I am using i.MX6UL and i want to access the SPI from "void kernel_power_off(void)" function before shutdown process. so please guide me that how can i access SPI from this function which is in reboot.c file. I want to send some data to my slave device using SPI from this function. I have accessed SPI from user space using spidev and it is working fine. But i could not able to access it from reboot.c file so please guide me ASAP. Thanks in advance.