Thanks Peter. The Blackfin SPI controller provides built-in Chip Select signals and one can choose to assign one of several CS lines to a device. However we need a GPIO-style CS rather than one generated by the controller and while I see that there's certainly room to implement that in the SPI controller driver, I don't see a way to have both that and the automatically-generated CS as options. That is, if I understand correctly, there's no way to configure spi_board_info with, say, a flag that tells the driver "hey, use this specific GPIO line", instead you can pick between 0 and num_chipselect for your chip_select value and, in Blackfin's case, this would configure one of the automatically-generated lines. We appreciate additional feedback about this. Thanks, On Fri, Dec 19, 2008 at 8:57 AM, Peter Wippich <pewi@xxxxxxxxxxxxxxxxx> wrote: > > Hi Andrey, > >> The '8686 requires us to assert CS# and then hold it asserted for the >> entire transaction. The transaction is an arbitrary number of SPI >> transfers. Most host controllers cannot do this (they'll toggle CS# >> between individual transactions) and therefore we chose to not use the >> controller CS# line and use a GPIO. Can you suggest a different way >> to do this given the current SPI framework? > > This can be handled by the SPI driver. See pxa2xx_spi.c as an example. > Look for cs_control() to get the picture..... > Perhaps this should go to the general driver and not be handled by the > chip specific code. Seems a problem general enough. > > Chears, > > Peter > -- Andrey Yurovsky cozybit Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
