From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756696AbbLDWfc (ORCPT ); Fri, 4 Dec 2015 17:35:32 -0500 Received: from down.free-electrons.com ([37.187.137.238]:40084 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755039AbbLDWfa (ORCPT ); Fri, 4 Dec 2015 17:35:30 -0500 From: Antoine Tenart To: computersforpeace@gmail.com, dwmw2@infradead.org, boris.brezillon@free-electrons.com Cc: Antoine Tenart , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] mtd: nand: support JEDEC additional redundant parameter pages Date: Fri, 4 Dec 2015 23:35:28 +0100 Message-Id: <1449268528-18154-1-git-send-email-antoine.tenart@free-electrons.com> X-Mailer: git-send-email 2.6.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The JEDEC standard defines the JEDEC parameter page data structure. One page plus two redundant pages are always there, in bits 0-1535. Additionnal redundant parameter pages can be stored at bits 1536+. Add support to read these pages. The first 3 JEDEC parameter pages are always checked, and if none is valid we try to read additional redundant pages following the standard definition: we continue while at least two of the four bytes of the parameter page signature match (stored in the first dword). There is no limit to the number of additional redundant parameter page. Signed-off-by: Antoine Tenart --- drivers/mtd/nand/nand_base.c | 44 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 10 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index cc74142938b0..31f4a6585703 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -3392,6 +3392,32 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip, return 1; } +static int nand_flash_jedec_read_param(struct mtd_info *mtd, + struct nand_chip *chip, + struct nand_jedec_params *p) +{ + int i, match = 0; + char sig[4] = "JESD"; + + for (i = 0; i < sizeof(*p); i++) + ((uint8_t *)p)[i] = chip->read_byte(mtd); + + for (i = 0; i < 4; i++) + if (p->sig[i] == sig[i]) + match++; + + if (match < 2) { + pr_warn("Invalid JEDEC page\n"); + return -EINVAL; + } + + if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) == + le16_to_cpu(p->crc)) + return 0; + + return -EAGAIN; +} + /* * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise. */ @@ -3400,8 +3426,7 @@ static int nand_flash_detect_jedec(struct mtd_info *mtd, struct nand_chip *chip, { struct nand_jedec_params *p = &chip->jedec_params; struct jedec_ecc_info *ecc; - int val; - int i, j; + int val, i, ret = 0; /* Try JEDEC for unknown chip or LP */ chip->cmdfunc(mtd, NAND_CMD_READID, 0x40, -1); @@ -3411,16 +3436,15 @@ static int nand_flash_detect_jedec(struct mtd_info *mtd, struct nand_chip *chip, return 0; chip->cmdfunc(mtd, NAND_CMD_PARAM, 0x40, -1); - for (i = 0; i < 3; i++) { - for (j = 0; j < sizeof(*p); j++) - ((uint8_t *)p)[j] = chip->read_byte(mtd); - - if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) == - le16_to_cpu(p->crc)) + for (i = 0; i < 3; i++) + if (!nand_flash_jedec_read_param(mtd, chip, p)) break; - } - if (i == 3) { + /* Try reading additional parameter pages */ + if (i == 3) + while ((ret = nand_flash_jedec_read_param(mtd, chip, p)) == + -EAGAIN); + if (ret) { pr_err("Could not find valid JEDEC parameter page; aborting\n"); return 0; } -- 2.6.3