From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753948AbcFTJcf (ORCPT ); Mon, 20 Jun 2016 05:32:35 -0400 Received: from down.free-electrons.com ([37.187.137.238]:45155 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752020AbcFTJ3E (ORCPT ); Mon, 20 Jun 2016 05:29:04 -0400 From: Boris Brezillon To: David Woodhouse , Brian Norris , linux-mtd@lists.infradead.org, Boris Brezillon , Richard Weinberger Cc: linux-kernel@vger.kernel.org, Hans de Goede , Aleksei Mamlin , valdis.kletnieks@vt.edu Subject: [PATCH v3 14/16] mtd: nand: samsung: retrieve ECC requirements from extended ID Date: Mon, 20 Jun 2016 11:27:00 +0200 Message-Id: <1466414822-18948-15-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1466414822-18948-1-git-send-email-boris.brezillon@free-electrons.com> References: <1466414822-18948-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hans de Goede On some nand controllers with hw-ecc the controller code wants to know the ecc strength and size and having these as 0, 0 is not accepted. Specifying these in devicetree is possible but undesirable as the nand may be different in different production runs of the same board, so it is better to get this info from the nand id where possible. This commit adds code to read the ecc strength and size from the nand for Samsung extended-id nands. This code is based on the info for the 5th id byte in the datasheets for the following Samsung nands: K9GAG08U0E, K9GAG08U0F, K9GAG08X0D, K9GBG08U0A, K9GBG08U0B. These all use these bits in the exact same way. Signed-off-by: Hans de Goede Signed-off-by: Boris Brezillon --- drivers/mtd/nand/nand_samsung.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/mtd/nand/nand_samsung.c b/drivers/mtd/nand/nand_samsung.c index 863be01a2232..5d973d45b223 100644 --- a/drivers/mtd/nand/nand_samsung.c +++ b/drivers/mtd/nand/nand_samsung.c @@ -63,6 +63,26 @@ static void samsung_nand_decode_id(struct nand_chip *chip) extid >>= 2; mtd->erasesize = (128 * 1024) << (((extid >> 1) & 0x04) | (extid & 0x03)); + + /* Extract ECC requirements from 5th id byte*/ + extid = (chip->id.data[4] >> 4) & 0x07; + if (extid < 5) { + chip->ecc_step_ds = 512; + chip->ecc_strength_ds = 1 << extid; + } else { + chip->ecc_step_ds = 1024; + switch (extid) { + case 5: + chip->ecc_strength_ds = 24; + break; + case 6: + chip->ecc_strength_ds = 40; + break; + case 7: + chip->ecc_strength_ds = 60; + break; + } + } } else { nand_decode_ext_id(chip); } -- 2.7.4