On Wed, 2021-05-05 at 07:02 -0700, Guenter Roeck wrote:

On Tue, May 04, 2021 at 10:46:53PM +0300, Ivan Mikhaylov wrote:

quoted

On Fri, 2021-04-30 at 09:38 -0700, Guenter Roeck wrote:

quoted

On Fri, Apr 30, 2021 at 06:24:19PM +0300, Ivan Mikhaylov wrote:

quoted

Intrusion status detection via Interrupt Status Register.

Signed-off-by: Ivan Mikhaylov <redacted>

I think this should, if at all, be handled using the
iio->hwmon bridge (or, in other words, require a solution
which is not chip specific).

Thanks a lot for suggestion, it's actually looks what's needed here instead
of
this driver. Anyways, there is no IIO_PROXIMITY support inside supported
types
in iio_hwmon.c. Should I add additional case inside this driver for
IIO_PROXIMITY type?

quoted

I am also not sure if "proximity" is really appropriate to use
for intrusion detection in the sense of hardware monitoring.
This would require a proximity sensor within a chassis, which
would be both overkill and unlikely to happen in the real world.
"Intrusion", in hardware monitoring context, means "someone
opened the chassis", not "someone got [too] close".

I'm not sure either but it exists :) And it's exactly for this purpose:
"someone opened the chassis", "how near/far is cover?".

The cost for VCNL3020, for a full reel with 3,300 chips, is $1.17 per chip
at Mouser. A mechanical switch costs a couple of cents. A single proximity
sensor won't cover all parts of a chassis; one would likely need several
chips to be sure that are no blind spots (if that is even possible - I don't
think it is in any of my PC chassis due to mechanical limitations). This
is on top of programming, which would be sensitive to generating false
alarms (or missing alarms, for that matter). That sounds quite impractical
and expensive to me. I'd really like to see the actual use case where a
proximity sensor (or set of proximity sensors) is used for intrusion
detection in the sense of hardware monitoring - not just the technical
possibility of doing so, but an actual use case (as in "this vendor,
in this chassis, is doing it").

Thanks,
Guenter

Guenter, VCNL3020 is indeed used as an intrusion detection sensor at least in
one real design. That is YADRO VESNIN Rev. C where the proximity sensor is
installed in a very tight space on an nvme switch board where installation of a
mechanical switch was not possible without substantial redesign of the existing
other components that would cost a lot more than the price of VCNL3020.

VESNIN is a very tight-packed design of 4 x POWER8 CPUs, up to 8TB of RAM, and 26 nvme disks, all that in just 2U.
* https://imgur.com/a/wU9wEd4