/usr/src/linux-headers-4.4.0-31/drivers/iio/ is in linux-headers-4.4.0-31 4.4.0-31.50.
This file is owned by root:root, with mode 0o755.
..
/usr/src/linux-headers-4.4.0-31/drivers/iio/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/accel/
/usr/src/linux-headers-4.4.0-31/drivers/iio/accel/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/accel/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/adc/
/usr/src/linux-headers-4.4.0-31/drivers/iio/adc/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/adc/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/amplifiers/
/usr/src/linux-headers-4.4.0-31/drivers/iio/amplifiers/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/amplifiers/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/buffer/
/usr/src/linux-headers-4.4.0-31/drivers/iio/buffer/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/buffer/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/chemical/
/usr/src/linux-headers-4.4.0-31/drivers/iio/chemical/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/chemical/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/hid-sensors/
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/hid-sensors/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/hid-sensors/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/ms_sensors/
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/ms_sensors/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/ms_sensors/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/ssp_sensors/
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/ssp_sensors/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/ssp_sensors/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/st_sensors/
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/st_sensors/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/common/st_sensors/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/dac/
/usr/src/linux-headers-4.4.0-31/drivers/iio/dac/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/dac/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/frequency/
/usr/src/linux-headers-4.4.0-31/drivers/iio/frequency/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/frequency/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/gyro/
/usr/src/linux-headers-4.4.0-31/drivers/iio/gyro/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/gyro/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/humidity/
/usr/src/linux-headers-4.4.0-31/drivers/iio/humidity/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/humidity/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/imu/
/usr/src/linux-headers-4.4.0-31/drivers/iio/imu/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/imu/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/imu/inv_mpu6050/
/usr/src/linux-headers-4.4.0-31/drivers/iio/imu/inv_mpu6050/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/imu/inv_mpu6050/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/light/
/usr/src/linux-headers-4.4.0-31/drivers/iio/light/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/light/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/magnetometer/
/usr/src/linux-headers-4.4.0-31/drivers/iio/magnetometer/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/magnetometer/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/orientation/
/usr/src/linux-headers-4.4.0-31/drivers/iio/orientation/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/orientation/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/potentiometer/
/usr/src/linux-headers-4.4.0-31/drivers/iio/potentiometer/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/potentiometer/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/pressure/
/usr/src/linux-headers-4.4.0-31/drivers/iio/pressure/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/pressure/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/proximity/
/usr/src/linux-headers-4.4.0-31/drivers/iio/proximity/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/proximity/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/temperature/
/usr/src/linux-headers-4.4.0-31/drivers/iio/temperature/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/temperature/Makefile
/usr/src/linux-headers-4.4.0-31/drivers/iio/trigger/
/usr/src/linux-headers-4.4.0-31/drivers/iio/trigger/Kconfig
/usr/src/linux-headers-4.4.0-31/drivers/iio/trigger/Makefile