mtd: bcm47xxpart: support TRX data partition being UBI

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/bcm47xxpart.c

@@ -40,6 +40,7 @@
 #define ML_MAGIC2			0x26594131
 #define TRX_MAGIC			0x30524448
 #define SQSH_MAGIC			0x71736873	/* shsq */
+#define UBI_EC_MAGIC			0x23494255	/* UBI# */
 
 struct trx_header {
 	uint32_t magic;
@@ -50,14 +51,34 @@ struct trx_header {
 	uint32_t offset[3];
 } __packed;
 
-static void bcm47xxpart_add_part(struct mtd_partition *part, char *name,
+static void bcm47xxpart_add_part(struct mtd_partition *part, const char *name,
 				 u64 offset, uint32_t mask_flags)
 {
 	part->name = name;
 	part->offset = offset;
 	part->mask_flags = mask_flags;
 }
 
+static const char *bcm47xxpart_trx_data_part_name(struct mtd_info *master,
+						  size_t offset)
+{
+	uint32_t buf;
+	size_t bytes_read;
+
+	if (mtd_read(master, offset, sizeof(buf), &bytes_read,
+		     (uint8_t *)&buf) < 0) {
+		pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
+			offset);
+		goto out_default;
+	}
+
+	if (buf == UBI_EC_MAGIC)
+		return "ubi";
+
+out_default:
+	return "rootfs";
+}
+
 static int bcm47xxpart_parse(struct mtd_info *master,
 			     struct mtd_partition **pparts,
 			     struct mtd_part_parser_data *data)
@@ -186,8 +207,11 @@ static int bcm47xxpart_parse(struct mtd_info *master,
 			 * we want to have jffs2 (overlay) in the same mtd.
 			 */
 			if (trx->offset[i]) {
+				const char *name;
+
+				name = bcm47xxpart_trx_data_part_name(master, offset + trx->offset[i]);
 				bcm47xxpart_add_part(&parts[curr_part++],
-						     "rootfs",
+						     name,
 						     offset + trx->offset[i],
 						     0);
 				i++;