1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * This file does the necessary interface mapping between the bootwrapper
4 * device tree operations and the interface provided by shared source
5 * files flatdevicetree.[ch].
6 *
7 * Copyright 2007 David Gibson, IBM Corporation.
8 */
9
10 #include <stddef.h>
11 #include <stdio.h>
12 #include <page.h>
13 #include <libfdt.h>
14 #include "ops.h"
15
16 #define DEBUG 0
17 #define BAD_ERROR(err) (((err) < 0) \
18 && ((err) != -FDT_ERR_NOTFOUND) \
19 && ((err) != -FDT_ERR_EXISTS))
20
21 #define check_err(err) \
22 ({ \
23 if (BAD_ERROR(err) || ((err < 0) && DEBUG)) \
24 printf("%s():%d %s\n\r", __func__, __LINE__, \
25 fdt_strerror(err)); \
26 if (BAD_ERROR(err)) \
27 exit(); \
28 (err < 0) ? -1 : 0; \
29 })
30
31 #define offset_devp(off) \
32 ({ \
33 unsigned long _offset = (off); \
34 check_err(_offset) ? NULL : (void *)(_offset+1); \
35 })
36
37 #define devp_offset_find(devp) (((unsigned long)(devp))-1)
38 #define devp_offset(devp) (devp ? ((unsigned long)(devp))-1 : 0)
39
40 static void *fdt;
41 static void *buf; /* = NULL */
42
43 #define EXPAND_GRANULARITY 1024
44
45 static void expand_buf(int minexpand)
46 {
47 int size = fdt_totalsize(fdt);
48 int rc;
49
50 size = _ALIGN(size + minexpand, EXPAND_GRANULARITY);
51 buf = platform_ops.realloc(buf, size);
52 if (!buf)
53 fatal("Couldn't find %d bytes to expand device tree\n\r", size);
54 rc = fdt_open_into(fdt, buf, size);
55 if (rc != 0)
56 fatal("Couldn't expand fdt into new buffer: %s\n\r",
57 fdt_strerror(rc));
58
59 fdt = buf;
60 }
61
62 static void *fdt_wrapper_finddevice(const char *path)
63 {
64 return offset_devp(fdt_path_offset(fdt, path));
65 }
66
67 static int fdt_wrapper_getprop(const void *devp, const char *name,
68 void *buf, const int buflen)
69 {
70 const void *p;
71 int len;
72
73 p = fdt_getprop(fdt, devp_offset(devp), name, &len);
74 if (!p)
75 return check_err(len);
76 memcpy(buf, p, min(len, buflen));
77 return len;
78 }
79
80 static int fdt_wrapper_setprop(const void *devp, const char *name,
81 const void *buf, const int len)
82 {
83 int rc;
84
85 rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
86 if (rc == -FDT_ERR_NOSPACE) {
87 expand_buf(len + 16);
88 rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
89 }
90
91 return check_err(rc);
92 }
93
94 static int fdt_wrapper_del_node(const void *devp)
95 {
96 return fdt_del_node(fdt, devp_offset(devp));
97 }
98
99 static void *fdt_wrapper_get_parent(const void *devp)
100 {
101 return offset_devp(fdt_parent_offset(fdt, devp_offset(devp)));
102 }
103
104 static void *fdt_wrapper_create_node(const void *devp, const char *name)
105 {
106 int offset;
107
108 offset = fdt_add_subnode(fdt, devp_offset(devp), name);
109 if (offset == -FDT_ERR_NOSPACE) {
110 expand_buf(strlen(name) + 16);
111 offset = fdt_add_subnode(fdt, devp_offset(devp), name);
112 }
113
114 return offset_devp(offset);
115 }
116
117 static void *fdt_wrapper_find_node_by_prop_value(const void *prev,
118 const char *name,
119 const char *val,
120 int len)
121 {
122 int offset = fdt_node_offset_by_prop_value(fdt, devp_offset_find(prev),
123 name, val, len);
124 return offset_devp(offset);
125 }
126
127 static void *fdt_wrapper_find_node_by_compatible(const void *prev,
128 const char *val)
129 {
130 int offset = fdt_node_offset_by_compatible(fdt, devp_offset_find(prev),
131 val);
132 return offset_devp(offset);
133 }
134
135 static char *fdt_wrapper_get_path(const void *devp, char *buf, int len)
136 {
137 int rc;
138
139 rc = fdt_get_path(fdt, devp_offset(devp), buf, len);
140 if (check_err(rc))
141 return NULL;
142 return buf;
143 }
144
145 static unsigned long fdt_wrapper_finalize(void)
146 {
147 int rc;
148
149 rc = fdt_pack(fdt);
150 if (rc != 0)
151 fatal("Couldn't pack flat tree: %s\n\r",
152 fdt_strerror(rc));
153 return (unsigned long)fdt;
154 }
155
156 void fdt_init(void *blob)
157 {
158 int err;
159 int bufsize;
160
161 dt_ops.finddevice = fdt_wrapper_finddevice;
162 dt_ops.getprop = fdt_wrapper_getprop;
163 dt_ops.setprop = fdt_wrapper_setprop;
164 dt_ops.get_parent = fdt_wrapper_get_parent;
165 dt_ops.create_node = fdt_wrapper_create_node;
166 dt_ops.find_node_by_prop_value = fdt_wrapper_find_node_by_prop_value;
167 dt_ops.find_node_by_compatible = fdt_wrapper_find_node_by_compatible;
168 dt_ops.del_node = fdt_wrapper_del_node;
169 dt_ops.get_path = fdt_wrapper_get_path;
170 dt_ops.finalize = fdt_wrapper_finalize;
171
172 /* Make sure the dt blob is the right version and so forth */
173 fdt = blob;
174 bufsize = fdt_totalsize(fdt) + EXPAND_GRANULARITY;
175 buf = malloc(bufsize);
176 if(!buf)
177 fatal("malloc failed. can't relocate the device tree\n\r");
178
179 err = fdt_open_into(fdt, buf, bufsize);
180
181 if (err != 0)
182 fatal("fdt_init(): %s\n\r", fdt_strerror(err));
183
184 fdt = buf;
185 }
186
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