On Thu, 08 May 2025 at 11:52:51 +0200, Mark Kettenis wrote:
> > From: joshua stein <j...@jcs.org>
> > Date: Wed, 7 May 2025 21:52:22 -0500
> >
> > This is found on the XPI-3128
>
> I'm fairly confident this is the same chip that is already supported
> by abcrtc(4). The registers match and the datasheet for the Abracon
> AB18X5 RTC that I can find has a disclaimer that says:
>
> AB18X5 series of devices are based on innovative SPOT technology,
> proprietary to Ambiq Micro.
>
> The compatible string you're using ("geniatech,rtc_am1805") isn't
> documented anywhere in the Linux. The fact that it uses "geniatech"
> as the vendor prefix makes me suspect that you're using a vendor
> device tree. We try to stick to proper upstream Linux device trees as
> much as possible as vendors put all sorts of crap in their device
> trees. That said, adding a non-standard compatible string to a driver
> isn't a big issue, as long as we annotate as such.
>
> Can you try whether the abcrtc(4) driver works for you once you add
> the appropriate compatible string?
Yes, abcrtc seems to work here without the trickle charger stuff.
The upstream XPI-3128 device tree has no mention of the RTC (I don't
think it was submitted by the vendor) but the one I extracted from
the device before erasing it did. It ships with a very old
Rockchip-specific U-Boot and Linux kernel.
So I copied the geniatech,rtc_am1805 block to the device tree I'm
using on my unit. I'm not sure what to use as the actual compatible
string in the device tree.
