mtd: nand: vf610_nfc: add hardware BCH-ECC support

This adds hardware ECC support using the BCH encoder in the NFC IP.
The ECC encoder supports up to 32-bit correction by using 60 error
correction bytes. There is no sub-page ECC step, ECC is calculated
always across the whole page (up to 2k pages).

Limitations:
- HW ECC: Only 2K page with 64+ OOB.
- HW ECC: Only 24 and 32-bit error correction implemented.

Raw writes have been tested using the generic nand_write_page_raw
implementation. However, raw reads are currently not possible
because the controller need to know whether we are going to use
the ECC mode already at NAND_CMD_READ0 command time. At this point
we do not have the information whether it is a raw read or a
regular read at driver level...

Signed-off-by: Bill Pringlemeir <bpringlemeir@nbsps.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 9f9736c76956..ccd1158715be 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -466,8 +466,10 @@ config MTD_NAND_VF610_NFC
 	help
 	  Enables support for NAND Flash Controller on some Freescale
 	  processors like the VF610, MPC5125, MCF54418 or Kinetis K70.
-	  The driver supports a maximum 2k page size. The driver
-	  currently does not support hardware ECC.
+	  The driver supports a maximum 2k page size. With 2k pages and
+	  64 bytes or more of OOB, hardware ECC with up to 32-bit error
+	  correction is supported. Hardware ECC is only enabled through
+	  device tree.
 
 config MTD_NAND_MXC
 	tristate "MXC NAND support"