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
