Re: Re: Re: [PATCH v4 1/2] dt-bindings: pwm: dwc: add reset optional
From: Conor Dooley
Date: Fri Apr 17 2026 - 11:15:25 EST
On Fri, Apr 17, 2026 at 11:11:51AM +0800, Xuyang Dong wrote:
> > > > > >
> > > > > > The DesignWare PWM includes separate reset signals dedicated to each clock
> > > > > > domain:
> > > > > > The presetn signal resets logic in pclk domain.
> > > > > > The timer_N_resetn signal resets logic in the timer_N_clk domain.
> > > > > > The resets are active-low.
> > > > > >
> > > > > > Signed-off-by: Xuyang Dong <dongxuyang@xxxxxxxxxxxxxxxxxx>
> > > > >
> > > > > This commit implies that your hardware differs from existing devices,
> > > > > I think you should add a device-specific compatible.
> > > > >
> > >
> > > Hi Conor and Krzysztof,
> > >
> > > The DesignWare PWM Databook for 2.13a says: "The DW_apb_timers includes
> > > separate reset signals dedicated to each clock domain". They are:
> > > The presetn signal resets logic in pclk domain (i.e., the bus clock in DT).
> > > The timer_N_resetn signal resets logic in the timer_N_clk domain (i.e.,
> > > the timer clock in DT).
> > >
> > > These reset signals are optional; it is up to the designer's
> > > implementation.
> >
> > Right, and it's that "designer's implementation" that warrants a
> > device-specific compatible.
> >
>
> Hi Conor,
>
> The YAML update for the new device-specific compatible is as follows:
>
> properties:
> compatible:
> oneOf:
> - const: snps,dw-apb-timers-pwm2
> - items:
> - enum:
> - snps,dw-apb-timers-pwm-2.13a
This is not a device-specific compatible.
Hint: device-specific means it needs to start with "eswin,eic7700" (and
probably end with "-pwm".
> - const: snps,dw-apb-timers-pwm2
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