Hi List,
A lot of driver add an extra frequency attribute to allow user to tune
triggers frequency from sysfs. This is a lot of code duplication, while most
do the exact same thing.
I added here two extra fields to struct iio_trigger, frequency and info_mask,
which might not be needed at first, but will allow us to add extra parameters
more easily.
I added as well a callback for info_mask changes in trigger_ops so that drivers
can take action when frequency has been changed by the user, but will also be
easily extendable.