mtd: nand: add lock/unlock routines

Add nand lock / unlock routines. At least 'micron' parts
support this.

Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index ccab9df..48bc2c5 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -38,6 +38,12 @@
 /* Internal helper for board drivers which need to override command function */
 extern void nand_wait_ready(struct mtd_info *mtd);
 
+/* locks all blockes present in the device */
+extern int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+
+/* unlocks specified locked blockes */
+extern int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+
 /* The maximum number of NAND chips in an array */
 #define NAND_MAX_CHIPS		8
 
@@ -82,6 +88,10 @@
 #define NAND_CMD_ERASE2		0xd0
 #define NAND_CMD_RESET		0xff
 
+#define NAND_CMD_LOCK		0x2a
+#define NAND_CMD_UNLOCK1	0x23
+#define NAND_CMD_UNLOCK2	0x24
+
 /* Extended commands for large page devices */
 #define NAND_CMD_READSTART	0x30
 #define NAND_CMD_RNDOUTSTART	0xE0