From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH 19/19] ASoC: fsi: Add DMAEngine support Date: Fri, 3 Feb 2012 14:14:40 +0000 Message-ID: <20120203141440.GR3151@opensource.wolfsonmicro.com> References: <871uqcjo9i.wl%kuninori.morimoto.gx@renesas.com> <87aa50i971.wl%kuninori.morimoto.gx@renesas.com> <20120203134850.GM3151@opensource.wolfsonmicro.com> <4F2BE998.4020903@metafoo.de> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7291547118371262427==" Return-path: Received: from opensource.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 75F6211CDFF for ; Fri, 3 Feb 2012 15:14:43 +0100 (CET) In-Reply-To: <4F2BE998.4020903@metafoo.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Lars-Peter Clausen Cc: Linux-ALSA , Vinod Koul , Kuninori Morimoto , Sascha Hauer , Wolfram Sang , Ralf Baechle , H Hartley Sweeten , Kuninori Morimoto , Liam Girdwood List-Id: alsa-devel@alsa-project.org --===============7291547118371262427== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="U5J2I87mWnf1KeOw" Content-Disposition: inline --U5J2I87mWnf1KeOw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Feb 03, 2012 at 03:05:12PM +0100, Lars-Peter Clausen wrote: > Yes, I was faced with the task of writing yet another dmaengine based ASoC > PCM driver last week. At first I thought it might be a good idea to come up > with a common ASoC PCM driver which could be used by all platforms using DMA > engine. Unfortunately this turned out to be not feasible due to how > dmaengine works. Each dmaengine driver has it's custom API for configuring > the DMA controller. :/ That doesn't sound insurmountible - you need a callback to allow the individual drivers to set the parameters but hopefully the data flow is more generic? There will probably be some other setup type stuff that needs doing. > The other ASoC platforms using dmaengine for their PCM driver (including the > one in this patch series) don't have this function implemented and so the > PCM drivers manually have to setup the cyclic SG lists. So while we could > add a common set up functions for this to ASoC or ALSA I think the better > place for this is in the dmaengine framework and implement > device_prep_dma_cyclic for those drivers which don't do yet. That seems like a good plan, that way other users of cyclic DMA will also benefit. --U5J2I87mWnf1KeOw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJPK+vJAAoJEBus8iNuMP3d4mwP/0MpyrqYJKYV4gIYy8RCbBYA 65O+2S9vyUp3ml95C8jNc/ivbKrQc4EBCdQiE2j/nHTKQBax+msOl12+YUZGk7qr 7B1PMiw9riaElU1BpDSfJhQCNjaf8/pAQIOehmoTwP+fWif7F9uHNJ65eHMQ9V8w S/MvgZq8E1iNxqMtvLRH4OB7MFwSL+ldRFh2RBUV8bg24TRZORv4bBY70rNmjQwY S0akxhFcBe90/mp1YbAtQ8sPx0ZJek+mdON+Su352RDNf7VUBLRqOy4rwmbYT04G cwzDFGNZQPnZ3Dqyo908t8AFiqTb8nLd4YXG/cSFR1ByXbk8sTOfvtaTV7C0LNqW c/wv/9M5fxKcW8Yz0g8GQpoPS9KhpHtHqZdeiour4JPGk34mcFiSGCUiCZBDCOlg CKokMLoUaofZyjzvHS136lV195T4YDrvy7aQKIOznEqD14BA0v9xfljN9+ISYqpB QoAUcKXS/ovI90hZgE09iyQAPMbZDVjqB0vLu3SpEVh6tT9I5Dnk9D2KZrE/39vI h10DhbtuqJPBORMZYTSvemRkC30Bc8DXjStJ2LeKYBTDBNwS+Q1rJtOwLv+/QEVf qMV50nT/4w/wzI+dE1vsxAjw0XCuZqquKgKymH1ytRg3+MQEj/EA5F+51+Z1tx2Z ZAW289MPNduH4UBs7iWX =uhg/ -----END PGP SIGNATURE----- --U5J2I87mWnf1KeOw-- --===============7291547118371262427== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============7291547118371262427==--