1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * drivers/mtd/scpart.c: Sercomm Partition Parser
5 * Copyright (C) 2018 NOGUCHI Hiroshi
6 * Copyright (C) 2022 Mikhail Zhilkin
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/mtd/mtd.h>
12 #include <linux/mtd/partitions.h>
13 #include <linux/module.h>
15 #define MOD_NAME "scpart"
21 #define pr_fmt(fmt) MOD_NAME ": " fmt
23 #define ID_ALREADY_FOUND 0xffffffffUL
25 #define MAP_OFFS_IN_BLK 0x800
26 #define MAP_MIRROR_NUM 2
28 static const char sc_part_magic[] = {
29 'S', 'C', 'F', 'L', 'M', 'A', 'P', 'O', 'K', '\0',
31 #define PART_MAGIC_LEN sizeof(sc_part_magic)
33 /* assumes that all fields are set by CPU native endian */
40 static uint32_t scpart_desc_is_valid(struct sc_part_desc *pdesc)
42 return ((pdesc->part_id != 0xffffffffUL) &&
43 (pdesc->part_offs != 0xffffffffUL) &&
44 (pdesc->part_bytes != 0xffffffffUL));
47 static int scpart_scan_partmap(struct mtd_info *master, loff_t partmap_offs,
48 struct sc_part_desc **ppdesc)
55 struct sc_part_desc *pdesc = NULL;
56 struct sc_part_desc *tmpdesc;
59 buf = kzalloc(master->erasesize, GFP_KERNEL);
65 res2 = mtd_read(master, partmap_offs, master->erasesize, &retlen, buf);
66 if (res2 || retlen != master->erasesize) {
71 for (offs = MAP_OFFS_IN_BLK;
72 offs < master->erasesize - sizeof(*tmpdesc);
73 offs += sizeof(*tmpdesc)) {
74 tmpdesc = (struct sc_part_desc *)&buf[offs];
75 if (!scpart_desc_is_valid(tmpdesc))
81 int bytes = cnt * sizeof(*pdesc);
83 pdesc = kcalloc(cnt, sizeof(*pdesc), GFP_KERNEL);
88 memcpy(pdesc, &(buf[MAP_OFFS_IN_BLK]), bytes);
101 static int scpart_find_partmap(struct mtd_info *master,
102 struct sc_part_desc **ppdesc)
109 uint8_t rdbuf[PART_MAGIC_LEN];
111 while ((magic_found < MAP_MIRROR_NUM) &&
112 (offs < master->size) &&
113 !mtd_block_isbad(master, offs)) {
114 res2 = mtd_read(master, offs, PART_MAGIC_LEN, &retlen, rdbuf);
115 if (res2 || retlen != PART_MAGIC_LEN) {
119 if (!memcmp(rdbuf, sc_part_magic, PART_MAGIC_LEN)) {
120 pr_debug("Signature found at 0x%llx\n", offs);
122 res = scpart_scan_partmap(master, offs, ppdesc);
126 offs += master->erasesize;
131 pr_info("Valid 'SC PART MAP' (%d partitions) found at 0x%llx\n", res, offs);
133 pr_info("No valid 'SC PART MAP' was found\n");
138 static int scpart_parse(struct mtd_info *master,
139 const struct mtd_partition **pparts,
140 struct mtd_part_parser_data *data)
142 const char *partname;
147 struct sc_part_desc *scpart_map = NULL;
148 struct mtd_partition *parts = NULL;
149 struct device_node *mtd_node;
150 struct device_node *ofpart_node;
151 struct device_node *pp;
153 mtd_node = mtd_get_of_node(master);
159 ofpart_node = of_get_child_by_name(mtd_node, "partitions");
161 pr_info("%s: 'partitions' subnode not found on %pOF.\n",
162 master->name, mtd_node);
167 nr_scparts = scpart_find_partmap(master, &scpart_map);
168 if (nr_scparts <= 0) {
169 pr_info("No any partitions was found in 'SC PART MAP'.\n");
174 parts = kcalloc(of_get_child_count(ofpart_node), sizeof(*parts),
181 for_each_child_of_node(ofpart_node, pp) {
184 if (of_property_read_u32(pp, "sercomm,scpart-id", &scpart_id))
187 for (n = 0 ; n < nr_scparts ; n++)
188 if ((scpart_map[n].part_id != ID_ALREADY_FOUND) &&
189 (scpart_id == scpart_map[n].part_id))
195 /* add the partition found in OF into MTD partition array */
196 parts[nr_parts].offset = scpart_map[n].part_offs;
197 parts[nr_parts].size = scpart_map[n].part_bytes;
198 parts[nr_parts].of_node = pp;
200 if (!of_property_read_string(pp, "label", &partname))
201 parts[nr_parts].name = partname;
202 if (of_property_read_bool(pp, "read-only"))
203 parts[nr_parts].mask_flags |= MTD_WRITEABLE;
204 if (of_property_read_bool(pp, "lock"))
205 parts[nr_parts].mask_flags |= MTD_POWERUP_LOCK;
208 scpart_map[n].part_id = ID_ALREADY_FOUND;
217 pr_info("No partition in OF matches partition ID with 'SC PART MAP'.\n");
222 of_node_put(ofpart_node);
231 static const struct of_device_id scpart_parser_of_match_table[] = {
232 { .compatible = "sercomm,sc-partitions" },
235 MODULE_DEVICE_TABLE(of, scpart_parser_of_match_table);
237 static struct mtd_part_parser scpart_parser = {
238 .parse_fn = scpart_parse,
240 .of_match_table = scpart_parser_of_match_table,
242 module_mtd_part_parser(scpart_parser);
244 /* mtd parsers will request the module by parser name */
245 MODULE_ALIAS("scpart");
246 MODULE_LICENSE("GPL");
247 MODULE_AUTHOR("NOGUCHI Hiroshi <drvlabo@gmail.com>");
248 MODULE_AUTHOR("Mikhail Zhilkin <csharper2005@gmail.com>");
249 MODULE_DESCRIPTION("Sercomm partition parser");