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authorLinus Torvalds <torvalds@linux-foundation.org>2021-02-22 21:05:12 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-22 21:05:12 +0300
commita99163e9e708d5d773b7de6da952fcddc341f977 (patch)
treec60a65c58ab7b3f654ac53f46d9b2024e479bd68 /Documentation/devicetree/bindings/graph.txt
parent882d6edfc45cd2b6e33cf973eab9a1ae1dbad5d1 (diff)
parentcb8be8b4b27f6eea88268d6991175df1a27e557e (diff)
downloadlinux-a99163e9e708d5d773b7de6da952fcddc341f977.tar.xz
Merge tag 'devicetree-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring: - Sync dtc to upstream version v1.6.0-51-g183df9e9c2b9 and build host fdtoverlay - Add kbuild support to build DT overlays (%.dtbo) - Drop NULLifying match table in of_match_device(). In preparation for this, there are several driver cleanups to use (of_)?device_get_match_data(). - Drop pointless wrappers from DT struct device API - Convert USB binding schemas to use graph schema and remove old plain text graph binding doc - Convert spi-nor and v3d GPU bindings to DT schema - Tree wide schema fixes for if/then schemas, array size constraints, and undocumented compatible strings in examples - Handle 'no-map' correctly for already reserved memblock regions * tag 'devicetree-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (35 commits) driver core: platform: Drop of_device_node_put() wrapper of: Remove of_dev_{get,put}() dt-bindings: usb: Change descibe to describe in usbmisc-imx.txt dt-bindings: can: rcar_canfd: Group tuples in pin control properties dt-bindings: power: renesas,apmu: Group tuples in cpus properties dt-bindings: mtd: spi-nor: Convert to DT schema format dt-bindings: Use portable sort for version cmp dt-bindings: ethernet-controller: fix fixed-link specification dt-bindings: irqchip: Add node name to PRUSS INTC dt-bindings: interconnect: Fix the expected number of cells dt-bindings: Fix errors in 'if' schemas dt-bindings: iommu: renesas,ipmmu-vmsa: Make 'power-domains' conditionally required dt-bindings: Fix undocumented compatible strings in examples kbuild: Add support to build overlays (%.dtbo) scripts: dtc: Remove the unused fdtdump.c file scripts: dtc: Build fdtoverlay tool scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9 scripts: dtc: Fetch fdtoverlay.c from external DTC project dt-bindings: thermal: sun8i: Fix misplaced schema keyword in compatible strings dt-bindings: iio: dac: Fix AD5686 references ...
Diffstat (limited to 'Documentation/devicetree/bindings/graph.txt')
-rw-r--r--Documentation/devicetree/bindings/graph.txt129
1 files changed, 1 insertions, 128 deletions
diff --git a/Documentation/devicetree/bindings/graph.txt b/Documentation/devicetree/bindings/graph.txt
index 0415e2c53ba0..14733b5cb61e 100644
--- a/Documentation/devicetree/bindings/graph.txt
+++ b/Documentation/devicetree/bindings/graph.txt
@@ -1,128 +1 @@
-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.
-
+This file has moved to graph.yaml in dt-schema repo