This patch add support for BCH16_ECC to omap_gpmc driver.
*need to BCH16 ECC scheme*
With newer SLC Flash technologies and MLC NAND, and large densities, pagesizes
Flash devices have become more suspectible to bit-flips. Thus stronger
ECC schemes are required for protecting the data.
But stronger ECC schemes have come with larger-sized ECC syndromes which require
more space in OOB/Spare. This puts constrains like;
(a) BCH16_ECC can correct 16 bit-flips per 512Bytes of data.
(b) BCH16_ECC generates 26-bytes of ECC syndrome / 512B.
Due to (b) this scheme can only be used with NAND devices which have enough
OOB to satisfy following equation:
OOBsize per page >= 26 * (page-size / 512)
Signed-off-by: Pekon Gupta <pekon@ti.com>
omap_gpmc.h is a generic header used by OMAP NAND driver for all TI platfoms.
Hence this file should be present in generic folder instead of architecture
specific include folder.
Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5
Signed-off-by: Pekon Gupta <pekon@ti.com>
Each SoC platform (AM33xx, OMAP3, OMAP4, OMAP5) has its own copy of GPMC related
defines and declarations scattered in SoC platform specific header files
like include/asm/arch-xx/cpu.h
However, GPMC hardware remains same across all platforms thus this patch merges
GPMC data scattered across different arch-xx specific header files into single
header file include/asm/arch/omap_gpmc.h
Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5
Signed-off-by: Pekon Gupta <pekon@ti.com>
OMAP NAND driver can detect Page-size and OOB-size of NAND device from ONFI
params or nand_id[] table. And based on that it defines ECC layout.
This patch
1) removes following board configs used for defining NAND ECC layout
- GPMC_NAND_ECC_LP_x16_LAYOUT (for large page x16 NAND)
- GPMC_NAND_ECC_LP_x8_LAYOUT (for large page x8 NAND)
- GPMC_NAND_ECC_SP_x16_LAYOUT (for small page x16 NAND)
- GPMC_NAND_ECC_SP_x8_LAYOUT (for small page x8 NAND)
2) removes unused #defines in common omap_gpmc.h depending on above configs
Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5
Signed-off-by: Pekon Gupta <pekon@ti.com>
Currently there are two sets of omap_gpmc.h header files
(a) arch/arm/include/asm/omap_gpmc.h
common header file for all platforms, containing defines and declarations used
by GPMC NAND driver.
(b) arch/arm/include/asm/arch-xx/omap_gpmc.h
SoC platform specific header file containing defines like ECC layout.
This patch removes platform specific arch-xx/omap_gpmc.c because:
- GPMC hardware engine is common for all SoC platforms hence only (a) is enough
- ECC layout is now defined in omap_nand.c driver itself based on ecc-scheme
selected. Hence all ECC layout declarations in (b) are redundant.
Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5
Signed-off-by: Pekon Gupta <pekon@ti.com>
chip->ecc.hwctl() is used for preparing the H/W controller before read/write
NAND accesses (like assigning data-buf, enabling ECC scheme configs, etc.)
Though all ECC schemes in OMAP NAND driver use GPMC controller for generating
ECC syndrome (for both Read/Write accesses). But but in current code
HAM1_ECC and BCHx_ECC schemes implement individual function to achieve this.
This patch
(1) removes omap_hwecc_init() and omap_hwecc_init_bch()
as chip->ecc.hwctl will re-initializeGPMC before every read/write call.
omap_hwecc_init_bch() -> omap_enable_ecc_bch()
(2) merges the GPMC configuration code for all ECC schemes into
single omap_enable_hwecc(), thus adding scalability for future ECC schemes.
omap_enable_hwecc() + omap_enable_ecc_bch() -> omap_enable_hwecc()
Signed-off-by: Pekon Gupta <pekon@ti.com>
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/arch-am33xx/omap_gpmc.h and
arch/arm/include/asm/arch-omap3/omap_gpmc.h are almost the same, consolidate
the common parts into a new header.
Introduce a new asm/omap_gpmc.h which defines the command part and pulls in
the architecture specific one.
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Cc: Tom Rini <trini@ti.com>
Reviewed-by: Tom Rini <trini@ti.com>
The existing timing does not quite meet the minimum requirements
in the LAN9221 datasheet. The timing in this patch solves problems
noticed on some parts. The patch also combines the CS configuration
for the overo and igep0020 boards per request.
Signed-off-by: Philip Balister <philip@opensdr.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
This helps to clean up the include/ directory so that it only contains
non-architecture-specific headers and also matches Linux's directory
layout which many U-Boot developers are already familiar with.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
pekon gupta
Wolfgang Denk
Andreas Bießmann
Philip Balister
Peter Tyser
Dirk Behme