What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_refin_frequency
KernelVersion:	3.4.0
Contact:	linux-iio@vger.kernel.org
Description:
		Sets channel Y REFin frequency in Hz. In some clock chained
		applications, the reference frequency used by the PLL may
		change during runtime. This attribute allows the user to
		adjust the reference frequency accordingly.
		The value written has no effect until out_altvoltageY_frequency
		is updated. Consider to use out_altvoltageY_powerdown to power
		down the PLL and its RFOut buffers during REFin changes.