From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: Re: [Socketcan-users] Fwd: sja1000 BasicCAN mode Date: Thu, 17 Nov 2011 17:24:17 +0100 Message-ID: <4EC53531.8050707@hartkopp.net> References: <20111115082136.GB331@e-circ.dyndns.org> <20111117161120.GE366@e-circ.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mo-p00-ob.rzone.de ([81.169.146.161]:57034 "EHLO mo-p00-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757933Ab1KQQYX (ORCPT ); Thu, 17 Nov 2011 11:24:23 -0500 In-Reply-To: <20111117161120.GE366@e-circ.dyndns.org> Sender: linux-can-owner@vger.kernel.org List-ID: To: Yuriy Kiselev Cc: socketcan-users@lists.berlios.de, "linux-can@vger.kernel.org" On 17.11.2011 17:11, Kurt Van Dijck wrote: > On Thu, Nov 17, 2011 at 07:58:09PM +0400, Yuriy Kiselev wrote: >> 2011/11/15 Heinz-J=C3=BCrgen Oertel >> >>> >>>> -----Original Message----- >>>> From: socketcan-users-bounces@lists.berlios.de [mailto:socketcan-u= sers- >>>> bounces@lists.berlios.de] On Behalf Of Kurt Van Dijck >>>> Sent: Tuesday, November 15, 2011 9:22 AM >>>> To: Yuriy Kiselev >>>> Cc: socketcan-users@lists.berlios.de; linux-can@vger.kernel.org >>>> Subject: Re: [Socketcan-users] sja1000 BasicCAN mode >>>> >>>> On Mon, Nov 14, 2011 at 09:08:29PM +0400, Yuriy Kiselev wrote: >>>>> Hello! >>>>> Implementation of BasicCAN mode for SJA1000 is in attachment. >>>>> Now SJA1000_PELICAN_MODE macros in sja1000.h is used for definiti= on >>>> PeliCAN >>>>> or BasicCAN mode. It would be nice to create some menuconfig-wrap= per, I >>>>> think. >>>>> I use this code for a few weeks and it looks stable. >>>> I see no reason to use BasicCAN mode instead of PeliCAN mode. >>>> Instead, I do see reasons to use PeliCAN mode: >>>> >>>> * no problems when 29bit frames appear on the bus >>>> * rx queue of 64 byte. >>>> >>>> What is your motivation not to use PeliCAN mode? >>>> >>>> Kurt >>> >>> Kurt is correct. For my understanding, the so-called basic CAN mode= of the >>> SJA1000 is a compatibility mode for the 82c200. It makes no sense t= o >>> support it any more with SJA1000 devices. >>> >>> Heinz >>> >> >> Yes, BasicCAN mode is for specific designed devices. My device has o= nly >> 5-bits address bus and I can't use PeliCAN mode. > Still, properly attached SJA1000 is better used in PELICAN mode. I'm = sure > you agree. >=20 > But I see your point. > Must your hardware be supported by SJA1000? > Or by a completely seperate 82c200 driver? > You probably can start from the SJA1000. AFAIK the SJA1000 driver only uses 32 byte of address space - so 5 bit = are ok! Even if the address space of the SJA1000 can be 128 bytes in PeliCAN mo= de, these addresses beyond register 31 are usually not in use. Registers 32 - 127 only contain a view into the internal registers and = =46IFOs nobody is using, as the FIFO is also implemented in the standard RX/TX = frame registers. Please check the SJA1000 spec, page 21/22 (PeliCAN address space layout= ) Regards, Oliver