From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: OMAP Audio Date: Wed, 17 Feb 2010 09:03:39 +0200 Message-ID: <20100217090339.c11d2e8a.jhnikula@gmail.com> References: <4B7AE1AD.7080400@mlbassoc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f228.google.com ([209.85.219.228]:57023 "EHLO mail-ew0-f228.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933857Ab0BQG6d (ORCPT ); Wed, 17 Feb 2010 01:58:33 -0500 Received: by ewy28 with SMTP id 28so2491519ewy.28 for ; Tue, 16 Feb 2010 22:58:31 -0800 (PST) In-Reply-To: <4B7AE1AD.7080400@mlbassoc.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Gary Thomas Cc: OMAP Linux discussion On Tue, 16 Feb 2010 11:19:25 -0700 Gary Thomas wrote: > I need to connect the OMAP (3530) to a 24bit CODEC. So far > my attempts at getting this to go have not gone well. Then > I ran across this comment in sound/soc/omap/omap-pcm.c: > /* > * Note: Regardless of interface data formats supported by OMAP McBSP > * or EAC blocks, internal representation is always fixed 16-bit/sample > */ > > Does this mean that this setup is just not supported? even though > the hardware can handle it? > Yep, comment is bit misleading but true until some patch will remove it. IRCC, the EAC was limited to 16-bit and also there wasn't need and HW to test other formats than S16_LE in McBSP DAI. > Thanks for any pointers or ideas on how to get this going. > I would first start adding support for the S32_LE into omap-pcm.c (DMA part). Worth to look this thread: http://mailman.alsa-project.org/pipermail/alsa-devel/2010-January/024704.html Then add support for this format to the omap-mcbsp.c (link configuration part). Next step would be to add support for the S24_LE on 4-byte boundaries. I.e. the DMA is moving 32-bit samples between the memory and McBSP but only 24-bits are transferred over the McBSP and codec. -- Jarkko