GPIO operations, you should be able to leverage that for better
speed with a custom version of this driver; see the source code.
+config SPI_IMX
+ tristate "Freescale i.MX SPI controllers"
+ depends on ARCH_MXC
+ select SPI_BITBANG
+ help
+ This enables using the Freescale i.MX SPI controllers in master
+ mode.
+
config SPI_LM70_LLP
tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)"
depends on PARPORT && EXPERIMENTAL
tristate "ARM AMBA PL022 SSP controller (EXPERIMENTAL)"
depends on ARM_AMBA && EXPERIMENTAL
default y if MACH_U300
+ default y if ARCH_REALVIEW
+ default y if INTEGRATOR_IMPD1
+ default y if ARCH_VERSATILE
help
This selects the ARM(R) AMBA(R) PrimeCell PL022 SSP
controller. If you have an embedded system with an AMBA(R)
bus and a PL022 controller, say Y or M here.
+config SPI_PPC4xx
+ tristate "PPC4xx SPI Controller"
+ depends on PPC32 && 4xx && SPI_MASTER
+ select SPI_BITBANG
+ help
+ This selects a driver for the PPC4xx SPI Controller.
+
config SPI_PXA2XX
tristate "PXA2xx SSP SPI master"
depends on ARCH_PXA && EXPERIMENTAL
help
SPI driver for SuperH SCI blocks.
+config SPI_STMP3XXX
+ tristate "Freescale STMP37xx/378x SPI/SSP controller"
+ depends on ARCH_STMP3XXX && SPI_MASTER
+ help
+ SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
config SPI_TXX9
tristate "Toshiba TXx9 SPI controller"
depends on GENERIC_GPIO && CPU_TX49XX