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1 /* prom_common.c: OF device tree support common 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  *
11  *      This program is free software; you can redistribute it and/or
12  *      modify it under the terms of the GNU General Public License
13  *      as published by the Free Software Foundation; either version
14  *      2 of the License, or (at your option) any later version.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/of.h>
23 #include <asm/prom.h>
24 #include <asm/oplib.h>
25 
26 #include "prom.h"
27 
28 struct device_node *of_console_device;
29 EXPORT_SYMBOL(of_console_device);
30 
31 char *of_console_path;
32 EXPORT_SYMBOL(of_console_path);
33 
34 char *of_console_options;
35 EXPORT_SYMBOL(of_console_options);
36 
of_find_node_by_phandle(phandle handle)37 struct device_node *of_find_node_by_phandle(phandle handle)
38 {
39 	struct device_node *np;
40 
41 	for (np = allnodes; np; np = np->allnext)
42 		if (np->node == handle)
43 			break;
44 
45 	return np;
46 }
47 EXPORT_SYMBOL(of_find_node_by_phandle);
48 
of_getintprop_default(struct device_node * np,const char * name,int def)49 int of_getintprop_default(struct device_node *np, const char *name, int def)
50 {
51 	struct property *prop;
52 	int len;
53 
54 	prop = of_find_property(np, name, &len);
55 	if (!prop || len != 4)
56 		return def;
57 
58 	return *(int *) prop->value;
59 }
60 EXPORT_SYMBOL(of_getintprop_default);
61 
62 DEFINE_MUTEX(of_set_property_mutex);
63 EXPORT_SYMBOL(of_set_property_mutex);
64 
of_set_property(struct device_node * dp,const char * name,void * val,int len)65 int of_set_property(struct device_node *dp, const char *name, void *val, int len)
66 {
67 	struct property **prevp;
68 	void *new_val;
69 	int err;
70 
71 	new_val = kmalloc(len, GFP_KERNEL);
72 	if (!new_val)
73 		return -ENOMEM;
74 
75 	memcpy(new_val, val, len);
76 
77 	err = -ENODEV;
78 
79 	write_lock(&devtree_lock);
80 	prevp = &dp->properties;
81 	while (*prevp) {
82 		struct property *prop = *prevp;
83 
84 		if (!strcasecmp(prop->name, name)) {
85 			void *old_val = prop->value;
86 			int ret;
87 
88 			mutex_lock(&of_set_property_mutex);
89 			ret = prom_setprop(dp->node, name, val, len);
90 			mutex_unlock(&of_set_property_mutex);
91 
92 			err = -EINVAL;
93 			if (ret >= 0) {
94 				prop->value = new_val;
95 				prop->length = len;
96 
97 				if (OF_IS_DYNAMIC(prop))
98 					kfree(old_val);
99 
100 				OF_MARK_DYNAMIC(prop);
101 
102 				err = 0;
103 			}
104 			break;
105 		}
106 		prevp = &(*prevp)->next;
107 	}
108 	write_unlock(&devtree_lock);
109 
110 	/* XXX Upate procfs if necessary... */
111 
112 	return err;
113 }
114 EXPORT_SYMBOL(of_set_property);
115 
of_find_in_proplist(const char * list,const char * match,int len)116 int of_find_in_proplist(const char *list, const char *match, int len)
117 {
118 	while (len > 0) {
119 		int l;
120 
121 		if (!strcmp(list, match))
122 			return 1;
123 		l = strlen(list) + 1;
124 		list += l;
125 		len -= l;
126 	}
127 	return 0;
128 }
129 EXPORT_SYMBOL(of_find_in_proplist);
130 
131 unsigned int prom_unique_id;
132 
build_one_prop(phandle node,char * prev,char * special_name,void * special_val,int special_len)133 static struct property * __init build_one_prop(phandle node, char *prev,
134 					       char *special_name,
135 					       void *special_val,
136 					       int special_len)
137 {
138 	static struct property *tmp = NULL;
139 	struct property *p;
140 	const char *name;
141 
142 	if (tmp) {
143 		p = tmp;
144 		memset(p, 0, sizeof(*p) + 32);
145 		tmp = NULL;
146 	} else {
147 		p = prom_early_alloc(sizeof(struct property) + 32);
148 		p->unique_id = prom_unique_id++;
149 	}
150 
151 	p->name = (char *) (p + 1);
152 	if (special_name) {
153 		strcpy(p->name, special_name);
154 		p->length = special_len;
155 		p->value = prom_early_alloc(special_len);
156 		memcpy(p->value, special_val, special_len);
157 	} else {
158 		if (prev == NULL) {
159 			name = prom_firstprop(node, p->name);
160 		} else {
161 			name = prom_nextprop(node, prev, p->name);
162 		}
163 
164 		if (strlen(name) == 0) {
165 			tmp = p;
166 			return NULL;
167 		}
168 #ifdef CONFIG_SPARC32
169 		strcpy(p->name, name);
170 #endif
171 		p->length = prom_getproplen(node, p->name);
172 		if (p->length <= 0) {
173 			p->length = 0;
174 		} else {
175 			int len;
176 
177 			p->value = prom_early_alloc(p->length + 1);
178 			len = prom_getproperty(node, p->name, p->value,
179 					       p->length);
180 			if (len <= 0)
181 				p->length = 0;
182 			((unsigned char *)p->value)[p->length] = '\0';
183 		}
184 	}
185 	return p;
186 }
187 
build_prop_list(phandle node)188 static struct property * __init build_prop_list(phandle node)
189 {
190 	struct property *head, *tail;
191 
192 	head = tail = build_one_prop(node, NULL,
193 				     ".node", &node, sizeof(node));
194 
195 	tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
196 	tail = tail->next;
197 	while(tail) {
198 		tail->next = build_one_prop(node, tail->name,
199 					    NULL, NULL, 0);
200 		tail = tail->next;
201 	}
202 
203 	return head;
204 }
205 
get_one_property(phandle node,const char * name)206 static char * __init get_one_property(phandle node, const char *name)
207 {
208 	char *buf = "<NULL>";
209 	int len;
210 
211 	len = prom_getproplen(node, name);
212 	if (len > 0) {
213 		buf = prom_early_alloc(len);
214 		len = prom_getproperty(node, name, buf, len);
215 	}
216 
217 	return buf;
218 }
219 
prom_create_node(phandle node,struct device_node * parent)220 static struct device_node * __init prom_create_node(phandle node,
221 						    struct device_node *parent)
222 {
223 	struct device_node *dp;
224 
225 	if (!node)
226 		return NULL;
227 
228 	dp = prom_early_alloc(sizeof(*dp));
229 	dp->unique_id = prom_unique_id++;
230 	dp->parent = parent;
231 
232 	kref_init(&dp->kref);
233 
234 	dp->name = get_one_property(node, "name");
235 	dp->type = get_one_property(node, "device_type");
236 	dp->node = node;
237 
238 	dp->properties = build_prop_list(node);
239 
240 	irq_trans_init(dp);
241 
242 	return dp;
243 }
244 
build_full_name(struct device_node * dp)245 static char * __init build_full_name(struct device_node *dp)
246 {
247 	int len, ourlen, plen;
248 	char *n;
249 
250 	plen = strlen(dp->parent->full_name);
251 	ourlen = strlen(dp->path_component_name);
252 	len = ourlen + plen + 2;
253 
254 	n = prom_early_alloc(len);
255 	strcpy(n, dp->parent->full_name);
256 	if (!is_root_node(dp->parent)) {
257 		strcpy(n + plen, "/");
258 		plen++;
259 	}
260 	strcpy(n + plen, dp->path_component_name);
261 
262 	return n;
263 }
264 
prom_build_tree(struct device_node * parent,phandle node,struct device_node *** nextp)265 static struct device_node * __init prom_build_tree(struct device_node *parent,
266 						   phandle node,
267 						   struct device_node ***nextp)
268 {
269 	struct device_node *ret = NULL, *prev_sibling = NULL;
270 	struct device_node *dp;
271 
272 	while (1) {
273 		dp = prom_create_node(node, parent);
274 		if (!dp)
275 			break;
276 
277 		if (prev_sibling)
278 			prev_sibling->sibling = dp;
279 
280 		if (!ret)
281 			ret = dp;
282 		prev_sibling = dp;
283 
284 		*(*nextp) = dp;
285 		*nextp = &dp->allnext;
286 
287 		dp->path_component_name = build_path_component(dp);
288 		dp->full_name = build_full_name(dp);
289 
290 		dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
291 
292 		node = prom_getsibling(node);
293 	}
294 
295 	return ret;
296 }
297 
298 unsigned int prom_early_allocated __initdata;
299 
prom_build_devicetree(void)300 void __init prom_build_devicetree(void)
301 {
302 	struct device_node **nextp;
303 
304 	allnodes = prom_create_node(prom_root_node, NULL);
305 	allnodes->path_component_name = "";
306 	allnodes->full_name = "/";
307 
308 	nextp = &allnodes->allnext;
309 	allnodes->child = prom_build_tree(allnodes,
310 					  prom_getchild(allnodes->node),
311 					  &nextp);
312 	of_console_init();
313 
314 	printk("PROM: Built device tree with %u bytes of memory.\n",
315 	       prom_early_allocated);
316 
317 	of_fill_in_cpu_data();
318 }
319