Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932088Ab1DLGUc (ORCPT ); Tue, 12 Apr 2011 02:20:32 -0400 Received: from ganesha.gnumonks.org ([213.95.27.120]:38982 "EHLO ganesha.gnumonks.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932068Ab1DLGUb (ORCPT ); Tue, 12 Apr 2011 02:20:31 -0400 Date: Tue, 12 Apr 2011 08:08:13 +0200 From: Harald Welte To: Lauro Ramos Venancio Cc: linux-kernel@vger.kernel.org, Aloisio Almeida , Arnd Bergmann , Waldemar.Rymarkiewicz@tieto.com Subject: Re: [RFC] NFC subsystem prototype Message-ID: <20110412060813.GS9690@prithivi.gnumonks.org> References: <20110409130945.GC3248@prithivi.gnumonks.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2650 Lines: 55 Hi Lauro, On Mon, Apr 11, 2011 at 08:31:11PM -0300, Lauro Ramos Venancio wrote: > 2011/4/9 Harald Welte : > > > 0) why not create a general RFID subsystem instead of locking it down to > > ? NFC? ?NFC is sort-of a superset of ISO 14443, so it would make more > > ? sense to have a generic framework that can support not only Mifare + NFC > > ? but all types of ISO 14443 (A / B) as well as ISO 15693. ?This would mean > > ? other applications like electronic ID cards and ICAO-compliant passports > > ? would fit into the picture - even though not being NFC > > The prototype supports ISO 14443 (A/B), MIFARE, Felica and Jewel. It's > straightforward to add ISO 15693 support. So I think it is possible to > support these applications using the NFC subsystem. Then I suggest renaming the system. I think it is a bit confusing to call something NFC if in fact it is a way more generic RFID system for most common 13.56MHz based systems. In other words: NFC depends on ISO 14443, but ISO 14443 does not depend on NFC, so it would be a bit unconventional or unintuitive to use a NFC subsystem to talk with non-NFC ISO 14443 cards/transponders. Also, I'm not quite clear what's the situation with regard to the NFC trademark, i.e. if it wise to use the trademark. There has been one previous case with the 'firewire' situation, where firewire is the trademark and IEEE 1394 the name of the technical specification - and the the Linux subsystem is alled 'ieee1394'... > > 1) do you really think a kernel subsystem is the best idea for this? > > ? normally, the RFID/NFC ASIC is attached either to USB or serial lines, > > ? and there are no timing constraints against userspace drivers using libusb, > > ? like the existing libnfc or librfid. > > The advantages appear when you consider the NFC peer-to-peer use case > (LLCP). A socket interface for LLCP would fit better for implementing > some features, such as OBEX over LLCP and IP over LLCP. Ok, I fully agree for the case of OBEX and IP. This did not occur to me when I made my earlier comment. Regards, Harald -- - Harald Welte http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6) -- 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/