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

"Xuyang Dong" <[email protected]> Wed, 22 Jul 2026 15:41:28 +0800 (GMT+08:00)
Newsgroups org.kernel.vger.linux-pwm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
> 
> On Di, 2026-07-21 at 20:08 +0800, [email protected] wrote:
> > From: Xuyang Dong <[email protected]>
> > 
> > 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 <[email protected]>
> > Signed-off-by: Xuyang Dong <[email protected]>
> > ---
> >  .../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