[PATCH v4 08/15] Documentation: of: Convert graph bindings to json-schema
From: Sameer Pujar
Date: Fri Oct 16 2020 - 10:44:20 EST
Convert device tree bindings of graph to YAML format.
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
diff --git a/Documentation/devicetree/bindings/graph.txt b/Documentation/devicetree/bindings/graph.txt
deleted file mode 100644
index 0415e2c..0000000
--- a/Documentation/devicetree/bindings/graph.txt
+++ /dev/null
@@ -1,128 +0,0 @@
-Common bindings for device graphs
-
-General concept
----------------
-
-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.
-
-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 {
- ...
- endpoint@0 { ... };
- endpoint@1 { ... };
- };
-
- port@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>;
- };
- };
-};
-
-Required properties
--------------------
-
-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 the following
-properties are required in a relevant parent node:
-
- - #address-cells : number of cells required to define port/endpoint
- identifier, should be 1.
- - #size-cells : should be zero.
-
-Optional endpoint properties
-----------------------------
-
-- remote-endpoint: phandle to an 'endpoint' subnode of a remote device node.
-
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)
+%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.
+
+ patternProperties:
+ "^endpoint(@[0-9a-f]+)?$":
+ type: object
+ properties:
+ 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"
+
+properties:
+ ports:
+ $ref: "#/definitions/ports"
+
+patternProperties:
+ "^port(@[0-9a-f]+)?$":
+ $ref: "#/definitions/port"
+
+additionalProperties: false
+
+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