mtd: nand: extend NAND flash detection to new MLC chips

Some of the newer MLC devices have a 6-byte ID sequence in which
several field definitions differ from older chips in a manner that is
not backward compatible.  For instance:

Samsung K9GAG08U0M (5-byte sequence): ec d5 14 b6 74
4th byte, bits 1:0 encode the page size: 0=1KiB, 1=2KiB, 2=4KiB, 3=8KiB
4th byte, bits 5:4 encode the block size: 0=64KiB, 1=128KiB, ...
4th byte, bit 6 encodes the OOB size: 0=8B/512B, 1=16B/512B

Samsung K9GAG08U0D (6-byte sequence): ec d5 94 29 34 41
4th byte, bits 1:0 encode the page size: 0=2KiB, 1=4KiB, 3=8KiB, 4=rsvd
4th byte, bits 7;5:4 encode the block size: 0=128KiB, 1=256KiB, ...
4th byte, bits 6;3:2 encode the OOB size: 1=128B/page, 2=218B/page

This patch uses the new 6-byte scheme if the following conditions are
all true:

1) The ID code wraps around after exactly 6 bytes

2) Manufacturer is Samsung

3) 6th byte is zero

The patch also extends the maximum OOB size from 128B to 256B.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 8bdacb885f90..50f3aa00a452 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -53,7 +53,7 @@ extern int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
  * is supported now. If you add a chip with bigger oobsize/page
  * adjust this accordingly.
  */
-#define NAND_MAX_OOBSIZE        128
+#define NAND_MAX_OOBSIZE        256
 #define NAND_MAX_PAGESIZE       4096
 
 /*