On Fri, Oct 16, 2020 at 08:12:55PM +0530, Sameer Pujar wrote: > Convert device tree bindings of graph to YAML format. Thanks for doing this. > Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx> > Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/graph.txt | 128 -------------------- > Documentation/devicetree/bindings/graph.yaml | 170 +++++++++++++++++++++++++++ > 2 files changed, 170 insertions(+), 128 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/graph.txt > create mode 100644 Documentation/devicetree/bindings/graph.yaml I'd like to move this to the dtschema repository instead. > diff --git a/Documentation/devicetree/bindings/graph.yaml b/Documentation/devicetree/bindings/graph.yaml > new file mode 100644 > index 0000000..67804c1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/graph.yaml > @@ -0,0 +1,170 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) As the original text defaulted to GPL2, this needs Philipp's permission to re-license. > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/graph.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Common bindings for device graphs > + > +description: | > + The hierarchical organisation of the device tree is well suited to describe > + control flow to devices, but there can be more complex connections between > + devices that work together to form a logical compound device, following an > + arbitrarily complex graph. > + There already is a simple directed graph between devices tree nodes using > + phandle properties pointing to other nodes to describe connections that > + can not be inferred from device tree parent-child relationships. The device > + tree graph bindings described herein abstract more complex devices that can > + have multiple specifiable ports, each of which can be linked to one or more > + ports of other devices. > + > + These common bindings do not contain any information about the direction or > + type of the connections, they just map their existence. Specific properties > + may be described by specialized bindings depending on the type of connection. > + > + To see how this binding applies to video pipelines, for example, see > + Documentation/devicetree/bindings/media/video-interfaces.txt. > + Here the ports describe data interfaces, and the links between them are > + the connecting data buses. A single port with multiple connections can > + correspond to multiple devices being connected to the same physical bus. > + > +maintainers: > + - Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > + > +definitions: > + > + port: > + type: object > + description: | > + If there is more than one 'port' or more than one 'endpoint' node > + or 'reg' property present in the port and/or endpoint nodes then > + '#address-cells' and '#size-cells' properties are required in relevant > + parent node. reg property. > + > + patternProperties: > + "^endpoint(@[0-9a-f]+)?$": > + type: object > + properties: reg? > + remote-endpoint: > + description: | > + phandle to an 'endpoint' subnode of a remote device node. > + $ref: /schemas/types.yaml#/definitions/phandle > + > + ports: > + type: object > + patternProperties: > + "^port(@[0-9a-f]+)?$": > + $ref: "#/definitions/port" No reason for this to be under 'definitions'. Just move down. > + > +properties: > + ports: > + $ref: "#/definitions/ports" > + > +patternProperties: > + "^port(@[0-9a-f]+)?$": > + $ref: "#/definitions/port" > + > +additionalProperties: false This needs to be true here. But you need this within 'ports' and 'port'. (I think... I think we only have extra properties within endpoint nodes.) > + > +examples: > + # Organisation of ports and endpoints: > + # > + # Ports are described by child 'port' nodes contained in the device node. > + # Each port node contains an 'endpoint' subnode for each remote device port > + # connected to this port. If a single port is connected to more than one > + # remote device, an 'endpoint' child node must be provided for each link. > + # If more than one port is present in a device node or there is more than > + # one endpoint at a port, or a port node needs to be associated with a > + # selected hardware interface, a common scheme using '#address-cells', > + # '#size-cells' and 'reg' properties is used to number the nodes. > + - | > + device { > + #address-cells = <1>; > + #size-cells = <0>; > + > + port@0 { > + #address-cells = <1>; > + #size-cells = <0>; > + reg = <0>; > + > + endpoint@0 { > + reg = <0>; > + // ... > + }; > + endpoint@1 { > + reg = <1>; > + // ... > + }; > + }; > + > + port@1 { > + reg = <1>; > + > + endpoint { > + // ... > + }; > + }; > + }; > + > + # All 'port' nodes can be grouped under an optional 'ports' node, which > + # allows to specify #address-cells, #size-cells properties for the 'port' > + # nodes independently from any other child device nodes a device might > + # have. > + - | > + device { > + // ... > + ports { > + #address-cells = <1>; > + #size-cells = <0>; > + > + port@0 { > + #address-cells = <1>; > + #size-cells = <0>; > + reg = <0>; > + // ... > + > + endpoint@0 { > + reg = <0>; > + // ... > + }; > + endpoint@1 { > + reg = <1>; > + // ... > + }; > + }; > + > + port@1 { > + #address-cells = <1>; > + #size-cells = <0>; > + reg = <1>; > + // ... > + }; > + }; > + }; > + > + # Links between endpoints: > + # > + # Each endpoint should contain a 'remote-endpoint' phandle property that > + # points to the corresponding endpoint in the port of the remote device. > + # In turn, the remote endpoint should contain a 'remote-endpoint' property. > + # If it has one, it must not point to anything other than the local endpoint. > + # Two endpoints with their 'remote-endpoint' phandles pointing at each other > + # form a link between the containing ports. > + - | > + device-1 { > + port { > + device_1_output: endpoint { > + remote-endpoint = <&device_2_input>; > + }; > + }; > + }; > + > + device-2 { > + port { > + device_2_input: endpoint { > + remote-endpoint = <&device_1_output>; > + }; > + }; > + }; > + > +... > -- > 2.7.4 >
