> 于 2011年12月09日 17:11, Marek Vasut 写道:
> >> 于 2011年12月09日 16:27, Marek Vasut 写道:
> >>>> 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 ?
> >>
> >> memcpy_fromio(dst, src, len);
> >
> > Ok, why not use it consistently then.
>
> I think it is pellucid. I still don't think it is very important.
Ok, enough of this stuff, apparently I'm loosing time here. Let's see what
others think.
M
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