mtd: nand: omap: enable BCH ECC scheme using ELM for generic platform
authorpekon gupta <pekon@ti.com>
Mon, 18 Nov 2013 13:33:00 +0000 (19:03 +0530)
committerScott Wood <scottwood@freescale.com>
Thu, 21 Nov 2013 19:33:41 +0000 (13:33 -0600)
commitd016dc42cedbf6102e100fa9ecb58462edfb14f8
treea9d18ed5230c98f8f8ccd0d4b504edafdf3424b2
parentbeba5f04f2215c81016fbfb727257ea6667aca85
mtd: nand: omap: enable BCH ECC scheme using ELM for generic platform

BCH8_ECC scheme implemented in omap_gpmc.c driver has following favours
+-----------------------------------+-----------------+-----------------+
|ECC Scheme                         | ECC Calculation | Error Detection |
+-----------------------------------+-----------------+-----------------+
|OMAP_ECC_BCH8_CODE_HW              |GPMC             |ELM H/W engine   |
|OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |GPMC             |S/W BCH library  |
+-----------------------------------+-----------------+-----------------+

Current implementation limits the BCH8_CODE_HW only for AM33xx device family.
(using CONFIG_AM33XX). However, other SoC families (like TI81xx) also have
ELM hardware module, and can support ECC error detection using ELM.

This patch
- removes CONFIG_AM33xx
Thus this driver can be reused by all devices having ELM h/w engine.
- adds omap_select_ecc_scheme()
A common function to handle ecc-scheme related configurations. This
can be used both during device-probe and via user-space u-boot commads
to change ecc-scheme. During device probe ecc-scheme is selected based
on CONFIG_NAND_OMAP_ELM or CONFIG_NAND_OMAP_BCH8
- enables CONFIG_BCH
S/W library (lib/bch.c) required by OMAP_ECC_BCHx_CODE_HW_DETECTION_SW
   is enabled by CONFIG_BCH.
- enables CONFIG_SYS_NAND_ONFI_DETECTION
for auto-detection of ONFI compliant NAND devices
- updates following README doc
doc/README.nand
board/ti/am335x/README
doc/README.omap3

Signed-off-by: Pekon Gupta <pekon@ti.com>
[scottwood@freescale.com: fixed unused variable warning]
Signed-off-by: Scott Wood <scottwood@freescale.com>
arch/arm/include/asm/omap_gpmc.h
doc/README.nand
drivers/mtd/nand/omap_gpmc.c