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
node_has_compatible(struct device_node * pp)23 static bool node_has_compatible(struct device_node *pp)
24 {
25 return of_get_property(pp, "compatible", NULL);
26 }
27
parse_fixed_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)28 static int parse_fixed_partitions(struct mtd_info *master,
29 const struct mtd_partition **pparts,
30 struct mtd_part_parser_data *data)
31 {
32 struct mtd_partition *parts;
33 struct device_node *mtd_node;
34 struct device_node *ofpart_node;
35 const char *partname;
36 struct device_node *pp;
37 int nr_parts, i, ret = 0;
38 bool dedicated = true;
39
40
41 /* Pull of_node from the master device node */
42 mtd_node = mtd_get_of_node(master);
43 if (!mtd_node)
44 return 0;
45
46 ofpart_node = of_get_child_by_name(mtd_node, "partitions");
47 if (!ofpart_node) {
48 /*
49 * We might get here even when ofpart isn't used at all (e.g.,
50 * when using another parser), so don't be louder than
51 * KERN_DEBUG
52 */
53 pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
54 master->name, mtd_node);
55 ofpart_node = mtd_node;
56 dedicated = false;
57 } else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
58 /* The 'partitions' subnode might be used by another parser */
59 return 0;
60 }
61
62 /* First count the subnodes */
63 nr_parts = 0;
64 for_each_child_of_node(ofpart_node, pp) {
65 if (!dedicated && node_has_compatible(pp))
66 continue;
67
68 nr_parts++;
69 }
70
71 if (nr_parts == 0)
72 return 0;
73
74 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
75 if (!parts)
76 return -ENOMEM;
77
78 i = 0;
79 for_each_child_of_node(ofpart_node, pp) {
80 const __be32 *reg;
81 int len;
82 int a_cells, s_cells;
83
84 if (!dedicated && node_has_compatible(pp))
85 continue;
86
87 reg = of_get_property(pp, "reg", &len);
88 if (!reg) {
89 if (dedicated) {
90 pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
91 master->name, pp,
92 mtd_node);
93 goto ofpart_fail;
94 } else {
95 nr_parts--;
96 continue;
97 }
98 }
99
100 a_cells = of_n_addr_cells(pp);
101 s_cells = of_n_size_cells(pp);
102 if (len / 4 != a_cells + s_cells) {
103 pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
104 master->name, pp,
105 mtd_node);
106 goto ofpart_fail;
107 }
108
109 parts[i].offset = of_read_number(reg, a_cells);
110 parts[i].size = of_read_number(reg + a_cells, s_cells);
111 parts[i].of_node = pp;
112
113 partname = of_get_property(pp, "label", &len);
114 if (!partname)
115 partname = of_get_property(pp, "name", &len);
116 parts[i].name = partname;
117
118 if (of_get_property(pp, "read-only", &len))
119 parts[i].mask_flags |= MTD_WRITEABLE;
120
121 if (of_get_property(pp, "lock", &len))
122 parts[i].mask_flags |= MTD_POWERUP_LOCK;
123
124 i++;
125 }
126
127 if (!nr_parts)
128 goto ofpart_none;
129
130 *pparts = parts;
131 return nr_parts;
132
133 ofpart_fail:
134 pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
135 master->name, pp, mtd_node);
136 ret = -EINVAL;
137 ofpart_none:
138 of_node_put(pp);
139 kfree(parts);
140 return ret;
141 }
142
143 static const struct of_device_id parse_ofpart_match_table[] = {
144 { .compatible = "fixed-partitions" },
145 {},
146 };
147 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
148
149 static struct mtd_part_parser ofpart_parser = {
150 .parse_fn = parse_fixed_partitions,
151 .name = "fixed-partitions",
152 .of_match_table = parse_ofpart_match_table,
153 };
154
parse_ofoldpart_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)155 static int parse_ofoldpart_partitions(struct mtd_info *master,
156 const struct mtd_partition **pparts,
157 struct mtd_part_parser_data *data)
158 {
159 struct mtd_partition *parts;
160 struct device_node *dp;
161 int i, plen, nr_parts;
162 const struct {
163 __be32 offset, len;
164 } *part;
165 const char *names;
166
167 /* Pull of_node from the master device node */
168 dp = mtd_get_of_node(master);
169 if (!dp)
170 return 0;
171
172 part = of_get_property(dp, "partitions", &plen);
173 if (!part)
174 return 0; /* No partitions found */
175
176 pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
177
178 nr_parts = plen / sizeof(part[0]);
179
180 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
181 if (!parts)
182 return -ENOMEM;
183
184 names = of_get_property(dp, "partition-names", &plen);
185
186 for (i = 0; i < nr_parts; i++) {
187 parts[i].offset = be32_to_cpu(part->offset);
188 parts[i].size = be32_to_cpu(part->len) & ~1;
189 /* bit 0 set signifies read only partition */
190 if (be32_to_cpu(part->len) & 1)
191 parts[i].mask_flags = MTD_WRITEABLE;
192
193 if (names && (plen > 0)) {
194 int len = strlen(names) + 1;
195
196 parts[i].name = names;
197 plen -= len;
198 names += len;
199 } else {
200 parts[i].name = "unnamed";
201 }
202
203 part++;
204 }
205
206 *pparts = parts;
207 return nr_parts;
208 }
209
210 static struct mtd_part_parser ofoldpart_parser = {
211 .parse_fn = parse_ofoldpart_partitions,
212 .name = "ofoldpart",
213 };
214
ofpart_parser_init(void)215 static int __init ofpart_parser_init(void)
216 {
217 register_mtd_parser(&ofpart_parser);
218 register_mtd_parser(&ofoldpart_parser);
219 return 0;
220 }
221
ofpart_parser_exit(void)222 static void __exit ofpart_parser_exit(void)
223 {
224 deregister_mtd_parser(&ofpart_parser);
225 deregister_mtd_parser(&ofoldpart_parser);
226 }
227
228 module_init(ofpart_parser_init);
229 module_exit(ofpart_parser_exit);
230
231 MODULE_LICENSE("GPL");
232 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
233 MODULE_AUTHOR("Vitaly Wool, David Gibson");
234 /*
235 * When MTD core cannot find the requested parser, it tries to load the module
236 * with the same name. Since we provide the ofoldpart parser, we should have
237 * the corresponding alias.
238 */
239 MODULE_ALIAS("fixed-partitions");
240 MODULE_ALIAS("ofoldpart");
241
