On Thu 23 Aug 2007 11:01, Steve Strobel pondered: > I am working on a Blackfin 537 project running uClinux. The BF537 has a > built-in hardware SPI port with up to seven slave select outputs, of > which I can use four or five (the others aren't available because they > share I/O pins with something else I need more). I have 10 SPI devices > I need to control.
> I am looking for advice about the best way to access more SPI devices > (the way that will fit the best with how the Linux SPI driver works). I can > think of four options: > > #1: Chain multiple SPI devices together like shift registers > using the same slave select. > #2: Use GPIO lines as additional slave select outputs. > #3: Use software and GPIO lines to make an additional > bit-banged SPI interface for the slow devices. > #4: Demultiplex the existing slave select outputs. > > Option #2: It is easy enough to turn on a GPIO-based slave select > before > causing an SPI transfer, but how can I tell when the transfer has > finished and > it is safe to turn it off? Is there a hook in the SPI driver for that? Which uClinux-dist for blackfin are you using? I think in the latest dist (2007R1.1) there is a hook for this (GPIO controlled slave selects). -Robin _______________________________________________ uClinux-dev mailing list [email protected] http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by [email protected] To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
