Re: [PATCH v1] hwmon: (lm90) Use edge-triggered interrupt

From: Dmitry Osipenko
Date: Thu Jun 17 2021 - 11:28:03 EST


17.06.2021 18:12, Guenter Roeck пишет:
>> For now I see that the rising edge isn't needed, the TEMP_ALERT goes
>> HIGH by itself when temperature backs to normal. But I will try to
>> double check.
>>
> The point is that a sysfs event should be sent to userspace on both
> edges, not only when an alarm is raised. But, you are correct,
> IRQ_TYPE_EDGE_RISING is currently not needed since sysfs events
> are not generated.

Ok, thank you for the clarification.

>>> Anyway, the tegra30 dts files in the upstream kernel either use
>>> IRQ_TYPE_LEVEL_LOW or no interrupts for nct1008. The Nexus 7 dts file
>>> in the upstream kernel has no interrupt configured (and coincidentally
>>> it was you who added that entry). Where do you see IRQ_TYPE_LEVEL_HIGH ?
>> I have a patch that will add the interrupt property, it's stashed
>> locally for the next kernel release.
>>
>> IIUC, it's not only the Tegra30 dts, but all the TegraXXX boards that
>> use IRQ_TYPE_LEVEL_LOW are in the same position.
> I still don't see a IRQ_TYPE_LEVEL_HIGH, though.

Could you please clarify why you're looking for HIGH and not for LOW?
The TEMP_ALERT is active-low.