xref: /openbmc/linux/drivers/of/pdt.c (revision ff4a7481c3898ffc3cc271d6aca431d190c37247)
1 // SPDX-License-Identifier: GPL-2.0+
2 /* pdt.c: OF PROM device tree support code.
3  *
4  * Paul Mackerras	August 1996.
5  * Copyright (C) 1996-2005 Paul Mackerras.
6  *
7  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8  *    {engebret|bergner}@us.ibm.com
9  *
10  *  Adapted for sparc by David S. Miller davem@davemloft.net
11  *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/errno.h>
17 #include <linux/mutex.h>
18 #include <linux/slab.h>
19 #include <linux/of.h>
20 #include <linux/of_pdt.h>
21 
22 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
23 
24 void __initdata (*of_pdt_build_more)(struct device_node *dp);
25 
26 #if defined(CONFIG_SPARC)
27 unsigned int of_pdt_unique_id __initdata;
28 
29 #define of_pdt_incr_unique_id(p) do { \
30 	(p)->unique_id = of_pdt_unique_id++; \
31 } while (0)
32 
33 static char * __init of_pdt_build_full_name(struct device_node *dp)
34 {
35 	return build_path_component(dp);
36 }
37 
38 #else /* CONFIG_SPARC */
39 
40 static inline void of_pdt_incr_unique_id(void *p) { }
41 static inline void irq_trans_init(struct device_node *dp) { }
42 
43 static char * __init of_pdt_build_full_name(struct device_node *dp)
44 {
45 	static int failsafe_id = 0; /* for generating unique names on failure */
46 	const char *name;
47 	char path[256];
48 	char *buf;
49 	int len;
50 
51 	if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
52 		name = kbasename(path);
53 		buf = prom_early_alloc(strlen(name) + 1);
54 		strcpy(buf, name);
55 		return buf;
56 	}
57 
58 	name = of_get_property(dp, "name", &len);
59 	buf = prom_early_alloc(len + 16);
60 	sprintf(buf, "%s@unknown%i", name, failsafe_id++);
61 	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
62 	return buf;
63 }
64 
65 #endif /* !CONFIG_SPARC */
66 
67 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
68 					       char *special_name,
69 					       void *special_val,
70 					       int special_len)
71 {
72 	static struct property *tmp = NULL;
73 	struct property *p;
74 	int err;
75 
76 	if (tmp) {
77 		p = tmp;
78 		memset(p, 0, sizeof(*p) + 32);
79 		tmp = NULL;
80 	} else {
81 		p = prom_early_alloc(sizeof(struct property) + 32);
82 		of_pdt_incr_unique_id(p);
83 	}
84 
85 	p->name = (char *) (p + 1);
86 	if (special_name) {
87 		strcpy(p->name, special_name);
88 		p->length = special_len;
89 		p->value = prom_early_alloc(special_len);
90 		memcpy(p->value, special_val, special_len);
91 	} else {
92 		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
93 		if (err) {
94 			tmp = p;
95 			return NULL;
96 		}
97 		p->length = of_pdt_prom_ops->getproplen(node, p->name);
98 		if (p->length <= 0) {
99 			p->length = 0;
100 		} else {
101 			int len;
102 
103 			p->value = prom_early_alloc(p->length + 1);
104 			len = of_pdt_prom_ops->getproperty(node, p->name,
105 					p->value, p->length);
106 			if (len <= 0)
107 				p->length = 0;
108 			((unsigned char *)p->value)[p->length] = '\0';
109 		}
110 	}
111 	return p;
112 }
113 
114 static struct property * __init of_pdt_build_prop_list(phandle node)
115 {
116 	struct property *head, *tail;
117 
118 	head = tail = of_pdt_build_one_prop(node, NULL,
119 				     ".node", &node, sizeof(node));
120 
121 	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
122 	tail = tail->next;
123 	while(tail) {
124 		tail->next = of_pdt_build_one_prop(node, tail->name,
125 					    NULL, NULL, 0);
126 		tail = tail->next;
127 	}
128 
129 	return head;
130 }
131 
132 static char * __init of_pdt_get_one_property(phandle node, const char *name)
133 {
134 	char *buf = "<NULL>";
135 	int len;
136 
137 	len = of_pdt_prom_ops->getproplen(node, name);
138 	if (len > 0) {
139 		buf = prom_early_alloc(len);
140 		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
141 	}
142 
143 	return buf;
144 }
145 
146 static struct device_node * __init of_pdt_create_node(phandle node,
147 						    struct device_node *parent)
148 {
149 	struct device_node *dp;
150 
151 	if (!node)
152 		return NULL;
153 
154 	dp = prom_early_alloc(sizeof(*dp));
155 	of_node_init(dp);
156 	of_pdt_incr_unique_id(dp);
157 	dp->parent = parent;
158 
159 	dp->name = of_pdt_get_one_property(node, "name");
160 	dp->type = of_pdt_get_one_property(node, "device_type");
161 	dp->phandle = node;
162 
163 	dp->properties = of_pdt_build_prop_list(node);
164 
165 	dp->full_name = of_pdt_build_full_name(dp);
166 
167 	irq_trans_init(dp);
168 
169 	return dp;
170 }
171 
172 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
173 						   phandle node)
174 {
175 	struct device_node *ret = NULL, *prev_sibling = NULL;
176 	struct device_node *dp;
177 
178 	while (1) {
179 		dp = of_pdt_create_node(node, parent);
180 		if (!dp)
181 			break;
182 
183 		if (prev_sibling)
184 			prev_sibling->sibling = dp;
185 
186 		if (!ret)
187 			ret = dp;
188 		prev_sibling = dp;
189 
190 		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
191 
192 		if (of_pdt_build_more)
193 			of_pdt_build_more(dp);
194 
195 		node = of_pdt_prom_ops->getsibling(node);
196 	}
197 
198 	return ret;
199 }
200 
201 static void * __init kernel_tree_alloc(u64 size, u64 align)
202 {
203 	return prom_early_alloc(size);
204 }
205 
206 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
207 {
208 	BUG_ON(!ops);
209 	of_pdt_prom_ops = ops;
210 
211 	of_root = of_pdt_create_node(root_node, NULL);
212 	of_root->full_name = "/";
213 
214 	of_root->child = of_pdt_build_tree(of_root,
215 				of_pdt_prom_ops->getchild(of_root->phandle));
216 
217 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
218 	of_alias_scan(kernel_tree_alloc);
219 }
220