From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rene Herman Subject: Re: Userspace drivers Date: Thu, 27 Sep 2007 14:54:38 +0200 Message-ID: <46FBA80E.7010004@keyaccess.nl> References: <6cc714350709261228v519ab4dcx657969fd07f022b0@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtpq2.groni1.gr.home.nl (smtpq2.groni1.gr.home.nl [213.51.130.201]) by alsa0.perex.cz (Postfix) with ESMTP id 7AAE624493 for ; Thu, 27 Sep 2007 14:54:46 +0200 (CEST) In-Reply-To: <6cc714350709261228v519ab4dcx657969fd07f022b0@mail.gmail.com> 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: Josh Litherland Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On 09/26/2007 09:28 PM, Josh Litherland wrote: > Is there any facility for developing an ALSA device driver in userspace? > I'm particularly interested in mixer devices; my goal is to expose the > Thinkpad hardware volume buttons as an ALSA mixer. > > Thanks for any pointers! Most of the cheaper hardware today does volume control in software which ALSA supports through the softvol plugin that runs in userspace. I've never actually owned any of this hardware but assuming the volume control shows up in say alsamixer same as if it had been a hardware control, you'd have an example of a userspace volume control there. Actually talking to the buttons is another matter ofcourse but it may serve as a useful example of how to expose the control through alsa at least. Or not, comments obviously welcome -- never look at it but also have a use in mind... Rene.