Re: Re: [PATCH v12 2/4] dt-bindings: pwm: dwc: Add eswin compatible

From: Xuyang Dong

Date: Wed Jul 22 2026 - 03:43:28 EST


>
> On Di, 2026-07-21 at 20:08 +0800, dongxuyang@xxxxxxxxxxxxxxxxxx wrote:
> > From: Xuyang Dong <dongxuyang@xxxxxxxxxxxxxxxxxx>
> >
> > EIC7700 integrates the DesignWare PWM IP described by the generic
> > snps,dw-apb-timers-pwm2 binding. On this SoC, the presetn and
> > timer_N_resetn inputs are physically tied together to a single reset
> > line, so exactly one reset is both required and sufficient, unlike
> > the generic binding where up to two independent lines are optional.
> >
> > Add the eswin,eic7700-pwm compatible string and constrain its resets
> > property to exactly one entry.
> >
> > Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> > Signed-off-by: Xuyang Dong <dongxuyang@xxxxxxxxxxxxxxxxxx>
> > ---
> > .../bindings/pwm/snps,dw-apb-timers-pwm2.yaml | 32 ++++++++++++++++---
> > 1 file changed, 28 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
> > index 213fdaef25d9..9a9a24ddc61b 100644
> > --- a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
> > +++ b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
> > @@ -20,12 +20,11 @@ description:
> > instead of having to encode the IP version number in the device tree
> > compatible.
> >
> > -allOf:
> > - - $ref: pwm.yaml#
> > -
> > properties:
> > compatible:
> > - const: snps,dw-apb-timers-pwm2
> > + enum:
> > + - snps,dw-apb-timers-pwm2
> > + - eswin,eic7700-pwm
> >
> > reg:
> > maxItems: 1
> > @@ -44,6 +43,7 @@ properties:
> > - const: timer
> >
> > resets:
> > + minItems: 1
> > items:
> > - description: Interface bus (presetn) reset
>
> I'm not sure if that is better than just keeping both resets and
> pointing them to the same reset control, but as it stands, the
> description is incorrect. On eswin, the first item is a combined
> presetn + timer_n_resetn reset input, not presetn.
>

Hi Philipp,

If we add a description of resets under the eswin,eic7700-pwm compatible, 
do you think this modification is appropriate?

  - if:
      properties:
        compatible:
          contains:
            const: eswin,eic7700-pwm
    then:
      properties:
        resets:
          items:
            - description:
                Presetn and timer_N_resetn are tied together to a
                single combined bus-interface and timer-counter
                reset line.
        reset-names: false
      required:
        - resets

Best regards,
Xuyang Dong