From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ned Forrester Subject: Re: DSPI slave linux driver Date: Mon, 02 Mar 2009 13:41:03 -0500 Message-ID: <49AC283F.2000708@whoi.edu> References: <5a775e870903020620k56f84f7cwfa6c11cbb4a9277a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: sivakumar borela Return-path: In-Reply-To: <5a775e870903020620k56f84f7cwfa6c11cbb4a9277a-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org sivakumar borela wrote: > Hi, > > My selef, SivaKumar working as Embedded software engineer. One of our > products is based on MCF5485 coldfire processor. We are using Embedded linux > from Freescale on our board. The BSP does have DSPI(DMA enabled SPI) master > driver. But our requirement is to configure MCF5485 as DSPI slave to > communicate with the external master which is 68332 processor board. The > protocol demands request/response model to communicate with the master. We > could not able to succeed in making the DSPI slave to work. > > "Changed the chip control register from master to salve by modifying the bit > in mode control register" > > We are not getting any interrupts from the processor to call read and write > functions. > > Freescale has done customization of coldfire_spi driver for MCF5485. > > First of all my query is > 1) is there any piece of linux spi slave driver till now? > 2) If you have any slave driver implementation , could you please provide > the code for me to implement the SPI slave? There is no support for a Linux host slave. This has been discussed several times before. I suggest you search the archives of this mailing list, and read the previous discussion. The official archive of spi-devel-general is at: http://sourceforge.net/mailarchive/forum.php?forum_name=spi-devel-general but I don't find that very searchable. Try this thread: http://www.mail-archive.com/spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org/msg00306.html which I found by googling these four key words: spi-devel-general spi slave support And another thread is here... http://www.mail-archive.com/spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org/msg01123.html -- The most serious problem for generalized slave support is the response time of the kernel to external requests; this is discussed in the threads above. Some limited slave support can be created, where applications are transmit-only or receive-only, but not both, or any other situation in which the communication sequence is completely predictable and thus the response data can be queued in advance. All of these possibilities are probably limited to configurations where there is only one device attached to the SPI bus. -- Ned Forrester nforrester-/d+BM93fTQY@public.gmane.org Oceanographic Systems Lab 508-289-2226 Applied Ocean Physics and Engineering Dept. Woods Hole Oceanographic Institution Woods Hole, MA 02543, USA http://www.whoi.edu/sbl/liteSite.do?litesiteid=7212 http://www.whoi.edu/hpb/Site.do?id=1532 http://www.whoi.edu/page.do?pid=10079 ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H