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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 2E9F6C4360F for ; Mon, 18 Feb 2019 10:31:57 +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 00B7B214DA for ; Mon, 18 Feb 2019 10:31:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="HR60R/Yq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00B7B214DA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=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:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iNVU8pnPz7xICYkziixdg3MmNgND6tYTRsnXVL7hUvU=; b=HR60R/YqQCsafI t8O5zUbZZ7OFYrSlaJIbddAtz1lepAY/zb9YlQguDR7/P07M8AZRbYkCzmRsEN0QizA0nV8AOcJ27 hxtiQW/yu51yjABDMbUhp2jwks4Bk3ffEnOIa/ZZvq6NzSQAuvgGu2/gdicjMBj+WNu8ZH3gWrtBY 1ZjtVmpppOCmB+aSFYacJubKbRF+7BXtDlSWMRuMLEI3JeThSkxYtgA4G5FACFPTS7bVCUvh8bobM exlb49yu6OME5wBN3RroVfYJF+2Xwhaf4ou3Yxajoge84ldtvALhyX5nox8jhFmONLHdEu5WzQS/C 9geruGPOgkvuZwNChIrw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvgDJ-00076s-Da; Mon, 18 Feb 2019 10:31:53 +0000 Received: from mail-qt1-f194.google.com ([209.85.160.194]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvgDG-000750-7f for linux-arm-kernel@lists.infradead.org; Mon, 18 Feb 2019 10:31:51 +0000 Received: by mail-qt1-f194.google.com with SMTP id b8so18540121qtr.9 for ; Mon, 18 Feb 2019 02:31:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=JeAiCwTdj8ylL6sF0x2uByC9gBRqCOAVMEnpZGUkBbU=; b=tAO47uwiNB03uv8VYzlRzcqWihtWYw90QJEibZDhwX8jTgq0KZomAZO2g/DQp8yYI2 t3G5mQusg+9lt/gtsmK1Ckz1B/2Y2Bs8F6Qwgn3ssfNCTKGHMVYLq3t5nnG7FKMMyCGh 4s6O0/188wP6wCsozLpJfF1LvyUWMh+3+t4yhMDQSq6UoctJpy5Y0pTABs3DFBoexHIQ lVFW2itbhZKbz3pCicttdG16Nd3jKOcds+0lAJXMADa/u7M4jmpVuQHhtyuGvCtuLZmX VD+FYKUsBjYJsevbqogDsAg+5TiG1WhA36xsH3Kn+Bt5vuYd9I2iK5IOxr1A25K8WCge xyYA== X-Gm-Message-State: AHQUAuZha/Bg9gEmA9MYjWSAc4A3mgPwg9+/9mNQCJqYli1ofgUPeMvC yJ62dmJ+lgTuWWoXv+K9EGNVq7KbYSpjqNZRgAc= X-Google-Smtp-Source: AHgI3IZjx670/rKQSNrH8eBwkan7S+nY3zbrV1tknWzuZbWoqV5NUEmuqmCi/hYmoX8yMTiCvNurMGPgE2hy0HBWVrw= X-Received: by 2002:ac8:4141:: with SMTP id e1mr16997325qtm.96.1550485909026; Mon, 18 Feb 2019 02:31:49 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Mon, 18 Feb 2019 11:31:32 +0100 Message-ID: Subject: Re: [PATCH 1/3] dt-bindings: dmaengine: Add one new cell to present hardware slave id To: Baolin Wang X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190218_023150_273602_54A34331 X-CRM114-Status: GOOD ( 22.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , DTML , eric.long@unisoc.com, arm-soc , Lyra Zhang , Mark Brown , Linux Kernel Mailing List , dmaengine@vger.kernel.org, Vinod Koul , Rob Herring , Olof Johansson , Orson Zhai , Dan Williams , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Feb 12, 2019 at 9:25 AM Baolin Wang wrote: > On Fri, 1 Feb 2019 at 19:53, Baolin Wang wrote: > > On Thu, 31 Jan 2019 at 00:52, Arnd Bergmann wrote: > > > On Tue, Jan 22, 2019 at 2:21 PM Baolin Wang wrote: > > > > > > > > Client: > > > > DMA clients connected to the Spreadtrum DMA controller must use the format > > > > -described in the dma.txt file, using a two-cell specifier for each channel. > > > > -The two cells in order are: > > > > +described in the dma.txt file, using a three-cell specifier for each channel. > > > > +The three cells in order are: > > > > 1. A phandle pointing to the DMA controller. > > > > 2. The channel id. > > > > +3. The hardware slave id which is used for clients to trigger DMA engine > > > > +automatically. > > > > > > I notice that this is an incompatible binding change. Is that necessary? > > > If the current code works, I'd suggest allowing both #dma-cells=<2> > > > and <3>, and then implementing both in the driver. > > > > Yes, this is necessary. > > > > Yes, current code can work, but the problem is that the DMA clients > > must add one property (something like "sprd,slave-id") to specify the > > slave id. So considering this, we want to change the dma-cells to 2, > > including dma channel and dma slave id, which can avoid introducing > > some similar properties for DMA clients. > > > > Now there are no DMA clients in mainline for Spreadtrum platform, and > > we want to upstream our first DMA clients: SPI controller. So no other > > drivers need to change when we changing dma cells. Thanks. > > Do you have any other concerns about this patch set? If not, I think > Vinod can apply this patch set. Thanks. Sorry for the late reply. Yes, this makes sense since there are no existing users then. For the DT changes going through the dmaengine tree Acked-by: Arnd Bergmann One more question, to make sure we don't need to edit it again: Why do you need both a 'channel id' and a 'slave id' here? Is this a strict hardware requirement for your DMA engine? In many other designs, only a DMA request line number needs to be described, and I think this would correspond to what you call the 'hardware slave id' in your documentation. Does each request line here correspond to a fixed channel id as well, or can a channel be shared between multiple slave devices? Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel