Q: SPI support compiled in

[mhaberler]

while the RT-CAN support is shaking out, I'm looking into RT SPI support on Xenomai (BB for now)
for instance, one of the peripherals I'm looking at is the Mesanet 7i90 (http://www.mesanet.com/); Mesanet has great reputation with the LinuxCNC community

to drive it from RT, we cannot use stock SPI drivers on Xenomai (possibly withRT-PREEMPT kernels, but those are not yet widely available on ARM's)

meaning we have to either cook up or find a Xenomai RTDM SPI driver (I'm on the case), or use a similar method we use for GPIO - memory-mapped register fiddling in the HAL driver

now I see spidev is compiled in into your kernel (CONFIG_SPI_OMAP24XX=y)

• assuming we do a register-peek/poke or RTDM SPI driver: would the fact that it's compiled-into the kernel stand in the way? we'd have to disable stock spidev so it wont get in the way, at least for the device in use by RT
• if yes, would it have any significant impact if we changed that to CONFIG_SPI_OMAP24XX=m?

thanks in advance! sorry - I'm still a bit fuzzy on DT

• Michael

[mhaberler]

this does answer the issue: https://lwn.net/Articles/143397/ - please disregard