From patchwork Mon Dec 6 17:42:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Cercueil X-Patchwork-Id: 12659233 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75ABEC433F5 for ; Mon, 6 Dec 2021 17:43:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245224AbhLFRq7 (ORCPT ); Mon, 6 Dec 2021 12:46:59 -0500 Received: from aposti.net ([89.234.176.197]:59656 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245375AbhLFRqx (ORCPT ); Mon, 6 Dec 2021 12:46:53 -0500 From: Paul Cercueil To: Vinod Koul , Rob Herring Cc: list@opendingux.net, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, Paul Cercueil Subject: [PATCH v2 2/6] dt-bindings: dma: ingenic: Support #dma-cells = <3> Date: Mon, 6 Dec 2021 17:42:55 +0000 Message-Id: <20211206174259.68133-3-paul@crapouillou.net> In-Reply-To: <20211206174259.68133-1-paul@crapouillou.net> References: <20211206174259.68133-1-paul@crapouillou.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Extend the binding to support specifying a different request type for each direction. Signed-off-by: Paul Cercueil --- Notes: v2: Enhance documentation .../devicetree/bindings/dma/ingenic,dma.yaml | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/ingenic,dma.yaml b/Documentation/devicetree/bindings/dma/ingenic,dma.yaml index 2607b403277e..3b0b3b919af8 100644 --- a/Documentation/devicetree/bindings/dma/ingenic,dma.yaml +++ b/Documentation/devicetree/bindings/dma/ingenic,dma.yaml @@ -44,13 +44,19 @@ properties: maxItems: 1 "#dma-cells": - const: 2 + enum: [2, 3] description: > DMA clients must use the format described in dma.txt, giving a phandle - to the DMA controller plus the following 2 integer cells: - - - Request type: The DMA request type for transfers to/from the - device on the allocated channel, as defined in the SoC documentation. + to the DMA controller plus the following integer cells: + + - Request type: The DMA request type specifies the device endpoint that + will be the source or destination of the DMA transfer. + If "#dma-cells" is 2, the request type is a single cell, and the + direction will be unidirectional (either RX or TX but not both). + If "#dma-cells" is 3, the request type has two cells; the first + one corresponds to the host to device direction (TX), the second one + corresponds to the device to host direction (RX). The DMA channel is + then bidirectional. - Channel: If set to 0xffffffff, any available channel will be allocated for the client. Otherwise, the exact channel specified will be used.