> 于 2011年12月09日 00:37, Marek Vasut 写道:
> >> Freescale FCM controller has a 2K size limitation of buffer RAM. In
> >> order to support the Nand flash chip whose page size is larger than 2K
> >> bytes, we read/write 2k data repeatedly by issuing FIR_OP_RB/FIR_OP_WB
> >> and save them to a large buffer.
> >>
> >> Signed-off-by: Shengzhou Liu<shengzhou....@freescale.com>
> >> Signed-off-by: Liu Shuo<b35...@freescale.com>
> >> ---
> >>
> >> drivers/mtd/nand/fsl_elbc_nand.c | 279
> >>
> >> +++++++++++++++++++++++++++++++++---- 1 files changed, 248
> >> insertions(+), 31 deletions(-)
> >>
> >> diff --git a/drivers/mtd/nand/fsl_elbc_nand.c
> >> b/drivers/mtd/nand/fsl_elbc_nand.c index 52362b1..3983c8c 100644
> >> --- a/drivers/mtd/nand/fsl_elbc_nand.c
> >> +++ b/drivers/mtd/nand/fsl_elbc_nand.c
> >> @@ -64,7 +64,6 @@ struct fsl_elbc_mtd {
> >>
> >> struct device *dev;
> >> int bank; /* Chip select bank number */
> >> u8 __iomem *vbase; /* Chip select base virtual address */
> >>
> >> - int page_size; /* NAND page size (0=512, 1=2048) */
> >>
> >> unsigned int fmr; /* FCM Flash Mode Register value */
> >>
> >> };
> >>
> >> @@ -85,6 +84,8 @@ struct fsl_elbc_ctrl {
> >>
> >> unsigned int mdr; /* UPM/FCM Data Register value */
> >> unsigned int use_mdr; /* Non zero if the MDR is to be set */
> >> unsigned int oob; /* Non zero if operating on OOB data */
> >>
> >> + char *buffer; /* just used when pagesize is greater */
> >
> > Start sentence with capital letter
> >
> >> + /* than FCM RAM 2K limitation */
> >>
> >> };
> >>
> >> /* These map to the positions used by the FCM hardware ECC generator
> >> */
> >>
> >> @@ -159,6 +160,44 @@ static struct nand_bbt_descr bbt_mirror_descr = {
> >>
> >> .pattern = mirror_pattern,
> >>
> >> };
> >>
> >> +static void io_to_buffer(struct mtd_info *mtd, int subpage, int oob)
> >> +{
> >> + struct nand_chip *chip = mtd->priv;
> >> + struct fsl_elbc_mtd *priv = chip->priv;
> >> + struct fsl_elbc_ctrl *ctrl = priv->ctrl;
> >> + void *src, *dst;
> >> + int len = (oob ? 64 : 2048);
> >
> > No parenthesis ...
> >
> >> +
> >> + /* for emulating 4096+ bytes NAND using 2048-byte FCM RAM */
> >> + if (oob)
> >> + dst = ctrl->buffer + mtd->writesize + subpage * 64;
> >> + else
> >> + dst = ctrl->buffer + subpage * 2048;
> >
> > subpage * len ?
>
> dst = ctrl->buffer + (oob ? mtd->writesize : 0) + subpage * len ?
> Is this important ? I think it is ok.
dst = ctrl->buffer + subpage * len;
if (oob)
dst += mtd->writesize;
it's important, this code looks like mess. You introduce len and don't use it
anywhere then ?
M
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