diff options
Diffstat (limited to 'drivers/mtd/parsers/scpart.c')
| -rw-r--r-- | drivers/mtd/parsers/scpart.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/mtd/parsers/scpart.c b/drivers/mtd/parsers/scpart.c new file mode 100644 index 000000000000..02601bb33de4 --- /dev/null +++ b/drivers/mtd/parsers/scpart.c @@ -0,0 +1,249 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * drivers/mtd/scpart.c: Sercomm Partition Parser + * + * Copyright (C) 2018 NOGUCHI Hiroshi + * Copyright (C) 2022 Mikhail Zhilkin + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> +#include <linux/module.h> + +#define MOD_NAME "scpart" + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) MOD_NAME ": " fmt + +#define ID_ALREADY_FOUND 0xffffffffUL + +#define MAP_OFFS_IN_BLK 0x800 +#define MAP_MIRROR_NUM 2 + +static const char sc_part_magic[] = { + 'S', 'C', 'F', 'L', 'M', 'A', 'P', 'O', 'K', '\0', +}; +#define PART_MAGIC_LEN sizeof(sc_part_magic) + +/* assumes that all fields are set by CPU native endian */ +struct sc_part_desc { + uint32_t part_id; + uint32_t part_offs; + uint32_t part_bytes; +}; + +static uint32_t scpart_desc_is_valid(struct sc_part_desc *pdesc) +{ + return ((pdesc->part_id != 0xffffffffUL) && + (pdesc->part_offs != 0xffffffffUL) && + (pdesc->part_bytes != 0xffffffffUL)); +} + +static int scpart_scan_partmap(struct mtd_info *master, loff_t partmap_offs, + struct sc_part_desc **ppdesc) +{ + int cnt = 0; + int res = 0; + int res2; + loff_t offs; + size_t retlen; + struct sc_part_desc *pdesc = NULL; + struct sc_part_desc *tmpdesc; + uint8_t *buf; + + buf = kzalloc(master->erasesize, GFP_KERNEL); + if (!buf) { + res = -ENOMEM; + goto out; + } + + res2 = mtd_read(master, partmap_offs, master->erasesize, &retlen, buf); + if (res2 || retlen != master->erasesize) { + res = -EIO; + goto free; + } + + for (offs = MAP_OFFS_IN_BLK; + offs < master->erasesize - sizeof(*tmpdesc); + offs += sizeof(*tmpdesc)) { + tmpdesc = (struct sc_part_desc *)&buf[offs]; + if (!scpart_desc_is_valid(tmpdesc)) + break; + cnt++; + } + + if (cnt > 0) { + int bytes = cnt * sizeof(*pdesc); + + pdesc = kcalloc(cnt, sizeof(*pdesc), GFP_KERNEL); + if (!pdesc) { + res = -ENOMEM; + goto free; + } + memcpy(pdesc, &(buf[MAP_OFFS_IN_BLK]), bytes); + + *ppdesc = pdesc; + res = cnt; + } + +free: + kfree(buf); + +out: + return res; +} + +static int scpart_find_partmap(struct mtd_info *master, + struct sc_part_desc **ppdesc) +{ + int magic_found = 0; + int res = 0; + int res2; + loff_t offs = 0; + size_t retlen; + uint8_t rdbuf[PART_MAGIC_LEN]; + + while ((magic_found < MAP_MIRROR_NUM) && + (offs < master->size) && + !mtd_block_isbad(master, offs)) { + res2 = mtd_read(master, offs, PART_MAGIC_LEN, &retlen, rdbuf); + if (res2 || retlen != PART_MAGIC_LEN) { + res = -EIO; + goto out; + } + if (!memcmp(rdbuf, sc_part_magic, PART_MAGIC_LEN)) { + pr_debug("Signature found at 0x%llx\n", offs); + magic_found++; + res = scpart_scan_partmap(master, offs, ppdesc); + if (res > 0) + goto out; + } + offs += master->erasesize; + } + +out: + if (res > 0) + pr_info("Valid 'SC PART MAP' (%d partitions) found at 0x%llx\n", res, offs); + else + pr_info("No valid 'SC PART MAP' was found\n"); + + return res; +} + +static int scpart_parse(struct mtd_info *master, + const struct mtd_partition **pparts, + struct mtd_part_parser_data *data) +{ + const char *partname; + int n; + int nr_scparts; + int nr_parts = 0; + int res = 0; + struct sc_part_desc *scpart_map = NULL; + struct mtd_partition *parts = NULL; + struct device_node *mtd_node; + struct device_node *ofpart_node; + struct device_node *pp; + + mtd_node = mtd_get_of_node(master); + if (!mtd_node) { + res = -ENOENT; + goto out; + } + + ofpart_node = of_get_child_by_name(mtd_node, "partitions"); + if (!ofpart_node) { + pr_info("%s: 'partitions' subnode not found on %pOF.\n", + master->name, mtd_node); + res = -ENOENT; + goto out; + } + + nr_scparts = scpart_find_partmap(master, &scpart_map); + if (nr_scparts <= 0) { + pr_info("No any partitions was found in 'SC PART MAP'.\n"); + res = -ENOENT; + goto free; + } + + parts = kcalloc(of_get_child_count(ofpart_node), sizeof(*parts), + GFP_KERNEL); + if (!parts) { + res = -ENOMEM; + goto free; + } + + for_each_child_of_node(ofpart_node, pp) { + u32 scpart_id; + + if (of_property_read_u32(pp, "sercomm,scpart-id", &scpart_id)) + continue; + + for (n = 0 ; n < nr_scparts ; n++) + if ((scpart_map[n].part_id != ID_ALREADY_FOUND) && + (scpart_id == scpart_map[n].part_id)) + break; + if (n >= nr_scparts) + /* not match */ + continue; + + /* add the partition found in OF into MTD partition array */ + parts[nr_parts].offset = scpart_map[n].part_offs; + parts[nr_parts].size = scpart_map[n].part_bytes; + parts[nr_parts].of_node = pp; + + if (!of_property_read_string(pp, "label", &partname)) + parts[nr_parts].name = partname; + if (of_property_read_bool(pp, "read-only")) + parts[nr_parts].mask_flags |= MTD_WRITEABLE; + if (of_property_read_bool(pp, "lock")) + parts[nr_parts].mask_flags |= MTD_POWERUP_LOCK; + + /* mark as 'done' */ + scpart_map[n].part_id = ID_ALREADY_FOUND; + + nr_parts++; + } + + if (nr_parts > 0) { + *pparts = parts; + res = nr_parts; + } else + pr_info("No partition in OF matches partition ID with 'SC PART MAP'.\n"); + + of_node_put(pp); + +free: + of_node_put(ofpart_node); + kfree(scpart_map); + if (res <= 0) + kfree(parts); + +out: + return res; +} + +static const struct of_device_id scpart_parser_of_match_table[] = { + { .compatible = "sercomm,sc-partitions" }, + {}, +}; +MODULE_DEVICE_TABLE(of, scpart_parser_of_match_table); + +static struct mtd_part_parser scpart_parser = { + .parse_fn = scpart_parse, + .name = "scpart", + .of_match_table = scpart_parser_of_match_table, +}; +module_mtd_part_parser(scpart_parser); + +/* mtd parsers will request the module by parser name */ +MODULE_ALIAS("scpart"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("NOGUCHI Hiroshi <drvlabo@gmail.com>"); +MODULE_AUTHOR("Mikhail Zhilkin <csharper2005@gmail.com>"); +MODULE_DESCRIPTION("Sercomm partition parser"); |