iio: inkern: add iio_read_channel_average_raw

Add iio_read_channel_average_raw to support reading
averaged raw values in consumer drivers.

Signed-off-by: Sebastian Reichel <sre@debian.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 0cf5f8e..adeba5a 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -443,6 +443,24 @@
 }
 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
 
+int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
+{
+	int ret;
+
+	mutex_lock(&chan->indio_dev->info_exist_lock);
+	if (chan->indio_dev->info == NULL) {
+		ret = -ENODEV;
+		goto err_unlock;
+	}
+
+	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
+err_unlock:
+	mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
+
 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
 	int raw, int *processed, unsigned int scale)
 {