Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760877Ab2JaV4X (ORCPT ); Wed, 31 Oct 2012 17:56:23 -0400 Received: from mail-ea0-f174.google.com ([209.85.215.174]:40497 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760596Ab2JaV4W (ORCPT ); Wed, 31 Oct 2012 17:56:22 -0400 MIME-Version: 1.0 In-Reply-To: <1351702333-8456-1-git-send-email-panto@antoniou-consulting.com> References: <1351702333-8456-1-git-send-email-panto@antoniou-consulting.com> Date: Wed, 31 Oct 2012 14:56:20 -0700 X-Google-Sender-Auth: 2r1SY8joBBW3GecHOaOqRNP1jpM Message-ID: Subject: Re: [RFC 0/7] Capebus; a bus for SoCs using simple expansion connectors From: Russ Dill To: Pantelis Antoniou Cc: Tony Lindgren , linux-arm-kernel@lists.infradead.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Koen Kooi , Matt Porter , linux-omap@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1825 Lines: 38 On Wed, Oct 31, 2012 at 9:52 AM, Pantelis Antoniou wrote: > Capebus is created to address the problem of many SoCs that can provide a > multitude of hardware interfaces but in order to keep costs down the main > boards only support a limited number of them. The rest are typically brought > out to pin connectors on to which other boards, named capes are connected and > allow those peripherals to be used. > > These capes connect to the SoC interfaces but might also contain various other > parts that may need some kind of driver to work. > > Since SoCs have limited pins and pin muxing options, not all capes can work > together so some kind of resource tracking (at least for the pins in use) is > required. > > Before capebus all of this took place in the board support file, and frankly > for boards with too many capes it was becoming unmanageable. > > Capebus provides a virtual bus, which along with a board specific controller, > cape drivers can be written using the standard Linux device model. > > The core capebus infrastructure is not depended on any specific board. > However capebus needs a board controller to provide services to the cape devices > it controls. Services like addressing and resource reservation are provided > by the board controller. > > Capebus at the moment only support TI's Beaglebone platform. > > This RFC introduces the core concept; most supporting patches > have been posted to the relevant places. There are quite a few TODOs in the code, any chance you could summarize them in the next header email? -- 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/