xref: /openbmc/linux/drivers/of/pdt.c (revision 089a49b6)
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 		struct device_node ***nextp);
30 
31 #if defined(CONFIG_SPARC)
32 unsigned int of_pdt_unique_id __initdata;
33 
34 #define of_pdt_incr_unique_id(p) do { \
35 	(p)->unique_id = of_pdt_unique_id++; \
36 } while (0)
37 
38 static char * __init of_pdt_build_full_name(struct device_node *dp)
39 {
40 	int len, ourlen, plen;
41 	char *n;
42 
43 	dp->path_component_name = build_path_component(dp);
44 
45 	plen = strlen(dp->parent->full_name);
46 	ourlen = strlen(dp->path_component_name);
47 	len = ourlen + plen + 2;
48 
49 	n = prom_early_alloc(len);
50 	strcpy(n, dp->parent->full_name);
51 	if (!of_node_is_root(dp->parent)) {
52 		strcpy(n + plen, "/");
53 		plen++;
54 	}
55 	strcpy(n + plen, dp->path_component_name);
56 
57 	return n;
58 }
59 
60 #else /* CONFIG_SPARC */
61 
62 static inline void of_pdt_incr_unique_id(void *p) { }
63 static inline void irq_trans_init(struct device_node *dp) { }
64 
65 static char * __init of_pdt_build_full_name(struct device_node *dp)
66 {
67 	static int failsafe_id = 0; /* for generating unique names on failure */
68 	char *buf;
69 	int len;
70 
71 	if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
72 		goto failsafe;
73 
74 	buf = prom_early_alloc(len + 1);
75 	if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
76 		goto failsafe;
77 	return buf;
78 
79  failsafe:
80 	buf = prom_early_alloc(strlen(dp->parent->full_name) +
81 			       strlen(dp->name) + 16);
82 	sprintf(buf, "%s/%s@unknown%i",
83 		of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
84 		dp->name, failsafe_id++);
85 	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
86 	return buf;
87 }
88 
89 #endif /* !CONFIG_SPARC */
90 
91 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
92 					       char *special_name,
93 					       void *special_val,
94 					       int special_len)
95 {
96 	static struct property *tmp = NULL;
97 	struct property *p;
98 	int err;
99 
100 	if (tmp) {
101 		p = tmp;
102 		memset(p, 0, sizeof(*p) + 32);
103 		tmp = NULL;
104 	} else {
105 		p = prom_early_alloc(sizeof(struct property) + 32);
106 		of_pdt_incr_unique_id(p);
107 	}
108 
109 	p->name = (char *) (p + 1);
110 	if (special_name) {
111 		strcpy(p->name, special_name);
112 		p->length = special_len;
113 		p->value = prom_early_alloc(special_len);
114 		memcpy(p->value, special_val, special_len);
115 	} else {
116 		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
117 		if (err) {
118 			tmp = p;
119 			return NULL;
120 		}
121 		p->length = of_pdt_prom_ops->getproplen(node, p->name);
122 		if (p->length <= 0) {
123 			p->length = 0;
124 		} else {
125 			int len;
126 
127 			p->value = prom_early_alloc(p->length + 1);
128 			len = of_pdt_prom_ops->getproperty(node, p->name,
129 					p->value, p->length);
130 			if (len <= 0)
131 				p->length = 0;
132 			((unsigned char *)p->value)[p->length] = '\0';
133 		}
134 	}
135 	return p;
136 }
137 
138 static struct property * __init of_pdt_build_prop_list(phandle node)
139 {
140 	struct property *head, *tail;
141 
142 	head = tail = of_pdt_build_one_prop(node, NULL,
143 				     ".node", &node, sizeof(node));
144 
145 	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
146 	tail = tail->next;
147 	while(tail) {
148 		tail->next = of_pdt_build_one_prop(node, tail->name,
149 					    NULL, NULL, 0);
150 		tail = tail->next;
151 	}
152 
153 	return head;
154 }
155 
156 static char * __init of_pdt_get_one_property(phandle node, const char *name)
157 {
158 	char *buf = "<NULL>";
159 	int len;
160 
161 	len = of_pdt_prom_ops->getproplen(node, name);
162 	if (len > 0) {
163 		buf = prom_early_alloc(len);
164 		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
165 	}
166 
167 	return buf;
168 }
169 
170 static struct device_node * __init of_pdt_create_node(phandle node,
171 						    struct device_node *parent)
172 {
173 	struct device_node *dp;
174 
175 	if (!node)
176 		return NULL;
177 
178 	dp = prom_early_alloc(sizeof(*dp));
179 	of_pdt_incr_unique_id(dp);
180 	dp->parent = parent;
181 
182 	kref_init(&dp->kref);
183 
184 	dp->name = of_pdt_get_one_property(node, "name");
185 	dp->type = of_pdt_get_one_property(node, "device_type");
186 	dp->phandle = node;
187 
188 	dp->properties = of_pdt_build_prop_list(node);
189 
190 	irq_trans_init(dp);
191 
192 	return dp;
193 }
194 
195 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
196 						   phandle node,
197 						   struct device_node ***nextp)
198 {
199 	struct device_node *ret = NULL, *prev_sibling = NULL;
200 	struct device_node *dp;
201 
202 	while (1) {
203 		dp = of_pdt_create_node(node, parent);
204 		if (!dp)
205 			break;
206 
207 		if (prev_sibling)
208 			prev_sibling->sibling = dp;
209 
210 		if (!ret)
211 			ret = dp;
212 		prev_sibling = dp;
213 
214 		*(*nextp) = dp;
215 		*nextp = &dp->allnext;
216 
217 		dp->full_name = of_pdt_build_full_name(dp);
218 
219 		dp->child = of_pdt_build_tree(dp,
220 				of_pdt_prom_ops->getchild(node), nextp);
221 
222 		if (of_pdt_build_more)
223 			of_pdt_build_more(dp, nextp);
224 
225 		node = of_pdt_prom_ops->getsibling(node);
226 	}
227 
228 	return ret;
229 }
230 
231 static void * __init kernel_tree_alloc(u64 size, u64 align)
232 {
233 	return prom_early_alloc(size);
234 }
235 
236 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
237 {
238 	struct device_node **nextp;
239 
240 	BUG_ON(!ops);
241 	of_pdt_prom_ops = ops;
242 
243 	of_allnodes = of_pdt_create_node(root_node, NULL);
244 #if defined(CONFIG_SPARC)
245 	of_allnodes->path_component_name = "";
246 #endif
247 	of_allnodes->full_name = "/";
248 
249 	nextp = &of_allnodes->allnext;
250 	of_allnodes->child = of_pdt_build_tree(of_allnodes,
251 			of_pdt_prom_ops->getchild(of_allnodes->phandle), &nextp);
252 
253 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
254 	of_alias_scan(kernel_tree_alloc);
255 }
256