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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 ACFDEC11D3D for ; Thu, 27 Feb 2020 17:07:18 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7FEAE24697 for ; Thu, 27 Feb 2020 17:07:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ThxfvzZQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7FEAE24697 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XBzR/kc+hYh3Uu28I+dr7zxsTZ3jkCeSETMES7hSF4w=; b=ThxfvzZQU+Mius Vg+qrk4XX+7FsoupkAnW3FFzFbu+Clibe0/T5WzS9jB20GTO7HiDIbtpV7yMyNFd0S8ECgMtj59rv J/6tglTATkXQuE7lfonqBagj9kM3DEkjNJn8f2hSpGl74RAtItwWE3w9FputJduM0hBTW9ZzjRKfQ oTOWVkjS4/gzEuRvbTnaV57cJSDTnbSjdAX+R5Uh16cP3RZ1vxPtcIN3v+KA7xLqbcAUT5xI1LO0l 4qCE+quGH2PJhdE89wrKEwqSGb3C6iDOvCHbg3nmzHoOjKV/sabadzPnfYGUZE1EG5zB00AMXmVod N+xRbCVz1EJIw0c13xSg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j7Mcs-0000YO-Fd; Thu, 27 Feb 2020 17:07:06 +0000 Received: from bhuna.collabora.co.uk ([46.235.227.227]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j7Mcp-0000XP-2h for linux-mtd@lists.infradead.org; Thu, 27 Feb 2020 17:07:04 +0000 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 68AEA296385; Thu, 27 Feb 2020 17:07:01 +0000 (GMT) Date: Thu, 27 Feb 2020 18:06:58 +0100 From: Boris Brezillon To: Mark Brown Subject: Re: [PATCH v2 01/11] dt-bindings: spi: allow expressing DTR capability Message-ID: <20200227180658.58633141@collabora.com> In-Reply-To: <20200227164425.GF4062@sirena.org.uk> References: <20200226093703.19765-1-p.yadav@ti.com> <20200226093703.19765-2-p.yadav@ti.com> <20200227171147.32cc6fcf@collabora.com> <20200227162842.GE4062@sirena.org.uk> <20200227164425.GF4062@sirena.org.uk> Organization: Collabora X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200227_090703_250135_BA65220B X-CRM114-Status: GOOD ( 17.90 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Vignesh Raghavendra , Tudor Ambarus , Richard Weinberger , Sekhar Nori , Linux Kernel Mailing List , linux-spi , Rob Herring , Geert Uytterhoeven , Miquel Raynal , MTD Maling List , Pratyush Yadav Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Thu, 27 Feb 2020 16:44:25 +0000 Mark Brown wrote: > On Thu, Feb 27, 2020 at 05:40:31PM +0100, Geert Uytterhoeven wrote: > > On Thu, Feb 27, 2020 at 5:28 PM Mark Brown wrote: > > > > It's what we do for other properties, and if this is anything like the > > > other things adding extra wiring you can't assume that the ability to > > > use the feature for TX implies RX. > > > Double Transfer Rate uses the same wire. > > But is it still on either the TX or RX signals? There's no separate RX/TX pins when using xD-xD-xD modes (pins switch from RX to TX) and I doubt DTR will ever be used on single SPI. > > > But as you sample at both the rising and the falling edges of the clock, this > > makes the cpha setting meaningless for such transfers, I think ;-) > > Might affect what the first bit is possibly? > > > However, as the future may bring us QDR, perhaps this should not be a > > boolean flag, but an integer value? > > Cfr. spi-tx-bus-width vs. the original spi-tx-dual/spi-tx-quad proposal. > > > What would be a good name (as we only need one)? spi-data-phases? > > Sounds reasonable, apart from the increasingly vague connection with > something that's recognizably SPI :P Or maybe we should refrain from adding a new flag and wait a bit to see if this DTR mode is actually used for regular SPI transfers (AKA not spi-mem) :-). ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/