Re: [PATCH 1/9] dt-bindings: pwm: marvell,pxa: add optional property resets

[Alex Elder]

On 4/15/25 5:12 AM, Yixun Lan wrote:
> Hi Philipp,
>
> On 17:54 Tue 15 Apr     , Guodong Xu wrote:
> > On Tue, Apr 15, 2025 at 4:53 PM Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote:
> > > On Fr, 2025-04-11 at 17:44 +0100, Conor Dooley wrote:
> > > > On Fri, Apr 11, 2025 at 09:14:15PM +0800, Guodong Xu wrote:
> > > > > Add an optional resets property for the Marvell PWM PXA binding.
> > > > >
> > > > > Signed-off-by: Guodong Xu <guodong@xxxxxxxxxxxx>
> > > > > ---
> > > > >   Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml | 3 +++
> > > > >   1 file changed, 3 insertions(+)
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml b/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml
> > > > > index 9ee1946dc2e1..9640d4b627c2 100644
> > > > > --- a/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml
> > > > > +++ b/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml
> > > > > @@ -31,6 +31,9 @@ properties:
> > > > >     clocks:
> > > > >       maxItems: 1
> > > > >
> > > > > +  resets:
> > > > > +    maxItems: 1
> > > >
> > > > Do any of the currently supported devices use a reset? If not, then add
> > > > this in tandem with the new compatible and only allow it there please.
> > >
> > > Also, if spacemit,k1-pwm can not work without the reset being
> > > deasserted, mark it as required.
>
> If I inerpret correctly, only reset requires explicitly being de-asserted,
> need to mark as required? that's being said, if reset comes out as de-asserted
>   by default after power reset, then not necessary?
> (in other cases, some device block is in asserted state by default)

We can often benefit from the state that the boot loader has left
things in, but I think it's better not to assume it if possible.
I suppose it might not be required though.

Anyway, the reset line is available to use; why not require it?

					-Alex

> thanks
> > >
> >
> > Thank you Philipp. spacemit,k1-pwm can not work without the reset.
> > I will add that in the next version.
> >
> > -Guodong
> >
> > > The driver can still use reset_control_get_optional.
> > >
> > > regards
> > > Philipp