mtd: onenand: add new option to control initial onenand unlocking

A new option ONENAND_SKIP_INITIAL_UNLOCKING is added. This allows
to disable initial onenand unlocking when the driver is initialized.

Signed-off-by: Roman Tereshonkov <roman.tereshonkov@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/onenand/onenand_base.c

@@ -4085,7 +4085,8 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
 	mtd->writebufsize = mtd->writesize;
 
 	/* Unlock whole block */
-	this->unlock_all(mtd);
+	if (!(this->options & ONENAND_SKIP_INITIAL_UNLOCKING))
+		this->unlock_all(mtd);
 
 	ret = this->scan_bbt(mtd);
 	if ((!FLEXONENAND(this)) || ret)

include/linux/mtd/onenand.h

@@ -198,6 +198,7 @@ struct onenand_chip {
 #define ONENAND_SKIP_UNLOCK_CHECK	(0x0100)
 #define ONENAND_PAGEBUF_ALLOC		(0x1000)
 #define ONENAND_OOBBUF_ALLOC		(0x2000)
+#define ONENAND_SKIP_INITIAL_UNLOCKING	(0x4000)
 
 #define ONENAND_IS_4KB_PAGE(this)					\
 	(this->options & ONENAND_HAS_4KB_PAGE)