Devicetree/Bindings

Devicetrees are validated using devicetree schema; this schema specifies allowed properties for nodes based on their compatible string. Devicetree schema is defined through bindings, YAML files containing schema information (older bindings use TXT format, but this is deprecated).

Bindings for most Linux components can be found in Documentation/devicetree/bindings; there is also a core DT schema defining the most basic components and syntax.

Validating DT bindings

The Linux kernel has tools for validating devicetree schema bindings. Getting the DT binding check to pass is required for upstreaming the binding.

To verify all DT bindings, run:

$ make dt_binding_check

You can also verify only a specific binding by providing its filename in the DT_SCHEMA_FILES option. This option takes either a filename or a directory name:

$ make dt_binding_check DT_SCHEMA_FILES=brcm,bcm590xx.yaml  # Checks all bindings named brcm,bcm590xx.yaml
$ make dt_binding_check DT_SCHEMA_FILES=qcom    # Checks all bindings in any (sub)folder named "qcom"
$ make dt_binding_check DT_SCHEMA_FILES=/gpio/  # Checks all bindings in /gpio folder

To verify a DTS file against a DT schema, build the DTB target directly and provide the CHECK_DTBS=y option alongside DT_SCHEMA_FILES:

$ make CHECK_DTBS=y DT_SCHEMA_FILES=trivial-devices.yaml qcom/sm8450-hdk.dtb

See also

• From Linux kernel documentation:
  • Writing Devicetree Bindings in json-schema
  • DOs and DON’Ts for designing and writing Devicetree bindings
  • Submitting Devicetree (DT) binding patches