From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Boyer Subject: Re: iop_msg_pool Date: Mon, 1 Jul 2013 00:39:54 -0700 Message-ID: <20130701073954.GC8425@cynthia.pants.nu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cynthia.allandria.com ([76.245.85.235]:60798 "EHLO cynthia.pants.nu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752734Ab3GAHj6 (ORCPT ); Mon, 1 Jul 2013 03:39:58 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Finn Thain Cc: Geert Uytterhoeven , Linux/m68k On Wed, Jun 26, 2013 at 08:48:14PM +1000, Finn Thain wrote: > On Wed, 26 Jun 2013, Geert Uytterhoeven wrote: > > Do all Macs use the IOP functionality? > > No. iop_scc_present and iop_ism_present are accurate. In fact, very few Macs use the IOP chips. Only three models used them, and they are some of the rarest models on top of that. These chips can be found on the IIfx, the Quadra 900, and the Quadra 950. > So far, the only driver to make use of this functionality is > drivers/macintosh/adb-iop.c: > > int adb_iop_probe(void) > { > if (!iop_ism_present) return -ENODEV; > return 0; > } We did have an IOP SWIM driver at one point, but it got removed from the tree. It couldn't read or write blocks, so it wasn't actually useful. However, it did correctly detect drives and I think it had disk insert detection and eject as well. The block data transfer to and from the IOP is messy, and I couldn't get it working when I tried to fix it back then. Like the SCC IOP, it is possible to use bypass mode to access the SWIM chip directly. However, there is no way to have ADB if the ISM IOP is in bypass mode. Brad Boyer flar@allandria.com