From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Kuten Subject: Re: problem with converting from at91_spi to atmel_spi (AT91RM9200) Date: Thu, 24 May 2007 18:27:15 +0300 Message-ID: <20070524182715.47ff6cc8@newbox> References: <20070523143456.15fc49ab@newbox> <200705230906.13353.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Nicolas Ferre , Bill Gatliff , Skinnemoen , Haavard-MRDXTZLjjMs8G+1z+Pypc6QD96bmaF075NbjCUgZEJk@public.gmane.org, andrew-eS41wJS13H5l57MIdRCFDg@public.gmane.org, spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: David Brownell Return-path: In-Reply-To: <200705230906.13353.david-b-yBeKhBN/0LDR7s880joybQ@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 On Wed, 23 May 2007 09:06:12 -0700 David Brownell wrote: > > Chipselect zero ... I've had one report that this driver has some issues > on that chipselect. There seem to be two errata in conflict here: > > - One saying that when the controller manages chipselects, it > does so incorrectly ... releasing it before it's told to do so, > which prematurely terminates transactions. ("NPCSx rises if > no data is to be transmitted") > > - Another saying that if it does *not* manage chipselects, then > broken mode fault detect logic kicks in; this could be what > you're seeing. ("Mode Fault does not allow more than one > master on Chip Select 0") > David, as I understood new atmel_spi driver enables CONFIG_SPI_AT91_MANUAL_CS which in turn enables workaround for 1st errata item you mentioned at91rm9200_devices.c ... in at91_add_device_spi function: #ifdef CONFIG_SPI_AT91_MANUAL_CS at91_set_gpio_output(cs_pin, 1); #else at91_set_A_periph(cs_pin, 0); #endif Regarding second errata item - I have a single device (dataflash - 8MB) on SPI chip select 0, so I do not think this is an issue here. Best regards, Ivan ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/