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authorLars-Peter Clausen <lars@metafoo.de>2012-07-09 10:00:00 +0100
committerJonathan Cameron <jic23@kernel.org>2012-07-09 18:18:15 +0100
commit939546d1a9f47ed169554c711e1e05965b84ffe1 (patch)
tree80ee898547145c1b202a77d3ca5f642809ba9778 /drivers/iio
parentc732a24c5a9392cf3738f5957e0d97d37c09e6e1 (diff)
iio: Add callback to check whether a scan mask is valid
This is useful for cases where the number of valid scan masks grows exponentially, but it is rather easy to check whether a mask is valid or not programmatically. An example of such a case is a device with multiple ADCs where each ADC has a upstream MUX, which allows to select from a number of physical channels. +-------+ +-------+ | | | | --- Channel 1 | ADC 1 |---| MUX 1 | --- ... | | | | --- Channel M +-------+ +-------+ . . . . . . . . . +-------+ +-------+ | | | | --- Channel M * N + 1 | ADC N |---| MUX N | --- ... | | | | --- Channel M * N + M +-------+ +-------+ The number of necessary scan masks for this case is (M+1)**N - 1, on the other hand it is easy to check whether subsets for each ADC of the scanmask have only one bit set. 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.c27
1 files changed, 20 insertions, 7 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 3d8d187eef2..cc5db36fb75 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -570,6 +570,15 @@ int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
}
EXPORT_SYMBOL(iio_sw_buffer_preenable);
+static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
+ const unsigned long *mask)
+{
+ if (!indio_dev->setup_ops->validate_scan_mask)
+ return true;
+
+ return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
+}
+
/**
* iio_scan_mask_set() - set particular bit in the scan mask
* @buffer: the buffer whose scan mask we are interested in
@@ -589,27 +598,31 @@ int iio_scan_mask_set(struct iio_dev *indio_dev,
return -ENOMEM;
if (!indio_dev->masklength) {
WARN_ON("trying to set scanmask prior to registering buffer\n");
- kfree(trialmask);
- return -EINVAL;
+ goto err_invalid_mask;
}
bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
set_bit(bit, trialmask);
+ if (!iio_validate_scan_mask(indio_dev, trialmask))
+ goto err_invalid_mask;
+
if (indio_dev->available_scan_masks) {
mask = iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
trialmask);
- if (!mask) {
- kfree(trialmask);
- return -EINVAL;
- }
+ if (!mask)
+ goto err_invalid_mask;
}
bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
kfree(trialmask);
return 0;
-};
+
+err_invalid_mask:
+ kfree(trialmask);
+ return -EINVAL;
+}
EXPORT_SYMBOL_GPL(iio_scan_mask_set);
int iio_scan_mask_query(struct iio_dev *indio_dev,