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>
diff --git a/arch/arm/include/asm/omap_gpmc.h b/arch/arm/include/asm/omap_gpmc.h
index dd40cb6..d4143ec 100644
--- a/arch/arm/include/asm/omap_gpmc.h
+++ b/arch/arm/include/asm/omap_gpmc.h
@@ -68,4 +68,20 @@
}
#endif
+enum omap_ecc {
+ /* 1-bit ECC calculation by Software, Error detection by Software */
+ OMAP_ECC_HAM1_CODE_SW = 1, /* avoid un-initialized int can be 0x0 */
+ /* 1-bit ECC calculation by GPMC, Error detection by Software */
+ /* ECC layout compatible to legacy ROMCODE. */
+ OMAP_ECC_HAM1_CODE_HW,
+ /* 4-bit ECC calculation by GPMC, Error detection by Software */
+ OMAP_ECC_BCH4_CODE_HW_DETECTION_SW,
+ /* 4-bit ECC calculation by GPMC, Error detection by ELM */
+ OMAP_ECC_BCH4_CODE_HW,
+ /* 8-bit ECC calculation by GPMC, Error detection by Software */
+ OMAP_ECC_BCH8_CODE_HW_DETECTION_SW,
+ /* 8-bit ECC calculation by GPMC, Error detection by ELM */
+ OMAP_ECC_BCH8_CODE_HW,
+};
+
#endif /* __ASM_OMAP_GPMC_H */