summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/writing-schema.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/writing-schema.rst')
-rw-r--r--Documentation/devicetree/bindings/writing-schema.rst30
1 files changed, 26 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/writing-schema.rst b/Documentation/devicetree/bindings/writing-schema.rst
index 0a6cf19a1459..7e71cdd1d6de 100644
--- a/Documentation/devicetree/bindings/writing-schema.rst
+++ b/Documentation/devicetree/bindings/writing-schema.rst
@@ -31,7 +31,7 @@ $schema
Indicates the meta-schema the schema file adheres to.
title
- A one-line description on the contents of the binding schema.
+ A one-line description of the hardware being described in the binding schema.
maintainers
A DT specific property. Contains a list of email address(es)
@@ -39,7 +39,7 @@ maintainers
description
Optional. A multi-line text block containing any detailed
- information about this binding. It should contain things such as what the block
+ information about this hardware. It should contain things such as what the block
or device does, standards the device conforms to, and links to datasheets for
more information.
@@ -71,9 +71,31 @@ required
A list of DT properties from the 'properties' section that
must always be present.
+additionalProperties / unevaluatedProperties
+ Keywords controlling how schema will validate properties not matched by this
+ schema's 'properties' or 'patternProperties'. Each schema is supposed to
+ have exactly one of these keywords in top-level part, so either
+ additionalProperties or unevaluatedProperties. Nested nodes, so properties
+ being objects, are supposed to have one as well.
+
+ * additionalProperties: false
+ Most common case, where no additional schema is referenced or if this
+ binding allows subset of properties from other referenced schemas.
+
+ * unevaluatedProperties: false
+ Used when this binding references other schema whose all properties
+ should be allowed.
+
+ * additionalProperties: true
+ Rare case, used for schemas implementing common set of properties. Such
+ schemas are supposed to be referenced by other schemas, which then use
+ 'unevaluatedProperties: false'. Typically bus or common-part schemas.
+
examples
- Optional. A list of one or more DTS hunks implementing the
- binding. Note: YAML doesn't allow leading tabs, so spaces must be used instead.
+ Optional. A list of one or more DTS hunks implementing this binding only.
+ Example should not contain unrelated device nodes, e.g. consumer nodes in a
+ provider binding, other nodes referenced by phandle.
+ Note: YAML doesn't allow leading tabs, so spaces must be used instead.
Unless noted otherwise, all properties are required.