From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752752AbcFURik (ORCPT ); Tue, 21 Jun 2016 13:38:40 -0400 Received: from mail-bl2nam02on0045.outbound.protection.outlook.com ([104.47.38.45]:41427 "EHLO NAM02-BL2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752207AbcFURig convert rfc822-to-8bit (ORCPT ); Tue, 21 Jun 2016 13:38:36 -0400 Authentication-Results: spf=pass (sender IP is 149.199.60.100) smtp.mailfrom=xilinx.com; vger.kernel.org; dkim=none (message not signed) header.d=none;vger.kernel.org; dmarc=bestguesspass action=none header.from=xilinx.com; From: Appana Durga Kedareswara Rao To: Vinod Koul CC: "robh+dt@kernel.org" , "pawel.moll@arm.com" , "mark.rutland@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , Michal Simek , Soren Brinkmann , "dan.j.williams@intel.com" , "moritz.fischer@ettus.com" , "laurent.pinchart@ideasonboard.com" , "luis@debethencourt.com" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "dmaengine@vger.kernel.org" Subject: RE: [PATCH 2/4] dmaengine: vdma: Add support for mulit-channel dma mode Thread-Topic: [PATCH 2/4] dmaengine: vdma: Add support for mulit-channel dma mode Thread-Index: AQHRwvhG7GsWp3fGQ0KDXydjsS2JzJ/znn0AgACEjJA= Date: Tue, 21 Jun 2016 16:02:05 +0000 Message-ID: References: <1465549954-30220-1-git-send-email-appanad@xilinx.com> <1465549954-30220-3-git-send-email-appanad@xilinx.com> <20160621155502.GB16910@localhost> In-Reply-To: <20160621155502.GB16910@localhost> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.23.230.78] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-RCIS-Action: ALLOW X-TM-AS-Product-Ver: IMSS-7.1.0.1224-8.0.0.1202-22404.005 X-TM-AS-User-Approved-Sender: Yes;Yes X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-HT: Tenant X-Forefront-Antispam-Report: CIP:149.199.60.100;IPV:NLI;CTRY:US;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(7916002)(2980300002)(438002)(51914003)(189002)(199003)(24454002)(46406003)(86362001)(87936001)(110136002)(2900100001)(97756001)(8936002)(92566002)(2920100001)(586003)(106116001)(23726003)(7736002)(189998001)(6116002)(2950100001)(102836003)(106466001)(33656002)(4326007)(2906002)(3846002)(63266004)(8746002)(5250100002)(55846006)(50986999)(6806005)(76176999)(81156014)(54356999)(8676002)(81166006)(50466002)(356003)(47776003)(11100500001)(7846002)(7696003)(5003600100003)(107986001)(5001870100001);DIR:OUT;SFP:1101;SCL:1;SRVR:BL2NAM02HT059;H:xsj-pvapsmtpgw02;FPR:;SPF:Pass;PTR:unknown-60-100.xilinx.com,xapps1.xilinx.com;MX:1;A:1;CAT:NONE;LANG:en;CAT:NONE; X-MS-Office365-Filtering-Correlation-Id: 0f24293d-a658-4fce-1db5-08d399ed691b X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(8251501002);SRVR:BL2NAM02HT059; X-Microsoft-Antispam-PRVS: <61762fdc48df47369ac18b8f9a621b9c@BL2NAM02HT059.eop-nam02.prod.protection.outlook.com> X-Exchange-Antispam-Report-Test: UriScan:(21532816269658); X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(2401047)(13023025)(13015025)(13017025)(13024025)(5005006)(13018025)(8121501046)(3002001)(10201501046)(6055026);SRVR:BL2NAM02HT059;BCL:0;PCL:0;RULEID:;SRVR:BL2NAM02HT059; X-Forefront-PRVS: 098076C36C X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Jun 2016 16:02:13.6399 (UTC) X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c;Ip=[149.199.60.100];Helo=[xsj-pvapsmtpgw02] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL2NAM02HT059 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vinod, Thanks for the review... > > On Fri, Jun 10, 2016 at 02:42:32PM +0530, Kedareswara rao Appana wrote: > > This patch adds support for AXI DMA multi-channel dma mode > > Multichannel mode enables DMA to connect to multiple masters And > > slaves on the streaming side. > > In Multichannel mode AXI DMA supports 2D transfers. > > Funny formatting! Will fix in next version... > > Can you elobrate what you meant by Multichannel mode? This patch seems to > do two things, one is to add interleaved dma support and something else. Can > you explain the latter part? AXI DMA has two Stream interfaces (Memory to Stream MM2S and Stream to Memory S2MM) In Multi-Channel dma mode each stream interface can be configured up to 16 channels. In Multi-channel DMA mode IP supports only interleaved transfers (2-D transfers). > > > /** > > + * struct xilinx_mcdma_config - DMA Multi channel configuration > > +structure > > + * @tdest: Channel to operate on > > + * @tid: Channel configuration > > + * @tuser: Tuser configuration > > + * @ax_user: ax_user value > > + * @ax_cache: ax_cache value > > + */ > > +struct xilinx_mcdma_config { > > + u8 tdest; > > + u8 tid; > > + u8 tuser; > > + u8 ax_user; > > + u8 ax_cache; > > can you describe these in details, what do these do, what are the values to be > programmed? As said above In Multi-Channel Mode each Stream interface can be Configured up to 16 channels each channel is differentiated based on the tdest and tid values. tdest: TDEST provides routing information for the data stream. TDEST values are static for the entire packet. tid: Provides a stream identifier. TID values are static for entire packet. TID values provided in the TX descriptor field are presented on TID signals of the streaming side. tuser: Sideband signals used for user-defined information. TUSER values are static for entire packet. TUSER values provided in the TX Descriptor field are presented on TUSER signals of streaming side. ax_user: Sideband signals used for user-defined information ARUSER values and their interpretations are user-defined ax_cache: Cache type this signal provides additional information about the cacheable Characteristics of the transfer. In the above parameters tdest and tid are mandatory to differentiate b/w different channels Other parameters are optional please let me know if you don't want me to Include other optional parameters will remove in the next version. Regards, Kedar. > > -- > ~Vinod