From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.238]) by ozlabs.org (Postfix) with ESMTP id DB024DDE28 for ; Sat, 17 May 2008 06:48:18 +1000 (EST) Received: by wx-out-0506.google.com with SMTP id i30so819754wxd.15 for ; Fri, 16 May 2008 13:48:16 -0700 (PDT) Message-ID: Date: Fri, 16 May 2008 14:48:16 -0600 From: "Grant Likely" Sender: glikely@secretlab.ca To: "Jon Smirl" Subject: Re: [RFC PATCH 0/4] Describe SPI devices in the OF device tree and add mpc5200-spi driver In-Reply-To: <9e4733910805161327u4c42fd1dg5b09319d89db447c@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <20080516193054.28030.35126.stgit@trillian.secretlab.ca> <9e4733910805161327u4c42fd1dg5b09319d89db447c@mail.gmail.com> Cc: fabrizio.garetto@gmail.com, linuxppc-dev@ozlabs.org, dbrownell@users.sourceforge.net, 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 Fri, May 16, 2008 at 2:27 PM, Jon Smirl wrote: > On 5/16/08, Grant Likely wrote: >> This series is a set of changes to allow the slaves on an SPI bus to be >> described in the OF device tree (useful in arch/powerpc) and adds a driver >> that uses it (the Freescale MPC5200 SoC's SPI device). > > Right now we have SPI hooked up to PSC3. Hardware engineer is gone but > I'll see if I can get him to alter things to use the SPI controller. I > have an old mail from him where he thinks the Phytec board is missing > a signal needed to use the SPI controller. While I'd appreciate the testing, I suspect that you really don't want to do that. The dedicated SPI controller isn't very good. It only does a byte at a time and so is rather slow. A PSC is SPI mode should be better (but I haven't tried it personally it yet). > > Is the current SPI driver working on PSC3? I have a MMC card wired up > to it but I've never tried using it. It should work. > I have the MPC5200 PSC SPI driver enabled and "MMC/SD over SPI" > enabled in my kernel. The MMC bus gets created but there aren't any > devices on it. Do we need something in the SPI driver so that the MMC > layer can find it? Yes, see patch 3 in my series. the PSC SPI driver needs to do something like this. SPI busses don't really do autodetection (but some sub-protocols, like MMC, do IIRC). > Are you going to keeps this as two drivers or merge them? If it is two > drivers there should be one entry in Kconfig and two sub choices for > the types of drivers. It will remain as two drivers. The devices are entirely separate. I don't think putting them under a single Kconfig is needed or a good idea. They both depend on PPC_MPC52xx anyway so they only show up if you're building for a 5200 platform. Thanks for the comments. Cheers, g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.