Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754749AbZFPMrS (ORCPT ); Tue, 16 Jun 2009 08:47:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751830AbZFPMrI (ORCPT ); Tue, 16 Jun 2009 08:47:08 -0400 Received: from mail-gx0-f214.google.com ([209.85.217.214]:44832 "EHLO mail-gx0-f214.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750908AbZFPMrH convert rfc822-to-8bit (ORCPT ); Tue, 16 Jun 2009 08:47:07 -0400 MIME-Version: 1.0 In-Reply-To: <20090616090435.GA21321@pengutronix.de> References: <1244765062-14144-1-git-send-email-w.sang@pengutronix.de> <1244765062-14144-3-git-send-email-w.sang@pengutronix.de> <20090616090435.GA21321@pengutronix.de> From: Grant Likely Date: Tue, 16 Jun 2009 06:46:47 -0600 Message-ID: Subject: Re: [PATCH 2/2] uio: add an of_genirq driver To: Wolfram Sang Cc: linux-kernel@vger.kernel.org, devicetree-discuss@ozlabs.org, "Hans J. Koch" , Magnus Damm , linuxppc-dev@ozlabs.org, Greg KH Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2431 Lines: 62 On Tue, Jun 16, 2009 at 3:04 AM, Wolfram Sang wrote: > >> > diff --git a/Documentation/powerpc/dts-bindings/uio-generic.txt b/Documentation/powerpc/dts-bindings/uio-generic.txt >> > new file mode 100644 >> > index 0000000..8ad9861 >> > --- /dev/null >> > +++ b/Documentation/powerpc/dts-bindings/uio-generic.txt >> > @@ -0,0 +1,16 @@ >> > +UIO for custom devices >> > + >> > +A device which will be mapped using the UIO subsystem. >> > + >> > +Properties: >> > + - compatible : should contain the specific model used, followed by >> > + ? ? ? ? ? ? ? ?"generic-uio". >> > + - reg : address range(s) of the device (up to MAX_UIO_MAPS) >> > + - interrupts : interrupt of the device >> > + >> > +Example: >> > + ? ? ? ?c64fpga@0 { >> > + ? ? ? ? ? ? ? ?compatible = "ptx,c64fpga001", "generic-uio"; >> > + ? ? ? ? ? ? ? ?reg = <0x0 0x10000>; >> > + ? ? ? ? ? ? ? ?interrupts = <0 0 3>; >> > + ? ? ? ?}; >> >> Hmmm, I'm not happy about this. ?The device tree describes the >> hardware, not the way Linux uses the hardware. ?UIO definitely falls >> into the category of Linux implementation detail. > > Yes, I am aware of that. I just started with the mechanisms which are available > today and hoped we could find some compatible-value which will suit all needs. Trouble is a value that suits all needs today probably won't a year from now. :-) >> This should be approached from the other way around. ?Either the >> generic-uio of_platform driver should contain an explicit list of >> devices to be handled by UIO, > > Well, that could lead to a quite huge match_table over time. > >> or the OF infrastructure should be modified to allow things like force >> binding of_devices to of_drivers at runtime. > > That is an interesting idea. I could imagine something like a 'new_compatible" > entry in the sysfs-section of the driver similar to 'new_id' for PCI. After > writing a new compatible-string into it, matching will triggered again with the > new entry added. That could (should?) also be placed at the of-core-level. Or > did you have something else in mind? Yeah, that sounds appropriate. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/