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