1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Flash partitions described by the OF (or flattened) device tree
4 *
5 * Copyright © 2006 MontaVista Software Inc.
6 * Author: Vitaly Wool <vwool@ru.mvista.com>
7 *
8 * Revised to handle newer style flash binding by:
9 * Copyright © 2007 David Gibson, IBM Corporation.
10 */
11
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/of.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/slab.h>
17 #include <linux/mtd/partitions.h>
18
node_has_compatible(struct device_node * pp)19 static bool node_has_compatible(struct device_node *pp)
20 {
21 return of_get_property(pp, "compatible", NULL);
22 }
23
parse_fixed_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)24 static int parse_fixed_partitions(struct mtd_info *master,
25 const struct mtd_partition **pparts,
26 struct mtd_part_parser_data *data)
27 {
28 struct mtd_partition *parts;
29 struct device_node *mtd_node;
30 struct device_node *ofpart_node;
31 const char *partname;
32 struct device_node *pp;
33 int nr_parts, i, ret = 0;
34 bool dedicated = true;
35
36
37 /* Pull of_node from the master device node */
38 mtd_node = mtd_get_of_node(master);
39 if (!mtd_node)
40 return 0;
41
42 ofpart_node = of_get_child_by_name(mtd_node, "partitions");
43 if (!ofpart_node) {
44 /*
45 * We might get here even when ofpart isn't used at all (e.g.,
46 * when using another parser), so don't be louder than
47 * KERN_DEBUG
48 */
49 pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
50 master->name, mtd_node);
51 ofpart_node = mtd_node;
52 dedicated = false;
53 } else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
54 /* The 'partitions' subnode might be used by another parser */
55 return 0;
56 }
57
58 /* First count the subnodes */
59 nr_parts = 0;
60 for_each_child_of_node(ofpart_node, pp) {
61 if (!dedicated && node_has_compatible(pp))
62 continue;
63
64 nr_parts++;
65 }
66
67 if (nr_parts == 0)
68 return 0;
69
70 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
71 if (!parts)
72 return -ENOMEM;
73
74 i = 0;
75 for_each_child_of_node(ofpart_node, pp) {
76 const __be32 *reg;
77 int len;
78 int a_cells, s_cells;
79
80 if (!dedicated && node_has_compatible(pp))
81 continue;
82
83 reg = of_get_property(pp, "reg", &len);
84 if (!reg) {
85 if (dedicated) {
86 pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
87 master->name, pp,
88 mtd_node);
89 goto ofpart_fail;
90 } else {
91 nr_parts--;
92 continue;
93 }
94 }
95
96 a_cells = of_n_addr_cells(pp);
97 s_cells = of_n_size_cells(pp);
98 if (len / 4 != a_cells + s_cells) {
99 pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
100 master->name, pp,
101 mtd_node);
102 goto ofpart_fail;
103 }
104
105 parts[i].offset = of_read_number(reg, a_cells);
106 parts[i].size = of_read_number(reg + a_cells, s_cells);
107 parts[i].of_node = pp;
108
109 partname = of_get_property(pp, "label", &len);
110 if (!partname)
111 partname = of_get_property(pp, "name", &len);
112 parts[i].name = partname;
113
114 if (of_get_property(pp, "read-only", &len))
115 parts[i].mask_flags |= MTD_WRITEABLE;
116
117 if (of_get_property(pp, "lock", &len))
118 parts[i].mask_flags |= MTD_POWERUP_LOCK;
119
120 i++;
121 }
122
123 if (!nr_parts)
124 goto ofpart_none;
125
126 *pparts = parts;
127 return nr_parts;
128
129 ofpart_fail:
130 pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
131 master->name, pp, mtd_node);
132 ret = -EINVAL;
133 ofpart_none:
134 of_node_put(pp);
135 kfree(parts);
136 return ret;
137 }
138
139 static const struct of_device_id parse_ofpart_match_table[] = {
140 { .compatible = "fixed-partitions" },
141 {},
142 };
143 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
144
145 static struct mtd_part_parser ofpart_parser = {
146 .parse_fn = parse_fixed_partitions,
147 .name = "fixed-partitions",
148 .of_match_table = parse_ofpart_match_table,
149 };
150
parse_ofoldpart_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)151 static int parse_ofoldpart_partitions(struct mtd_info *master,
152 const struct mtd_partition **pparts,
153 struct mtd_part_parser_data *data)
154 {
155 struct mtd_partition *parts;
156 struct device_node *dp;
157 int i, plen, nr_parts;
158 const struct {
159 __be32 offset, len;
160 } *part;
161 const char *names;
162
163 /* Pull of_node from the master device node */
164 dp = mtd_get_of_node(master);
165 if (!dp)
166 return 0;
167
168 part = of_get_property(dp, "partitions", &plen);
169 if (!part)
170 return 0; /* No partitions found */
171
172 pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
173
174 nr_parts = plen / sizeof(part[0]);
175
176 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
177 if (!parts)
178 return -ENOMEM;
179
180 names = of_get_property(dp, "partition-names", &plen);
181
182 for (i = 0; i < nr_parts; i++) {
183 parts[i].offset = be32_to_cpu(part->offset);
184 parts[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 parts[i].mask_flags = MTD_WRITEABLE;
188
189 if (names && (plen > 0)) {
190 int len = strlen(names) + 1;
191
192 parts[i].name = names;
193 plen -= len;
194 names += len;
195 } else {
196 parts[i].name = "unnamed";
197 }
198
199 part++;
200 }
201
202 *pparts = parts;
203 return nr_parts;
204 }
205
206 static struct mtd_part_parser ofoldpart_parser = {
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("fixed-partitions");
236 MODULE_ALIAS("ofoldpart");
237