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@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() +{ + struct fsl_ifc *ifc = ifc_ctrl->regs; + uint32_t cs = 0, csor = 0, csor_8k = 0, csor_ext = 0; + long long end_tick; + + cs = ifc_ctrl->cs_nand >> IFC_NAND_CSEL_SHIFT; + + /* Save CSOR and CSOR_ext */ + csor = in_be32(&ifc_ctrl->regs->csor_cs[cs].csor); + csor_ext = in_be32(&ifc_ctrl->regs->csor_cs[cs].csor_ext); + + /* chage PageSize 8K and SpareSize 1K*/ + csor_8k = (csor & ~(CSOR_NAND_PGS_MASK)) | 0x0018C000; + out_be32(&ifc_ctrl->regs->csor_cs[cs].csor, csor_8k); + out_be32(&ifc_ctrl->regs->csor_cs[cs].csor_ext, 0x0000400); + + /* READID */ + out_be32(&ifc->ifc_nand.nand_fir0, + (IFC_FIR_OP_CMD0 << IFC_NAND_FIR0_OP0_SHIFT) | + (IFC_FIR_OP_UA << IFC_NAND_FIR0_OP1_SHIFT) | + (IFC_FIR_OP_RB << IFC_NAND_FIR0_OP2_SHIFT)); + out_be32(&ifc->ifc_nand.nand_fcr0, + NAND_CMD_READID << IFC_NAND_FCR0_CMD0_SHIFT); + out_be32(&ifc->ifc_nand.row3, 0x0); + + out_be32(&ifc->ifc_nand.nand_fbcr, 0x0); + + /* Program ROW0/COL0 */ + out_be32(&ifc->ifc_nand.row0, 0x0); + out_be32(&ifc->ifc_nand.col0, 0x0); + + /* set the chip select for NAND Transaction */ + out_be32(&ifc->ifc_nand.nand_csel, ifc_ctrl->cs_nand); + + /* start read seq */ + out_be32(&ifc->ifc_nand.nandseq_strt, IFC_NAND_SEQ_STRT_FIR_STRT); + + /* wait for NAND Machine complete flag or timeout */ + end_tick = usec2ticks(IFC_TIMEOUT_MSECS * 1000) + get_ticks(); + + while (end_tick > get_ticks()) { + ifc_ctrl->status = in_be32(&ifc->ifc_nand.nand_evter_stat); + + if (ifc_ctrl->status & IFC_NAND_EVTER_STAT_OPC) + break; + } + + out_be32(&ifc->ifc_nand.nand_evter_stat, ifc_ctrl->status); + + /* Restore CSOR and CSOR_ext */ + out_be32(&ifc_ctrl->regs->csor_cs[cs].csor, csor); + out_be32(&ifc_ctrl->regs->csor_cs[cs].csor_ext, csor_ext); +} + int board_nand_init(struct nand_chip *nand) { struct fsl_ifc_mtd *priv; struct nand_ecclayout *layout; - uint32_t cspr = 0, csor = 0; + uint32_t cspr = 0, csor = 0, ver = 0;

if (!ifc_ctrl) { fsl_ifc_ctrl_init(); @@ -860,5 +916,9 @@ int board_nand_init(struct nand_chip *nand) nand->ecc.mode = NAND_ECC_SOFT; }

+ ver = in_be32(&ifc_ctrl->regs->ifc_rev); + if (ver == FSL_IFC_V1_1_0) + fsl_ifc_sram_init(); + return 0; }