Hi Sergii, On 10/1/10, Sergii Kovalchuk <[email protected]> wrote: > Hi all, > > Probably, I should ask my quesiton on some SPI dedicated mailing lists, > however, the borders of "newbiness" are hard to estimate. > > As I can see, most SPI controller drivers currently attempting to control CS > (SS) line by themselves, usually enabling it just before spi_message > processing and disabling after it. Therefore, all transfers within a message > are going as one atomic transaction. > > However, what should I do, if device requires CS to be triggered to active > state and remained active until device will trigger IRQ, indicating that it > awoke and ready for transaction? > > I presume, that I need some kind of manual CS control. How does it fit into > general SPI subsystem paradigm and how I can implement it? >
Some processors let you to control its CS line manually. Take a look on this: arch/arm/plat-mxc/include/mach/spi.h arch/arm/mach-mx3/mach-mx31lilly.c Also you can define a delay time before and/or after the chip select activation, even on processors with automatic chip select. Best Regards, Alan -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [email protected] Please read the FAQ at http://kernelnewbies.org/FAQ
