Hi, Am Mittwoch, 10. Juli 2024, 09:02:34 CEST schrieb Alexander Stein: > Am Dienstag, 9. Juli 2024, 14:31:16 CEST schrieb Heiko Stuebner: > > 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. > > Fixed clocks are intended to be ungateable? Where does this come from? "DOC: basic fixed-rate clock that cannot gate" https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/clk-fixed-rate.c#n18 > > This adds a binding for such clock generators that are not configurable > > themself, but need to handle supplies for them to work. > > > > 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 > > + > > + compatible: > > + oneOf: > > + - const: clock-generator > > + - items: > > + - enum: > > + - diodes,pi6c557-03b > > + - 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 > > So essentially only enable-gpios and vdd-supply is added in comparison to > fixed-clock. Does it make sense to add that to the fixed-clocks instead? > Similar to fixed-regulator. I wasn't that sure which way to go in the first place. The deciding point was reading that line about the fixed clock not being gateable, so I opted to not touch the fixed-clock. But you're definitly right, this _could_ live inside the fixed-clock as well, if we decide to get rid of the not-gateable thing above. Heiko
