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
19 #include "ofpart_bcm4908.h"
20 #include "ofpart_linksys_ns.h"
21
22 struct fixed_partitions_quirks {
23 int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
24 };
25
26 static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
27 .post_parse = bcm4908_partitions_post_parse,
28 };
29
30 static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
31 .post_parse = linksys_ns_partitions_post_parse,
32 };
33
34 static const struct of_device_id parse_ofpart_match_table[];
35
node_has_compatible(struct device_node * pp)36 static bool node_has_compatible(struct device_node *pp)
37 {
38 return of_get_property(pp, "compatible", NULL);
39 }
40
parse_fixed_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)41 static int parse_fixed_partitions(struct mtd_info *master,
42 const struct mtd_partition **pparts,
43 struct mtd_part_parser_data *data)
44 {
45 const struct fixed_partitions_quirks *quirks;
46 const struct of_device_id *of_id;
47 struct mtd_partition *parts;
48 struct device_node *mtd_node;
49 struct device_node *ofpart_node;
50 const char *partname;
51 struct device_node *pp;
52 int nr_parts, i, ret = 0;
53 bool dedicated = true;
54
55 /* Pull of_node from the master device node */
56 mtd_node = mtd_get_of_node(master);
57 if (!mtd_node)
58 return 0;
59
60 ofpart_node = of_get_child_by_name(mtd_node, "partitions");
61 if (!ofpart_node && !master->parent) {
62 /*
63 * We might get here even when ofpart isn't used at all (e.g.,
64 * when using another parser), so don't be louder than
65 * KERN_DEBUG
66 */
67 pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
68 master->name, mtd_node);
69 ofpart_node = mtd_node;
70 dedicated = false;
71 }
72 if (!ofpart_node)
73 return 0;
74
75 of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
76 if (dedicated && !of_id) {
77 /* The 'partitions' subnode might be used by another parser */
78 return 0;
79 }
80
81 quirks = of_id ? of_id->data : NULL;
82
83 /* First count the subnodes */
84 nr_parts = 0;
85 for_each_child_of_node(ofpart_node, pp) {
86 if (!dedicated && node_has_compatible(pp))
87 continue;
88
89 nr_parts++;
90 }
91
92 if (nr_parts == 0)
93 return 0;
94
95 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
96 if (!parts)
97 return -ENOMEM;
98
99 i = 0;
100 for_each_child_of_node(ofpart_node, pp) {
101 const __be32 *reg;
102 int len;
103 int a_cells, s_cells;
104
105 if (!dedicated && node_has_compatible(pp))
106 continue;
107
108 reg = of_get_property(pp, "reg", &len);
109 if (!reg) {
110 if (dedicated) {
111 pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
112 master->name, pp,
113 mtd_node);
114 goto ofpart_fail;
115 } else {
116 nr_parts--;
117 continue;
118 }
119 }
120
121 a_cells = of_n_addr_cells(pp);
122 s_cells = of_n_size_cells(pp);
123 if (len / 4 != a_cells + s_cells) {
124 pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
125 master->name, pp,
126 mtd_node);
127 goto ofpart_fail;
128 }
129
130 parts[i].offset = of_read_number(reg, a_cells);
131 parts[i].size = of_read_number(reg + a_cells, s_cells);
132 parts[i].of_node = pp;
133
134 partname = of_get_property(pp, "label", &len);
135 if (!partname)
136 partname = of_get_property(pp, "name", &len);
137 parts[i].name = partname;
138
139 if (of_get_property(pp, "read-only", &len))
140 parts[i].mask_flags |= MTD_WRITEABLE;
141
142 if (of_get_property(pp, "lock", &len))
143 parts[i].mask_flags |= MTD_POWERUP_LOCK;
144
145 if (of_property_read_bool(pp, "slc-mode"))
146 parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
147
148 i++;
149 }
150
151 if (!nr_parts)
152 goto ofpart_none;
153
154 if (quirks && quirks->post_parse)
155 quirks->post_parse(master, parts, nr_parts);
156
157 *pparts = parts;
158 return nr_parts;
159
160 ofpart_fail:
161 pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
162 master->name, pp, mtd_node);
163 ret = -EINVAL;
164 ofpart_none:
165 of_node_put(pp);
166 kfree(parts);
167 return ret;
168 }
169
170 static const struct of_device_id parse_ofpart_match_table[] = {
171 /* Generic */
172 { .compatible = "fixed-partitions" },
173 /* Customized */
174 { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
175 { .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
176 {},
177 };
178 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
179
180 static struct mtd_part_parser ofpart_parser = {
181 .parse_fn = parse_fixed_partitions,
182 .name = "fixed-partitions",
183 .of_match_table = parse_ofpart_match_table,
184 };
185
parse_ofoldpart_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)186 static int parse_ofoldpart_partitions(struct mtd_info *master,
187 const struct mtd_partition **pparts,
188 struct mtd_part_parser_data *data)
189 {
190 struct mtd_partition *parts;
191 struct device_node *dp;
192 int i, plen, nr_parts;
193 const struct {
194 __be32 offset, len;
195 } *part;
196 const char *names;
197
198 /* Pull of_node from the master device node */
199 dp = mtd_get_of_node(master);
200 if (!dp)
201 return 0;
202
203 part = of_get_property(dp, "partitions", &plen);
204 if (!part)
205 return 0; /* No partitions found */
206
207 pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
208
209 nr_parts = plen / sizeof(part[0]);
210
211 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
212 if (!parts)
213 return -ENOMEM;
214
215 names = of_get_property(dp, "partition-names", &plen);
216
217 for (i = 0; i < nr_parts; i++) {
218 parts[i].offset = be32_to_cpu(part->offset);
219 parts[i].size = be32_to_cpu(part->len) & ~1;
220 /* bit 0 set signifies read only partition */
221 if (be32_to_cpu(part->len) & 1)
222 parts[i].mask_flags = MTD_WRITEABLE;
223
224 if (names && (plen > 0)) {
225 int len = strlen(names) + 1;
226
227 parts[i].name = names;
228 plen -= len;
229 names += len;
230 } else {
231 parts[i].name = "unnamed";
232 }
233
234 part++;
235 }
236
237 *pparts = parts;
238 return nr_parts;
239 }
240
241 static struct mtd_part_parser ofoldpart_parser = {
242 .parse_fn = parse_ofoldpart_partitions,
243 .name = "ofoldpart",
244 };
245
ofpart_parser_init(void)246 static int __init ofpart_parser_init(void)
247 {
248 register_mtd_parser(&ofpart_parser);
249 register_mtd_parser(&ofoldpart_parser);
250 return 0;
251 }
252
ofpart_parser_exit(void)253 static void __exit ofpart_parser_exit(void)
254 {
255 deregister_mtd_parser(&ofpart_parser);
256 deregister_mtd_parser(&ofoldpart_parser);
257 }
258
259 module_init(ofpart_parser_init);
260 module_exit(ofpart_parser_exit);
261
262 MODULE_LICENSE("GPL");
263 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
264 MODULE_AUTHOR("Vitaly Wool, David Gibson");
265 /*
266 * When MTD core cannot find the requested parser, it tries to load the module
267 * with the same name. Since we provide the ofoldpart parser, we should have
268 * the corresponding alias.
269 */
270 MODULE_ALIAS("fixed-partitions");
271 MODULE_ALIAS("ofoldpart");
272