From mboxrd@z Thu Jan 1 00:00:00 1970 From: LiuShuo Date: Fri, 9 Dec 2011 16:58:26 +0800 Subject: [U-Boot] [PATCH 5/5] mtd/nand: workaround for Freescale FCM to support 4k pagesize Nand chip In-Reply-To: <201112090927.51821.marek.vasut@gmail.com> References: <1323341352-14996-1-git-send-email-Shengzhou.Liu@freescale.com> <201112081737.22273.marek.vasut@gmail.com> <4EE17395.5010308@freescale.com> <201112090927.51821.marek.vasut@gmail.com> Message-ID: <4EE1CDB2.6010102@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de ? 2011?12?09? 16:27, Marek Vasut ??: >> ? 2011?12?09? 00:37, Marek Vasut ??: >>>> 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 >>>> Signed-off-by: Liu Shuo >>>> --- >>>> >>>> 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); -Liu Shuo > M >