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 int a_cells, s_cells;
59
60 reg = of_get_property(pp, "reg", &len);
61 if (!reg) {
62 nr_parts--;
63 continue;
64 }
65
66 a_cells = of_n_addr_cells(pp);
67 s_cells = of_n_size_cells(pp);
68 (*pparts)[i].offset = of_read_number(reg, a_cells);
69 (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
70
71 partname = of_get_property(pp, "label", &len);
72 if (!partname)
73 partname = of_get_property(pp, "name", &len);
74 (*pparts)[i].name = (char *)partname;
75
76 if (of_get_property(pp, "read-only", &len))
77 (*pparts)[i].mask_flags |= MTD_WRITEABLE;
78
79 if (of_get_property(pp, "lock", &len))
80 (*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
81
82 i++;
83 }
84
85 if (!i) {
86 of_node_put(pp);
87 pr_err("No valid partition found on %s\n", node->full_name);
88 kfree(*pparts);
89 *pparts = NULL;
90 return -EINVAL;
91 }
92
93 return nr_parts;
94 }
95
96 static struct mtd_part_parser ofpart_parser = {
97 .owner = THIS_MODULE,
98 .parse_fn = parse_ofpart_partitions,
99 .name = "ofpart",
100 };
101
parse_ofoldpart_partitions(struct mtd_info * master,struct mtd_partition ** pparts,struct mtd_part_parser_data * data)102 static int parse_ofoldpart_partitions(struct mtd_info *master,
103 struct mtd_partition **pparts,
104 struct mtd_part_parser_data *data)
105 {
106 struct device_node *dp;
107 int i, plen, nr_parts;
108 const struct {
109 __be32 offset, len;
110 } *part;
111 const char *names;
112
113 if (!data)
114 return 0;
115
116 dp = data->of_node;
117 if (!dp)
118 return 0;
119
120 part = of_get_property(dp, "partitions", &plen);
121 if (!part)
122 return 0; /* No partitions found */
123
124 pr_warning("Device tree uses obsolete partition map binding: %s\n",
125 dp->full_name);
126
127 nr_parts = plen / sizeof(part[0]);
128
129 *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
130 if (!*pparts)
131 return -ENOMEM;
132
133 names = of_get_property(dp, "partition-names", &plen);
134
135 for (i = 0; i < nr_parts; i++) {
136 (*pparts)[i].offset = be32_to_cpu(part->offset);
137 (*pparts)[i].size = be32_to_cpu(part->len) & ~1;
138 /* bit 0 set signifies read only partition */
139 if (be32_to_cpu(part->len) & 1)
140 (*pparts)[i].mask_flags = MTD_WRITEABLE;
141
142 if (names && (plen > 0)) {
143 int len = strlen(names) + 1;
144
145 (*pparts)[i].name = (char *)names;
146 plen -= len;
147 names += len;
148 } else {
149 (*pparts)[i].name = "unnamed";
150 }
151
152 part++;
153 }
154
155 return nr_parts;
156 }
157
158 static struct mtd_part_parser ofoldpart_parser = {
159 .owner = THIS_MODULE,
160 .parse_fn = parse_ofoldpart_partitions,
161 .name = "ofoldpart",
162 };
163
ofpart_parser_init(void)164 static int __init ofpart_parser_init(void)
165 {
166 int rc;
167 rc = register_mtd_parser(&ofpart_parser);
168 if (rc)
169 goto out;
170
171 rc = register_mtd_parser(&ofoldpart_parser);
172 if (!rc)
173 return 0;
174
175 deregister_mtd_parser(&ofoldpart_parser);
176 out:
177 return rc;
178 }
179
ofpart_parser_exit(void)180 static void __exit ofpart_parser_exit(void)
181 {
182 deregister_mtd_parser(&ofpart_parser);
183 deregister_mtd_parser(&ofoldpart_parser);
184 }
185
186 module_init(ofpart_parser_init);
187 module_exit(ofpart_parser_exit);
188
189 MODULE_LICENSE("GPL");
190 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
191 MODULE_AUTHOR("Vitaly Wool, David Gibson");
192 /*
193 * When MTD core cannot find the requested parser, it tries to load the module
194 * with the same name. Since we provide the ofoldpart parser, we should have
195 * the corresponding alias.
196 */
197 MODULE_ALIAS("ofoldpart");
198