mtd: nand: export default read/write oob functions

Export the default read/write oob functions (for the standard and syndrome
scheme), so that drivers can use them for their raw implementation and
implement their own functions for the normal oob operation.

This is required if your ECC engine is capable of fixing some of the OOB
data. In this case you have to overload the ->read_oob() and ->write_oob(),
but if you don't specify the ->read/write_oob_raw() functions they are
assigned to the ->read/write_oob() implementation, which is not what you
want.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 0f0c5b1..13fcddc 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1893,13 +1893,13 @@
  * @chip: nand chip info structure
  * @page: page number to read
  */
-static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
-			     int page)
+int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page)
 {
 	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
 	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
 	return 0;
 }
+EXPORT_SYMBOL(nand_read_oob_std);
 
 /**
  * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
@@ -1908,8 +1908,8 @@
  * @chip: nand chip info structure
  * @page: page number to read
  */
-static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
-				  int page)
+int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+			   int page)
 {
 	int length = mtd->oobsize;
 	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
@@ -1937,6 +1937,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL(nand_read_oob_syndrome);
 
 /**
  * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
@@ -1944,8 +1945,7 @@
  * @chip: nand chip info structure
  * @page: page number to write
  */
-static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
-			      int page)
+int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page)
 {
 	int status = 0;
 	const uint8_t *buf = chip->oob_poi;
@@ -1960,6 +1960,7 @@
 
 	return status & NAND_STATUS_FAIL ? -EIO : 0;
 }
+EXPORT_SYMBOL(nand_write_oob_std);
 
 /**
  * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
@@ -1968,8 +1969,8 @@
  * @chip: nand chip info structure
  * @page: page number to write
  */
-static int nand_write_oob_syndrome(struct mtd_info *mtd,
-				   struct nand_chip *chip, int page)
+int nand_write_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+			    int page)
 {
 	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
 	int eccsize = chip->ecc.size, length = mtd->oobsize;
@@ -2019,6 +2020,7 @@
 
 	return status & NAND_STATUS_FAIL ? -EIO : 0;
 }
+EXPORT_SYMBOL(nand_write_oob_syndrome);
 
 /**
  * nand_do_read_oob - [INTERN] NAND read out-of-band