1 /*
2 * Flash partitions described by the OF (or flattened) device tree
3 *
4 * Copyright © 2006 MontaVista Software Inc.
5 * Author: Vitaly Wool <vwool@ru.mvista.com>
6 *
7 * Revised to handle newer style flash binding by:
8 * Copyright © 2007 David Gibson, IBM Corporation.
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 */
15
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/of.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/slab.h>
21 #include <linux/mtd/partitions.h>
22
parse_ofpart_partitions(struct mtd_info * master,struct mtd_partition ** pparts,struct mtd_part_parser_data * data)23 static int parse_ofpart_partitions(struct mtd_info *master,
24 struct mtd_partition **pparts,
25 struct mtd_part_parser_data *data)
26 {
27 struct device_node *node;
28 const char *partname;
29 struct device_node *pp;
30 int nr_parts, i;
31
32
33 if (!data)
34 return 0;
35
36 node = data->of_node;
37 if (!node)
38 return 0;
39
40 /* First count the subnodes */
41 pp = NULL;
42 nr_parts = 0;
43 while ((pp = of_get_next_child(node, pp)))
44 nr_parts++;
45
46 if (nr_parts == 0)
47 return 0;
48
49 *pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
50 if (!*pparts)
51 return -ENOMEM;
52
53 pp = NULL;
54 i = 0;
55 while ((pp = of_get_next_child(node, pp))) {
56 const __be32 *reg;
57 int len;
58
59 reg = of_get_property(pp, "reg", &len);
60 if (!reg) {
61 nr_parts--;
62 continue;
63 }
64
65 (*pparts)[i].offset = be32_to_cpu(reg[0]);
66 (*pparts)[i].size = be32_to_cpu(reg[1]);
67
68 partname = of_get_property(pp, "label", &len);
69 if (!partname)
70 partname = of_get_property(pp, "name", &len);
71 (*pparts)[i].name = (char *)partname;
72
73 if (of_get_property(pp, "read-only", &len))
74 (*pparts)[i].mask_flags = MTD_WRITEABLE;
75
76 i++;
77 }
78
79 if (!i) {
80 of_node_put(pp);
81 pr_err("No valid partition found on %s\n", node->full_name);
82 kfree(*pparts);
83 *pparts = NULL;
84 return -EINVAL;
85 }
86
87 return nr_parts;
88 }
89
90 static struct mtd_part_parser ofpart_parser = {
91 .owner = THIS_MODULE,
92 .parse_fn = parse_ofpart_partitions,
93 .name = "ofpart",
94 };
95
parse_ofoldpart_partitions(struct mtd_info * master,struct mtd_partition ** pparts,struct mtd_part_parser_data * data)96 static int parse_ofoldpart_partitions(struct mtd_info *master,
97 struct mtd_partition **pparts,
98 struct mtd_part_parser_data *data)
99 {
100 struct device_node *dp;
101 int i, plen, nr_parts;
102 const struct {
103 __be32 offset, len;
104 } *part;
105 const char *names;
106
107 if (!data)
108 return 0;
109
110 dp = data->of_node;
111 if (!dp)
112 return 0;
113
114 part = of_get_property(dp, "partitions", &plen);
115 if (!part)
116 return 0; /* No partitions found */
117
118 pr_warning("Device tree uses obsolete partition map binding: %s\n",
119 dp->full_name);
120
121 nr_parts = plen / sizeof(part[0]);
122
123 *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
124 if (!pparts)
125 return -ENOMEM;
126
127 names = of_get_property(dp, "partition-names", &plen);
128
129 for (i = 0; i < nr_parts; i++) {
130 (*pparts)[i].offset = be32_to_cpu(part->offset);
131 (*pparts)[i].size = be32_to_cpu(part->len) & ~1;
132 /* bit 0 set signifies read only partition */
133 if (be32_to_cpu(part->len) & 1)
134 (*pparts)[i].mask_flags = MTD_WRITEABLE;
135
136 if (names && (plen > 0)) {
137 int len = strlen(names) + 1;
138
139 (*pparts)[i].name = (char *)names;
140 plen -= len;
141 names += len;
142 } else {
143 (*pparts)[i].name = "unnamed";
144 }
145
146 part++;
147 }
148
149 return nr_parts;
150 }
151
152 static struct mtd_part_parser ofoldpart_parser = {
153 .owner = THIS_MODULE,
154 .parse_fn = parse_ofoldpart_partitions,
155 .name = "ofoldpart",
156 };
157
ofpart_parser_init(void)158 static int __init ofpart_parser_init(void)
159 {
160 int rc;
161 rc = register_mtd_parser(&ofpart_parser);
162 if (rc)
163 goto out;
164
165 rc = register_mtd_parser(&ofoldpart_parser);
166 if (!rc)
167 return 0;
168
169 deregister_mtd_parser(&ofoldpart_parser);
170 out:
171 return rc;
172 }
173
174 module_init(ofpart_parser_init);
175
176 MODULE_LICENSE("GPL");
177 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
178 MODULE_AUTHOR("Vitaly Wool, David Gibson");
179 /*
180 * When MTD core cannot find the requested parser, it tries to load the module
181 * with the same name. Since we provide the ofoldpart parser, we should have
182 * the corresponding alias.
183 */
184 MODULE_ALIAS("ofoldpart");
185