On Mon, Feb 8, 2021 at 2:53 PM Oleksij Rempel [off-list ref] wrote:

Add simple IRQ or GPIO base event counter. This device is used to measure
rotation speed of some agricultural devices, so no high frequency on the
counter pin is expected.

The maximal measurement frequency depends on the CPU and system load. On
the idle iMX6S I was able to measure up to 20kHz without count drops.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

From GPIO and interrupt point of view this driver looks good to me.
I don't know about the userspace interface etc.

Yours,
Linus Walleij