Controlling the same I2C device from user and kernel space

Hi, I've got a question. I have an I2C device (FPGA) connected to my board. This device implements a hardware watchdog and GPIO expander. My question is - can I control this device from userspace (watchdog part) using spidev driver and still be able to develop a kernel driver that controls GPIO expander part without any additional locking mechanisms? Best regards Patryk