mtd: onenand: add new callback for bufferram read

This patch adds a new callback for the underlying drivers, which is
called instead of accessing the buffer ram directly. This callback will
be used by Samsung OneNAND driver to implement DMA transfers on S5PC110
SoC.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/onenand/onenand_base.c

@@ -1635,7 +1635,6 @@ static int onenand_verify_oob(struct mtd_info *mtd, const u_char *buf, loff_t to
 static int onenand_verify(struct mtd_info *mtd, const u_char *buf, loff_t addr, size_t len)
 {
 	struct onenand_chip *this = mtd->priv;
-	void __iomem *dataram;
 	int ret = 0;
 	int thislen, column;
 
@@ -1655,10 +1654,9 @@ static int onenand_verify(struct mtd_info *mtd, const u_char *buf, loff_t addr,
 
 		onenand_update_bufferram(mtd, addr, 1);
 
-		dataram = this->base + ONENAND_DATARAM;
-		dataram += onenand_bufferram_offset(mtd, ONENAND_DATARAM);
+		this->read_bufferram(mtd, ONENAND_DATARAM, this->verify_buf, 0, mtd->writesize);
 
-		if (memcmp(buf, dataram + column, thislen))
+		if (memcmp(buf, this->verify_buf, thislen))
 			return -EBADMSG;
 
 		len -= thislen;

include/linux/mtd/onenand.h

@@ -212,6 +212,8 @@ struct mtd_partition;
 
 struct onenand_platform_data {
 	void		(*mmcontrol)(struct mtd_info *mtd, int sync_read);
+	int		(*read_bufferram)(struct mtd_info *mtd, int area,
+			unsigned char *buffer, int offset, size_t count);
 	struct mtd_partition *parts;
 	unsigned int	nr_parts;
 };