mtd: nand: introduce NAND_CREATE_EMPTY_BBT

it will create an empty BBT table without considering vendor's BBT
information. Vendor's information may be unavailable if the NAND
controller has a different DATA & OOB layout or this information may be
allready purged.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/nand_bbt.c

@@ -999,6 +999,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc
 			continue;
 
 		/* Create the table in memory by scanning the chip(s) */
+		if (!(this->options & NAND_CREATE_EMPTY_BBT))
 			create_bbt(mtd, buf, bd, chipsel);
 
 		td->version[i] = 1;

include/linux/mtd/bbm.h

@@ -84,7 +84,7 @@ struct nand_bbt_descr {
 #define NAND_BBT_PERCHIP	0x00000080
 /* bbt has a version counter at offset veroffs */
 #define NAND_BBT_VERSION	0x00000100
-/* Create a bbt if none axists */
+/* Create a bbt if none exists */
 #define NAND_BBT_CREATE		0x00000200
 /* Search good / bad pattern through all pages of a block */
 #define NAND_BBT_SCANALLPAGES	0x00000400

include/linux/mtd/nand.h

@@ -223,6 +223,8 @@ typedef enum {
  * the OOB area.
  */
 #define NAND_USE_FLASH_BBT_NO_OOB	0x00100000
+/* Create an empty BBT with no vendor information if the BBT is available */
+#define NAND_CREATE_EMPTY_BBT		0x00200000
 
 /* Options set by nand scan */
 /* Nand scan has allocated controller struct */