Lines Matching +full:dt +full:- +full:property
1 .. SPDX-License-Identifier: GPL-2.0
3 Writing Devicetree Bindings in json-schema
6 Devicetree bindings are written using json-schema vocabulary. Schema files are
7 written in a JSON-compatible subset of YAML. YAML is used instead of JSON as it
11 Also see :ref:`example-schema`.
14 ---------------
16 Each schema doc is a structured json-schema which is defined by a set of
17 top-level properties. Generally, there is one binding defined per file. The
18 top-level json-schema properties used are:
21 A json-schema unique identifier string. The string must be a valid
22 URI typically containing the binding's filename and path. For DT schema, it must
31 Indicates the meta-schema the schema file adheres to.
34 A one-line description of the hardware being described in the binding schema.
37 A DT specific property. Contains a list of email address(es)
41 Optional. A multi-line text block containing any detailed
70 multi-line YAML text blocks can be found online:
72 https://yaml-multiline.info/
77 Optional. A json-schema used to match nodes for applying the
79 compatible-string values or node name. Most bindings should not need select.
87 A set of sub-schema defining all the DT properties for the
89 common properties (e.g. 'interrupts') or are binding/vendor-specific
92 A property can also define a child DT node with child properties defined
95 For more details on properties sections, see 'Property Schema' section.
101 A list of DT properties from the 'properties' section that
107 have exactly one of these keywords in top-level part, so either
122 'unevaluatedProperties: false'. Typically bus or common-part schemas.
132 Property Schema
133 ---------------
135 The 'properties' section of the schema contains all the DT properties for a
136 binding. Each property contains a set of constraints using json-schema
137 vocabulary for that property. The properties schemas are what are used for
138 validation of DT files.
144 Vendor-specific properties will typically need more detailed schema. With the
146 schemas/types.yaml. A "description" property is always required.
148 The Devicetree schemas don't exactly match the YAML-encoded DT data produced by
153 The default for arrays in json-schema is they are variable-sized and allow more
164 ------------
166 Use YAML coding style (two-space indentation). For DTS examples in the schema,
167 preferred is four-space indentation.
170 -------
175 The DT schema project must be installed in order to validate the DT schema
176 binding documents and validate DTS files using the DT schema. The DT schema
184 apt install swig python3-dev
186 Several executables (dt-doc-validate, dt-mk-schema, dt-validate) will be
194 The DT schema binding documents must be validated using the meta-schema (the
195 schema for the schema) to ensure they are both valid json-schema and valid
196 binding schema. All of the DT binding documents can be validated using the
201 In order to perform validation of DT source files, use the ``dtbs_check`` target::
220 make dt_binding_check DT_SCHEMA_FILES=trivial-devices.yaml
221 make dt_binding_check DT_SCHEMA_FILES=trivial-devices.yaml:rtc.yaml
223 make dtbs_check DT_SCHEMA_FILES=trivial-devices.yaml
226 json-schema Resources
227 ---------------------
230 `JSON-Schema Specifications <http://json-schema.org/>`_
234 .. _example-schema:
237 ------------------------
239 Also available as a separate file: :download:`example-schema.yaml`
241 .. literalinclude:: example-schema.yaml