From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [PATCH 3/6] ASoC: TWL4030: Enable all audio paths Date: Tue, 7 Apr 2009 13:30:22 +0300 Message-ID: <200904071330.22727.peter.ujfalusi@nokia.com> References: <1239020372-8457-1-git-send-email-peter.ujfalusi@nokia.com> <200904070759.19600.peter.ujfalusi@nokia.com> <20090407094558.GA24788@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mgw-mx06.nokia.com (smtp.nokia.com [192.100.122.233]) by alsa0.perex.cz (Postfix) with ESMTP id 60F61244F1 for ; Tue, 7 Apr 2009 12:30:43 +0200 (CEST) In-Reply-To: <20090407094558.GA24788@sirena.org.uk> Content-Disposition: inline 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: ext Mark Brown Cc: "sakoman@gmail.com" , "alsa-devel@alsa-project.org" , "Nikula Jarkko (Nokia-D/Helsinki)" List-Id: alsa-devel@alsa-project.org On Tuesday 07 April 2009 12:45:59 ext Mark Brown wrote: > On Tue, Apr 07, 2009 at 07:59:19AM +0300, Peter Ujfalusi wrote: > > On Monday 06 April 2009 15:45:21 ext Mark Brown wrote: > > > What does this mean by "enable" - I'm guessing it's powering blocks > > > within the CODEC rather than connecting any audio paths? > > > > The TRM calls these as Audio/Voice digital filters. > > In effect, they enable the shifting out bits from the Capture path to t= he > > bus and shifting in bits on the Playback side. > > Hrm, so this is a routing thing then - from your description I'm a bit > surprised that this can be turned on unconditionally since it sounds > like it'll give you a sidetone all the time which might not be what > people want. Not quite. The sidetone/loopback can be turned off inside of twl4030 with t= he 'Left Digital Loopback' and 'Right Digital Loopback' set to 0. With the current implementation the capture path is powered only when there= is = need for it, which means that ADCs, TX PGAs are powered off. So even if the = Digital filters are enabled on the capture end, you will not see data going= to = the bus (from twl4030). I think the twl4030 codec still holds some interesting 'features'... > > > But as I said, this is not so nice thing to do, so it need to be > > revisited. > > It needs digital routing. In the interim another option would be to > provide switches to user space, possibly? It is possible to add 8 switches, or 4 stereo switch - I have to check the = code ;) Placing them to the correct location in the paths might be possible. I have to check it. But than there is this Option selection... twl4030 has two modes: Option1 a= nd = Option2. In same cases the config is the same, but in most of the cases it = behaves like two different codec... Option1 has only HiFi interface with up to 4 channel RX/TX The interface for the host processor in this case: i2s, l_just, r_just or TDM (stereo or 4 channel). Option2 has HiFi (up to 2 channel RX/TX) + Voice stereo uplink and mono = downlink. Than it has interface: i2s, l_just, r_just (stereo only) PCM BT Some of the bits in the OPTION register (and also in other registers) means = totally different things (or not valid for the mode) in Option1 than in = Option2... -- = P=E9ter