The user-mode calibration tool can then call DeviceIoControl to update coefficients without a driver reload.
Read the X and Y bytes from the I2C register. kmdf hid minidriver for touch i2c device calibration
To allow a user-mode calibration tool to interact with your driver, you must provide a private IOCTL. This is how the calibration GUI collects raw points and sends back coefficients. The user-mode calibration tool can then call DeviceIoControl