From patchwork Fri May 17 11:50:16 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pekon gupta X-Patchwork-Id: 244623 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:770:15f::2]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1C06E2C00A0 for ; Fri, 17 May 2013 21:53:15 +1000 (EST) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UdJCS-00027h-Ly; Fri, 17 May 2013 11:51:53 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UdJCG-0003Ug-3h; Fri, 17 May 2013 11:51:40 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UdJBt-0003Qq-PW for linux-mtd@lists.infradead.org; Fri, 17 May 2013 11:51:22 +0000 Received: from dbdlxv05.itg.ti.com ([172.24.171.60]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id r4HBoXpc018483; Fri, 17 May 2013 06:50:34 -0500 Received: from DBDE73.ent.ti.com (dbde73.ent.ti.com [172.24.171.98]) by dbdlxv05.itg.ti.com (8.14.3/8.13.8) with ESMTP id r4HBoSWa004140; Fri, 17 May 2013 06:50:29 -0500 Received: from dbdp32.itg.ti.com (172.24.170.251) by DBDE73.ent.ti.com (172.24.171.98) with Microsoft SMTP Server id 14.2.342.3; Fri, 17 May 2013 19:50:28 +0800 Received: from psplinux064.india.ti.com (smtpvbd.itg.ti.com [172.24.170.250]) by dbdp32.itg.ti.com (8.13.8/8.13.8) with ESMTP id r4HBoNG0008737; Fri, 17 May 2013 17:20:27 +0530 From: "Gupta, Pekon" To: , Subject: [PATCH 2/4 v2] ARM: OMAP2+: cleaned-up DT support of various ECC schemes Date: Fri, 17 May 2013 17:20:16 +0530 Message-ID: <1368791418-14330-3-git-send-email-pekon@ti.com> X-Mailer: git-send-email 1.8.1 In-Reply-To: <1368791418-14330-1-git-send-email-pekon@ti.com> References: <1368791418-14330-1-git-send-email-pekon@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130517_075117_953881_CD8B8F83 X-CRM114-Status: GOOD ( 12.86 ) X-Spam-Score: -7.5 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [198.47.26.153 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.6 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: arnd@arndb.de, tony@atomide.com, jp.francois@cynove.com, balbi@ti.com, "Gupta, Pekon" X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: "Gupta, Pekon" ECC scheme on NAND devices can be implemented in multiple ways.Some using Software algorithm, while others using in-build Hardware engines. omap2-nand driver currently supports following flavours of ECC schemes, selectable via DTB. +---------------------------------------+---------------+---------------+ | ECC scheme |ECC calculation|Error detection| +---------------------------------------+---------------+---------------+ |OMAP_ECC_HAMMING_CODE_DEFAULT |S/W |S/W | |OMAP_ECC_HAMMING_CODE_HW |H/W (GPMC) |S/W | |OMAP_ECC_HAMMING_CODE_HW_ROMCODE |H/W (GPMC) |S/W | +---------------------------------------+---------------+---------------+ |(requires CONFIG_MTD_NAND_ECC_BCH) | | | |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | +---------------------------------------+---------------+---------------+ |(requires CONFIG_MTD_NAND_OMAP_BCH) | | | |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | +---------------------------------------+---------------+---------------+ Selection of some ECC schemes also require enabling following Kconfig options. This was done to optimize footprint of omap2-nand driver. -Kconfig:CONFIG_MTD_NAND_ECC_BCH enables S/W based BCH ECC algorithm -Kconfig:CONFIG_MTD_NAND_OMAP_BCH enables H/W based BCH ECC algorithm Signed-off-by: Gupta, Pekon --- .../devicetree/bindings/mtd/gpmc-nand.txt | 37 +++++++++++++++------- arch/arm/boot/dts/am335x-evm.dts | 2 +- arch/arm/mach-omap2/gpmc.c | 12 ++++--- 3 files changed, 34 insertions(+), 17 deletions(-) diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt index e7f8d7e..de180be 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt @@ -17,20 +17,35 @@ Required properties: Optional properties: - - nand-bus-width: Set this numeric value to 16 if the hardware - is wired that way. If not specified, a bus - width of 8 is assumed. + - nand-bus-width: Determines data-width of the connected device + x16 = "16" + x8 = "8" (default) - - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: - "sw" Software method (default) - "hw" Hardware method - "hw-romcode" gpmc hamming mode method & romcode layout - "bch4" 4-bit BCH ecc code - "bch8" 8-bit BCH ecc code + - ti,nand-ecc-opt: Determines the ECC scheme used by driver. + It can be any of the following strings: + + "hamming_sw" 1-bit Hamming ECC using software + + "hamming_hw" 1-bit Hamming ECC using hardware + + "hamming_hw_romcode" 1-bit Hamming ECC using hardware + - ECC layout compatible to ROM code + + "bch8_hw_detection_sw" 8-bit BCH with ECC calculation in hardware + and error detection in software + - requires Kconfig CONFIG_MTD_NAND_ECC_BCH + + "bch8_hw" 8-bit BCH with ECC calculation in hardware + and error detection in hardware + - requires to be specified + - requires Kconfig CONFIG_MTD_NAND_OMAP_BCH + + + + - elm_id: Specifies elm device node. This is required to + support some BCH ECC schemes mentioned above. - - elm_id: Specifies elm device node. This is required to support BCH - error correction using ELM module. For inline partiton table parsing (optional): diff --git a/arch/arm/boot/dts/am335x-evm.dts b/arch/arm/boot/dts/am335x-evm.dts index 0b8f161..60e8f59 100644 --- a/arch/arm/boot/dts/am335x-evm.dts +++ b/arch/arm/boot/dts/am335x-evm.dts @@ -135,7 +135,7 @@ nand@0,0 { reg = <0 0 0>; /* CS0, offset 0 */ nand-bus-width = <8>; - ti,nand-ecc-opt = "bch8"; + ti,nand-ecc-opt = "bch8_hw"; gpmc,sync-clk = <0>; gpmc,cs-on = <0>; diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 410e1ba..03b8027 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -1205,11 +1205,13 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np, #ifdef CONFIG_MTD_NAND static const char * const nand_ecc_opts[] = { - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw", - [OMAP_ECC_HAMMING_CODE_HW] = "hw", - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw-romcode", - [OMAP_ECC_BCH4_CODE_HW] = "bch4", - [OMAP_ECC_BCH8_CODE_HW] = "bch8", + [OMAP_ECC_HAMMING_CODE_DEFAULT] = "hamming_sw", + [OMAP_ECC_HAMMING_CODE_HW] = "hamming_hw", + [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hamming_hw_romcode", + [OMAP_ECC_BCH4_CODE_HW] = "bch4_hw", + [OMAP_ECC_BCH4_CODE_HW_DETECTION_SW] = "bch4_hw_detection_sw", + [OMAP_ECC_BCH8_CODE_HW] = "bch8_hw", + [OMAP_ECC_BCH8_CODE_HW_DETECTION_SW] = "bch8_hw_detection_sw" }; static int gpmc_probe_nand_child(struct platform_device *pdev,