From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756413AbZGCHBt (ORCPT ); Fri, 3 Jul 2009 03:01:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752456AbZGCHBm (ORCPT ); Fri, 3 Jul 2009 03:01:42 -0400 Received: from qw-out-2122.google.com ([74.125.92.27]:17570 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752691AbZGCHBl convert rfc822-to-8bit (ORCPT ); Fri, 3 Jul 2009 03:01:41 -0400 MIME-Version: 1.0 In-Reply-To: <20090618142610.GC10629@pengutronix.de> References: <20090618025030.12363.69402.stgit@localhost.localdomain> <20090618065814.GA12942@pengutronix.de> <20090618142610.GC10629@pengutronix.de> From: Grant Likely Date: Fri, 3 Jul 2009 01:01:24 -0600 Message-ID: Subject: Re: [spi-devel-general] [PATCH v4] powerpc/5200: Add mpc5200-spi (non-PSC) device driver To: Wolfram Sang Cc: linuxppc-dev@ozlabs.org, David Brownell , spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, jonsmirl@gmail.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 18, 2009 at 8:26 AM, Wolfram Sang wrote: >> There used to be a sysfs interface for dumping these, but it was an >> ugly misuse.  I'd like to leave these in.  I still have the sysfs bits >> in a private patch and I'm going to rework them for debugfs. > > Okay. Maybe a comment stating the future use will be nice. okay >> > But I wonder more about the usage of the SS pin and if this chipsel is needed >> > at all (sadly I cannot test as I don't have any board with SPI connected to >> > that device). You define the SS-pin as output, but do not set the SSOE-bit. >> > More, you use the MODF-feature, so the SS-pin should be defined as input? >> > According to Table 17.3 in the PM, you have that pin defined as generic purpose >> > output. >> >> That's right.  The SS handling by the SPI device is completely >> useless, so this driver uses it as a GPIO and asserts it manually. > > That definately needs a comment :D (perhaps with some more details if you know them). > >> The MODF irq is probably irrelevant, but I'd like to leave it in for >> completeness. > > But it won't work if the pin is set to output, no? yes > Are you sure there are no side-effects? I'm sure. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.