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 LiuShengzhou.Liu@freescale.com > Signed-off-by: Liu Shuob35362@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