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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 F1E84C4332F for ; Sun, 8 Sep 2019 12:12:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4AE0218AC for ; Sun, 8 Sep 2019 12:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567944729; bh=UmeDjAzR6/3LB9jjoTbqWWv9lFExcVwjpss84j0OuUM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=QInmmdnQfgatptWBujznrdghgTkmEQISyZFexE6M9sYJVwBMWGhvllr9/swbedlqy CwRTLOBOi9WehD0VZF0H6dOGVkNIiI229kqDvmDnAs52m972CYt2ZCE769vCzYVx/k n2seNe70h0YpKfnCeHvEDYfbdwUieoHxidIE2+II= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728891AbfIHMMJ (ORCPT ); Sun, 8 Sep 2019 08:12:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:39470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728818AbfIHMMJ (ORCPT ); Sun, 8 Sep 2019 08:12:09 -0400 Received: from localhost (unknown [122.182.221.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4146320863; Sun, 8 Sep 2019 12:12:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567944728; bh=UmeDjAzR6/3LB9jjoTbqWWv9lFExcVwjpss84j0OuUM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PCditvPD0UQC6dVxIKH3ICuj3ZIA1Dy+Dle+f8rL1WQecFnEwS/c5Tvxeg8OHPjZJ /v8+4LCoekmWFchXedhGGwXcdlR2c74fCa51qg6FqmzK2y/yPDRa4llpTfXpBBVT/T kt8JpNhlZRuyb4HwSLIkwv/ZJO3qm7JX/kDhX+J4= Date: Sun, 8 Sep 2019 17:40:58 +0530 From: Vinod Koul To: Peter Ujfalusi Cc: robh+dt@kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, dan.j.williams@intel.com, devicetree@vger.kernel.org Subject: Re: [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains Message-ID: <20190908121058.GL2672@vkoul-mobl> References: <20190906141816.24095-1-peter.ujfalusi@ti.com> <20190906141816.24095-2-peter.ujfalusi@ti.com> <961d30ea-d707-1120-7ecf-f51c11c41891@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <961d30ea-d707-1120-7ecf-f51c11c41891@ti.com> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 08-09-19, 10:47, Peter Ujfalusi wrote: > > > On 06/09/2019 17.18, Peter Ujfalusi wrote: > > On systems where multiple DMA controllers available, none Slave (for example > > memcpy operation) users can not be described in DT as there is no device > > involved from the DMA controller's point of view, DMA binding is not usable. > > However in these systems still a peripheral might need to be serviced by or > > it is better to serviced by specific DMA controller. > > When a memcpy is used to/from a memory mapped region for example a DMA in the > > same domain can perform better. > > For generic software modules doing mem 2 mem operations it also matter that > > they will get a channel from a controller which is faster in DDR to DDR mode > > rather then from the first controller happen to be loaded. > > > > This property is inherited, so it may be specified in a device node or in any > > of its parent nodes. > > > > Signed-off-by: Peter Ujfalusi > > --- > > .../devicetree/bindings/dma/dma-domain.yaml | 59 +++++++++++++++++++ > > 1 file changed, 59 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/dma/dma-domain.yaml > > > > diff --git a/Documentation/devicetree/bindings/dma/dma-domain.yaml b/Documentation/devicetree/bindings/dma/dma-domain.yaml > > new file mode 100644 > > index 000000000000..c2f182f30081 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/dma/dma-domain.yaml > > @@ -0,0 +1,59 @@ > > +# SPDX-License-Identifier: GPL-2.0 > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/dma/dma-controller.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: DMA Domain Controller Definition > > + > > +maintainers: > > + - Vinod Koul > > + > > +allOf: > > + - $ref: "dma-controller.yaml#" > > + > > +description: > > + On systems where multiple DMA controllers available, none Slave (for example > > + memcpy operation) users can not be described in DT as there is no device > > + involved from the DMA controller's point of view, DMA binding is not usable. > > + However in these systems still a peripheral might need to be serviced by or > > + it is better to serviced by specific DMA controller. > > + When a memcpy is used to/from a memory mapped region for example a DMA in the > > + same domain can perform better. > > + For generic software modules doing mem 2 mem operations it also matter that > > + they will get a channel from a controller which is faster in DDR to DDR mode > > + rather then from the first controller happen to be loaded. > > + > > + This property is inherited, so it may be specified in a device node or in any > > + of its parent nodes. > > + > > +properties: > > + $dma-domain-controller: > > or domain-dma-controller? I feel dma-domain-controller sounds fine as we are defining domains for dmaengine. Another thought which comes here is that why not extend this to slave as well and define dma-domain-controller for them as use that for filtering, that is what we really need along with slave id in case a specific channel is to be used by a peripheral Thoughts..? -- ~Vinod