Re: [PATCH v3 net-next 1/8] dt-bindings: dpll: Add device tree bindings for DPLL device and pin

Rob Herring
2025-04-21T22:29:20Z

On Mon, Apr 21, 2025 at 5:20 PM Rob Herring <robh@kernel.org> wrote:
>
> On Wed, Apr 16, 2025 at 06:21:37PM +0200, Ivan Vecera wrote:
> > Add a common DT schema for DPLL device and associated pin.
> > The DPLL (device phase-locked loop) is a device used for precise clock
> > synchronization in networking and telecom hardware.
>
> In the subject, drop 'device tree binding for'. You already said that
> with 'dt-bindings'.
>
> >
> > The device itself is equipped with one or more DPLLs (channels) and
> > one or more physical input and output pins.
> >
> > Each DPLL channel is used either to provide pulse-per-clock signal or
> > to drive ethernet equipment clock.
> >
> > The input and output pins have a label (specifies board label),
> > type (specifies its usage depending on wiring), list of supported
> > or allowed frequencies (depending on how the pin is connected and
> > where) and can support embedded sync capability.
>
> Convince me this is something generic... Some example parts or
> datasheets would help. For example, wouldn't these devices have 1 or
> more power supplies or a reset line?

Never mind, I read the next patch...

>
> >
> > Signed-off-by: Ivan Vecera <ivecera@redhat.com>
> > ---
> > v1->v3:
> > * rewritten description for both device and pin
> > * dropped num-dplls property
> > * supported-frequencies property renamed to supported-frequencies-hz
> > ---
> > .../devicetree/bindings/dpll/dpll-device.yaml | 76 +++++++++++++++++++
> > .../devicetree/bindings/dpll/dpll-pin.yaml | 44 +++++++++++
> > MAINTAINERS | 2 +
> > 3 files changed, 122 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/dpll/dpll-device.yaml
> > create mode 100644 Documentation/devicetree/bindings/dpll/dpll-pin.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/dpll/dpll-device.yaml b/Documentation/devicetree/bindings/dpll/dpll-device.yaml
> > new file mode 100644
> > index 0000000000000..11a02b74e28b7
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/dpll/dpll-device.yaml
> > @@ -0,0 +1,76 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/dpll/dpll-device.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Digital Phase-Locked Loop (DPLL) Device
> > +
> > +maintainers:
> > + - Ivan Vecera <ivecera@redhat.com>
> > +
> > +description:
> > + Digital Phase-Locked Loop (DPLL) device is used for precise clock
> > + synchronization in networking and telecom hardware. The device can
> > + have one or more channels (DPLLs) and one or more physical input and
> > + output pins. Each DPLL channel can either produce pulse-per-clock signal
> > + or drive ethernet equipment clock. The type of each channel can be
> > + indicated by dpll-types property.
> > +
> > +properties:
> > + $nodename:
> > + pattern: "^dpll(@.*)?$"
>
> There's no 'reg' property, so you can't ever have a unit-address. I
> suppose you can have more than 1, so you need a '-[0-9]+' suffix.

And forget this too.

Rob