From mboxrd@z Thu Jan 1 00:00:00 1970 From: Caleb Crome Subject: Re: [ASoc] TDM over one SSC channel on AT91 possible? Date: Thu, 23 Jun 2011 23:07:16 -0700 Message-ID: References: <1308676512.32380.11.camel@alice.bigman.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pz0-f51.google.com (mail-pz0-f51.google.com [209.85.210.51]) by alsa0.perex.cz (Postfix) with ESMTP id 53951248B2 for ; Fri, 24 Jun 2011 08:07:18 +0200 (CEST) Received: by pzk26 with SMTP id 26so1703846pzk.38 for ; Thu, 23 Jun 2011 23:07:17 -0700 (PDT) In-Reply-To: <1308676512.32380.11.camel@alice.bigman.com> 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: Jason Fox Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Heh, this is kind of the opposite problem I had to manage -- I had 8 codecs that needed to appear as a single card, over a single TDM bus. I could not find a good way to do it, so i did it in a bad way, by modifying the codec driver to appear to the kernel as a single codec, but drive all 8 codecs directly from a single instantiated codec. The sticky point that I couldn't find a good resolution to, is that the dai_link specifies a physical connection from CPU to codec. However, it's a point to point link, which does not allow for multiple codecs on the same active dai link at the same time. the sound/soc/soc-core.c does does not currently start multiple codecs when starting a card (as far as I can tell). i think you can create 8 dai_links, but I don't suspect you'll be able to open all 8, at the same time. What's the point of doing this anyway? Why do you want it to appear as 8 sound cards? It seems that you can manage the 8 channels from user space easily enough. -Caleb On Tue, Jun 21, 2011 at 10:15 AM, Jason Fox wrote: > Hello everyone, > > I am looking for some help where I need an AD193X codec to be shared > between 8 audio streams using one SSC channel on an AT91SAM9263, in > other words, I need it to look like 8 different soundcards. We have the > 8 TDM channels working in the driver but I can't figure out how to > create the proper interface of 8 soundcards for ALSA. In an earlier > email in this topic was posted: > > > I would instantiate one driver with 3 pcms. This would allow:- > > > > pcm0: 2 channel, slot 0,1 > > pcm1: 2 channel, slot 2,3 > > pcm2: 4 channel, slot 0,1,2,3 > > > > Giving full flexibility for many use cases. The pcms would be mutually > > exclusive (enforced by machine driver). > > > > HTH > > > > Liam > > I think that maybe that I want to instantiate one driver with 8 pcms. > Where/how do I > instantiate the PCMs? I guess it in in the machine driver? > > This is our first attempt at developing a Linux based system so please > forgive my > newbie question. I am sure this is really simple but I'm not following > somewhere. > > Thanks for your help, > Jason Fox > GAI-Tronics > ******************************************************************* > This email and any files transmitted with it are confidential and > intended solely for the use of the individual or entity to whom > they are addressed. If you have received this email in error please > notify the system manager. This footnote also confirms that this > email message has been swept for the presence of computer viruses. > www.Hubbell.com - Hubbell Incorporated** > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@alsa-project.org > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel >