From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: Does ASoC support sound card with multiple interfaces? Date: Thu, 5 Jan 2012 06:02:55 +0000 Message-ID: <20120105060255.GF11867@opensource.wolfsonmicro.com> References: <1325516773.12508.57.camel@matrix> <20120102201642.GA30932@sirena.org.uk> <1325655413.12508.79.camel@matrix> <4F03E80B.907@st.com> <1325660401.12508.113.camel@matrix> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 48328103918 for ; Thu, 5 Jan 2012 07:02:57 +0100 (CET) Content-Disposition: inline In-Reply-To: <1325660401.12508.113.camel@matrix> 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: Ashish Chavan Cc: alsa-devel , Rajeev kumar , "; Liam Girdwood" List-Id: alsa-devel@alsa-project.org On Wed, Jan 04, 2012 at 12:30:01PM +0530, Ashish Chavan wrote: > Is it really mandatory to specify card and device id? Isn't there a > middle layer that takes care of using "first free" interface for > playback or recording, if interface is not explicitly specified? As we > register DAIs with ALSA subsystem, it should be fairly easy for alsa-lib > to find out "first free" interface. That's not implemented since genuinely identical interfaces should be implemented by supporting multiple opens on a single device but those essentailly don't exist in embedded hardware. Pretty much all embedded hardware with multiple routes out of the CPU has either distinct fixed functions for the outputs or independant routing of them so they can't reliably be used interchangibly. You could implement it but it'd have to be a system specific option to use it.