Re: [PATCH v3 3/4] counter: Add character device interface

David Lechner
2020-06-22T14:08:54Z

On 6/21/20 2:53 PM, William Breathitt Gray wrote:
> Synapses simply indicate a change in a Count value

Ah, ok. I understand now that synapse is the wrong term for things like
the change in direction event or error events.

> For example, in the dual-axes positioning table scenario, a user
> application would likely want to know the exact X and Y position at the
> time of a given event -- that means an event should provide two Count
> values (and possibly associated device flags) when it occurs. I'm not
> sure yet how the struct counter_event should be defined in order to
> support this; we will need to indicate the format of data as well as
> provide the data itself. Perhaps, we can handle this by providing an
> unique id field so that only a single datum (e.g. a single count value)
> is provided via the value field, but subsequent struct counter_event
> items share the same id so that the user knows that a particular datum
> is part of a larger group of data for a specific event.

The timestamp could act as the "id" to correlate multiple values of a
single event.