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 #ifdef CONFIG_MTD_OF_PARTS_BCM4908
27 static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
28 .post_parse = bcm4908_partitions_post_parse,
29 };
30 #endif
31
32 #ifdef CONFIG_MTD_OF_PARTS_LINKSYS_NS
33 static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
34 .post_parse = linksys_ns_partitions_post_parse,
35 };
36 #endif
37
38 static const struct of_device_id parse_ofpart_match_table[];
39
node_has_compatible(struct device_node * pp)40 static bool node_has_compatible(struct device_node *pp)
41 {
42 return of_get_property(pp, "compatible", NULL);
43 }
44
parse_fixed_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)45 static int parse_fixed_partitions(struct mtd_info *master,
46 const struct mtd_partition **pparts,
47 struct mtd_part_parser_data *data)
48 {
49 const struct fixed_partitions_quirks *quirks;
50 const struct of_device_id *of_id;
51 struct mtd_partition *parts;
52 struct device_node *mtd_node;
53 struct device_node *ofpart_node;
54 const char *partname;
55 struct device_node *pp;
56 int nr_parts, i, ret = 0;
57 bool dedicated = true;
58
59 /* Pull of_node from the master device node */
60 mtd_node = mtd_get_of_node(master);
61 if (!mtd_node)
62 return 0;
63
64 if (!master->parent) { /* Master */
65 ofpart_node = of_get_child_by_name(mtd_node, "partitions");
66 if (!ofpart_node) {
67 /*
68 * We might get here even when ofpart isn't used at all (e.g.,
69 * when using another parser), so don't be louder than
70 * KERN_DEBUG
71 */
72 pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
73 master->name, mtd_node);
74 ofpart_node = mtd_node;
75 dedicated = false;
76 }
77 } else { /* Partition */
78 ofpart_node = mtd_node;
79 }
80
81 of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
82 if (dedicated && !of_id) {
83 /* The 'partitions' subnode might be used by another parser */
84 of_node_put(ofpart_node);
85 return 0;
86 }
87
88 quirks = of_id ? of_id->data : NULL;
89
90 /* First count the subnodes */
91 nr_parts = 0;
92 for_each_child_of_node(ofpart_node, pp) {
93 if (!dedicated && node_has_compatible(pp))
94 continue;
95
96 nr_parts++;
97 }
98
99 if (nr_parts == 0) {
100 if (dedicated)
101 of_node_put(ofpart_node);
102 return 0;
103 }
104
105 parts = kzalloc_objs(*parts, nr_parts);
106 if (!parts) {
107 if (dedicated)
108 of_node_put(ofpart_node);
109 return -ENOMEM;
110 }
111
112 i = 0;
113 for_each_child_of_node(ofpart_node, pp) {
114 const __be32 *reg;
115 int len;
116 int a_cells, s_cells;
117
118 if (!dedicated && node_has_compatible(pp))
119 continue;
120
121 reg = of_get_property(pp, "reg", &len);
122 if (!reg) {
123 if (dedicated) {
124 pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
125 master->name, pp,
126 mtd_node);
127 goto ofpart_fail;
128 } else {
129 nr_parts--;
130 continue;
131 }
132 }
133
134 a_cells = of_n_addr_cells(pp);
135 s_cells = of_n_size_cells(pp);
136 if (!dedicated && s_cells == 0) {
137 /*
138 * This is a ugly workaround to not create
139 * regression on devices that are still creating
140 * partitions as direct children of the nand controller.
141 * This can happen in case the nand controller node has
142 * #size-cells equal to 0 and the firmware (e.g.
143 * U-Boot) just add the partitions there assuming
144 * 32-bit addressing.
145 *
146 * If you get this warning your firmware and/or DTS
147 * should be really fixed.
148 *
149 * This is working only for devices smaller than 4GiB.
150 */
151 pr_warn("%s: ofpart partition %pOF (%pOF) #size-cells is wrongly set to <0>, assuming <1> for parsing partitions.\n",
152 master->name, pp, mtd_node);
153 s_cells = 1;
154 }
155 if (len / 4 != a_cells + s_cells) {
156 pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
157 master->name, pp,
158 mtd_node);
159 goto ofpart_fail;
160 }
161
162 parts[i].offset = of_read_number(reg, a_cells);
163 parts[i].size = of_read_number(reg + a_cells, s_cells);
164 parts[i].of_node = pp;
165
166 partname = of_get_property(pp, "label", &len);
167 if (!partname)
168 partname = of_get_property(pp, "name", &len);
169 parts[i].name = partname;
170
171 if (of_property_read_bool(pp, "read-only"))
172 parts[i].mask_flags |= MTD_WRITEABLE;
173
174 if (of_property_read_bool(pp, "lock"))
175 parts[i].mask_flags |= MTD_POWERUP_LOCK;
176
177 if (of_property_read_bool(pp, "slc-mode"))
178 parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
179
180 i++;
181 }
182
183 if (!nr_parts)
184 goto ofpart_none;
185
186 if (quirks && quirks->post_parse)
187 quirks->post_parse(master, parts, nr_parts);
188
189 if (dedicated)
190 of_node_put(ofpart_node);
191
192 *pparts = parts;
193 return nr_parts;
194
195 ofpart_fail:
196 pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
197 master->name, pp, mtd_node);
198 ret = -EINVAL;
199 ofpart_none:
200 if (dedicated)
201 of_node_put(ofpart_node);
202 of_node_put(pp);
203 kfree(parts);
204 return ret;
205 }
206
207 static const struct of_device_id parse_ofpart_match_table[] = {
208 /* Generic */
209 { .compatible = "fixed-partitions" },
210 /* Customized */
211 #ifdef CONFIG_MTD_OF_PARTS_BCM4908
212 { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
213 #endif
214 #ifdef CONFIG_MTD_OF_PARTS_LINKSYS_NS
215 { .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
216 #endif
217 {},
218 };
219 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
220
221 static struct mtd_part_parser ofpart_parser = {
222 .parse_fn = parse_fixed_partitions,
223 .name = "fixed-partitions",
224 .of_match_table = parse_ofpart_match_table,
225 };
226
parse_ofoldpart_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)227 static int parse_ofoldpart_partitions(struct mtd_info *master,
228 const struct mtd_partition **pparts,
229 struct mtd_part_parser_data *data)
230 {
231 struct mtd_partition *parts;
232 struct device_node *dp;
233 int i, plen, nr_parts;
234 const struct {
235 __be32 offset, len;
236 } *part;
237 const char *names;
238
239 /* Pull of_node from the master device node */
240 dp = mtd_get_of_node(master);
241 if (!dp)
242 return 0;
243
244 part = of_get_property(dp, "partitions", &plen);
245 if (!part)
246 return 0; /* No partitions found */
247
248 pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
249
250 nr_parts = plen / sizeof(part[0]);
251
252 parts = kzalloc_objs(*parts, nr_parts);
253 if (!parts)
254 return -ENOMEM;
255
256 names = of_get_property(dp, "partition-names", &plen);
257
258 for (i = 0; i < nr_parts; i++) {
259 parts[i].offset = be32_to_cpu(part->offset);
260 parts[i].size = be32_to_cpu(part->len) & ~1;
261 /* bit 0 set signifies read only partition */
262 if (be32_to_cpu(part->len) & 1)
263 parts[i].mask_flags = MTD_WRITEABLE;
264
265 if (names && (plen > 0)) {
266 int len = strlen(names) + 1;
267
268 parts[i].name = names;
269 plen -= len;
270 names += len;
271 } else {
272 parts[i].name = "unnamed";
273 }
274
275 part++;
276 }
277
278 *pparts = parts;
279 return nr_parts;
280 }
281
282 static struct mtd_part_parser ofoldpart_parser = {
283 .parse_fn = parse_ofoldpart_partitions,
284 .name = "ofoldpart",
285 };
286
ofpart_parser_init(void)287 static int __init ofpart_parser_init(void)
288 {
289 register_mtd_parser(&ofpart_parser);
290 register_mtd_parser(&ofoldpart_parser);
291 return 0;
292 }
293
ofpart_parser_exit(void)294 static void __exit ofpart_parser_exit(void)
295 {
296 deregister_mtd_parser(&ofpart_parser);
297 deregister_mtd_parser(&ofoldpart_parser);
298 }
299
300 module_init(ofpart_parser_init);
301 module_exit(ofpart_parser_exit);
302
303 MODULE_LICENSE("GPL");
304 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
305 MODULE_AUTHOR("Vitaly Wool, David Gibson");
306 /*
307 * When MTD core cannot find the requested parser, it tries to load the module
308 * with the same name. Since we provide the ofoldpart parser, we should have
309 * the corresponding alias.
310 */
311 MODULE_ALIAS("fixed-partitions");
312 MODULE_ALIAS("ofoldpart");
313