This seems like a left-over froma7348347ba("staging:iio: Add polling of events on the ring access chrdev."). Then it was moved into the sca3000 driver around9dd4694daf("iio: staging: sca3000: hide stufftoread logic"), and that one seemed to be the only user of this. Then it eventually was no longer used after152a6a884a("staging:iio:accel:sca3000 move to hybrid hard / soft buffer design.") Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>