Re: [PATCH] dt-bindings: rtc: pcf2127: update bindings

From: Rasmus Villemoes
Date: Wed Jan 27 2021 - 08:12:24 EST


On 26/01/2021 23.48, Alexandre Belloni wrote:
> On 21/12/2020 22:17:54+0100, Rasmus Villemoes wrote:
>> On 19/12/2020 02.34, Alexandre Belloni wrote:
>>> pcf2127, pcf2129 and pca2129 support start-year and reset-source.
>>>
>>
>> No, the 2129 variant doesn't even have a reset output pin. Not sure if
>> there's any way to reflect that, and it probably doesn't matter, since
>> nobody's going to add the reset-source property to a 2129 node. But the
>> commit message is a bit misleading.
>>
>
> Actually no, the INT pin can be used as a reset, the pcf/pca2129
> can be used as a watchdog and so it may need the reset-source property.

Unless I'm missing something, that would require some rather creative
extra circuitry: The interrupt pin is kept low until the appropriate bit
in the rtc is cleared, so if that is routed directly to a reset pin on
the SOC, the SOC would be kept in reset indefinitely.

Rasmus