From patchwork Fri Sep 6 14:18:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 11135361 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 0F9C0924 for ; Fri, 6 Sep 2019 14:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E44402173E for ; Fri, 6 Sep 2019 14:18:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="ofwXpHE7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394355AbfIFOR5 (ORCPT ); Fri, 6 Sep 2019 10:17:57 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:60276 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394353AbfIFOR5 (ORCPT ); Fri, 6 Sep 2019 10:17:57 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id x86EHsid033204; Fri, 6 Sep 2019 09:17:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1567779474; bh=lL+zXXpiAMPM0yEzqtzknYNhG5vy2NXPPxTYA7JesO0=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=ofwXpHE7AsqrsmL6NeU0jtuoK4b5jvfACKy6wPiinroLAiTz5FQeJg3Y9kKn+qEdu f3lNvBdPkGA9mdzRoHlVqX0Ht+ZkdVkUrv/uxhZIf8xK0InD8d9/Lt2RxVaaX6Iq2e tEYlJwoAgYBuKjgoj/7ecdZWS23/S72u2LIbobHg= Received: from DLEE104.ent.ti.com (dlee104.ent.ti.com [157.170.170.34]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id x86EHs7h129321; Fri, 6 Sep 2019 09:17:54 -0500 Received: from DLEE106.ent.ti.com (157.170.170.36) by DLEE104.ent.ti.com (157.170.170.34) 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 09:17:52 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE106.ent.ti.com (157.170.170.36) 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 09:17:52 -0500 Received: from feketebors.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x86EHlOe032723; Fri, 6 Sep 2019 09:17:50 -0500 From: Peter Ujfalusi To: , CC: , , , Subject: [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains Date: Fri, 6 Sep 2019 17:18:14 +0300 Message-ID: <20190906141816.24095-2-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190906141816.24095-1-peter.ujfalusi@ti.com> References: <20190906141816.24095-1-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>; + }; +...