> 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.
M
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