iio_read_channel_label
if (iio_read_channel_label(&st->channels[i], buf) < 0)
return iio_read_channel_label(chan, buf);
&iio_read_channel_label,
EXPORT_SYMBOL_GPL(iio_read_channel_label);
ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf);