Hi Sameer, Rob, On Mon, 2020-10-19 at 16:56 -0500, Rob Herring wrote: > 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. Seconded. > > Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx> > > Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > > --- > > Documentation/devicetree/bindings/graph.txt | 128 -------------------- The removed Documentation/devicetree/bindings/graph.txt is referenced by a lot of files, tree-wide. Should the references be updated in the same series? > > 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. Acked-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > > +%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. What about #address-cells and #size-cells in port and ports nodes? These must either be #address-cells = <1>, #size-cells = <0>, or they can be absent if the parent node already has the same, or if a port node only contains a single endpoint. > > + > > + 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 > > regards Philipp
