From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: [PATCH 1/7] [RFC] OMAP: MCBSP: hwmod database for 2xxx devices Date: Fri, 15 Oct 2010 09:51:09 +0300 Message-ID: <20101015095109.2d76babe.jhnikula@gmail.com> References: <1286296662-7639-1-git-send-email-kishon@ti.com> <201010061017.13908.peter.ujfalusi@nokia.com> <201010131131.49967.peter.ujfalusi@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f51.google.com (mail-ew0-f51.google.com [209.85.215.51]) by alsa0.perex.cz (Postfix) with ESMTP id 20A0F10388A for ; Fri, 15 Oct 2010 08:50:58 +0200 (CEST) Received: by ewy9 with SMTP id 9so193599ewy.38 for ; Thu, 14 Oct 2010 23:50:57 -0700 (PDT) In-Reply-To: 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: "Varadarajan, Charulatha" Cc: "Girdwood, Liam" , "alsa-devel@alsa-project.org" , "Kamat, Nishant" , "broonie@opensource.wolfsonmicro.com" , Peter Ujfalusi , "ABRAHAM, KISHON VIJAY" , "Basak, Partha" , "linux-omap@vger.kernel.org" , "Datta, Shubhrajyoti" List-Id: alsa-devel@alsa-project.org On Thu, 14 Oct 2010 20:21:15 +0530 "Varadarajan, Charulatha" wrote: > If other users should be allowed to use McBSP ports, it is good to > have DMA support in plat-omap/mcbsp.c itself and modify the asoc > implementation to take advantage of the proposed new mcbsp > design. If agreed, this shall be addressed later. Please let > me know your thoughts on this. > ASoC design allows to have other data movers (ASoC platfrom driver) also than SDMA only [1]. So tieing McBSP and DMA together means leaving out DSP<->McBSP<->Codec setup. I think API between McBSP driver and client should deal only with port transfer setup and a layer above that should take care of data transfer setup and implement an use-case specific API. E.g. where ALSA is using continuous transmission from/to circular buffer some another use-case would need chained scatter-gather DMA transfers, PIO, etc. So things can get complicated if trying to implement generic transfer API to general purpose block like McBSP compared to some dedicated block where transfer setup is always more or less the same. -- Jarkko 1. http://mailman.alsa-project.org/pipermail/alsa-devel/2010-August/030392.html