From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Girish" Subject: Re: Status of Linux SPI slave Date: Mon, 15 Oct 2007 21:38:22 +0530 Message-ID: <00bc01c80f45$9d218980$6a8918ac@ent.ti.com> References: <20071013154747.2F7B023A5F4@adsl-69-226-248-13.dsl.pltn13.pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "'David Brownell'" , , Return-path: In-reply-to: <20071013154747.2F7B023A5F4-ZcXrCSuhvln6VZ3dlLfH/g4gEjPzgfUyLrfjE7I9kuVHxeISYlDBzl6hYfS7NtTn@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org Sorry, my outlook was wrapping up mail automatically, corrected it. >-----Original Message----- >From: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org [mailto:spi-devel- >general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] On Behalf Of David Brownell >The first task is to come up with a workable design. Then would >come implementing it. > > >A second issue is how to factor the programming interface. The >notion of an spi_message isn't necessarily wrong, but when should >it get issued? How would commands sent by the host be packaged? >How should chipselect/deselect be visible? I was looking for such discussion to be started on this thread from quite some time. Well, in my case, I have SPI hardware which can work in Master and Slave mode as well. Specifically speaking, Slave mode capabilities are as same as Master mode. Only major difference is in chipselect and clock generation. As such, in this case, notion of spi_message would definitely hold good for both and also to some extent the whole stack which exists today. I see in community, some use SPI slave for minimal functionality. As I understand, we have to have a stack support for 1. SPI in slave side transaction (as similar as Master's). 2. SPI in slave side transaction with minimal functionality. I don't know how the latter one is. But, in my case I was able to modify the controller driver to work for Master/Slave with full transaction without any stack changes. I know this is bad, as stack would never come to know about the slave side transaction :). I would like to know the best way we can make the stack know slave side transaction happening? Regards, girish > > >------------------------------------------------------------------------- >This SF.net email is sponsored by: Splunk Inc. >Still grepping through log files to find problems? Stop. >Now Search log events and configuration files using AJAX and a browser. >Download your FREE copy of Splunk now >> http://get.splunk.com/ >_______________________________________________ >spi-devel-general mailing list >spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org >https://lists.sourceforge.net/lists/listinfo/spi-devel-general ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/