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iio: core: add function to retrieve active_scan_mask index

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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@baylibre.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20240731-ad7380-add-single-ended-chips-v2-2-cd63bf05744c@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Julien Stephan 2024-07-31 09:05:43 +02:00 committed by Jonathan Cameron
parent 2043594d64
commit d092b68698
2 changed files with 45 additions and 0 deletions
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43
drivers/iio/industrialio-core.c
View File

@ -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);

2
include/linux/iio/iio.h
View File

@ -864,6 +864,8 @@ static inline unsigned int iio_get_masklength(const struct iio_dev *indio_dev)
return ACCESS_PRIVATE(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