Re: [PATCH] counter: ti-eqep: implement over/underflow events

From: William Breathitt Gray
Date: Sat Jun 15 2024 - 03:02:09 EST


On Sun, Jun 09, 2024 at 04:49:33PM -0500, David Lechner wrote:
> This adds support to the TI eQEP counter driver for subscribing to
> overflow and underflow events using the counter chrdev interface.
>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
> ---
> This is split out from a series that was sent a few years back [1] that
> I never finished, so I'm calling it v2. This was tested on a BeagleBone
> Blue using LEGO MINDSTORMS EV3 motors and this script[2].
>
> [1]: https://lore.kernel.org/linux-iio/20211017013343.3385923-2-david@xxxxxxxxxxxxxx/
> [2]: https://github.com/dlech/linux-counter-ti-eqep-python/blob/3745b0840736248d8e60cc675a0f43558fcbb2af/test.py
>
> v2 changes:
> * Only clear interrupts that were handled.
> * Don't set default QPOSMAX value.
> * Don't error when setting QPOSMAX to 0.
> * Use regmap_write() when appropriate.
> * Validate watch channel.
> * Use counter_priv().

Hi David,

It's nice to see progress on this again. I remember there being some
sort of interrupt storm if QPOSMAX was set to 0. Is that still the case,
or was it resolved with the changes in this version?

Willia Breathitt Gray

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