Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752995Ab1DRMTp (ORCPT ); Mon, 18 Apr 2011 08:19:45 -0400 Received: from mail-qw0-f46.google.com ([209.85.216.46]:60830 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751869Ab1DRMTj convert rfc822-to-8bit (ORCPT ); Mon, 18 Apr 2011 08:19:39 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=dXgoIlK2B4nQ82ZpVGy38XX+MUXW/Jx+awXQXo7H7ZAlqVEeMuJdLRwndVnXzuO7bM uMAr5k1nXyAE2TaqhQNnDFWYMK73xwiEInALUJne5l8EakcluzlXYPXQo6Lwa0rl6iiL iJB4p9bjLP+kLf4UctaRSy5BiYGkY6RQxQRyM= MIME-Version: 1.0 In-Reply-To: <201104171938.12834.arnd@arndb.de> References: <1302892585.30441.12.camel@dev.znau.edu.ua> <201104171938.12834.arnd@arndb.de> Date: Mon, 18 Apr 2011 14:19:38 +0200 Message-ID: Subject: Re: Could I (ab)use bus (struct bus_type) for virtual Broadcom bus? From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= To: Arnd Bergmann Cc: George Kashperko , Hauke Mehrtens , Russell King , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Arend van Spriel , Jonas Gorski , b43-dev@lists.infradead.org, Greg KH , Andy Botting , Larry Finger Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2626 Lines: 58 W dniu 17 kwietnia 2011 19:38 użytkownik Arnd Bergmann napisał: > On Friday 15 April 2011, Rafał Miłecki wrote: >> W dniu 15 kwietnia 2011 20:36 użytkownik George Kashperko >> napisał: >> >> >> Arnd: I found you saying: >> >> >> > I believe the one thing we really want from this driver is the bus >> >> >> > scan code, which is not present in the amba bus implementation, >> >> >> I explained how it works, I believe scanning (EPROM in this case) it >> >> >> Broadcom specific, not really AMBA standard. How do you see it? >> >> >> >> Maybe EPROM is not Broadcom specific, but I suspect the content we >> >> deal with in bcmai/axi is Broadcom specific. I didn't see any notes of >> >> manuf/id/rev/class we deal with. So I guess everything we (out >> >> driver) read from EPROM is Bcm specific. >> >> >> > >> > Played around amba registers on bcm4716. For all amba cores present >> > (under all I mean broadcom ip core agents, oob router core, erom core, >> > and other I-dont-know-what-for cores present at 0x18100000). All those >> > feature AMBA_CID (0xb105f00d) as PrimeCell ID, and slightly different >> > PrimeCell PeripheralIDs: >> > * vendor 0xBB, part_number 0x368 for broadcom cores' agents; >> > * vendor 0xBB, part_number 0x367 for OOB router core (don't ask me wth >> > is this please); >> > * vendor 0xBB, part_number 0x366 for EROM core; >> > >> > ARM vendor id is 0x41. Might 0xBB is Broadcom vendor id but I've found >> > no evidence for that with google. >> >> Yeah, as I suspected, everything except Broadcom specific cores >> matches AMBA standards quite nicely. Still, I don't see anything in it >> we could use for driver. >> >> Let's wait for Russell and Arnd to comment. > > In general, the bus_type directly relates to how a device gets probed. > If broadcom uses the same basic register layout as regular AMBA devices, > it should use the amba bus type. >From Broadcom side we *could* use some registers that are AMBA specific, they are present... but there is totally no point in doing that. Everything we use is Broadcom specific. > I think it would be fine to extend the AMBA bus slightly if there are > just minor differences. As I said, Broadcom specific driver use nothing from AMBA common things. Plus we implement routines that are Broadcom specific and no other platform will use them. -- Rafał -- 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/