diff options
| author | Lars-Peter Clausen <lars@metafoo.de> | 2012-07-09 11:00:00 +0200 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2012-07-09 19:18:15 +0200 |
| commit | 81636632057cc1bece2531220dd5803036f95ea9 (patch) | |
| tree | 6c1d73dbc88d32e49a2c5b44423a972a9b8da0c0 /drivers/iio | |
| parent | iio: Add callback to check whether a scan mask is valid (diff) | |
| download | linux-81636632057cc1bece2531220dd5803036f95ea9.tar.xz linux-81636632057cc1bece2531220dd5803036f95ea9.zip | |
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>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/industrialio-buffer.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index cc5db36fb75a..8c1dc9a683fb 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -570,6 +570,22 @@ int iio_sw_buffer_preenable(struct iio_dev *indio_dev) } EXPORT_SYMBOL(iio_sw_buffer_preenable); +/** + * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected + * @indio_dev: the iio device + * @mask: scan mask to be checked + * + * Return true if exactly one bit is set in the scan mask, false otherwise. It + * can be used for devices where only one channel can be active for sampling at + * a time. + */ +bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, + const unsigned long *mask) +{ + return bitmap_weight(mask, indio_dev->masklength) == 1; +} +EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot); + static bool iio_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) { |