[U-Boot] driver/mtd:IFC NAND:Initialise internal SRAM before any write
Scott Wood
scottwood at freescale.com
Fri Nov 16 00:54:28 CET 2012
On Wed, Sep 12, 2012 at 10:26:05PM -0000, Prabhakar Kushwaha wrote:
> IFC-1.1.0 uses 28nm techenology for SRAM. This tech has known limitaion for
> SRAM i.e. "byte select" is not supported. Hence Read Modify Write is
> implemented in IFC for any "system side write" into sram buffer. Reading an
> uninitialized memory results in ECC Error from sram wrapper.
>
> Hence we must initialize/prefill SRAM buffer by any data before writing
> anything in SRAM from system side. To initialize SRAM user can use "READID"
> NAND command with read bytes equal to SRAM size. It will be a one time
> activity post boot
>
> Signed-off-by: Prabhakar Kushwaha <prabhakar at freescale.com>
>
> ---
> Based upon git://git.denx.de/u-boot.git (branch master)
>
> This patchs depends upon following patch
> http://patchwork.ozlabs.org/patch/178332/
>
> drivers/mtd/nand/fsl_ifc_nand.c | 62 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 61 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c
> index a518526..140fdc7 100644
> --- a/drivers/mtd/nand/fsl_ifc_nand.c
> +++ b/drivers/mtd/nand/fsl_ifc_nand.c
> @@ -30,6 +30,7 @@
> #include <asm/errno.h>
> #include <asm/fsl_ifc.h>
>
> +#define FSL_IFC_V1_1_0 0x01010000
> #define MAX_BANKS 4
> #define ERR_BYTE 0xFF /* Value returned for read bytes
> when read failed */
> @@ -738,11 +739,66 @@ static void fsl_ifc_select_chip(struct mtd_info *mtd, int chip)
> {
> }
>
> +static void fsl_ifc_sram_init()
fsl_ifc_nand.c:742:13: warning: function declaration isn't a prototype
Fixed and applied to u-boot-nand-flash
-Scott
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