xref: /openbmc/u-boot/lib/fdtdec.c (revision daa4b2f7)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * See file CREDITS for list of people who contributed to this
4  * project.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of
9  * the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
19  * MA 02111-1307 USA
20  */
21 
22 #include <common.h>
23 #include <serial.h>
24 #include <libfdt.h>
25 #include <fdtdec.h>
26 
27 DECLARE_GLOBAL_DATA_PTR;
28 
29 /*
30  * Here are the type we know about. One day we might allow drivers to
31  * register. For now we just put them here. The COMPAT macro allows us to
32  * turn this into a sparse list later, and keeps the ID with the name.
33  */
34 #define COMPAT(id, name) name
35 static const char * const compat_names[COMPAT_COUNT] = {
36 };
37 
38 /**
39  * Look in the FDT for an alias with the given name and return its node.
40  *
41  * @param blob	FDT blob
42  * @param name	alias name to look up
43  * @return node offset if found, or an error code < 0 otherwise
44  */
45 static int find_alias_node(const void *blob, const char *name)
46 {
47 	const char *path;
48 	int alias_node;
49 
50 	debug("find_alias_node: %s\n", name);
51 	alias_node = fdt_path_offset(blob, "/aliases");
52 	if (alias_node < 0)
53 		return alias_node;
54 	path = fdt_getprop(blob, alias_node, name, NULL);
55 	if (!path)
56 		return -FDT_ERR_NOTFOUND;
57 	return fdt_path_offset(blob, path);
58 }
59 
60 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
61 		const char *prop_name)
62 {
63 	const fdt_addr_t *cell;
64 	int len;
65 
66 	debug("get_addr: %s\n", prop_name);
67 	cell = fdt_getprop(blob, node, prop_name, &len);
68 	if (cell && (len == sizeof(fdt_addr_t) ||
69 			len == sizeof(fdt_addr_t) * 2))
70 		return fdt_addr_to_cpu(*cell);
71 	return FDT_ADDR_T_NONE;
72 }
73 
74 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
75 		s32 default_val)
76 {
77 	const s32 *cell;
78 	int len;
79 
80 	debug("get_size: %s\n", prop_name);
81 	cell = fdt_getprop(blob, node, prop_name, &len);
82 	if (cell && len >= sizeof(s32))
83 		return fdt32_to_cpu(cell[0]);
84 	return default_val;
85 }
86 
87 int fdtdec_get_is_enabled(const void *blob, int node, int default_val)
88 {
89 	const char *cell;
90 
91 	cell = fdt_getprop(blob, node, "status", NULL);
92 	if (cell)
93 		return 0 == strcmp(cell, "ok");
94 	return default_val;
95 }
96 
97 enum fdt_compat_id fd_dec_lookup(const void *blob, int node)
98 {
99 	enum fdt_compat_id id;
100 
101 	/* Search our drivers */
102 	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
103 		if (0 == fdt_node_check_compatible(blob, node,
104 				compat_names[id]))
105 			return id;
106 	return COMPAT_UNKNOWN;
107 }
108 
109 int fdtdec_next_compatible(const void *blob, int node,
110 		enum fdt_compat_id id)
111 {
112 	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
113 }
114 
115 int fdtdec_next_alias(const void *blob, const char *name,
116 		enum fdt_compat_id id, int *upto)
117 {
118 #define MAX_STR_LEN 20
119 	char str[MAX_STR_LEN + 20];
120 	int node, err;
121 
122 	/* snprintf() is not available */
123 	assert(strlen(name) < MAX_STR_LEN);
124 	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
125 	(*upto)++;
126 	node = find_alias_node(blob, str);
127 	if (node < 0)
128 		return node;
129 	err = fdt_node_check_compatible(blob, node, compat_names[id]);
130 	if (err < 0)
131 		return err;
132 	return err ? -FDT_ERR_NOTFOUND : node;
133 }
134 
135 /*
136  * This function is a little odd in that it accesses global data. At some
137  * point if the architecture board.c files merge this will make more sense.
138  * Even now, it is common code.
139  */
140 int fdtdec_check_fdt(void)
141 {
142 	/* We must have an fdt */
143 	if (fdt_check_header(gd->fdt_blob))
144 		panic("No valid fdt found - please append one to U-Boot\n"
145 			"binary or define CONFIG_OF_EMBED\n");
146 	return 0;
147 }
148