From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Wegner Date: Fri, 29 Jan 2010 17:18:10 +0100 Subject: [U-Boot] SPI and spi_cs_activate In-Reply-To: <201001291111.36767.vapier@gentoo.org> References: <20100129155928.GU23389@leila.ping.de> <201001291111.36767.vapier@gentoo.org> Message-ID: <20100129161810.GV23389@leila.ping.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Mike, On Fri, Jan 29, 2010 at 11:11:36AM -0500, Mike Frysinger wrote: > On Friday 29 January 2010 10:59:28 Wolfgang Wegner wrote: > > I am trying to get the spi_mmc driver by Robert Selberg and Hans Eklund > > to run on my new Coldfire board. (The driver was posted as a patch some > > time ago, clearly marked as not ready for mainline. I just did not figure > > out the correct search term to give the message ID.) > > > > Now I am running into problems because the driver uses spi_cs_[de]activate, > > which is rather useless on coldfire which does automatic cs. > > > > Looking through other drivers' code it seems to me that spi_cs_[de]activate > > was never meant to be called from anybody else but some special SPI > > drivers that can not aotumatically control cs lines or for systems > > where SPI is done in software and so setting the appropriate GPIOs > > is handed over to special board-dependent code. > > there are plenty of SPI controllers which allow the CS to be manually > controlled. this isnt a "special" driver. OK, of course controlling CS manually is possible on most systems (via GPIO). What I meant is that most systems do not care to control it automatically (mostly for complexity reasons or because of real HW limitations, as far as I understand). > the MMC/SPI driver was written on a Blackfin system. it working on any other > system is coincidental as a result of leveraging the common frameworks. feel > free to submit fixes. This is my intention in case I understand in which direction I have to fix. (And in case I then get it to work in such a way, of course.) So, maybe a more clear question: Are all SPI drivers supposed to supply functions to manually control the CS lines? If so, what means shall be provided to disable automatic control? Regards, Wolfgang