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.
- LiuShuo
M
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