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 --- include/linux/iio/iio.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 2afbb6f01afc..be82936c4089 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -363,12 +363,16 @@ struct iio_info { * @predisable: [DRIVER] function to run prior to marking buffer * disabled * @postdisable: [DRIVER] function to run after marking buffer disabled + * @validate_scan_mask: [DRIVER] function callback to check whether a given + * scan mask is valid for the device. */ struct iio_buffer_setup_ops { int (*preenable)(struct iio_dev *); int (*postenable)(struct iio_dev *); int (*predisable)(struct iio_dev *); int (*postdisable)(struct iio_dev *); + bool (*validate_scan_mask)(struct iio_dev *indio_dev, + const unsigned long *scan_mask); }; /** -- cgit v1.2.3