Quoting Heiko Stuebner (2024-07-09 05:31:16) > In contrast to fixed clocks that are described as ungateable, boards > sometimes use additional clock generators for things like PCIe reference > clocks, that need actual supplies to get enabled and enable-gpios to be > toggled for them to work. > > This adds a binding for such clock generators that are not configurable > themself, but need to handle supplies for them to work. Sounds like vdd-supply is required? > > While in a lot of cases the type of the IC used is described in board > schematics, in some cases just a generic type description like > "100MHz, 3.3V" might also be used. The binding therefore allows both > cases. Specifying the type is of course preferred. > > The clock-frequency is set in devicetree, because while some clock > generators have pins to decide between multipls output rates, those > are generally set statically on the board-layout-level. > > Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx> > --- > .../bindings/clock/clock-generator.yaml | 62 +++++++++++++++++++ > 1 file changed, 62 insertions(+) > create mode 100644 Documentation/devicetree/bindings/clock/clock-generator.yaml > > diff --git a/Documentation/devicetree/bindings/clock/clock-generator.yaml b/Documentation/devicetree/bindings/clock/clock-generator.yaml > new file mode 100644 > index 0000000000000..f44e61e414e89 > --- /dev/null > +++ b/Documentation/devicetree/bindings/clock/clock-generator.yaml > @@ -0,0 +1,62 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/clock/clock-generator.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Simple clock generators > + > +maintainers: > + - Heiko Stuebner <heiko@xxxxxxxxx> > + > +properties: > + $nodename: > + anyOf: > + - description: > + Preferred name is 'clock-<freq>' with <freq> being the output > + frequency as defined in the 'clock-frequency' property. > + pattern: "^clock-([0-9]+|[a-z0-9-]+)$" > + - description: Any name allowed > + deprecated: true Drop the deprecated stuff from the fixed-clock binding? > + > + compatible: > + oneOf: > + - const: clock-generator > + - items: > + - enum: > + - diodes,pi6c557-03b I see this datasheet[1]. Can that link be included somewhere? That shows there's a clock input pin, which means I expect a 'clocks' property. Maybe instead of creating a generic binding just make a binding for these diodes parts? It certainly looks like a generic binding could come later when another vendor supports the same binding. > + - diodes,pi6c557-05b > + - const: clock-generator > + > + "#clock-cells": > + const: 0 > + > + clock-frequency: true > + > + clock-output-names: > + maxItems: 1 > + > + enable-gpios: > + description: > + Contains a single GPIO specifier for the GPIO that enables and disables > + the clock generator. > + maxItems: 1 > + > + vdd-supply: > + description: handle of the regulator that provides the supply voltage > + > +required: > + - compatible > + - "#clock-cells" > + - clock-frequency This is the same required properties as fixed rate clocks. I'd guess that at least 'enable-gpios' or 'vdd-supply' should also be required, or the node would simply use fixed-clock compatible. > + > +additionalProperties: false > + > +examples: > + - | > + clock { > + compatible = "clock-generator"; > + #clock-cells = <0>; > + clock-frequency = <1000000000>; > + }; [1] https://diodes.com/assets/Datasheets/PI6C557-03B.pdf
