From patchwork Sat Jun 22 21:03:48 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pekon gupta X-Patchwork-Id: 2766431 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 367D7C0AB1 for ; Sat, 22 Jun 2013 21:05:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2E03F2011C for ; Sat, 22 Jun 2013 21:05:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC3B120117 for ; Sat, 22 Jun 2013 21:05:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751469Ab3FVVEy (ORCPT ); Sat, 22 Jun 2013 17:04:54 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:43665 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751342Ab3FVVEv (ORCPT ); Sat, 22 Jun 2013 17:04:51 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id r5ML4Mqf021018; Sat, 22 Jun 2013 16:04:22 -0500 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id r5ML4MmH000324; Sat, 22 Jun 2013 16:04:22 -0500 Received: from dlelxv22.itg.ti.com (172.17.1.197) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.2.342.3; Sat, 22 Jun 2013 16:04:21 -0500 Received: from psplinux064.india.ti.com (psplinux064.india.ti.com [10.24.100.118]) by dlelxv22.itg.ti.com (8.13.8/8.13.8) with ESMTP id r5ML4Bmp017338; Sat, 22 Jun 2013 16:04:19 -0500 From: Pekon Gupta To: , , CC: , , , , , , "Gupta, Pekon" Subject: [PATCH v3 2/4] ARM: OMAP2+: cleaned-up DT support of various ECC schemes Date: Sun, 23 Jun 2013 02:33:48 +0530 Message-ID: <1371935030-20773-3-git-send-email-pekon@ti.com> X-Mailer: git-send-email 1.8.1 In-Reply-To: <1371935030-20773-1-git-send-email-pekon@ti.com> References: <1371935030-20773-1-git-send-email-pekon@ti.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-8.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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: Pekon Gupta --- .../devicetree/bindings/mtd/gpmc-nand.txt | 44 ++++++++++++++++------ arch/arm/mach-omap2/gpmc.c | 14 ++++--- include/linux/platform_data/mtd-nand-omap2.h | 22 +++++++---- 3 files changed, 56 insertions(+), 24 deletions(-) diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt index 6a983c1..690070e 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt @@ -17,20 +17,42 @@ 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_code_sw" 1-bit Hamming ECC + - ECC calculation in software + - Error detection in software + + "hamming_code_hw" 1-bit Hamming ECC + - ECC calculation in hardware + - Error detection in software + + "hamming_code_hw_romcode" 1-bit Hamming ECC + - ECC calculation in hardware + - Error detection in software + - ECC layout compatible to ROM code + + "bch8_hw_code_detection_sw" 8-bit BCH ECC + - ECC calculation in hardware + - Error detection in software + - depends on CONFIG_MTD_NAND_ECC_BCH + + "bch8_code_hw" 8-bit BCH ECC + - ECC calculation in hardware + - Error detection in hardware + - depends on CONFIG_MTD_NAND_OMAP_BCH + - requires to be specified + + + - 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/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 6c4da12..ae8bb70 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -1338,11 +1338,13 @@ 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_code_sw", + [OMAP_ECC_HAMMING_CODE_HW] = "hamming_code_hw", + [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hamming_code_hw_romcode", + [OMAP_ECC_BCH4_CODE_HW] = "bch4_code_hw", + [OMAP_ECC_BCH4_CODE_HW_DETECTION_SW] = "bch4_code_hw_detection_sw", + [OMAP_ECC_BCH8_CODE_HW] = "bch8_code_hw", + [OMAP_ECC_BCH8_CODE_HW_DETECTION_SW] = "bch8_code_hw_detection_sw" }; static int gpmc_probe_nand_child(struct platform_device *pdev, @@ -1369,7 +1371,7 @@ static int gpmc_probe_nand_child(struct platform_device *pdev, if (!of_property_read_string(child, "ti,nand-ecc-opt", &s)) for (val = 0; val < ARRAY_SIZE(nand_ecc_opts); val++) - if (!strcasecmp(s, nand_ecc_opts[val])) { + if (!strcmp(s, nand_ecc_opts[val])) { gpmc_nand_data->ecc_opt = val; break; } diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h index 6bf9ef4..ce74576 100644 --- a/include/linux/platform_data/mtd-nand-omap2.h +++ b/include/linux/platform_data/mtd-nand-omap2.h @@ -23,13 +23,21 @@ enum nand_io { }; enum omap_ecc { - /* 1-bit ecc: stored at end of spare area */ - OMAP_ECC_HAMMING_CODE_DEFAULT = 0, /* Default, s/w method */ - OMAP_ECC_HAMMING_CODE_HW, /* gpmc to detect the error */ - /* 1-bit ecc: stored at beginning of spare area as romcode */ - OMAP_ECC_HAMMING_CODE_HW_ROMCODE, /* gpmc method & romcode layout */ - OMAP_ECC_BCH4_CODE_HW, /* 4-bit BCH ecc code */ - OMAP_ECC_BCH8_CODE_HW, /* 8-bit BCH ecc code */ + /* 1-bit ECC calculation by Software, Error detection by Software */ + OMAP_ECC_HAMMING_CODE_DEFAULT = 0, + /* 1-bit ECC calculation by GPMC, Error detection by Software */ + OMAP_ECC_HAMMING_CODE_HW, + /* 1-bit ECC calculation by GPMC, Error detection by Software */ + /* ECC layout compatible to legacy ROMCODE. */ + OMAP_ECC_HAMMING_CODE_HW_ROMCODE, + /* 4-bit ECC calculation by GPMC, Error detection by ELM */ + OMAP_ECC_BCH4_CODE_HW, + /* 4-bit ECC calculation by GPMC, Error detection by Software */ + OMAP_ECC_BCH4_CODE_HW_DETECTION_SW, + /* 8-bit ECC calculation by GPMC, Error detection by ELM */ + OMAP_ECC_BCH8_CODE_HW, + /* 8-bit ECC calculation by GPMC, Error detection by Software */ + OMAP_ECC_BCH8_CODE_HW_DETECTION_SW }; struct gpmc_nand_regs {