From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935889AbdAIL0T (ORCPT ); Mon, 9 Jan 2017 06:26:19 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:54683 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935020AbdAIKEe (ORCPT ); Mon, 9 Jan 2017 05:04:34 -0500 From: Boris Brezillon To: Boris Brezillon , Richard Weinberger , linux-mtd@lists.infradead.org, David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen Cc: Icenowy Zheng , Valdis.Kletnieks@vt.edu, Aleksei Mamlin , Hans de Goede , linux-kernel@vger.kernel.org Subject: [PATCH v6 15/17] mtd: nand: samsung: Retrieve ECC requirements from extended ID Date: Mon, 9 Jan 2017 11:04:22 +0100 Message-Id: <1483956264-3335-16-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1483956264-3335-1-git-send-email-boris.brezillon@free-electrons.com> References: <1483956264-3335-1-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 Acked-by: Richard Weinberger 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 5c259dd5b652..9cfc4035a420 100644 --- a/drivers/mtd/nand/nand_samsung.c +++ b/drivers/mtd/nand/nand_samsung.c @@ -66,6 +66,26 @@ 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