mtd: nand: zynq: Add support for the NAND lock/unlock operation

Zynq NAND driver is not support for NAND lock or unlock operation.
Hence, accidentally write into the critical NAND region might cause
data corruption to occur.

This commit is to add NAND lock/unlock command into NAND SMC register
set for NAND lock/unlock operaion.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Keng Soon Cheah <keng.soon.cheah@ni.com>
Cc: Chen Yee Chew <chen.yee.chew@ni.com>
Cc: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Scott Wood <oss@buserror.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/mtd/nand/zynq_nand.c b/drivers/mtd/nand/zynq_nand.c
index e6c80b5..076b878 100644
--- a/drivers/mtd/nand/zynq_nand.c
+++ b/drivers/mtd/nand/zynq_nand.c
@@ -84,6 +84,13 @@
 #define ZYNQ_NAND_ECC_BUSY	(1 << 6)	/* ECC block is busy */
 #define ZYNQ_NAND_ECC_MASK	0x00FFFFFF	/* ECC value mask */
 
+#ifndef NAND_CMD_LOCK_TIGHT
+#define NAND_CMD_LOCK_TIGHT 0x2c
+#endif
+
+#ifndef NAND_CMD_LOCK_STATUS
+#define NAND_CMD_LOCK_STATUS 0x7a
+#endif
 
 /* SMC register set */
 struct zynq_nand_smc_regs {
@@ -144,6 +151,11 @@
 	{NAND_CMD_PARAM, NAND_CMD_NONE, 1, 0},
 	{NAND_CMD_GET_FEATURES, NAND_CMD_NONE, 1, 0},
 	{NAND_CMD_SET_FEATURES, NAND_CMD_NONE, 1, 0},
+	{NAND_CMD_LOCK, NAND_CMD_NONE, 0, 0},
+	{NAND_CMD_LOCK_TIGHT, NAND_CMD_NONE, 0, 0},
+	{NAND_CMD_UNLOCK1, NAND_CMD_NONE, 3, 0},
+	{NAND_CMD_UNLOCK2, NAND_CMD_NONE, 3, 0},
+	{NAND_CMD_LOCK_STATUS, NAND_CMD_NONE, 3, 0},
 	{NAND_CMD_NONE, NAND_CMD_NONE, 0, 0},
 	/* Add all the flash commands supported by the flash device */
 };