1 // SPDX-License-Identifier: GPL-2.0+
2 /* pdt.c: OF PROM device tree support code.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc by David S. Miller davem@davemloft.net
11 * Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
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>
20 #include <linux/of_pdt.h>
22 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
24 void __initdata (*of_pdt_build_more)(struct device_node *dp);
26 #if defined(CONFIG_SPARC)
27 unsigned int of_pdt_unique_id __initdata;
29 #define of_pdt_incr_unique_id(p) do { \
30 (p)->unique_id = of_pdt_unique_id++; \
33 static char * __init of_pdt_build_full_name(struct device_node *dp)
35 return build_path_component(dp);
38 #else /* CONFIG_SPARC */
40 static inline void of_pdt_incr_unique_id(void *p) { }
41 static inline void irq_trans_init(struct device_node *dp) { }
43 static char * __init of_pdt_build_full_name(struct device_node *dp)
45 static int failsafe_id = 0; /* for generating unique names on failure */
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);
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);
65 #endif /* !CONFIG_SPARC */
67 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
72 static struct property *tmp = NULL;
78 memset(p, 0, sizeof(*p) + 32);
81 p = prom_early_alloc(sizeof(struct property) + 32);
82 of_pdt_incr_unique_id(p);
85 p->name = (char *) (p + 1);
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);
92 err = of_pdt_prom_ops->nextprop(node, prev, p->name);
97 p->length = of_pdt_prom_ops->getproplen(node, p->name);
103 p->value = prom_early_alloc(p->length + 1);
104 len = of_pdt_prom_ops->getproperty(node, p->name,
105 p->value, p->length);
108 ((unsigned char *)p->value)[p->length] = '\0';
114 static struct property * __init of_pdt_build_prop_list(phandle node)
116 struct property *head, *tail;
118 head = tail = of_pdt_build_one_prop(node, NULL,
119 ".node", &node, sizeof(node));
121 tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
124 tail->next = of_pdt_build_one_prop(node, tail->name,
132 static char * __init of_pdt_get_one_property(phandle node, const char *name)
134 char *buf = "<NULL>";
137 len = of_pdt_prom_ops->getproplen(node, name);
139 buf = prom_early_alloc(len);
140 len = of_pdt_prom_ops->getproperty(node, name, buf, len);
146 static struct device_node * __init of_pdt_create_node(phandle node,
147 struct device_node *parent)
149 struct device_node *dp;
154 dp = prom_early_alloc(sizeof(*dp));
156 of_pdt_incr_unique_id(dp);
159 dp->name = of_pdt_get_one_property(node, "name");
160 dp->type = of_pdt_get_one_property(node, "device_type");
163 dp->properties = of_pdt_build_prop_list(node);
165 dp->full_name = of_pdt_build_full_name(dp);
172 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
175 struct device_node *ret = NULL, *prev_sibling = NULL;
176 struct device_node *dp;
179 dp = of_pdt_create_node(node, parent);
184 prev_sibling->sibling = dp;
190 dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
192 if (of_pdt_build_more)
193 of_pdt_build_more(dp);
195 node = of_pdt_prom_ops->getsibling(node);
201 static void * __init kernel_tree_alloc(u64 size, u64 align)
203 return prom_early_alloc(size);
206 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
209 of_pdt_prom_ops = ops;
211 of_root = of_pdt_create_node(root_node, NULL);
212 of_root->full_name = "/";
214 of_root->child = of_pdt_build_tree(of_root,
215 of_pdt_prom_ops->getchild(of_root->phandle));
217 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
218 of_alias_scan(kernel_tree_alloc);