This patch adds CONFIG_SPL_NAND_DEVICE_WIDTH to specify bus-width of NAND device
CONFIG_SPL_NAND_DEVICE_WIDTH == 16: NAND device with x16 bus-width
CONFIG_SPL_NAND_DEVICE_WIDTH == 8: NAND device with x8 bus-width
Need for a separate CONFIG_xx arise from following situations.
(1) SPL NAND drivers does not have framework to parse ONFI parameter page.
(2) if !defined(CONFIG_SYS_NAND_SELF_INIT)
|- board_nand_init()
|- nand_scan()
|- nand_scan_ident()
|- nand_scan_tail()
This means board_nand_init() is called before nand_scan_ident(). So NAND
controller is initialized before the actual probing of NAND device.
However some controller (like GPMC) need to be specifically configured for
bus-width of NAND device.
In such cases, bus-width of the NAND device should be known in advance
of actual device probing. Hence, CONFIG_SPL_NAND_DEVICE_WIDTH is useful.
(3) Non-ONFI compliant devices need some mechanism to specify device bus-width
to driver.
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>
This patch adds new CONFIG_NAND_OMAP_ECCSCHEME, replacing other distributed
CONFIG_xx used for selecting NAND ecc-schemes.
This patch aims at solving following issues.
1) Currently ecc-scheme is tied to SoC platform, which prevents user to select
other ecc-schemes also supported in hardware. like;
- most of OMAP3 SoC platforms use only 1-bit Hamming ecc-scheme, inspite
the fact that they can use higher ecc-schemes like 8-bit ecc-schemes with
software based error detection (OMAP_ECC_BCH4_CODE_HW_DETECTION_SW).
- most of AM33xx SoC plaforms use 8-bit BCH ecc-scheme for now, but hardware
supports BCH16 ecc-scheme also.
2) Different platforms use different CONFIG_xx to select ecc-schemes, which
adds confusion for user while migrating platforms.
- *CONFIG_NAND_OMAP_ELM* which enables ELM hardware engine, selects only
8-bit BCH ecc-scheme with h/w based error-correction (OMAP_ECC_BCH8_CODE_HW)
whereas ELM hardware engine supports other ecc-schemes also like; BCH4,
and BCH16 (in future).
- *CONFIG_NAND_OMAP_BCH8* selects 8-bit BCH ecc-scheme with s/w based error
correction (OMAP_ECC_BCH8_CODE_HW_DETECTION_SW).
- *CONFIG_SPL_NAND_SOFTECC* selects 1-bit Hamming ecc-scheme using s/w library
Thus adding new *CONFIG_NAND_OMAP_ECCSCHEME* de-couples ecc-scheme dependency
on SoC platform and NAND driver. And user can select ecc-scheme independently
foreach board.
However, selection some hardware based ecc-schemes (OMAP_ECC_BCHx_CODE_HW) still
depends on presence of ELM hardware engine on SoC. (Refer doc/README.nand)
Signed-off-by: Pekon Gupta <pekon@ti.com>
ELM hardware engine which is used for ECC error detection, is present on all
latest OMAP SoC (like OMAP4xxx, OMAP5xxx, DRA7xxx, AM33xx, AM43xx). Thus ELM
driver should be moved to common drivers/mtd/nand/ folder so that all SoC
having on-chip ELM hardware engine can re-use it.
This patch has following changes:
- mv arch/arm/include/asm/arch-am33xx/elm.h arch/arm/include/asm/omap_elm.h
- mv arch/arm/cpu/armv7/am33xx/elm.c drivers/mtd/nand/omap_elm.c
- update Makefiles
- update #include <asm/elm.h>
- add CONFIG_NAND_OMAP_ELM to compile driver/mtd/nand/omap_elm.c
and include in all board configs using AM33xx SoC platform.
Signed-off-by: Pekon Gupta <pekon@ti.com>
Pekon Gupta
Tom Rini
Heiko Schocher