projects/linux·blob master · refs

215 lines · 4.8 KiB

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 [email protected]
11 * Adapted for multiple architectures by Andres Salomon <[email protected]>
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#include "of_private.h"
23
24static struct of_pdt_ops *of_pdt_prom_ops __initdata;
25
26#if defined(CONFIG_SPARC)
27unsigned 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
33static 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
40static inline void of_pdt_incr_unique_id(void *p) { }
41static inline void irq_trans_init(struct device_node *dp) { }
42
43static 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
67static 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
114static 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
132static 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
146static 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->phandle = node;
161
162 dp->properties = of_pdt_build_prop_list(node);
163
164 dp->full_name = of_pdt_build_full_name(dp);
165
166 irq_trans_init(dp);
167
168 return dp;
169}
170
171static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
172 phandle node)
173{
174 struct device_node *ret = NULL, *prev_sibling = NULL;
175 struct device_node *dp;
176
177 while (1) {
178 dp = of_pdt_create_node(node, parent);
179 if (!dp)
180 break;
181
182 if (prev_sibling)
183 prev_sibling->sibling = dp;
184
185 if (!ret)
186 ret = dp;
187 prev_sibling = dp;
188
189 dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
190
191 node = of_pdt_prom_ops->getsibling(node);
192 }
193
194 return ret;
195}
196
197static void * __init kernel_tree_alloc(u64 size, u64 align)
198{
199 return prom_early_alloc(size);
200}
201
202void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
203{
204 BUG_ON(!ops);
205 of_pdt_prom_ops = ops;
206
207 of_root = of_pdt_create_node(root_node, NULL);
208 of_root->full_name = "/";
209
210 of_root->child = of_pdt_build_tree(of_root,
211 of_pdt_prom_ops->getchild(of_root->phandle));
212
213 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
214 of_alias_scan(kernel_tree_alloc);
215}