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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham 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 BC4CDC43218 for ; Sat, 27 Apr 2019 19:02:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A24A2087E for ; Sat, 27 Apr 2019 19:02:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cogentembedded-com.20150623.gappssmtp.com header.i=@cogentembedded-com.20150623.gappssmtp.com header.b="WIyeq621" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726268AbfD0TCK (ORCPT ); Sat, 27 Apr 2019 15:02:10 -0400 Received: from mail-lf1-f67.google.com ([209.85.167.67]:37457 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725921AbfD0TCJ (ORCPT ); Sat, 27 Apr 2019 15:02:09 -0400 Received: by mail-lf1-f67.google.com with SMTP id h126so4934959lfh.4 for ; Sat, 27 Apr 2019 12:02:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cogentembedded-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:organization:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=AZgxJWhbIDvKlGzRsWxiCN2W+xAkX6lkUd7t0yIDidU=; b=WIyeq621iyHX/Df/naNbN++OglZ6+VJNZpSAlZCMMzGDen3MlM7ODEgIJQ1XQ2Tsqe KoJUHEW44tSNFSyj1vxGoq7osfTu8C31TTPKvFDACvT5BT8pCNdNSulm6+SNzryjG0jJ ZHJEhTrup0ZDDiurfGdqH+hNSl0x8iXtHBqp64Hxkwc2ccRvHB3cPcalLC9kC/ghLcRc 35M5jbvnwnt3gTxeBiJwRtl/Nz9DCtpkHDDFc5i3HECb/37NvQFDD1RM9HKuhymhT1Lg 2P3C0WmTAv6VIGddHgt9HGv2f178ruKcl3BbINX6FItiTouYD86sr7pKClUmtBG6Mg8y GyVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=AZgxJWhbIDvKlGzRsWxiCN2W+xAkX6lkUd7t0yIDidU=; b=ULJWPEQmAtArcVZO6gcBjAsMoR06lZDTI8rJ/etGxN0xy/nX3n+MYyGoZ7TX0m1O3v WxqduQ+WDu2QsGh0Uifgr4xOajmMu8x2Haphf1yZfVFd0/hduodrAo2scfaLRCtzid9r kTVruULBk+oJ27N6wnUHVCVH81ypLMYwxIXLoKUMG80HRUXkjuOIMpgavfx3stMv+LIT U8cWPiRovpV9dzSxgbyz1J1q75mp4N7kPRjBw7jIyeczvmPW2AkcRiz2nhD2PWr+Jzza GREufUYIJFVDI6lNq/F7y0dc3y7wuwur0N1YcAmKdFg/60/S3KO3mtgSCwDB0j3bq4ek 0b/g== X-Gm-Message-State: APjAAAWMZrS4CliGhOyZIWU5L0uQqriH0B1j3l+lqAkn1fJrIaG2LXi6 YE7AF6p6j8+k2HO5uQtFFB5h7w== X-Google-Smtp-Source: APXvYqzzsRMRu10ni8xp9BNlmHXddNxg6m8pR41FcPmRC7oDP+jBy5UZJMOqZ/1dKJN8fNr7zihdcA== X-Received: by 2002:a19:428c:: with SMTP id p134mr29296072lfa.108.1556391727674; Sat, 27 Apr 2019 12:02:07 -0700 (PDT) Received: from wasted.cogentembedded.com ([31.173.81.185]) by smtp.gmail.com with ESMTPSA id x2sm1199162ljx.13.2019.04.27.12.02.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 27 Apr 2019 12:02:07 -0700 (PDT) Subject: Re: [PATCH v4 1/5] mtd: cfi_cmdset_0002: Add support for polling status register To: Vignesh Raghavendra , David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Rob Herring Cc: linux-mtd@lists.infradead.org, Tudor Ambarus , Miquel Raynal , Joakim Tjernlund , devicetree@vger.kernel.org, Mason Yang , linux-arm-kernel@lists.infradead.org, nsekhar@ti.com, linux-kernel@vger.kernel.org, Mark Rutland References: <20190423104814.5762-1-vigneshr@ti.com> <20190423104814.5762-2-vigneshr@ti.com> From: Sergei Shtylyov Organization: Cogent Embedded Message-ID: <093ef590-ae3d-2db2-09af-573a138a9416@cogentembedded.com> Date: Sat, 27 Apr 2019 22:02:05 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20190423104814.5762-2-vigneshr@ti.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-MW Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! On 04/23/2019 01:48 PM, Vignesh Raghavendra wrote: > HyperFlash devices are compliant with CFI AMD/Fujitsu Extended Command > Set(0x0002) for flash operations, therefore drivers/mtd/chips/cfi_cmdset_0002.c > can be used as is. But these devices do not support DQ polling method of > determining chip ready/good status. These flashes provide Status > Register whose bits can be polled to know status of flash operation. > > Cypress HyperFlash datasheet here[1], talks about CFI Amd/Fujitsu > Extended Query version 1.5. Bit 0 of "Software Features supported" field > of CFI Primary Vendor-Specific Extended Query table indicates > presence/absence of status register and Bit 1 indicates whether or not > DQ polling is supported. Using these bits, its possible to determine > whether flash supports DQ polling or need to use Status Register. > > Add support for polling Status Register to know device ready/status of > erase/write operations when DQ polling is not supported. > Print error messages on erase/program failure by looking at related > Status Register bits. > > [1] https://www.cypress.com/file/213346/download > > Signed-off-by: Vignesh Raghavendra Sorry, only superficial review, I'm not an MTD expert. :-) > --- > drivers/mtd/chips/cfi_cmdset_0002.c | 90 +++++++++++++++++++++++++++++ > include/linux/mtd/cfi.h | 5 ++ > 2 files changed, 95 insertions(+) > > diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c > index 7b7286b4d81e..55c4d81098d5 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0002.c > +++ b/drivers/mtd/chips/cfi_cmdset_0002.c > @@ -49,6 +49,16 @@ > #define SST49LF008A 0x005a > #define AT49BV6416 0x00d6 > > +/* > + * Status Register bit description. Used by flash devices that don't > + * support DQ polling (Eg.: HyperFlash) It's "e.g. " :-) [...] > @@ -97,6 +107,48 @@ static struct mtd_chip_driver cfi_amdstd_chipdrv = { > .module = THIS_MODULE > }; > > +/* > + * Use status register to poll for Erase/write completion when DQ is not > + * supported. This is indicated by Bit[1:0] of SoftwareFeatures field in > + * CFI Primary Vendor-Specific Extended Query table 1.5 > + */ > +static int cfi_use_status_reg(struct cfi_private *cfi) > +{ > + struct cfi_pri_amdstd *extp = cfi->cmdset_priv; > + > + return (extp->MinorVersion >= '5') && Parens not needed here, especially as the next operator isn't enclosed. > + (extp->SoftwareFeatures & 0x3) == 0x1; > +} [...] MBR, Sergei