mtd: nand: Create a NAND reset function

When NAND devices are resetted some initialization may have to be done,
like for example they have to be configured for the timing mode that
shall be used. To get a common place where this initialization can be
implemented create a nand_reset() function. This currently only issues
a NAND_CMD_RESET to the NAND device. The places issuing this command
manually are replaced with a call to nand_reset().

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Linux commit: 2f94abfe35b210e7711af9202a3dcfc9e779219a]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 3facbbd..df00fd1 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -1115,4 +1115,8 @@
 				void *ecc, int ecclen,
 				void *extraoob, int extraooblen,
 				int threshold);
+
+/* Reset and initialize a NAND device */
+int nand_reset(struct nand_chip *chip);
+
 #endif /* __LINUX_MTD_NAND_H */