Re: [PATCH net-next 1/7] dt-binding: ti: am65x: document common platform time sync cpts module

[Grygorii Strashko]

On 06/05/2020 22:07, Rob Herring wrote:
> On Tue, May 5, 2020 at 10:01 AM Grygorii Strashko
> <grygorii.strashko@xxxxxx> wrote:
> > On 05/05/2020 07:04, Rob Herring wrote:
> > > On Fri, May 01, 2020 at 11:50:05PM +0300, Grygorii Strashko wrote:
> > > > Document device tree bindings for TI AM654/J721E SoC The Common Platform
> > > > Time Sync (CPTS) module. The CPTS module is used to facilitate host control
> > > > of time sync operations. Main features of CPTS module are:
> > > >     - selection of multiple external clock sources
> > > >     - 64-bit timestamp mode in ns with ppm and nudge adjustment.
> > > >     - control of time sync events via interrupt or polling
> > > >     - hardware timestamp of ext. events (HWx_TS_PUSH)
> > > >     - periodic generator function outputs (TS_GENFx)
> > > >     - PPS in combination with timesync router
> > > >     - Depending on integration it enables compliance with the IEEE 1588-2008
> > > > standard for a precision clock synchronization protocol, Ethernet Enhanced
> > > > Scheduled Traffic Operations (CPTS_ESTFn) and PCIe Subsystem Precision Time
> > > > Measurement (PTM).
> > > >
> > > > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> > > > ---
> > > >    .../bindings/net/ti,k3-am654-cpsw-nuss.yaml   |   7 +
> > > >    .../bindings/net/ti,k3-am654-cpts.yaml        | 152 ++++++++++++++++++
> > > >    2 files changed, 159 insertions(+)
> > > >    create mode 100644 Documentation/devicetree/bindings/net/ti,k3-am654-cpts.yaml
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/net/ti,k3-am654-cpsw-nuss.yaml b/Documentation/devicetree/bindings/net/ti,k3-am654-cpsw-nuss.yaml
> > > > index 78bf511e2892..0f3fde45e200 100644
> > > > --- a/Documentation/devicetree/bindings/net/ti,k3-am654-cpsw-nuss.yaml
> > > > +++ b/Documentation/devicetree/bindings/net/ti,k3-am654-cpsw-nuss.yaml
> > > > @@ -144,6 +144,13 @@ patternProperties:
> > > >        description:
> > > >          CPSW MDIO bus.
> > > >
> > > > +  "^cpts$":
> >
> > ok
> >
> > > Fixed strings go under 'properties'.
> > >
> > > > +    type: object
> > > > +    allOf:
> > > > +      - $ref: "ti,am654-cpts.yaml#"
> > > > +    description:
> > > > +      CPSW Common Platform Time Sync (CPTS) module.
> > > > +
> > > >    required:
> > > >      - compatible
> > > >      - reg
> > > > diff --git a/Documentation/devicetree/bindings/net/ti,k3-am654-cpts.yaml b/Documentation/devicetree/bindings/net/ti,k3-am654-cpts.yaml
> > > > new file mode 100644
> > > > index 000000000000..1b535d41e5c6
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/net/ti,k3-am654-cpts.yaml
> > > > @@ -0,0 +1,152 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/net/ti,am654-cpts.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: The TI AM654x/J721E Common Platform Time Sync (CPTS) module Device Tree Bindings
> > > > +
> > > > +maintainers:
> > > > +  - Grygorii Strashko <grygorii.strashko@xxxxxx>
> > > > +  - Sekhar Nori <nsekhar@xxxxxx>
> > > > +
> > > > +description: |+
> > > > +  The TI AM654x/J721E CPTS module is used to facilitate host control of time
> > > > +  sync operations.
> > > > +  Main features of CPTS module are
> > > > +  - selection of multiple external clock sources
> > > > +  - Software control of time sync events via interrupt or polling
> > > > +  - 64-bit timestamp mode in ns with PPM and nudge adjustment.
> > > > +  - hardware timestamp push inputs (HWx_TS_PUSH)
> > > > +  - timestamp counter compare output (TS_COMP)
> > > > +  - timestamp counter bit output (TS_SYNC)
> > > > +  - periodic Generator function outputs (TS_GENFx)
> > > > +  - Ethernet Enhanced Scheduled Traffic Operations (CPTS_ESTFn) (TSN)
> > > > +  - external hardware timestamp push inputs (HWx_TS_PUSH) timestamping
> > > > +
> > > > +   Depending on integration it enables compliance with the IEEE 1588-2008
> > > > +   standard for a precision clock synchronization protocol, Ethernet Enhanced
> > > > +   Scheduled Traffic Operations (CPTS_ESTFn) and PCIe Subsystem Precision Time
> > > > +   Measurement (PTM).
> > > > +
> > > > +  TI AM654x/J721E SoCs has several similar CPTS modules integrated into the
> > > > +  different parts of the system which could be synchronized with each other
> > > > +  - Main CPTS
> > > > +  - MCU CPSW CPTS with IEEE 1588-2008 support
> > > > +  - PCIe subsystem CPTS for PTM support
> > > > +
> > > > +  Depending on CPTS module integration and when CPTS is integral part of
> > > > +  another module (MCU CPSW for example) "compatible" and "reg" can
> > > > +  be omitted - parent module is fully responsible for CPTS enabling and
> > > > +  configuration.
> > >
> > > That's fine, but you should still have compatible and reg.
> >
> > I'll add reg as below. But compatible is an issue, because
> > k3-am654-cpsw-nuss call of_platform_populate() to create mdio device.
> > But for CPTS I do not want to create device as k3-am654-cpsw-nuss uses direct
> > function calls to CPTS.
> >
> > Will it be correct to switch to of_platform_device_create() instead of
> > of_platform_populate()?
>
> That should be fine I think.

Thanks. I've sent follow up patches.

--
Best regards,
grygorii