Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161019AbVIOUz0 (ORCPT ); Thu, 15 Sep 2005 16:55:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932598AbVIOUz0 (ORCPT ); Thu, 15 Sep 2005 16:55:26 -0400 Received: from rproxy.gmail.com ([64.233.170.194]:22277 "EHLO rproxy.gmail.com") by vger.kernel.org with ESMTP id S932597AbVIOUzZ convert rfc822-to-8bit (ORCPT ); Thu, 15 Sep 2005 16:55:25 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=GBwASRa5OQPcxccb7/vmfbqS6gvn6L+187cufbARIvuYhUnsKdSNkDXrRCVTFjHb1pmpTmdLlYABnD3MdiUbHIMTbWMKM41/6M4fDVgvhLdPknYm5XAoZaCKqRo3NnGlJ0i4myOT110eeOlzipsPqWHOR1Rjw2dQfmBVqmBZ0Rw= Message-ID: Date: Thu, 15 Sep 2005 15:55:23 -0500 From: Dmitry Torokhov Reply-To: dtor_core@ameritech.net To: Vojtech Pavlik Subject: Re: [patch 09/28] Input: convert net/bluetooth to dynamic input_dev allocation Cc: Marcel Holtmann , linux-kernel@vger.kernel.org, Andrew Morton , Greg KH , Kay Sievers , Hannes Reinecke In-Reply-To: <20050915202553.GA3977@midnight.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20050915070131.813650000.dtor_core@ameritech.net> <20050915070302.931769000.dtor_core@ameritech.net> <1126770894.28510.10.camel@station6.example.com> <1126795310.3505.47.camel@station6.example.com> <20050915190700.GA3354@midnight.suse.cz> <20050915202553.GA3977@midnight.suse.cz> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1635 Lines: 36 On 9/15/05, Vojtech Pavlik wrote: > On Thu, Sep 15, 2005 at 02:22:34PM -0500, Dmitry Torokhov wrote: > > They are devices - class devices :). I have the following distinction > > in my head - "normal" devices (bus devices) are real hardware devices > > and their drivers need to do resource and/or power management. Class > > devices represent virtual devices - some kind of abstraction - that > > unify and combine "real" devices from several buses into one class. > > Yes. While input drivers do need to care about power management usually, > the input device abstraction itself doesn't have to, which makes it > indeed a special kind of a device. > Right. They just signal to underlying hardware driver when they are in use (open), but the actual power management is left to the specific bus/driver, not input core. > I was always wondering whether the distinction between bus/class was > needed, as the border isn't very clear. > Classes combine devices which are logically the same, i.e. they perform similar functions. Buses combine devices that are perform different functions but have similar hardware interface. For example a network cards - it is a class. You can have network card sit on a PCI, USB, ISA buses but for the rest of the kernel they are accesses through netdev abstraction. At least this is my understanding of our device model ;) -- Dmitry - 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/