From patchwork Thu Jul 16 21:59:50 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: nsnehaprabha@ti.com X-Patchwork-Id: 35949 Received: from comal.ext.ti.com (comal.ext.ti.com [198.47.26.152]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n6GM3ami010715 for ; Thu, 16 Jul 2009 22:03:36 GMT Received: from dlep34.itg.ti.com ([157.170.170.115]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id n6GM0cPb001886; Thu, 16 Jul 2009 17:00:43 -0500 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep34.itg.ti.com (8.13.7/8.13.7) with ESMTP id n6GM0aLZ000637; Thu, 16 Jul 2009 17:00:37 -0500 (CDT) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id B6985807DD; Thu, 16 Jul 2009 17:00:12 -0500 (CDT) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dlep34.itg.ti.com (dlep34.itg.ti.com [157.170.170.115]) by linux.omap.com (Postfix) with ESMTP id A5E9380642 for ; Thu, 16 Jul 2009 16:59:51 -0500 (CDT) Received: from legion.dal.design.ti.com (localhost [127.0.0.1]) by dlep34.itg.ti.com (8.13.7/8.13.7) with ESMTP id n6GLxojb029690; Thu, 16 Jul 2009 16:59:51 -0500 (CDT) Received: from gt9szxw61.gt.design.ti.com (gt9szxw61.gt.design.ti.com [158.218.100.25]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id n6GLxo907341; Thu, 16 Jul 2009 16:59:50 -0500 (CDT) Received: from gt9szxw61.gt.design.ti.com (localhost [127.0.0.1]) by gt9szxw61.gt.design.ti.com (8.13.1/8.13.1) with ESMTP id n6GLxo9t011350; Thu, 16 Jul 2009 17:59:50 -0400 Received: (from a0869522@localhost) by gt9szxw61.gt.design.ti.com (8.13.1/8.13.1/Submit) id n6GLxofK011347; Thu, 16 Jul 2009 17:59:50 -0400 From: nsnehaprabha@ti.com To: linux-mtd@lists.infradead.org, davinci-linux-open-source@linux.davincidsp.com, dwmw2@infradead.org, tglx@linutronix.de, akpm@linux-foundation.org Date: Thu, 16 Jul 2009 17:59:50 -0400 Message-Id: <1247781590-11323-1-git-send-email-nsnehaprabha@ti.com> X-Mailer: git-send-email 1.6.0.4 Cc: Subject: [PATCH v3 3/3] mtd-nand: DaVinci: Add 4-bit ECC support for large page NAND chips X-BeenThere: davinci-linux-open-source@linux.davincidsp.com X-Mailman-Version: 2.1.4 Precedence: list List-Id: davinci-linux-open-source.linux.davincidsp.com List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: davinci-linux-open-source-bounces@linux.davincidsp.com Errors-To: davinci-linux-open-source-bounces@linux.davincidsp.com From: Sneha Narnakaje This patch adds 4-bit ECC support for large page NAND chips using the new ECC mode NAND_ECC_HW_OOB_FIRST. The platform data from board-dm355-evm has been adjusted to use this mode. The patches have been verified on DM355 device with 2K Micron devices using mtd-tests and JFFS2. Error correction upto 4-bits has also been verified using nandwrite/nanddump utilities. This patch series applies to linux-mtd next (mmotm) GIT tree. This version (v3) addresses the review comment to keep OOB bytes towards the end of sparebytes region. It also fixes a bug in the ECC correction handler. When we introduce 5 bit-errors in chunk, error correction stops working. When errors are detected the 4BITECC_START bit was left high, which should be cleared. Reviewed-by: David Brownell Signed-off-by: Sneha Narnakaje Signed-off-by: Sandeep Paulraj --- drivers/mtd/nand/davinci_nand.c | 45 +++++++++++++++++++++++++++++++++----- 1 files changed, 39 insertions(+), 6 deletions(-) diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c index 0fad648..14c72d2 100644 --- a/drivers/mtd/nand/davinci_nand.c +++ b/drivers/mtd/nand/davinci_nand.c @@ -348,6 +348,12 @@ compare: if (!(syndrome[0] | syndrome[1] | syndrome[2] | syndrome[3])) return 0; + /* + * Clear any previous address calculation by doing a dummy read of an + * error address register. + */ + davinci_nand_readl(info, NAND_ERR_ADD1_OFFSET); + /* Start address calculation, and wait for it to complete. * We _could_ start reading more data while this is working, * to speed up the overall page read. @@ -359,8 +365,10 @@ compare: switch ((fsr >> 8) & 0x0f) { case 0: /* no error, should not happen */ + davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET); return 0; case 1: /* five or more errors detected */ + davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET); return -EIO; case 2: /* error addresses computed */ case 3: @@ -500,6 +508,26 @@ static struct nand_ecclayout hwecc4_small __initconst = { }, }; +/* An ECC layout for using 4-bit ECC with large-page (2048bytes) flash, + * storing ten ECC bytes plus the manufacturer's bad block marker byte, + * and not overlapping the default BBT markers. + */ +static struct nand_ecclayout hwecc4_2048 __initconst = { + .eccbytes = 40, + .eccpos = { + /* at the end of spare sector */ + 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, + 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, + 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, + 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, + }, + .oobfree = { + /* 1 byte at offset 0 holds manufacturer badblock marker */ + {.offset = 1, .length = 23, }, + /* 5 bytes at offset 8 hold BBT markers */ + /* 8 bytes at offset 16 hold JFFS2 clean markers */ + }, +}; static int __init nand_davinci_probe(struct platform_device *pdev) { @@ -690,15 +718,20 @@ static int __init nand_davinci_probe(struct platform_device *pdev) info->mtd.oobsize - 16; goto syndrome_done; } + if (chunks == 4) { + info->ecclayout = hwecc4_2048; + info->chip.ecc.mode = NAND_ECC_HW_OOB_FIRST; + goto syndrome_done; + } - /* For large page chips we'll be wanting to use a - * not-yet-implemented mode that reads OOB data - * before reading the body of the page, to avoid - * the "infix OOB" model of NAND_ECC_HW_SYNDROME - * (and preserve manufacturer badblock markings). + /* 4K page chips are not yet supported. The eccpos from + * nand_ecclayout cannot hold 80 bytes and change to eccpos[] + * breaks userspace ioctl interface with mtd-utils. Once we + * resolve this issue, NAND_ECC_HW_OOB_FIRST mode can be used + * for the 4K page chips. */ dev_warn(&pdev->dev, "no 4-bit ECC support yet " - "for large page NAND\n"); + "for 4K page NAND\n"); ret = -EIO; goto err_scan;