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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 BD640C2D0A3 for ; Thu, 29 Oct 2020 07:56:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7270D20782 for ; Thu, 29 Oct 2020 07:56:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732464AbgJ2H4d convert rfc822-to-8bit (ORCPT ); Thu, 29 Oct 2020 03:56:33 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:59949 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731495AbgJ2Hx4 (ORCPT ); Thu, 29 Oct 2020 03:53:56 -0400 X-Originating-IP: 91.224.148.103 Received: from xps13 (unknown [91.224.148.103]) (Authenticated sender: miquel.raynal@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 1E0AC240002; Thu, 29 Oct 2020 07:53:45 +0000 (UTC) Date: Thu, 29 Oct 2020 08:53:44 +0100 From: Miquel Raynal To: mdalam@codeaurora.org Cc: agross@kernel.org, bjorn.andersson@linaro.org, richard@nod.at, vigneshr@ti.com, robh+dt@kernel.org, linux-arm-msm@vger.kernel.org, linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sricharan@codeaurora.org Subject: Re: [PATCH 0/5] mtd: rawnand: qcom: Add support for QSPI nand Message-ID: <20201029085344.5b2a4b51@xps13> In-Reply-To: <10db598eed716d7759bc0125b6977cf1@codeaurora.org> References: <1602307902-16761-1-git-send-email-mdalam@codeaurora.org> <20201028104835.3dc31745@xps13> <10db598eed716d7759bc0125b6977cf1@codeaurora.org> Organization: Bootlin X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, mdalam@codeaurora.org wrote on Wed, 28 Oct 2020 23:54:23 +0530: > On 2020-10-28 15:18, Miquel Raynal wrote: > > Hello, > > > > Md Sadre Alam wrote on Sat, 10 Oct 2020 > > 11:01:37 +0530: > > > >> QPIC 2.0 supports Serial NAND support in addition to all features and > >> commands in QPIC 1.0 for parallel NAND. Parallel and Serial NAND >> cannot > >> operate simultaneously. QSPI nand devices will connect to QPIC >> IO_MACRO > >> block of QPIC controller. There is a separate IO_MACRO clock for >> IO_MACRO > >> block. Default IO_MACRO block divide the input clock by 4. so if >> IO_MACRO > >> input clock is 320MHz then on bus it will be 80MHz, so QSPI nand >> device > >> should also support this frequency. > >> >> QPIC provides 4 data pins to QSPI nand. In standard SPI mode (x1 mode) >> data > >> transfer will occur on only 2 pins one pin for Serial data in and one >> for > >> serial data out. In QUAD SPI mode (x4 mode) data transfer will occur >> at all > >> the four data lines. QPIC controller supports command for x1 mode and >> x4 mode. > >> >> Md Sadre Alam (5): > >> dt-bindings: qcom_nandc: IPQ5018 QPIC NAND documentation > >> mtd: rawnand: qcom: Add initial support for qspi nand > >> mtd: rawnand: qcom: Read QPIC version > >> mtd: rawnand: qcom: Enable support for erase,read & write for serial > >> nand. > >> mtd: rawnand: qcom: Add support for serial training. > >> >> .../devicetree/bindings/mtd/qcom_nandc.txt | 3 + > >> drivers/mtd/nand/raw/nand_ids.c | 13 + > >> drivers/mtd/nand/raw/qcom_nandc.c | 502 >> ++++++++++++++++++++- > >> 3 files changed, 494 insertions(+), 24 deletions(-) > >> > > I'm sorry but this series clearly breaks the current layering. I cannot > > authorize SPI-NAND code to fall into the raw NAND subsystem. > > > > I am agree with you, we should not add SPI-NAND changes inside > raw NAND subsystem. > > > As both typologies cannot be used at the same time, I guess you should > > have another driver handling this feature under the spi/ subsystem + > > a few declarations in the SPI-NAND devices list. > > > > Initially I was started writing separate driver under SPI-NAND subsystem then I > realized that more than 85% of raw/qcom_nand.c code getting duplicated. > > That's why I have added this SPI-NAND change in raw/qcom_nand.c since > more than 85% of code will be reused. > > If I will add this change inside SPI-NAND subsystem then much of > raw/qcom_nand.c code will get duplicated. Would it be ok ? What about moving the generic code to drivers/mtd/nand/common/ and referring to it from drivers/mtd/nand/raw/qcom_nand.c and drivers/spi/spi-qcom.c (or such)? Thanks, Miquèl