 		if (!dp)
202 			break;
203 
204 		if (prev_sibling)
205 			prev_sibling->sibling = dp;
206 
207 		if (!ret)
208 			ret = dp;
209 		prev_sibling = dp;
210 
211 		dp->full_name = of_pdt_build_full_name(dp);
212 
213 		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
214 
215 		if (of_pdt_build_more)
216 			of_pdt_build_more(dp);
217 
218 		node = of_pdt_prom_ops->getsibling(node);
219 	}
220 
221 	return ret;
222 }
223 
224 static void * __init kernel_tree_alloc(u64 size, u64 align)
225 {
226 	return prom_early_alloc(size);
227 }
228 
229 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
230 {
231 	BUG_ON(!ops);
232 	of_pdt_prom_ops = ops;
233 
234 	of_root = of_pdt_create_node(root_node, NULL);
235 #if defined(CONFIG_SPARC)
236 	of_root->path_component_name = "";
237 #endif
238 	of_root->full_name = "/";
239 
240 	of_root->child = of_pdt_build_tree(of_root,
241 				of_pdt_prom_ops->getchild(of_root->phandle));
242 
243 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
244 	of_alias_scan(kernel_tree_alloc);
245 }
246