devicetree/bindings/graph.txt

4 ---------------
8 devices that work together to form a logical compound device, following an
10 There already is a simple directed graph between devices tree nodes using
12 can not be inferred from device tree parent-child relationships. The device
22 Documentation/devicetree/bindings/media/video-interfaces.txt.
24 the connecting data buses. A single port with multiple connections can
28 -----------------------------------
30 Ports are described by child 'port' nodes contained in the device node.
31 Each port node contains an 'endpoint' subnode for each remote device port
32 connected to this port. If a single port is connected to more than one
33 remote device, an 'endpoint' child node must be provided for each link.
34 If more than one port is present in a device node or there is more than one
35 endpoint at a port, or a port node needs to be associated with a selected
36 hardware interface, a common scheme using '#address-cells', '#size-cells'
41         #address-cells = <1>;
42         #size-cells = <0>;
45 	        #address-cells = <1>;
46 	        #size-cells = <0>;
66 All 'port' nodes can be grouped under an optional 'ports' node, which
67 allows to specify #address-cells, #size-cells properties for the 'port'
68 nodes independently from any other child device nodes a device might
74                 #address-cells = <1>;
75                 #size-cells = <0>;
88 -----------------------
90 Each endpoint should contain a 'remote-endpoint' phandle property that points
92 remote endpoint should contain a 'remote-endpoint' property. If it has one, it
94 their 'remote-endpoint' phandles pointing at each other form a link between the
97 device-1 {
100                         remote-endpoint = <&device_2_input>;
105 device-2 {
108                         remote-endpoint = <&device_1_output>;
114 -------------------
116 If there is more than one 'port' or more than one 'endpoint' node or 'reg'
117 property present in the port and/or endpoint nodes then the following
118 properties are required in a relevant parent node:
120  - #address-cells : number of cells required to define port/endpoint
122  - #size-cells    : should be zero.
125 ----------------------------
127 - remote-endpoint: phandle to an 'endpoint' subnode of a remote device node.