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_MUTT 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 BB730C04AAF for ; Tue, 21 May 2019 04:38:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E71621743 for ; Tue, 21 May 2019 04:38:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558413492; bh=4XX4rftcytXAmMV6UJKvOiyXZ94mgRgAhcGdMVSOYYE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=zd8bu+yWxsEhi/w6cwv3tz0qcIFj/cB0SWs4Ezu9MDnWj0JKHFJZgQ2+fdz1Zz0Cl fiyB1RH9syIDLxprfrGC/M6nOQc6SusmIKcspvV8DN4BizaCdmlp4xQ4iwYVrkqV3p oP1q1wQSAixcmNsLn7ytXwNCDCWlp0da/SYE5YF0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725982AbfEUEiM (ORCPT ); Tue, 21 May 2019 00:38:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:46054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725804AbfEUEiL (ORCPT ); Tue, 21 May 2019 00:38:11 -0400 Received: from localhost (unknown [106.201.107.13]) (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 81ADB216B7; Tue, 21 May 2019 04:38:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558413491; bh=4XX4rftcytXAmMV6UJKvOiyXZ94mgRgAhcGdMVSOYYE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XUh+oiXpbm38TqLjIBnHnx97cGR+QEtHqrbEvcNlVtydTwJ8TmXVMG6VoRF5UMmL0 cytkPrj9S83s3Gz4AiqjY9HGxxgGyGORnMNQCJnrw+uqvgJiL2Kggl1vuwL7p6zfcT wMJzOQ36Rt41lGzEWPIxULTVMbZR6eKOdJwopdDg= Date: Tue, 21 May 2019 10:08:07 +0530 From: Vinod Koul To: Peng Ma Cc: robh+dt@kernel.org, shawnguo@kernel.org, mark.rutland@arm.com, leoyang.li@nxp.com, dan.j.williams@intel.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3/4] dmaengine: fsl-edma: support little endian for edma driver Message-ID: <20190521043807.GN15118@vkoul-mobl> References: <20190506090344.37784-1-peng.ma@nxp.com> <20190506090344.37784-3-peng.ma@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190506090344.37784-3-peng.ma@nxp.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 06-05-19, 09:03, Peng Ma wrote: > improve edma driver to support little endian. Can you explain a bit more how adding the below lines adds little endian support... > > Signed-off-by: Peng Ma > --- > drivers/dma/fsl-edma-common.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c > index 680b2a0..6bf238e 100644 > --- a/drivers/dma/fsl-edma-common.c > +++ b/drivers/dma/fsl-edma-common.c > @@ -83,9 +83,14 @@ void fsl_edma_chan_mux(struct fsl_edma_chan *fsl_chan, > u32 ch = fsl_chan->vchan.chan.chan_id; > void __iomem *muxaddr; > unsigned int chans_per_mux, ch_off; > + int endian_diff[4] = {3, 1, -1, -3}; > > chans_per_mux = fsl_chan->edma->n_chans / DMAMUX_NR; > ch_off = fsl_chan->vchan.chan.chan_id % chans_per_mux; > + > + if (!fsl_chan->edma->big_endian) > + ch_off += endian_diff[ch_off % 4]; > + > muxaddr = fsl_chan->edma->muxbase[ch / chans_per_mux]; > slot = EDMAMUX_CHCFG_SOURCE(slot); > > -- > 1.7.1 -- ~Vinod