From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752814AbbANMvc (ORCPT ); Wed, 14 Jan 2015 07:51:32 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:56795 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101AbbANMva (ORCPT ); Wed, 14 Jan 2015 07:51:30 -0500 Date: Wed, 14 Jan 2015 12:50:56 +0000 From: Mark Brown To: Philipp Zabel Cc: Russell King - ARM Linux , Jyri Sarha , Jean-Francois Moine , Andrew Jackson , Dave Airlie , "alsa-devel@alsa-project.org" , "devicetree@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" Message-ID: <20150114125056.GU4160@sirena.org.uk> References: <20150112175705.GN12302@n2100.arm.linux.org.uk> <1421151718.4519.24.camel@pengutronix.de> <20150113122715.GP12302@n2100.arm.linux.org.uk> <20150113165411.5469930d@armhf> <20150113160313.GR12302@n2100.arm.linux.org.uk> <20150113200252.3dbfab14@armhf> <20150113192648.GU12302@n2100.arm.linux.org.uk> <54B574CD.9020905@ti.com> <20150113195415.GV12302@n2100.arm.linux.org.uk> <1421232418.3155.31.camel@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="9o1Xi4ZMQ45MudWG" Content-Disposition: inline In-Reply-To: <1421232418.3155.31.camel@pengutronix.de> X-Cookie: Keep out of reach of children. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH v9 1/4] drm/i2c: tda998x: Add DT support for audio X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --9o1Xi4ZMQ45MudWG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Jan 14, 2015 at 11:46:58AM +0100, Philipp Zabel wrote: > So the question is mostly whether four I2S data pins with a single > shared WS/SCK input should be called "four I2S ports with shared clocks" > or "one I2S port with up to four data lanes". I'd lean towards the > latter. Yes, this is what we're doing for the Samsung CPU side controllers which implement this natively and seems to make sense here too - the different channels can't really work as separate interfaces in any practical way. > How audio2_i2s is forced to synchronize its clock output to audio1_i2s > is a problem their bindings will have to handle. Trying to hook up a controller that doesn't natively support this format to a device that uses it is definitely tricky, as well as describing the physical hookup we also need to worry about how things look to userspace - it's ideally going to want a single multi-channel audio stream. I think from a binding point of view we need a way to say "this endpoint on the link is constructed from these DAIs on the device side" and say if this is TDM or multi-data, and what's driving the clocks. --9o1Xi4ZMQ45MudWG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJUtmYvAAoJECTWi3JdVIfQt28H/1viMMw+EK2qHbR88BLH5iLi 9tbosp+jQxC+PTtsTI5YlUR3T/shxxV7+xA9D6wPezG2tyDghYicKvcDinxWGYnK 7wwtbmDBsRv69WPyeLNeZtZnTb4Oox5TYIYy1EtZluc1bYmpB3w1/MuOe4OU7ZdW lkaOaL9pw8Bjx7ycw1rBIPbxszsOhDiQkrDkYKoKD3SlkCeSxtBAtJJG2Fas5AfS yu8nGIGEI6f6EzXj4ry+j8/fAgftH+SMXj1/A+rOjFRWgjns9sCd8E9Sp2K7gEsl wTgiBH1gecrvcQ3gnO492ZqfBvST+U2J0pzzDrOEKmLfck/2hoqLe884+yKdWgQ= =pZEW -----END PGP SIGNATURE----- --9o1Xi4ZMQ45MudWG--