diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 7666c42..0f74454 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -396,6 +396,10 @@
  * @block_markbad:	[REPLACEABLE] mark the block bad
  * @cmd_ctrl:		[BOARDSPECIFIC] hardwarespecific funtion for controlling
  *			ALE/CLE/nCE. Also used to write command and address
+ * @init_size:		[BOARDSPECIFIC] hardwarespecific funtion for setting
+ *			mtd->oobsize, mtd->writesize and so on.
+ *			@id_data contains the 8 bytes values of NAND_CMD_READID.
+ *			Return with the bus width.
  * @dev_ready:		[BOARDSPECIFIC] hardwarespecific function for accesing device ready/busy line
  *			If set to NULL no access to ready/busy is available and the ready/busy information
  *			is read from the chip status register
@@ -452,6 +456,8 @@
 	int		(*block_markbad)(struct mtd_info *mtd, loff_t ofs);
 	void		(*cmd_ctrl)(struct mtd_info *mtd, int dat,
 				    unsigned int ctrl);
+	int		(*init_size)(struct mtd_info *mtd,
+					struct nand_chip *this, u8 *id_data);
 	int		(*dev_ready)(struct mtd_info *mtd);
 	void		(*cmdfunc)(struct mtd_info *mtd, unsigned command, int column, int page_addr);
 	int		(*waitfunc)(struct mtd_info *mtd, struct nand_chip *this);