From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xuebing Wang Subject: What is the command line commands to use UAC2 at USB client side? Date: Thu, 14 Aug 2014 14:16:30 +0800 Message-ID: <53EC543E.9050601@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by alsa0.perex.cz (Postfix) with ESMTP id A1ED626565A for ; Thu, 14 Aug 2014 08:16:36 +0200 (CEST) Received: by mail-pa0-f51.google.com with SMTP id ey11so1039361pad.38 for ; Wed, 13 Aug 2014 23:16:35 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: linux-usb-devel@vger.kernel.org, alsa-devel@alsa-project.org Cc: thomas.besemer@gmail.com, Richard.Jiang@infocus.com List-Id: alsa-devel@alsa-project.org Hi Community, Based on Freescale platform , I am trying to use USB Audio Class version 2.0. Host can detect this UAC2 device. At device side (after modprobe g_audio): root@imx6slevk:~# aplay -l **** List of PLAYBACK Hardware Devices **** card 0: wm8962audio [wm8962-audio], device 0: HiFi wm8962-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: imxspdif [imx-spdif], device 0: S/PDIF PCM Playback dit-hifi-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0 card 2: UAC2Gadget [UAC2_Gadget], device 0: UAC2 PCM [UAC2 PCM] Subdevices: 1/1 Subdevice #0: subdevice #0 At device side, in driver/usb/gadget/Kconfig, it says before for CONFIG_USB_AUDIO ------------------------- This driver doesn't expect any real Audio codec to be present on the device - the audio streams are simply sinked to and sourced from a virtual ALSA sound card created. The user-space application may choose to do whatever it wants with the data received from the USB Host and choose to provide whatever it wants as audio data to the USB Host. ------------------------- My question is: at device side, how to configure sink/source for UAC2 virtual ALSA sound card (hw:2,0, UAC2_Gadget)? Thank you very much. Xuebing Wang