From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Ribeiro Subject: Re: [PATCH 1/4] ASoC: pxa-ssp: enhance I2S and add Left_J support Date: Wed, 10 Jun 2009 19:24:09 -0300 Message-ID: <1244672649.25905.70.camel@brutus> References: <20090606201225.GA1029@sirena.org.uk> <74d0deb30906080512q29b9915fvec9b068bf4b2e126@mail.gmail.com> <20090608124045.GE7858@sirena.org.uk> <1244477000.30582.72.camel@brutus> <20090608165328.GB14026@rakim.wolfsonmicro.main> <1244481992.17327.22.camel@brutus> <20090608180656.GH7858@sirena.org.uk> <1244494349.17327.174.camel@brutus> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6450547785160796013==" Return-path: Received: from mail-qy0-f171.google.com (mail-qy0-f171.google.com [209.85.221.171]) by alsa0.perex.cz (Postfix) with ESMTP id B9A1210381C for ; Thu, 11 Jun 2009 00:24:16 +0200 (CEST) Received: by qyk1 with SMTP id 1so1602280qyk.16 for ; Wed, 10 Jun 2009 15:24:15 -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: Eric Miao Cc: alsa-devel@alsa-project.org, Mark Brown , linux-arm-kernel , pHilipp Zabel List-Id: alsa-devel@alsa-project.org --===============6450547785160796013== Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-ScBPui5Z6O3C9DpogpxB" --=-ScBPui5Z6O3C9DpogpxB Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Eric, Em Ter, 2009-06-09 =C3=A0s 17:39 +0800, Eric Miao escreveu: > frame_width =3D sample_width * channel ( =3D LRCLK for I2S ) >=20 > is no longer (and ever) correct. >=20 > E.g. the frame width could be 64fs, meaning a whole frame is > consisting > of 64 bitclks - that's saying, sample width from 1 - 64 are possible, > For typical 16-bit sample width I2S format, the envelope for each > sample > is 32 bitclks, and offseting by 1 bitclk starts the 16-bit sample. I'm working on supporting I2S right now, and I found some issues with this enveloping thing. First, it doesn't work on pxa2xx. DMYSTOP on pxa2xx is only 0-3. Second, is enveloping needed at all? The patch you sent supports 32bits frames for 2*16bits samples or 64bits frames for 2*32bits samples using FSRT. We already use FSRT for DSP_A, and if this works on littleton I2S we should just stick with FSRT (and frame_width =3D sample_width * channels) to keep the code simple. > And the TDM mode is actually special for PXA-SSP to emulate the I2S > protocol, it's no way generic TDM in a common sense. So talking about > set_tdm_slots(), I'd really like to hide into the format setting code > of I2S/Left_J to avoid further confusion. TDM is needed for frames larger than 32 bits on any dai format. Its not something specific to I2S. --=20 Daniel Ribeiro --=-ScBPui5Z6O3C9DpogpxB Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Esta =?ISO-8859-1?Q?=E9?= uma parte de mensagem assinada digitalmente -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkowMokACgkQw3OYl0G0liSx6QCfRxMcrzjjek7/oe4t3xeEl4J0 wQgAnj4UrjTegmrUWi/w5IZbWTywzPGp =IJp3 -----END PGP SIGNATURE----- --=-ScBPui5Z6O3C9DpogpxB-- --===============6450547785160796013== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel --===============6450547785160796013==--