From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030634AbXD1NAk (ORCPT ); Sat, 28 Apr 2007 09:00:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031160AbXD1NAk (ORCPT ); Sat, 28 Apr 2007 09:00:40 -0400 Received: from main.gmane.org ([80.91.229.2]:47394 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030634AbXD1NAh (ORCPT ); Sat, 28 Apr 2007 09:00:37 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Matthieu CASTET Subject: Re: [GIT PATCH] UIO patches for 2.6.21 Date: Sat, 28 Apr 2007 13:00:14 +0000 (UTC) Message-ID: References: <20070427224957.GA17967@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: cac94-1-81-57-151-96.fbx.proxad.net User-Agent: Pan/0.125 (Potzrebie) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, 27 Apr 2007 15:49:57 -0700, Greg KH wrote: > Here are the updated UIO (Userspace I/O driver framework) patches for > 2.6.21. > > > Documentation/DocBook/kernel-api.tmpl | 4 + > Documentation/DocBook/uio-howto.tmpl | 498 +++++++++++++++++++++++ > drivers/Kconfig | 1 + drivers/Makefile > | 1 + drivers/uio/Kconfig | 27 ++ > drivers/uio/Makefile | 2 + drivers/uio/uio.c > | 702 +++++++++++++++++++++++++++++++++ > drivers/uio/uio_cif.c | 156 ++++++++ > include/linux/uio_driver.h | 91 +++++ 9 files changed, > 1482 insertions(+), 0 deletions(-) create mode 100644 > Documentation/DocBook/uio-howto.tmpl create mode 100644 > drivers/uio/Kconfig create mode 100644 drivers/uio/Makefile create mode > 100644 drivers/uio/uio.c > create mode 100644 drivers/uio/uio_cif.c create mode 100644 > include/linux/uio_driver.h > uio_dummy.c (that should be present according documentation) seems missing. I find the doc not very clear for the devices where there is no interrupt : they speak of some kernel timer, but a userspace timer could be used (and even the userspace driver could be written without kernel support at all). At the end of the doc there is something about IRQ_HANDLED vs IRQ_NONE. Last time I check kernel irq code, in both case next irq handler are called. The only difference was that if all handler reply IRQ_NONE, the kernel gave an error about an unexpected interrupt. Also why sysfs is used for describing the mapping instead of something like an ioctl ? UIO could be useful in embedded system where sysfs is not always desirable. Matthieu