Re: [PATCH 2/3] dt-bindings: rtc: Add Mstar SSD20xD RTC devicetree bindings documentation

From: Daniel Palmer
Date: Tue May 30 2023 - 19:12:57 EST


Hi Krzysztof,

On Tue, 30 May 2023 at 17:01, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> > This is
> > exactly the case for rtc-msc313e and it was not an issue.
>
> So that was my question - can it be anything else? There is literally no
> description of the hardware... Neither in commit msg nor in description:
> field in bindings.

This RTC block is a block inside of the SSD201/SSD202D (they are the
same die with different memory attached) and is only found there.
The documentation we have for this is literally one page in a PDF that
says "RTC registers".
It could be an IP block licensed from somewhere and technically have a
better name but right now all we know is this RTC block is the one in
that chip and that chip is the first known instance of it.

Say we manage to get the ethernet mainlined at some point: That's a
lot easier as we know already it's a hacked up version of the cadence
macb so the compatible can be "macb something".

> >> What about interrupt line?
> >
> > There is currently no interrupt right now, we have not yet the irqchip
> > code for handling the alarm irq of this rtc block.
>
> So you are going to change the hardware and add the interrupt line? We
> do not talk about drivers, but hardware. Whether your driver handles it
> or not, matters less.
>
> Describe the hardware, not the current implementation of one driver.

We don't really know how the interrupt is wired up in the hardware properly yet.

Cheers,

Daniel