From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benoit Cousson Subject: Re: [RFC] ASoC: core: Add support for DAI multicodec Date: Thu, 13 Mar 2014 11:42:50 +0100 Message-ID: <53218BAA.9000600@baylibre.com> References: <1394536644-21438-1-git-send-email-bcousson@baylibre.com> <20140312002821.GD28112@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail-wg0-f50.google.com (mail-wg0-f50.google.com [74.125.82.50]) by alsa0.perex.cz (Postfix) with ESMTP id C612A265176 for ; Thu, 13 Mar 2014 11:42:53 +0100 (CET) Received: by mail-wg0-f50.google.com with SMTP id x13so654080wgg.21 for ; Thu, 13 Mar 2014 03:42:53 -0700 (PDT) In-Reply-To: <20140312002821.GD28112@sirena.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Mark Brown Cc: alsa-devel@alsa-project.org, lars@metafoo.de, lgirdwood@gmail.com, Misael Lopez Cruz List-Id: alsa-devel@alsa-project.org Hi Mark, On 12/03/2014 01:28, Mark Brown wrote: > On Tue, Mar 11, 2014 at 12:17:24PM +0100, Benoit Cousson wrote: >> From: Misael Lopez Cruz >> >> DAI link assumes a one to one mapping between CPU DAI and CODEC. In >> some cases, the same CPU DAI can be connected to several codecs. >> This is the case for example, if you connect two mono codecs to the >> same I2S link in order to have a stereo card. >> The current ASoC implementation does not allow such setup. > > First up thanks for working on this, it's a feature which has been > requested for a long time but nobody stepped forward to do it before > now. > > This is rather large so I've not had time to review it today, I'll try > to get at least a first pass at that done tomorrow. I did notice that > in your comment about rebasing you mentioned a series - it'd be good if > we could see this as a series, splitting it up would make review easier. Yeah, I know. The issue is that the original series was done on a 3.8 = Android branch with few refactor patches before that one to introduce = some helpers. During the 3.8 -> 3.13 rebase then 3.13 -> 3.14 rebase, a = lot of them did not survive due to internal asoc changes and cleanups = that happened since 3.8. At least, there are still few helpers that can be introduced sooner, but = it will still make the main patch pretty huge. I don't think we can make = the transition in smaller chunks. >> CPU DAI in a multicodec DAI link can have more channels than what each >> CODEC has. The number of channels each CODEC is responsible for is >> machine specific, hence it's fixed up in machine drivers in a similar >> way to what DPCM does. > > This one is interesting. It feels like most things will want a static > mapping because that's what the hardware does but there will doubtless > be things that could use flexibility. Liam has looked at this in the > past (more for TDM IIRC, I thought about it for that as well and I seem > to recall Liam's ideas covering it). It feels like we should start out > with static mappings and build up dynamic later on but equally well > getting something merged would mean we could improve on it. > >> The patch is based on 3.14-rc6. > > For such an invasive set of changes it's probably worth working off > -next, I forsee conflicts. Indeed, I've just tried rebasing it on asoc/next and it does conflict :-( But not a major conflict anyway. I'll do that for the repost. Thanks for the comments, Benoit -- = Beno=EEt Cousson BayLibre Embedded Linux Technology Lab www.baylibre.com