iio: Introduce iio_validate_scan_mask_onehot

Add a helper function for validating a scan mask for devices where exactly one
channel must be selected during sampling. This is a common case among devices
which have scan mask restrictions so it makes sense to provide this function in
the core.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h
index 2a2b6b4d8d05..8ba516fc2ec6 100644
--- a/include/linux/iio/buffer.h
+++ b/include/linux/iio/buffer.h
@@ -177,6 +177,9 @@ ssize_t iio_buffer_show_enable(struct device *dev,
 
 int iio_sw_buffer_preenable(struct iio_dev *indio_dev);
 
+bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
+        const unsigned long *mask);
+
 #else /* CONFIG_IIO_BUFFER */
 
 static inline int iio_buffer_register(struct iio_dev *indio_dev,