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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 CB943C433FE for ; Fri, 11 Dec 2020 03:35:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8169F23ECF for ; Fri, 11 Dec 2020 03:35:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395149AbgLKDec (ORCPT ); Thu, 10 Dec 2020 22:34:32 -0500 Received: from mail-oo1-f66.google.com ([209.85.161.66]:42748 "EHLO mail-oo1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395130AbgLKDeB (ORCPT ); Thu, 10 Dec 2020 22:34:01 -0500 Received: by mail-oo1-f66.google.com with SMTP id x203so1831595ooa.9; Thu, 10 Dec 2020 19:33:45 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=3GnJS91mExiBzt28XQgbgmRTyU/KP5iwnHySnsJrR+g=; b=W9tDr4aDMdj1t3B2NZPCy3IpBQyt7oY+pFLivGp6qO0+LJ958nfLQ8/jjyzYDphg6Z erPrtnSY3EtPA4q1MUYMEH3WsQKImRUB1nGE5Kv/V2nirzQXMJAnBOZBU6/0HC7Nm5OO nFxm1pPGNWow6KlMTDMj3+To1LNhNSQwS+0jq/M1yozwPK+PtENK453ZZCzl/d906UbP A1WhjcXJscoPALA7o3WhfTemoSzN5NFUW5kBGN45eVMLBIcMev2qf7+eM9Ijv0Y9JlGj 1nWW2mYY5nadl6qdn/C1k2eKoS+LvMXUzZe0DbiZ+k1yAHI1FUBWqZG1ByQwtAVY9Oui 5CqQ== X-Gm-Message-State: AOAM531rEOqiRdjuIvIFxcnuF11nxb5DbO8tLBSVtmnJAXE4Ho70FiaO 3D3Cy1G28b1XWUyywH+EOl3uiNvY4g== X-Google-Smtp-Source: ABdhPJyv+HjIJIG6vQ0mqx8wcxKerll2vL+hFq43z5m9733QezRGM9e/Qwbq1lN4LMs4idy5AaXIWQ== X-Received: by 2002:a4a:e687:: with SMTP id u7mr8551739oot.20.1607657600097; Thu, 10 Dec 2020 19:33:20 -0800 (PST) Received: from xps15 (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.gmail.com with ESMTPSA id n16sm187964oop.9.2020.12.10.19.33.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Dec 2020 19:33:19 -0800 (PST) Received: (nullmailer pid 3584435 invoked by uid 1000); Fri, 11 Dec 2020 03:33:18 -0000 Date: Thu, 10 Dec 2020 21:33:18 -0600 From: Rob Herring To: Aswath Govindraju Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann , Greg Kroah-Hartman , Vadym Kochan , Vignesh Raghavendra , Sekhar Nori Subject: Re: [PATCH RFC 1/2] Documentation: devicetree: Add property for ignoring the dummy bits sent before read transfer Message-ID: <20201211033301.GA3581630@robh.at.kernel.org> References: <20201209175708.16252-1-a-govindraju@ti.com> <20201209175708.16252-2-a-govindraju@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201209175708.16252-2-a-govindraju@ti.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 09, 2020 at 11:27:07PM +0530, Aswath Govindraju wrote: > Dummy zero bits are sent before data during a read transfer. This causes > the data read to be shifted to the right. To fix this send zero bits after > the address during a read transfer. > > Add property to send zero bits after the address during a read transfer. When is this necessary? Why can't it be implied by the compatible string which should be specific to the chip model? > > Suggested-by: Vignesh Raghavendra > Signed-off-by: Aswath Govindraju > --- > Documentation/devicetree/bindings/misc/eeprom-93xx46.txt | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt > index a8ebb4621f79..09fb1cec54f0 100644 > --- a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt > +++ b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt > @@ -10,7 +10,9 @@ Optional properties: > - read-only : parameter-less property which disables writes to the EEPROM > - select-gpios : if present, specifies the GPIO that will be asserted prior to > each access to the EEPROM (e.g. for SPI bus multiplexing) > - > +- read-op-dummy-cycles: If present specifies the number of dummy zero-bits to > + be sent after the address during a read transfer to ignore any bits sent > + preceding the data. > Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt > apply. In particular, "reg" and "spi-max-frequency" properties must be given. > > -- > 2.17.1 >