staging: comedi: comedi_test: support scan_begin_src == TRIG_FOLLOW
It is quite common for COMEDI subdevices that support commands to
support setting `scan_begin_src` to `TRIG_FOLLOW`. This means the next
scan begins once all conversions in the current scan are complete.
Support the following timing combinations for the AI subdevice:
scan_begin_src == TRIG_TIMER && convert_src == TRIG_TIMER
scan_begin_src == TRIG_TIMER && convert_src == TRIG_NOW
scan_begin_src == TRIG_FOLLOW && convert_src == TRIG_TIMER
The actual scan period in microseconds is stored in the `scan_period`
member of the private data structure `struct waveform_private`. An
`unsigned int` is still wide enough, because the conversion period is no
more than `UINT_MAX / 1000` microseconds and the number of conversions
is no more than 16 (`N_CHANS * 2`).
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed