Re: [PATCH RFC] pmdomain: core: add hierarchy support for onecell providers

["Rob Herring (Arm)" <robh@kernel.org>]

On Wed, 28 May 2025 13:03:43 -0700, Kevin Hilman wrote:
> Currently, PM domains can only support hierarchy for simple
> providers (e.g. ones with #power-domain-cells = 0).
> 
> Add support for oncell providers as well by adding a new property
> `power-domains-child-ids` to describe the parent/child relationship.
> 
> For example, an SCMI PM domain provider might be a subdomain of
> multiple parent domains. In this example, the parent domains are
> MAIN_PD and WKUP_PD:
> 
>     scmi_pds: protocol@11 {
>         reg = <0x11>;
>         #power-domain-cells = <1>;
>         power-domains = <&MAIN_PD>, <&WKUP_PD>;
>         power-domains-child-ids = <15>, <19>;
>     };
> 
> With the new property, child domain 15 (scmi_pds 15) becomes a
> subdomain of MAIN_PD, and child domain 19 (scmi_pds 19) becomes a
> subdomain of WKUP_PD.
> 
> Note: this idea was previously discussed on the arm-scmi mailing
> list[1] where this approach was proposed by Ulf.  This is my initial
> attempt at implementing it for discussion.  I'm definitely a noob at
> adding support new DT properties, so I got some help from an AI friend
> named Claude in writing this code, so feedback on the apprach is
> welcomed.
> 
> [1] https://lore.kernel.org/arm-scmi/CAPDyKFo_P129sVirHHYjOQT+QUmpymcRJme9obzKJeRgO7B-1A@mail.gmail.com/
> 
> Signed-off-by: Kevin Hilman <khilman@baylibre.com>
> ---
>  Documentation/devicetree/bindings/power/power-domain.yaml |  39 ++++++++++++++++++++++++++++++++
>  drivers/pmdomain/core.c                                   | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 150 insertions(+)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:
./Documentation/devicetree/bindings/power/power-domain.yaml:76:13: [error] missing starting space in comment (comments)
./Documentation/devicetree/bindings/power/power-domain.yaml:77:7: [error] syntax error: expected <block end>, but found '<scalar>' (syntax)

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/power-domain.yaml: ignoring, error parsing file
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/keystone/ti,sci.example.dtb: system-controller@44083000 (ti,k2g-sci): power-controller: {'compatible': ['ti,sci-pm-domain'], '#power-domain-cells': 2} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/keystone/ti,sci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/keystone/ti,sci.example.dtb: power-controller (ti,sci-pm-domain): {'compatible': ['ti,sci-pm-domain'], '#power-domain-cells': 2, '$nodename': ['power-controller']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/soc/ti/sci-pm-domain.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.example.dtb: psci (arm,psci-1.0): power-domain-cpu0: {'#power-domain-cells': 0, 'domain-idle-states': [3], 'power-domains': [[4]], 'phandle': 1} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/psci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.example.dtb: psci (arm,psci-1.0): power-domain-cpu0: Unevaluated properties are not allowed ('#power-domain-cells', 'domain-idle-states', 'power-domains' were unexpected)
	from schema $id: http://devicetree.org/schemas/arm/psci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.example.dtb: psci (arm,psci-1.0): power-domain-cpu1: {'#power-domain-cells': 0, 'domain-idle-states': [3], 'power-domains': [[4]], 'phandle': 2} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/psci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.example.dtb: psci (arm,psci-1.0): power-domain-cpu1: Unevaluated properties are not allowed ('#power-domain-cells', 'domain-idle-states', 'power-domains' were unexpected)
	from schema $id: http://devicetree.org/schemas/arm/psci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.example.dtb: psci (arm,psci-1.0): power-domain-cluster: {'#power-domain-cells': 0, 'domain-idle-states': [5, 6], 'phandle': 4} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/psci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.example.dtb: psci (arm,psci-1.0): power-domain-cluster: Unevaluated properties are not allowed ('#power-domain-cells', 'domain-idle-states' were unexpected)
	from schema $id: http://devicetree.org/schemas/arm/psci.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23b700000 (apple,t8103-pmgr): power-controller@1c0: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[448, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['sio'], 'apple,always-on': True, 'phandle': 1} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23b700000 (apple,t8103-pmgr): power-controller@220: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[544, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['uart_p'], 'power-domains': [[1]], 'phandle': 2} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23b700000 (apple,t8103-pmgr): power-controller@270: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[624, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['uart0'], 'power-domains': [[2]]} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@1c0 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[448, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['sio'], 'apple,always-on': True, 'phandle': 1, '$nodename': ['power-controller@1c0']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@220 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[544, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['uart_p'], 'power-domains': [[1]], 'phandle': 2, '$nodename': ['power-controller@220']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@270 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[624, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['uart0'], 'power-domains': [[2]], '$nodename': ['power-controller@270']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23d280000 (apple,t8103-pmgr): power-controller@4000: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16384, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_filter'], 'phandle': 3} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23d280000 (apple,t8103-pmgr): power-controller@4010: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16400, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_base'], 'power-domains': [[3]], 'phandle': 4} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23d280000 (apple,t8103-pmgr): power-controller@4038: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16440, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_shim'], 'power-domains': [[4]], 'phandle': 5} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-management@23d280000 (apple,t8103-pmgr): power-controller@4048: {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16456, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_uart0'], 'power-domains': [[5]]} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@4000 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16384, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_filter'], 'phandle': 3, '$nodename': ['power-controller@4000']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@4010 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16400, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_base'], 'power-domains': [[3]], 'phandle': 4, '$nodename': ['power-controller@4010']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@4038 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16440, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_shim'], 'power-domains': [[4]], 'phandle': 5, '$nodename': ['power-controller@4038']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/apple/apple,pmgr.example.dtb: power-controller@4048 (apple,t8103-pmgr-pwrstate): {'compatible': ['apple,t8103-pmgr-pwrstate', 'apple,pmgr-pwrstate'], 'reg': [[16456, 8]], '#power-domain-cells': 0, '#reset-cells': 0, 'label': ['aop_uart0'], 'power-domains': [[5]], '$nodename': ['power-controller@4048']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.example.dtb: power-controller (ti,sci-pm-domain): {'compatible': ['ti,sci-pm-domain'], '#power-domain-cells': 1, '$nodename': ['power-controller']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/soc/ti/sci-pm-domain.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.example.dtb: power-controller (ti,sci-pm-domain): {'compatible': ['ti,sci-pm-domain'], '#power-domain-cells': 2, '$nodename': ['power-controller']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/soc/ti/sci-pm-domain.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/fsl,scu-pd.example.dtb: power-controller (fsl,imx8qxp-scu-pd): {'compatible': ['fsl,imx8qxp-scu-pd', 'fsl,scu-pd'], '#power-domain-cells': 1, '$nodename': ['power-controller']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/fsl,scu-pd.yaml#
make[2]: *** Deleting file 'Documentation/devicetree/bindings/power/power-domain.example.dts'
Documentation/devicetree/bindings/power/power-domain.yaml:77:7: expected <block end>, but found '<scalar>'
make[2]: *** [Documentation/devicetree/bindings/Makefile:26: Documentation/devicetree/bindings/power/power-domain.example.dts] Error 1
make[2]: *** Waiting for unfinished jobs....
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/pd-samsung.example.dtb: power-domain@10023c80 (samsung,exynos4210-pd): {'compatible': ['samsung,exynos4210-pd'], 'reg': [[268582016, 32]], '#power-domain-cells': 0, 'label': ['LCD0'], '$nodename': ['power-domain@10023c80']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/pd-samsung.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/pd-samsung.example.dtb: power-domain@10044060 (samsung,exynos4210-pd): {'compatible': ['samsung,exynos4210-pd'], 'reg': [[268714080, 32]], '#power-domain-cells': 0, 'label': ['MFC'], '$nodename': ['power-domain@10044060']} should not be valid under {'description': "Can't find referenced schema: http://devicetree.org/schemas/power/power-domain.yaml#"}
	from schema $id: http://devicetree.org/schemas/power/pd-samsung.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/fsl,scu-pd.yaml:
	while parsing a block mapping
  in "<unicode string>", line 72, column 5:
        $ref: /schemas/types.yaml#/defin ... 
        ^ (line: 72)
expected <block end>, but found '<scalar>'
  in "<unicode string>", line 77, column 7:
          power domains). It specifies whi ... 
          ^ (line: 77)
./Documentation/devicetree/bindings/power/power-domain.yaml:77:7: expected <block end>, but found '<scalar>'
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/pd-samsung.yaml:
	while parsing a block mapping
  in "<unicode string>", line 72, column 5:
        $ref: /schemas/types.yaml#/defin ... 
        ^ (line: 72)
expected <block end>, but found '<scalar>'
  in "<unicode string>", line 77, column 7:
          power domains). It specifies whi ... 
          ^ (line: 77)
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/arm/psci.yaml:
	while parsing a block mapping
  in "<unicode string>", line 72, column 5:
        $ref: /schemas/types.yaml#/defin ... 
        ^ (line: 72)
expected <block end>, but found '<scalar>'
  in "<unicode string>", line 77, column 7:
          power domains). It specifies whi ... 
          ^ (line: 77)
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.yaml:
	while parsing a block mapping
  in "<unicode string>", line 72, column 5:
        $ref: /schemas/types.yaml#/defin ... 
        ^ (line: 72)
expected <block end>, but found '<scalar>'
  in "<unicode string>", line 77, column 7:
          power domains). It specifies whi ... 
          ^ (line: 77)
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml:
	while parsing a block mapping
  in "<unicode string>", line 72, column 5:
        $ref: /schemas/types.yaml#/defin ... 
        ^ (line: 72)
expected <block end>, but found '<scalar>'
  in "<unicode string>", line 77, column 7:
          power domains). It specifies whi ... 
          ^ (line: 77)
make[1]: *** [/builds/robherring/dt-review-ci/linux/Makefile:1519: dt_binding_check] Error 2
make: *** [Makefile:248: __sub-make] Error 2

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250528-pmdomain-hierarchy-onecell-v1-1-851780700c68@baylibre.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.