mtd: gpmi: rewrite the gpmi_ecc_write_oob() to support the jffs2

When we use the ECC info which is get from the nand chip's datasheet,
we may have some freed oob area now.

This patch rewrites the gpmi_ecc_write_oob() to implement the ecc.write_oob().
We also update the comment for gpmi_hw_ecclayout.

Yes! We can support the JFFS2 for the SLC nand now.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 20 insertions, 9 deletions

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 10a092dbaa71..37508eb350d0 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -45,7 +45,10 @@ static struct nand_bbt_descr gpmi_bbt_descr = {
         .pattern        = scan_ff_pattern
 };
 
-/*  We will use all the (page + OOB). */
+/*
+ * We may change the layout if we can get the ECC info from the datasheet,
+ * else we will use all the (page + OOB).
+ */
 static struct nand_ecclayout gpmi_hw_ecclayout = {
         .eccbytes = 0,
         .eccpos = { 0, },
@@ -1263,14 +1266,22 @@ static int gpmi_ecc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
 static int
 gpmi_ecc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page)
 {
-        /*
-         * The BCH will use all the (page + oob).
-         * Our gpmi_hw_ecclayout can only prohibit the JFFS2 to write the oob.
-         * But it can not stop some ioctls such MEMWRITEOOB which uses
-         * MTD_OPS_PLACE_OOB. So We have to implement this function to prohibit
-         * these ioctls too.
-         */
-        return -EPERM;
+        struct nand_oobfree *of = mtd->ecclayout->oobfree;
+        int status = 0;
+
+        /* Do we have available oob area? */
+        if (!of->length)
+                return -EPERM;
+
+        if (!nand_is_slc(chip))
+                return -EPERM;
+
+        chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize + of->offset, page);
+        chip->write_buf(mtd, chip->oob_poi + of->offset, of->length);
+        chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+
+        status = chip->waitfunc(mtd, chip);
+        return status & NAND_STATUS_FAIL ? -EIO : 0;
 }
 
 static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs)