xref: /openbmc/linux/drivers/of/pdt.c (revision 8ce5f841)
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 #if defined(CONFIG_SPARC)
25 unsigned int of_pdt_unique_id __initdata;
26 
27 #define of_pdt_incr_unique_id(p) do { \
28 	(p)->unique_id = of_pdt_unique_id++; \
29 } while (0)
30 
of_pdt_build_full_name(struct device_node * dp)31 static char * __init of_pdt_build_full_name(struct device_node *dp)
32 {
33 	return build_path_component(dp);
34 }
35 
36 #else /* CONFIG_SPARC */
37 
of_pdt_incr_unique_id(void * p)38 static inline void of_pdt_incr_unique_id(void *p) { }
irq_trans_init(struct device_node * dp)39 static inline void irq_trans_init(struct device_node *dp) { }
40 
of_pdt_build_full_name(struct device_node * dp)41 static char * __init of_pdt_build_full_name(struct device_node *dp)
42 {
43 	static int failsafe_id = 0; /* for generating unique names on failure */
44 	const char *name;
45 	char path[256];
46 	char *buf;
47 	int len;
48 
49 	if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
50 		name = kbasename(path);
51 		buf = prom_early_alloc(strlen(name) + 1);
52 		strcpy(buf, name);
53 		return buf;
54 	}
55 
56 	name = of_get_property(dp, "name", &len);
57 	buf = prom_early_alloc(len + 16);
58 	sprintf(buf, "%s@unknown%i", name, failsafe_id++);
59 	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
60 	return buf;
61 }
62 
63 #endif /* !CONFIG_SPARC */
64 
of_pdt_build_one_prop(phandle node,char * prev,char * special_name,void * special_val,int special_len)65 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
66 					       char *special_name,
67 					       void *special_val,
68 					       int special_len)
69 {
70 	static struct property *tmp = NULL;
71 	struct property *p;
72 	int err;
73 
74 	if (tmp) {
75 		p = tmp;
76 		memset(p, 0, sizeof(*p) + 32);
77 		tmp = NULL;
78 	} else {
79 		p = prom_early_alloc(sizeof(struct property) + 32);
80 		of_pdt_incr_unique_id(p);
81 	}
82 
83 	p->name = (char *) (p + 1);
84 	if (special_name) {
85 		strcpy(p->name, special_name);
86 		p->length = special_len;
87 		p->value = prom_early_alloc(special_len);
88 		memcpy(p->value, special_val, special_len);
89 	} else {
90 		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
91 		if (err) {
92 			tmp = p;
93 			return NULL;
94 		}
95 		p->length = of_pdt_prom_ops->getproplen(node, p->name);
96 		if (p->length <= 0) {
97 			p->length = 0;
98 		} else {
99 			int len;
100 
101 			p->value = prom_early_alloc(p->length + 1);
102 			len = of_pdt_prom_ops->getproperty(node, p->name,
103 					p->value, p->length);
104 			if (len <= 0)
105 				p->length = 0;
106 			((unsigned char *)p->value)[p->length] = '\0';
107 		}
108 	}
109 	return p;
110 }
111 
of_pdt_build_prop_list(phandle node)112 static struct property * __init of_pdt_build_prop_list(phandle node)
113 {
114 	struct property *head, *tail;
115 
116 	head = tail = of_pdt_build_one_prop(node, NULL,
117 				     ".node", &node, sizeof(node));
118 
119 	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
120 	tail = tail->next;
121 	while(tail) {
122 		tail->next = of_pdt_build_one_prop(node, tail->name,
123 					    NULL, NULL, 0);
124 		tail = tail->next;
125 	}
126 
127 	return head;
128 }
129 
of_pdt_get_one_property(phandle node,const char * name)130 static char * __init of_pdt_get_one_property(phandle node, const char *name)
131 {
132 	char *buf = "<NULL>";
133 	int len;
134 
135 	len = of_pdt_prom_ops->getproplen(node, name);
136 	if (len > 0) {
137 		buf = prom_early_alloc(len);
138 		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
139 	}
140 
141 	return buf;
142 }
143 
of_pdt_create_node(phandle node,struct device_node * parent)144 static struct device_node * __init of_pdt_create_node(phandle node,
145 						    struct device_node *parent)
146 {
147 	struct device_node *dp;
148 
149 	if (!node)
150 		return NULL;
151 
152 	dp = prom_early_alloc(sizeof(*dp));
153 	of_node_init(dp);
154 	of_pdt_incr_unique_id(dp);
155 	dp->parent = parent;
156 
157 	dp->name = of_pdt_get_one_property(node, "name");
158 	dp->phandle = node;
159 
160 	dp->properties = of_pdt_build_prop_list(node);
161 
162 	dp->full_name = of_pdt_build_full_name(dp);
163 
164 	irq_trans_init(dp);
165 
166 	return dp;
167 }
168 
of_pdt_build_tree(struct device_node * parent,phandle node)169 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
170 						   phandle node)
171 {
172 	struct device_node *ret = NULL, *prev_sibling = NULL;
173 	struct device_node *dp;
174 
175 	while (1) {
176 		dp = of_pdt_create_node(node, parent);
177 		if (!dp)
178 			break;
179 
180 		if (prev_sibling)
181 			prev_sibling->sibling = dp;
182 
183 		if (!ret)
184 			ret = dp;
185 		prev_sibling = dp;
186 
187 		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
188 
189 		node = of_pdt_prom_ops->getsibling(node);
190 	}
191 
192 	return ret;
193 }
194 
kernel_tree_alloc(u64 size,u64 align)195 static void * __init kernel_tree_alloc(u64 size, u64 align)
196 {
197 	return prom_early_alloc(size);
198 }
199 
of_pdt_build_devicetree(phandle root_node,struct of_pdt_ops * ops)200 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
201 {
202 	BUG_ON(!ops);
203 	of_pdt_prom_ops = ops;
204 
205 	of_root = of_pdt_create_node(root_node, NULL);
206 	of_root->full_name = "/";
207 
208 	of_root->child = of_pdt_build_tree(of_root,
209 				of_pdt_prom_ops->getchild(of_root->phandle));
210 
211 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
212 	of_alias_scan(kernel_tree_alloc);
213 }
214