From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 21 Jun 2001 09:34:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 21 Jun 2001 09:34:06 -0400 Received: from elektra.higherplane.net ([203.37.52.137]:31929 "EHLO elektra.higherplane.net") by vger.kernel.org with ESMTP id ; Thu, 21 Jun 2001 09:33:57 -0400 Date: Thu, 21 Jun 2001 23:50:25 +1000 From: john slee To: "Dmitry A. Fedorov" Cc: Balbir Singh , linux-kernel@vger.kernel.org Subject: Re: Is it useful to support user level drivers Message-ID: <20010621235025.J30872@higherplane.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.18i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 21, 2001 at 06:38:09PM +0700, Dmitry A. Fedorov wrote: > kernel module to delivery hardware interrupts to user space > programs. Hardware interrupts (IRQ) are accessible by > character devices /dev/irq[0-15]. Interrupts delivered by > signals and select(2)/poll(2) i believe libgpio uses the existing usb/iee1394/serial/parallel interfaces to provide a limited userspace driver capability. gphoto2 uses this to support a LOT of digital cameras entirely in userspace... obviously this concept isn't covering everything but it sure covers a lot of bases. also depends on what you understand a "driver" to be... from a "common user"'s perspective it just means "it makes my WinWidget work!" it's similar to what you describe above in that there's a kernel interface, but it's more specific than /dev/irq5. this is good in that you don't want a different usb driver for every userspace usb device driver... http://sourceforge.net/projects/gphoto/ (i think) j. -- "Bobby, jiggle Grandpa's rat so it looks alive, please" -- gary larson