--- /dev/null
+// 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:
+ 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");
projects / linux-2.6-microblaze.git / commitdiff