Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753876AbYFTHsm (ORCPT ); Fri, 20 Jun 2008 03:48:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752944AbYFTHsd (ORCPT ); Fri, 20 Jun 2008 03:48:33 -0400 Received: from smtpeu1.atmel.com ([195.65.72.27]:47319 "EHLO bagnes.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751609AbYFTHsc (ORCPT ); Fri, 20 Jun 2008 03:48:32 -0400 From: Haavard Skinnemoen To: David Woodhouse Cc: Andrew Victor , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Haavard Skinnemoen Subject: [PATCH 2/3] atmel_nand: Work around AT32AP7000 ECC errata Date: Fri, 20 Jun 2008 09:48:31 +0200 Message-Id: <1213948112-22348-2-git-send-email-haavard.skinnemoen@atmel.com> X-Mailer: git-send-email 1.5.5.3 In-Reply-To: <1213948112-22348-1-git-send-email-haavard.skinnemoen@atmel.com> References: <1213948112-22348-1-git-send-email-haavard.skinnemoen@atmel.com> X-OriginalArrivalTime: 20 Jun 2008 07:48:03.0582 (UTC) FILETIME=[F83889E0:01C8D2A9] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2111 Lines: 70 The ALE signal isn't correctly wired up to the ECC controller on the AP7000, so it starts calculating ECC during the address cycles. Work around this by resetting the ECC controller between the address and data cycles. Signed-off-by: Haavard Skinnemoen --- drivers/mtd/nand/atmel_nand.c | 25 +++++++++++++++++++++++-- 1 files changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index 4814fc9..99aec46 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -33,6 +33,7 @@ #include #include +#include #ifdef CONFIG_MTD_NAND_ATMEL_ECC_HW #define hard_ecc 1 @@ -264,6 +265,19 @@ static int atmel_nand_read_page(struct mtd_info *mtd, uint8_t *ecc_pos; int stat; + /* + * Errata: ALE is incorrectly wired up to the ECC controller + * on the AP7000, so it will include the address cycles in the + * ECC calculation. + * + * Workaround: Reset the parity registers before reading the + * actual data. + */ + if (cpu_is_at32ap7000()) { + struct atmel_nand_host *host = chip->priv; + ecc_writel(host->ecc, CR, ATMEL_ECC_RST); + } + /* read the page */ chip->read_buf(mtd, p, eccsize); @@ -377,9 +391,16 @@ static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat, } /* - * Enable HW ECC : unsused + * Enable HW ECC : unused on most chips */ -static void atmel_nand_hwctl(struct mtd_info *mtd, int mode) { ; } +static void atmel_nand_hwctl(struct mtd_info *mtd, int mode) +{ + if (cpu_is_at32ap7000()) { + struct nand_chip *nand_chip = mtd->priv; + struct atmel_nand_host *host = nand_chip->priv; + ecc_writel(host->ecc, CR, ATMEL_ECC_RST); + } +} #ifdef CONFIG_MTD_PARTITIONS static const char *part_probes[] = { "cmdlinepart", NULL }; -- 1.5.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/