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 (!dedicated && s_cells == 0) {
126 /*
127 * This is a ugly workaround to not create
128 * regression on devices that are still creating
129 * partitions as direct children of the nand controller.
130 * This can happen in case the nand controller node has
131 * #size-cells equal to 0 and the firmware (e.g.
132 * U-Boot) just add the partitions there assuming
133 * 32-bit addressing.
134 *
135 * If you get this warning your firmware and/or DTS
136 * should be really fixed.
137 *
138 * This is working only for devices smaller than 4GiB.
139 */
140 pr_warn("%s: ofpart partition %pOF (%pOF) #size-cells is wrongly set to <0>, assuming <1> for parsing partitions.\n",
141 master->name, pp, mtd_node);
142 s_cells = 1;
143 }
144 if (len / 4 != a_cells + s_cells) {
145 pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
146 master->name, pp,
147 mtd_node);
148 goto ofpart_fail;
149 }
150
151 parts[i].offset = of_read_number(reg, a_cells);
152 parts[i].size = of_read_number(reg + a_cells, s_cells);
153 parts[i].of_node = pp;
154
155 partname = of_get_property(pp, "label", &len);
156 if (!partname)
157 partname = of_get_property(pp, "name", &len);
158 parts[i].name = partname;
159
160 if (of_get_property(pp, "read-only", &len))
161 parts[i].mask_flags |= MTD_WRITEABLE;
162
163 if (of_get_property(pp, "lock", &len))
164 parts[i].mask_flags |= MTD_POWERUP_LOCK;
165
166 if (of_property_read_bool(pp, "slc-mode"))
167 parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
168
169 i++;
170 }
171
172 if (!nr_parts)
173 goto ofpart_none;
174
175 if (quirks && quirks->post_parse)
176 quirks->post_parse(master, parts, nr_parts);
177
178 *pparts = parts;
179 return nr_parts;
180
181 ofpart_fail:
182 pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
183 master->name, pp, mtd_node);
184 ret = -EINVAL;
185 ofpart_none:
186 of_node_put(pp);
187 kfree(parts);
188 return ret;
189 }
190
191 static const struct of_device_id parse_ofpart_match_table[] = {
192 /* Generic */
193 { .compatible = "fixed-partitions" },
194 /* Customized */
195 { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
196 { .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
197 {},
198 };
199 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
200
201 static struct mtd_part_parser ofpart_parser = {
202 .parse_fn = parse_fixed_partitions,
203 .name = "fixed-partitions",
204 .of_match_table = parse_ofpart_match_table,
205 };
206
parse_ofoldpart_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)207 static int parse_ofoldpart_partitions(struct mtd_info *master,
208 const struct mtd_partition **pparts,
209 struct mtd_part_parser_data *data)
210 {
211 struct mtd_partition *parts;
212 struct device_node *dp;
213 int i, plen, nr_parts;
214 const struct {
215 __be32 offset, len;
216 } *part;
217 const char *names;
218
219 /* Pull of_node from the master device node */
220 dp = mtd_get_of_node(master);
221 if (!dp)
222 return 0;
223
224 part = of_get_property(dp, "partitions", &plen);
225 if (!part)
226 return 0; /* No partitions found */
227
228 pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
229
230 nr_parts = plen / sizeof(part[0]);
231
232 parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
233 if (!parts)
234 return -ENOMEM;
235
236 names = of_get_property(dp, "partition-names", &plen);
237
238 for (i = 0; i < nr_parts; i++) {
239 parts[i].offset = be32_to_cpu(part->offset);
240 parts[i].size = be32_to_cpu(part->len) & ~1;
241 /* bit 0 set signifies read only partition */
242 if (be32_to_cpu(part->len) & 1)
243 parts[i].mask_flags = MTD_WRITEABLE;
244
245 if (names && (plen > 0)) {
246 int len = strlen(names) + 1;
247
248 parts[i].name = names;
249 plen -= len;
250 names += len;
251 } else {
252 parts[i].name = "unnamed";
253 }
254
255 part++;
256 }
257
258 *pparts = parts;
259 return nr_parts;
260 }
261
262 static struct mtd_part_parser ofoldpart_parser = {
263 .parse_fn = parse_ofoldpart_partitions,
264 .name = "ofoldpart",
265 };
266
ofpart_parser_init(void)267 static int __init ofpart_parser_init(void)
268 {
269 register_mtd_parser(&ofpart_parser);
270 register_mtd_parser(&ofoldpart_parser);
271 return 0;
272 }
273
ofpart_parser_exit(void)274 static void __exit ofpart_parser_exit(void)
275 {
276 deregister_mtd_parser(&ofpart_parser);
277 deregister_mtd_parser(&ofoldpart_parser);
278 }
279
280 module_init(ofpart_parser_init);
281 module_exit(ofpart_parser_exit);
282
283 MODULE_LICENSE("GPL");
284 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
285 MODULE_AUTHOR("Vitaly Wool, David Gibson");
286 /*
287 * When MTD core cannot find the requested parser, it tries to load the module
288 * with the same name. Since we provide the ofoldpart parser, we should have
289 * the corresponding alias.
290 */
291 MODULE_ALIAS("fixed-partitions");
292 MODULE_ALIAS("ofoldpart");
293