From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932741AbbAIL2a (ORCPT ); Fri, 9 Jan 2015 06:28:30 -0500 Received: from smtp6-g21.free.fr ([212.27.42.6]:55828 "EHLO smtp6-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754753AbbAIL22 convert rfc822-to-8bit (ORCPT ); Fri, 9 Jan 2015 06:28:28 -0500 Date: Fri, 9 Jan 2015 12:30:36 +0100 From: Jean-Francois Moine To: Jyri Sarha Cc: Mark Brown , Russell King - ARM Linux , Dave Airlie , Andrew Jackson , , , , Subject: Re: [PATCH v9 1/4] drm/i2c: tda998x: Add DT support for audio Message-ID: <20150109123036.4bc4bbf6@armhf> In-Reply-To: <54AFA9B0.6040405@ti.com> References: <0084acea5a3475a77531d6a77483f36d3469111a.1420628786.git.moinejf@free.fr> <54AE99F5.1010404@ti.com> <20150108174257.557f7ea5@armhf> <54AFA9B0.6040405@ti.com> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 9 Jan 2015 12:13:04 +0200 Jyri Sarha wrote: > On 01/08/2015 06:42 PM, Jean-Francois Moine wrote: > > From Andrew's datasheet, the TDA998x's which are handled by the tda998x > > driver have only 4 input audio pins, the first two ones being either > > S/PDIF or I2s, the last ones being I2S only. > > AFAIK, SPDIF is always a single pin connection so only one pin needs to > be selected. But i2s need for pins for full 8 channel output. There are 2 possible S/PDIF pins in the tda998x, and there may be many audio chips with S/PDIF outputs. > > So, the DT description could be reduced to a simple list indexed by > > the pin number (= DAI number) and defining the protocol type. > > > > Examples: > > > > - for the Cubox: > > > > audio-inputs = "i2s", "spdif"; > > > > - for some other board with I2S on the pins 3 and 4 only: > > > > audio-inputs = "none", "none", "i2s", "i2s"; > > > > - for a fully wired TDA9983B (no driver yet): > > > > audio-inputs = "i2s", "i2s", "i2s", "i2s", "spdif"; > > > > If you want to go closer to the original paradigm, then how about > defining following audio-port-names: i2s0, i2s1, i2s2, i2s3, and spdif. > With this approach we could go with your original binding with only > minor changes. A binding in your stereo i2s or spdif case would look > like this: > > audio-ports = <0x04>, <0x03>; > audio-port-names = "spdif", "i2s0"; > > A full 8 channel i2s or spdif output would look like this: > > audio-ports = <0x04>, <0x03>, <0x02>, <0x01>, <0x00>; > audio-port-names = "spdif", "i2s0", "i2s1", "i2s2", "i2s3"; > > This would also indicate the channel mapping to the audio pins (i2s0 for > first two channels, i2s1 for 3-4, etc.) > > The code could for now just look for "i2s0" and the port names for > channels 3-8 could be ignored until they are needed. In my original version, the audio-ports are a bitmap of the pins, the bit 0 being the WS used for I2S. A fully wired tda998x would have been as: audio-ports = <0x03>, <0x04>, <0x09>, <0x11>; audio-port-names = "i2s", "spdif", "i2s", "i2s"; With the new version, it would simply become: audio-inputs = "i2s", "spdif", "i2s", "i2s"; -- Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/