Add a function to retrieve the index of the active scan mask inside the available scan masks array. As in iio_scan_mask_match and iio_sanity_check_avail_scan_masks, this function does not handle multi-long masks correctly. It only checks the first long to be zero, and will use such mask as a terminator even if there was bits set after the first long. This should be fine since the available_scan_mask has already been sanity tested using iio_sanity_check_avail_scan_masks. See iio_scan_mask_match and iio_sanity_check_avail_scan_masks for more details Signed-off-by: Julien Stephan <jstephan@xxxxxxxxxxxx> --- drivers/iio/industrialio-core.c | 43 +++++++++++++++++++++++++++++++++++++++++ include/linux/iio/iio.h | 2 ++ 2 files changed, 45 insertions(+) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index e6fad8a6a1fc..f18f48c7eb03 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1965,6 +1965,49 @@ static void iio_sanity_check_avail_scan_masks(struct iio_dev *indio_dev) } } +/** + * iio_active_scan_mask_index - Get index of the active scan mask inside the + * available scan masks array + * @indio_dev: the IIO device containing the active and available scan masks + * + * Returns: the index or -EINVAL if active_scan_mask is not set + */ +int iio_active_scan_mask_index(struct iio_dev *indio_dev) + +{ + const unsigned long *av_masks; + unsigned int masklength = iio_get_masklength(indio_dev); + int i = 0; + + if (!indio_dev->active_scan_mask) + return -EINVAL; + + /* + * As in iio_scan_mask_match and iio_sanity_check_avail_scan_masks, + * the condition here do not handle multi-long masks correctly. + * It only checks the first long to be zero, and will use such mask + * as a terminator even if there was bits set after the first long. + * + * This should be fine since the available_scan_mask has already been + * sanity tested using iio_sanity_check_avail_scan_masks. + * + * See iio_scan_mask_match and iio_sanity_check_avail_scan_masks for + * more details + */ + av_masks = indio_dev->available_scan_masks; + while (*av_masks) { + if (indio_dev->active_scan_mask == av_masks) + return i; + av_masks += BITS_TO_LONGS(masklength); + i++; + } + + dev_warn(indio_dev->dev.parent, + "active scan mask is not part of the avaialable scan masks\n"); + return -EINVAL; +} +EXPORT_SYMBOL_GPL(iio_active_scan_mask_index); + int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index dd6bbc468283..73b75a9ff314 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -864,6 +864,8 @@ static inline unsigned int iio_get_masklength(const struct iio_dev *indio_dev) return indio_dev->masklength; } +int iio_active_scan_mask_index(struct iio_dev *indio_dev); + /** * iio_for_each_active_channel - Iterated over active channels * @indio_dev: the IIO device -- 2.45.1