Re: [PATCH v3] dt-bindings: timer: Add SiFive CLINT2

[Charles Perry <charles.perry@microchip.com>]

On Wed, Apr 08, 2026 at 02:15:19PM +0800, Nick Hu wrote:
> On Fri, Mar 27, 2026 at 4:56 AM Charles Perry
> <charles.perry@microchip.com> wrote:
> >
> > On Fri, Mar 21, 2025 at 04:35:06PM +0800, Nick Hu wrote:
> > > Add compatible string and property for the SiFive CLINT v2. The SiFive
> > > CLINT v2 is incompatible with the SiFive CLINT v0 due to differences
> > > in their control methods.
> >
> > Hello Nick,
> >
> > Can you help me understand what is this different control method? I've
> > found that both OpenSBI [1] and U-Boot [2] use the same match data in their
> > clint driver which would indicate that they are compatible.
> >
> Sorry for the late reply.

Hello Nick, no worries.

> Unlike v0, v2 requires a write to the mtime register to kick the timer.

A kick once at the beginning or every time a machine timer interrupt fires?

> 
> > Also, do you know if there's an easy way to tell if a sifive clint is a v0
> > or v2?
> >
> sifive,clint2 introduces additional MMIO registers

Is that the high resolution timers (HRT) mentionned in the description?

And last question, would you happen to know if sifive made a clint v1 that
does NOT require the mtime kick but does have the HRT?

I'm trying to figure out what should be the compatible for PIC64-HPSC.
Some code from a repository called "FSFM" used "sifive,clint1" for the
compatible. I'm wondering if I should add the clint v1 to this file.

Thanks,
Charles