From patchwork Tue Apr 15 15:13:32 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 3993641 X-Patchwork-Delegate: vinod.koul@intel.com Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4F7FA9F2CC for ; Tue, 15 Apr 2014 15:13:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5711E20200 for ; Tue, 15 Apr 2014 15:13:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E0362020F for ; Tue, 15 Apr 2014 15:13:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751054AbaDOPNk (ORCPT ); Tue, 15 Apr 2014 11:13:40 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:52304 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751107AbaDOPNk (ORCPT ); Tue, 15 Apr 2014 11:13:40 -0400 Received: from avalon.ideasonboard.com (55.138-246-81.adsl-dyn.isp.belgacom.be [81.246.138.55]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 516E9359FA; Tue, 15 Apr 2014 17:11:37 +0200 (CEST) From: Laurent Pinchart To: dmaengine@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Daniel Mack , Xiang Wang Subject: [PATCH 1/6] dmaengine: Add fly-by transfer flag to slave configuration structure Date: Tue, 15 Apr 2014 17:13:32 +0200 Message-Id: <1397574817-15559-2-git-send-email-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1397574817-15559-1-git-send-email-laurent.pinchart@ideasonboard.com> References: <1397574817-15559-1-git-send-email-laurent.pinchart@ideasonboard.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Fly-by transfer mode cuts down the number of bus transactions by letting the slave drive or latch the memory data bus during memory transactions instead of performing a dedicated transaction to read data from or write data to the slave. Support for fly-by mode by adding a new flag field to struct dma_slave_config. Signed-off-by: Laurent Pinchart --- include/linux/dmaengine.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index c5c92d5..ae99153 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -304,6 +304,17 @@ enum dma_slave_buswidth { }; /** + * enum dma_slave_flags - DMA slave configuration flags + * @DMA_SLAVE_FLAG_FLY_BY - perform DMA transfers for the slave in fly-by mode. + * Instead of performing a bus transaction to read (write) data from (to) the + * slave, let the slave drive (latch) the memory bus data signals during the + * memory write (read) transaction. + */ +enum dma_slave_flags { + DMA_SLAVE_FLAG_FLY_BY = (1 << 0), +}; + +/** * struct dma_slave_config - dma slave channel runtime config * @direction: whether the data shall go in or out on this slave * channel, right now. DMA_MEM_TO_DEV and DMA_DEV_TO_MEM are @@ -333,6 +344,7 @@ enum dma_slave_buswidth { * @slave_id: Slave requester id. Only valid for slave channels. The dma * slave peripheral will have unique id as dma requester which need to be * pass as slave config. + * @flags: DMA slave flags, a combination of enum dma_slave_flags flags. * * This struct is passed in as configuration data to a DMA engine * in order to set up a certain channel for DMA transport at runtime. @@ -361,6 +373,7 @@ struct dma_slave_config { u32 dst_maxburst; bool device_fc; unsigned int slave_id; + u32 flags; }; /**