From patchwork Fri Sep 6 14:17:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 11135351 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5E47E112B for ; Fri, 6 Sep 2019 14:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D9D520854 for ; Fri, 6 Sep 2019 14:17:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="bMPSYu3h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391823AbfIFOQ7 (ORCPT ); Fri, 6 Sep 2019 10:16:59 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:53072 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729017AbfIFOQ6 (ORCPT ); Fri, 6 Sep 2019 10:16:58 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x86EGrqM081318; Fri, 6 Sep 2019 09:16:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1567779413; bh=lL+zXXpiAMPM0yEzqtzknYNhG5vy2NXPPxTYA7JesO0=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=bMPSYu3h2iINSzphkoyAysVXm0iwyvy1a2EUt0dQQ2CW6AglsVw2xIayp6CImvkpF HRT8Z/IvKAgoQdyC+D5FNdoVy/vScxAeC1a0CmnzFsh0kZ33Hh5Rvl76Sr/nRbPYlC 3QSOVssDCgoEaihU3HP5w3hah29dn2/QNSPPUoKs= Received: from DFLE107.ent.ti.com (dfle107.ent.ti.com [10.64.6.28]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x86EGrAd092427 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 6 Sep 2019 09:16:53 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Fri, 6 Sep 2019 09:16:53 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Fri, 6 Sep 2019 09:16:53 -0500 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id x86EGmad042400; Fri, 6 Sep 2019 09:16:51 -0500 From: Peter Ujfalusi To: , CC: , , , Subject: [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains Date: Fri, 6 Sep 2019 17:17:15 +0300 Message-ID: <20190906141717.23859-2-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190906141717.23859-1-peter.ujfalusi@ti.com> References: <20190906141717.23859-1-peter.ujfalusi@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 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: + $ref: /schemas/types.yaml#definitions/phandle + description: + phande to the DMA controller node which should be used for the device or + domain. + +examples: + - | + / { + model = "Texas Instruments K3 AM654 SoC"; + compatible = "ti,am654"; + interrupt-parent = <&gic500>; + /* For modules without device, DDR to DDR is faster on main UDMAP */ + dma-domain-controller = <&main_udmap>; + #address-cells = <2>; + #size-cells = <2>; + ... + }; + + &cbass_main { + /* For modules within MAIN domain, use main UDMAP */ + dma-domain-controller = <&main_udmap>; + }; + + &cbass_mcu { + /* For modules within MCU domain, use mcu UDMAP */ + dma-domain-controller = <&mcu_udmap>; + }; +...