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 if (!master->parent) { /* Master */
61 ofpart_node = of_get_child_by_name(mtd_node, "partitions");
62 if (!ofpart_node) {
63 /*
64 * We might get here even when ofpart isn't used at all (e.g.,
65 * when using another parser), so don't be louder than
66 * KERN_DEBUG
67 */
68 pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
69 master->name, mtd_node);
70 ofpart_node = mtd_node;
71 dedicated = false;
72 }
73 } else { /* Partition */
74 ofpart_node = mtd_node;
75 }
76
77 of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
78 if (dedicated && !of_id) {
79 /* The 'partitions' subnode might be used by another parser */
80 return 0;
81 }
82
83 quirks = of_id ? of_id->data : NULL;
84
85 /* First count the subnodes */
86 nr_parts = 0;
87 for_each_child_of_node(ofpart_node, pp) {
88 if (!dedicated && node_has_compatible(pp))
89 continue;
90
91 nr_parts++;
92 }
93
94 if (nr_parts == 0)
95 return 0;
96
97 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
98 if (!parts)
99 return -ENOMEM;
100
101 i = 0;
102 for_each_child_of_node(ofpart_node, pp) {
103 const __be32 *reg;
104 int len;
105 int a_cells, s_cells;
106
107 if (!dedicated && node_has_compatible(pp))
108 continue;
109
110 reg = of_get_property(pp, "reg", &len);
111 if (!reg) {
112 if (dedicated) {
113 pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
114 master->name, pp,
115 mtd_node);
116 goto ofpart_fail;
117 } else {
118 nr_parts--;
119 continue;
120 }
121 }
122
123 a_cells = of_n_addr_cells(pp);
124 s_cells = of_n_size_cells(pp);
125 if (len / 4 != a_cells + s_cells) {
126 pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
127 master->name, pp,
128 mtd_node);
129 goto ofpart_fail;
130 }
131
132 parts[i].offset = of_read_number(reg, a_cells);
133 parts[i].size = of_read_number(reg + a_cells, s_cells);
134 parts[i].of_node = pp;
135
136 partname = of_get_property(pp, "label", &len);
137 if (!partname)
138 partname = of_get_property(pp, "name", &len);
139 parts[i].name = partname;
140
141 if (of_get_property(pp, "read-only", &len))
142 parts[i].mask_flags |= MTD_WRITEABLE;
143
144 if (of_get_property(pp, "lock", &len))
145 parts[i].mask_flags |= MTD_POWERUP_LOCK;
146
147 if (of_property_read_bool(pp, "slc-mode"))
148 parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
149
150 i++;
151 }
152
153 if (!nr_parts)
154 goto ofpart_none;
155
156 if (quirks && quirks->post_parse)
157 quirks->post_parse(master, parts, nr_parts);
158
159 *pparts = parts;
160 return nr_parts;
161
162 ofpart_fail:
163 pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
164 master->name, pp, mtd_node);
165 ret = -EINVAL;
166 ofpart_none:
167 of_node_put(pp);
168 kfree(parts);
169 return ret;
170 }
171
172 static const struct of_device_id parse_ofpart_match_table[] = {
173 /* Generic */
174 { .compatible = "fixed-partitions" },
175 /* Customized */
176 { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
177 { .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
178 {},
179 };
180 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
181
182 static struct mtd_part_parser ofpart_parser = {
183 .parse_fn = parse_fixed_partitions,
184 .name = "fixed-partitions",
185 .of_match_table = parse_ofpart_match_table,
186 };
187
parse_ofoldpart_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)188 static int parse_ofoldpart_partitions(struct mtd_info *master,
189 const struct mtd_partition **pparts,
190 struct mtd_part_parser_data *data)
191 {
192 struct mtd_partition *parts;
193 struct device_node *dp;
194 int i, plen, nr_parts;
195 const struct {
196 __be32 offset, len;
197 } *part;
198 const char *names;
199
200 /* Pull of_node from the master device node */
201 dp = mtd_get_of_node(master);
202 if (!dp)
203 return 0;
204
205 part = of_get_property(dp, "partitions", &plen);
206 if (!part)
207 return 0; /* No partitions found */
208
209 pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
210
211 nr_parts = plen / sizeof(part[0]);
212
213 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
214 if (!parts)
215 return -ENOMEM;
216
217 names = of_get_property(dp, "partition-names", &plen);
218
219 for (i = 0; i < nr_parts; i++) {
220 parts[i].offset = be32_to_cpu(part->offset);
221 parts[i].size = be32_to_cpu(part->len) & ~1;
222 /* bit 0 set signifies read only partition */
223 if (be32_to_cpu(part->len) & 1)
224 parts[i].mask_flags = MTD_WRITEABLE;
225
226 if (names && (plen > 0)) {
227 int len = strlen(names) + 1;
228
229 parts[i].name = names;
230 plen -= len;
231 names += len;
232 } else {
233 parts[i].name = "unnamed";
234 }
235
236 part++;
237 }
238
239 *pparts = parts;
240 return nr_parts;
241 }
242
243 static struct mtd_part_parser ofoldpart_parser = {
244 .parse_fn = parse_ofoldpart_partitions,
245 .name = "ofoldpart",
246 };
247
ofpart_parser_init(void)248 static int __init ofpart_parser_init(void)
249 {
250 register_mtd_parser(&ofpart_parser);
251 register_mtd_parser(&ofoldpart_parser);
252 return 0;
253 }
254
ofpart_parser_exit(void)255 static void __exit ofpart_parser_exit(void)
256 {
257 deregister_mtd_parser(&ofpart_parser);
258 deregister_mtd_parser(&ofoldpart_parser);
259 }
260
261 module_init(ofpart_parser_init);
262 module_exit(ofpart_parser_exit);
263
264 MODULE_LICENSE("GPL");
265 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
266 MODULE_AUTHOR("Vitaly Wool, David Gibson");
267 /*
268 * When MTD core cannot find the requested parser, it tries to load the module
269 * with the same name. Since we provide the ofoldpart parser, we should have
270 * the corresponding alias.
271 */
272 MODULE_ALIAS("fixed-partitions");
273 MODULE_ALIAS("ofoldpart");
274
