From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AC36C433DB for ; Fri, 29 Jan 2021 05:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F222E64DBD for ; Fri, 29 Jan 2021 05:06:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230135AbhA2FGJ (ORCPT ); Fri, 29 Jan 2021 00:06:09 -0500 Received: from a1.mail.mailgun.net ([198.61.254.60]:39896 "EHLO a1.mail.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229885AbhA2FGI (ORCPT ); Fri, 29 Jan 2021 00:06:08 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1611896745; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=ZJ29Q1zTcKf8BOTIllzMQ0k52SASQ7ZW0y10kmshp2I=; b=ixRTgxxYxYpCHf+WylYTl83llpVYhHeHLsv1necvQSvDJHxi1r8y8Q8j4shfDNPx/hRv5iS9 u8TtMW5JWhQ/v0ZNE2VIgXX6K77HQiAJkLXL40eLIapdodbgCq29RVjjFBbbhsRgGme3ylfg eAgaIH8XMQtnS9gQvqiJOkobfps= X-Mailgun-Sending-Ip: 198.61.254.60 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-west-2.postgun.com with SMTP id 60139789262adddd45b1c6ad (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 29 Jan 2021 05:05:13 GMT Sender: mdalam=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id CEC93C433ED; Fri, 29 Jan 2021 05:05:13 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: mdalam) by smtp.codeaurora.org (Postfix) with ESMTPSA id 11E29C433C6; Fri, 29 Jan 2021 05:05:13 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Fri, 29 Jan 2021 10:35:12 +0530 From: mdalam@codeaurora.org To: Miquel Raynal Cc: manivannan.sadhasivam@linaro.org, richard@nod.at, vigneshr@ti.com, boris.brezillon@collabora.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, sricharan@codeaurora.org Subject: Re: [PATCH V3] mtd: rawnand: qcom: update last code word register In-Reply-To: <20210128231110.64266932@xps13> References: <1610251305-20792-1-git-send-email-mdalam@codeaurora.org> <20210114165325.3d510355@xps13> <769ea3fe77eab9b37d863251e97bcb29@codeaurora.org> <20210128231110.64266932@xps13> Message-ID: <189aaad7cfaf9e4cadd525b936430c8b@codeaurora.org> X-Sender: mdalam@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-01-29 03:41, Miquel Raynal wrote: > Hello, > > mdalam@codeaurora.org wrote on Fri, 29 Jan 2021 03:18:46 +0530: > >> On 2021-01-14 21:23, Miquel Raynal wrote: >> > Hello, >> > >> > Md Sadre Alam wrote on Sun, 10 Jan 2021 >> > 09:31:45 +0530: >> > >> >> From QPIC version 2.0 onwards new register got added to >> > >> > a >> > >> >> read last codeword. This change will update the same. >> > >> > the? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> > Please reword this sentence. >> >> Fixed this in V4 patch. >> > >> >> For first three code word READ_LOCATION_n register will be >> >> use.For last code word READ_LOCATION_LAST_CW_n register will be >> >> use. >> > >> > "For the first three codewords, READ_LOCATION_n registers will be used. >> > The last codeword register will be accessed through >> > READ_LOCATION_LAST_CW_n." >> > >> > Also, please specify what these registers store. >> >> The location register is mainly use for reading controller >> buffer via BAM mode. The bits of the register >> "NAND_READ_LOCATION_LAST_CW_n, n=0..4" >> as follow: > > Perhaps what I do not understand is: when is this "last_cw" register > more useful than the previous set? From QPIC Version 2.0 onwards it is mandatory to use "NAND_READ_LOCATION_LAST_CW_n, n=0..4" register to extract last code word data from controller buffer. Using register "NAND_READ_LOCATION_n, n=0..4" we can extract all code words except last code word. > >> [9:0]-bits : (OFFSET) This bit defines the offset from the buffer >> base address to be picked up for DMA. >> [25:16]-bits: (SIZE) This bit of every register will define the >> size of the chunk for DMA. >> 31-bit : (LAST) If this bit is set, the controller takes the >> particular register to specify the last chunk >> of data made available for DMA. This chunk is >> part of the internal buffer of the controller. >> >> > > > Thanks, > Miquèl