On Fri, Oct 04, 2013 at 08:49:43PM +0100, Pekon Gupta wrote:
> OMAP NAND driver currently supports multiple flavours of 1-bit Hamming
> ecc-scheme, like:
> - OMAP_ECC_HAMMING_CODE_DEFAULT
> 1-bit hamming ecc code using software library
> - OMAP_ECC_HAMMING_CODE_HW
> 1-bit hamming ecc-code using GPMC h/w engine
> - OMAP_ECC_HAMMING_CODE_HW_ROMCODE
> 1-bit hamming ecc-code using GPMC h/w engin with ecc-layout compatible
> to ROM code.
>
> This patch combines above multiple ecc-schemes into single implementation:
> - OMAP_ECC_HAM1_CODE_HW
> 1-bit hamming ecc-code using GPMC h/w engine with ROM-code compatible
> ecc-layout.
If I have my NAND formatted with one of the existing ECC schemes (e.g.
OMAP_ECC_HAMMING_CODE_DEFAULT) will it work with the new
OMAP_ECC_HAM1_CODE_HW scheme?
Are they all compatible?
>
> Signed-off-by: Pekon Gupta <pekon@xxxxxx>
> ---
> Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++----
> arch/arm/mach-omap2/board-flash.c | 2 +-
> arch/arm/mach-omap2/gpmc.c | 4 +---
> drivers/mtd/nand/omap2.c | 9 +++------
> include/linux/platform_data/mtd-nand-omap2.h | 6 +-----
> 5 files changed, 10 insertions(+), 19 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
> index df338cb..25ee232 100644
> --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
> @@ -22,10 +22,10 @@ Optional properties:
> width of 8 is assumed.
>
> - ti,nand-ecc-opt: A string setting the ECC layout to use. One of:
> -
> - "sw" Software method (default)
> - "hw" Hardware method
> - "hw-romcode" gpmc hamming mode method & romcode layout
> + "sw" <deprecated> use "ham1" instead
> + "hw" <deprecated> use "ham1" instead
> + "hw-romcode" <deprecated> use "ham1" instead
> + "ham1" 1-bit Hamming ecc code
> "bch4" 4-bit BCH ecc code
> "bch8" 8-bit BCH ecc code
>
> diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c
> index fc20a61..ac82512 100644
> --- a/arch/arm/mach-omap2/board-flash.c
> +++ b/arch/arm/mach-omap2/board-flash.c
> @@ -142,7 +142,7 @@ __init board_nand_init(struct mtd_partition *nand_parts, u8 nr_parts, u8 cs,
> board_nand_data.nr_parts = nr_parts;
> board_nand_data.devsize = nand_type;
>
> - board_nand_data.ecc_opt = OMAP_ECC_HAMMING_CODE_DEFAULT;
> + board_nand_data.ecc_opt = OMAP_ECC_BCH8_CODE_HW;
> gpmc_nand_init(&board_nand_data, gpmc_t);
> }
> #endif /* CONFIG_MTD_NAND_OMAP2 || CONFIG_MTD_NAND_OMAP2_MODULE */
> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 9f4795a..1c45b72 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -1342,9 +1342,7 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
> #ifdef CONFIG_MTD_NAND
>
> static const char * const nand_ecc_opts[] = {
> - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw",
> - [OMAP_ECC_HAMMING_CODE_HW] = "hw",
> - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw-romcode",
> + [OMAP_ECC_HAM1_CODE_HW] = "ham1",
> [OMAP_ECC_BCH4_CODE_HW] = "bch4",
> [OMAP_ECC_BCH8_CODE_HW] = "bch8",
Won't this break existing dts which have "sw", "hw", or "hw-romcode"?
Someone may try to use a new kernel with an old dt, and we marked them
as deprecated, not removed.
Thanks,
Mark.
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