From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [4/5] dmaengine: sprd: Add Spreadtrum DMA configuration From: Vinod Koul Message-Id: <20180413063641.GL6014@localhost> Date: Fri, 13 Apr 2018 12:06:42 +0530 To: Baolin Wang Cc: Dan Williams , Eric Long , Mark Brown , dmaengine@vger.kernel.org, LKML List-ID: T24gRnJpLCBBcHIgMTMsIDIwMTggYXQgMDI6MTc6MzRQTSArMDgwMCwgQmFvbGluIFdhbmcgd3Jv dGU6Cgo+ID4gQWdyZWVkLCB1c2VycyBvbmx5IGNhcmUgYWJvdXQgZ3JhYmJpbmcgYSBjaGFubmVs LCBzZXR0aW5nIGEgZGVzY3JpcHRvciBhbmQKPiA+IHN1Ym1pdHRpbmcgdGhhdC4KPiA+Cj4gPiBJ IHRoaW5rIHlvdSBuZWVkIHRvIGdvIGJhY2sgYW5kIHRoaW5rIGFib3V0IHRoaXMgYSBiaXQsIHBs ZWFzZSBkbyBnbyB0aHJ1Cj4gPiBkbWFlbmdpbmUgZG9jdW1lbnRhdGlvbiBhbmQgc2VlIG90aGVy IGRyaXZlciBleGFtcGxlcy4KPiA+Cj4gPiBXZSBkb24ndCB0eXBpY2FsbHkgZXhwb3NlIHRoZXNl IHRvIHVzZXJzLCB0aGV5IGdpdmUgdXMgYSB0cmFuc2ZlciBhbmQgd2Ugc2V0Cj4gPiB0aGF0IHVw IGluIGhhcmR3YXJlIGZvciBlZmZpY2llbnQuIEl0cyBETUEgc28gcGVvcGxlIGV4cGVjdCB1cyB0 byB1c2UgZmFzdGVzdAo+ID4gbWVjaGFuaXNtIGF2YWlsYWJsZS4KPiAKPiBCdXQgdGhlcmUgYXJl IHNvbWUgY29uZmlndXJhdGlvbiBhcmUgcmVhbGx5IHNwZWNpYWwgZm9yIFNwcmVhZHRydW0KPiBE TUEsIGFuZCBtdXN0IG5lZWQgdXNlciB0byBzcGVjaWZ5IGhvdyB0byBjb25maWd1cmUsIGVzcGVj aWFsbHkgc29tZQo+IHNjZW5hcmlvcyBvZiBhdWRpby4gU28gSSB3YW5kZXIgaWYgd2UgY2FuIGFk ZCBvbmUgcG9pbnRlciBmb3IKPiAnZG1hX3NsYXZlX2NvbmZpZycgdG8gZXhwYW5kIHNvbWUgc3Bl Y2lhbCBETUEgY29uZmlndXJhdGlvbgo+IHJlcXVpcmVtZW50cywgbGlrZToKPiAKPiBzdHJ1Y3Qg ZG1hX3NsYXZlX2NvbmZpZyB7Cj4gICAgIC4uLi4uLgo+ICAgICB1bnNpZ25lZCBpbnQgc2xhdmVf aWQ7Cj4gICAgIHZvaWQgKnBsYXRmb3JtX2RhdGE7Cj4gfTsKPiAKPiBTbyBpZiBzb21lIERNQSBo YXMgc29tZSBzcGVjaWFsIGNvbmZpZ3VyYXRpb24gKHN1Y2ggYXMgU3ByZWFkdHJ1bQo+IERNQSks IHRoZXkgY2FuIHVzZXIgdGhpcyBwbGF0Zm9ybV9kYXRhIHBvaW50ZXIuIExpa2UgeGlsaW54IERN QSwgdGhleQo+IGFsc28gaGF2ZSBzb21lIHNwZWNpYWwgY29uZmlndXJhdGlvbi4KCldlbGwgd2Ug YWxsIHRoaW5rIG91ciBIVyBpcyBzcGVjaWFsIGFuZCBuZWVkcyBzb21lIGFkZGl0aW9uYWwgc3R1 ZmYsIG1vc3Qgb2YKdGhlIGNhc2VzIHR1cm5zIG91dCBub3QgdG8gYmUgdGhlIGNhc2UuCgpDYW4g eW91IGV4cGxhaW4gaG93IGF1ZGlvIGluIHRoaXMgY2FzZSBhZGRpdGlvbmFsIGNvbmZpZ3VyYXRp b24uLi4K From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753308AbeDMGcP (ORCPT ); Fri, 13 Apr 2018 02:32:15 -0400 Received: from mga01.intel.com ([192.55.52.88]:33912 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752005AbeDMGcO (ORCPT ); Fri, 13 Apr 2018 02:32:14 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,444,1517904000"; d="scan'208";a="191174992" Date: Fri, 13 Apr 2018 12:06:42 +0530 From: Vinod Koul To: Baolin Wang Cc: Dan Williams , Eric Long , Mark Brown , dmaengine@vger.kernel.org, LKML Subject: Re: [PATCH 4/5] dmaengine: sprd: Add Spreadtrum DMA configuration Message-ID: <20180413063641.GL6014@localhost> References: <0c2b76aba6a49e583f920ae582d6815fa9cc4361.1523346135.git.baolin.wang@linaro.org> <20180411093634.GC6014@localhost> <20180412093735.GF6014@localhost> <20180413034332.GI6014@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 13, 2018 at 02:17:34PM +0800, Baolin Wang wrote: > > Agreed, users only care about grabbing a channel, setting a descriptor and > > submitting that. > > > > I think you need to go back and think about this a bit, please do go thru > > dmaengine documentation and see other driver examples. > > > > We don't typically expose these to users, they give us a transfer and we set > > that up in hardware for efficient. Its DMA so people expect us to use fastest > > mechanism available. > > But there are some configuration are really special for Spreadtrum > DMA, and must need user to specify how to configure, especially some > scenarios of audio. So I wander if we can add one pointer for > 'dma_slave_config' to expand some special DMA configuration > requirements, like: > > struct dma_slave_config { > ...... > unsigned int slave_id; > void *platform_data; > }; > > So if some DMA has some special configuration (such as Spreadtrum > DMA), they can user this platform_data pointer. Like xilinx DMA, they > also have some special configuration. Well we all think our HW is special and needs some additional stuff, most of the cases turns out not to be the case. Can you explain how audio in this case additional configuration... -- ~Vinod