From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Simek Subject: Re: [PATCH] uio/pdrv_genirq: Add OF support Date: Thu, 31 Mar 2011 15:51:32 +0200 Message-ID: <4D9486E4.9030006@monstr.eu> References: <1301574600-4861-1-git-send-email-monstr@monstr.eu> <20110331124925.GA2202@pengutronix.de> <201103311525.52396.arnd@arndb.de> Reply-To: monstr@monstr.eu Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201103311525.52396.arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: John Williams , Wolfram Sang , devicetree-discuss@lists.ozlabs.org, grant.likely@secretlab.ca, linux-kernel@vger.kernel.org, hjk@linutronix.de, gregkh@suse.de List-Id: devicetree@vger.kernel.org Arnd Bergmann wrote: > On Thursday 31 March 2011, John Williams wrote: >> On Thu, Mar 31, 2011 at 10:49 PM, Wolfram Sang wrote: >>> On Thu, Mar 31, 2011 at 02:30:00PM +0200, Michal Simek wrote: >>>> Support OF support. "generic-uio" compatible property is used. >>> And exactly this was the issue last time (when I tried). This is a >>> generic property, which is linux-specific and not describing HW. The >>> agreement back then was to we probably need to add compatible-entries at >>> runtime (something like new_id for USB). So the uio-of-driver could be >>> matched against any device. Otherwise, we would collect a lot of >>> potential entries like "vendor,special-card1". Although I wonder >>> meanwhile if it is really going to be that bad; we don't have so much >>> UIO-driver in tree as well. Maybe worth a try? >> >> Maybe I misunderstand you, in my view it is the responsibility of >> to create their DTS files to indicate they want >> to bind to generic-uio. >> >> So, no great list of compat strings should grow in the driver, but >> rather the user of the driver must make it happen. >> >> Am I missing something? > > We try to make the device tree on describe the present hardware, > but not relate to how it is used. > > There are certainly cases where a specific piece of hardware can > be used either by a kernel-only driver or the UIO driver with a > user backend. I would argue that you should be able to use an > identical device tree for both cases, because the hardware is > the same. Chosing which driver to use can be either in the realm > of the kernel, or even user policy. ok. What about to keep of_device_id empty? Then there is compatible property string and everybody can choose what wants. OF is just a different driver initialization method but it is in the same category which is supported right now which is initialization through platform_device structure. Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian