Re: Intel Timed-IO driver in IIO/Counter subsystem

William Breathitt Gray
2022-06-17T14:03:36Z

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On Fri, Jun 17, 2022 at 06:37:14AM +0000, N, Pandith wrote:
> Hi,
>
> We have a Intel Timed IO peripheral with following functionalities :
>
> 1. Event capture capability - Captures event count and timestamp.
> 2. Pulse generation - periodic or single event generation.
> 3. Return cross-timestamp on request.
>
> Timed IO device is being used in various Industrial use cases such as : time capture, synchronization, fan speed calculation etc.
>
> IIO or counter subsystem seems to be suitable for timed-io driver.
>
> Is it favourable to implement as part of IIO or counter subsystem ? Wanted to know your feedback.
>
> We may need to use custom ABI for sysfs based user interaction OR
> Can we enhance ioctl interface to accommodate our use case (counter-chardev.c) ?
> Since timed-io works in nano second precision, ioctl is more suitable.
>
> Regards,
> Pandith and Sowjanya
>
> ps : resent the mail with plain text as delivery to linux-iio@vger.kernel.org failed.

Hello Pandith and Sowjanya,

What you are describing sounds similar to what counter-chardev.c tries
to solve (i.e. Counter events with timestamps). Would you elaborate more
on how this device works and what you are trying to accomplish with it?

For example, when you refer to an "event count and timestamp", does
count here mean the internal device hardware timestamp or is this the
Linux system timestamp? Does "pulse generation" refer to capturing the
count on some physical line signal, or is this a device-internal timer
countdown trigger event? Is "cross-timestamp" referring to a difference
calculation between two count events?

Thanks,

William Breathitt Gray

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