On Tue, Feb 4, 2025 at 4:21 AM Rob Herring <robh at kernel.org> wrote:
>
> On Mon, Feb 03, 2025 at 02:18:57PM +0530, Anup Patel wrote:
> > Add device tree bindings for the clock service group defined by the
> > RISC-V platform management interface (RPMI) specification.
> >
> > Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> > ---
> > .../bindings/clock/riscv,rpmi-clock.yaml | 77 +++++++++++++++++++
> > 1 file changed, 77 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml b/Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml
> > new file mode 100644
> > index 000000000000..c08491c04926
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml
> > @@ -0,0 +1,77 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/clock/riscv,rpmi-clock.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: RISC-V RPMI clock service group based clock controller
> > +
> > +maintainers:
> > + - Anup Patel <anup at brainfault.org>
> > +
> > +description: |
> > + The RISC-V Platform Management Interface (RPMI) [1] defines a
> > + messaging protocol which is modular and extensible. The supervisor
> > + software can send/receive RPMI messages via SBI MPXY extension [2]
> > + or some dedicated supervisor-mode RPMI transport.
> > +
> > + The RPMI specification [1] defines clock service group for accessing
> > + system clocks managed by a platform microcontroller.
> > +
> > + ===========================================
> > + References
> > + ===========================================
> > +
> > + [1] RISC-V Platform Management Interface (RPMI)
> > + https://github.com/riscv-non-isa/riscv-rpmi/releases
> > +
> > + [2] RISC-V Supervisor Binary Interface (SBI)
> > + https://github.com/riscv-non-isa/riscv-sbi-doc/releases
> > +
> > +properties:
> > + compatible:
> > + oneOf:
> > + - description:
> > + Intended for use by the SBI implementation in machine mode or
> > + software in supervisor mode.
> > + const: riscv,rpmi-clock
> > +
> > + - description:
> > + Intended for use by the SBI implementation in machine mode.
> > + const: riscv,rpmi-mpxy-clock
> > +
> > + mboxes:
> > + maxItems: 1
> > + description:
> > + Mailbox channel of the underlying RPMI transport or SBI message proxy.
> > +
> > + riscv,sbi-mpxy-channel-id:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + The SBI MPXY channel id to be used for providing RPMI access to
> > + the supervisor software. This property is mandatory when using
> > + riscv,rpmi-mpxy-clock compatible string.
>
> That constraint can be expressed as:
>
> dependentSchemas:
> riscv,sbi-mpxy-channel-id:
> properties:
> compatible:
> const: riscv,rpmi-mpxy-clock
>
> Please double check that works.
>
> > +
> > + "#clock-cells":
> > + const: 1
> > + description:
> > + This property is mandatory when using riscv,rpmi-clock compatible string.
>
> Similar constraint here.
>
> Though the only thing the 2 compatibles have in common is 'mboxes'. I
> think it would be better to just split this into 2 docs.
Yes, it is much simpler to have 2 separate docs. I will update
in the next revision.
Regards,
Anup
>
> > +
> > +required:
> > + - compatible
> > + - mboxes
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + mpxy_mbox: sbi-mpxy-mbox {
>
> mailbox {
>
> > + compatible = "riscv,sbi-mpxy-mbox";
> > + #mbox-cells = <2>;
> > + };
> > + rpmi-clk {
>
> clock-controller {
>
> > + compatible = "riscv,rpmi-clock";
> > + mboxes = <&mpxy_mbox 0x1000 0x0>;
> > + #clock-cells = <1>;
> > + };
> > +...
> > --
> > 2.43.0
> >