From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Help with multichannel High Speed USB audio device Date: Fri, 24 Jul 2009 11:12:48 +0200 Message-ID: <4A697B10.1020601@ladisch.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by alsa0.perex.cz (Postfix) with ESMTP id 28758103A7B for ; Fri, 24 Jul 2009 11:12:34 +0200 (CEST) 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: "Laurent ." Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Laurent . wrote: > I made an embedded device that has a CODEC with 6 inputs connected to an ARM9 > micro-controller that has an integrated high-speed USB controller. > Now, I need to write the USB code on that micro-controller so that i can capture those > channels in real-time at 24bits / 48 KHz with low latency (ie. sub 10ms), on a computer. > > I only need my device to work with Linux, and if possible, I would like to avoid writing a device > driver on the Linux-side. > > Is there already such a USB audio driver available that I could nearly use "as is" and to which > i would conform ? Yes, snd-usb-audio. > Would you have some general guideline on how to write the high-speed USB device code ? Just conform to the USB (2.0) and USB Audio (1.0) specifications. > For simplicity, my device is going to be the "clock master" of the system since it is already has > the exact clock that drives the CODEC. So you'd use an asynchronous endpoint. Best regards, Clemens