From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 11C6AB6F34 for ; Fri, 3 Jul 2009 17:01:49 +1000 (EST) Received: from qw-out-2122.google.com (qw-out-2122.google.com [74.125.92.27]) by ozlabs.org (Postfix) with ESMTP id 5E0B3DDD1B for ; Fri, 3 Jul 2009 17:01:47 +1000 (EST) Received: by qw-out-2122.google.com with SMTP id 5so982024qwd.15 for ; Fri, 03 Jul 2009 00:01:44 -0700 (PDT) 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 Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@ozlabs.org, David Brownell , linux-kernel@vger.kernel.org, spi-devel-general@lists.sourceforge.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. =A0I'd like to leave these in. =A0I still have the sysfs bi= ts >> 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 connect= ed 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 inp= ut? >> > According to Table 17.3 in the PM, you have that pin defined as generi= c purpose >> > output. >> >> That's right. =A0The 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. --=20 Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.