From 939546d1a9f47ed169554c711e1e05965b84ffe1 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Mon, 9 Jul 2012 10:00:00 +0100 Subject: 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 Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-buffer.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) (limited to 'drivers/iio/industrialio-buffer.c') diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 3d8d187eef2a..cc5db36fb75a 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, -- cgit v1.2.3