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| -rw-r--r-- | Documentation/acpi/dsd/graph.txt | 174 |
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diff --git a/Documentation/acpi/dsd/graph.txt b/Documentation/acpi/dsd/graph.txt deleted file mode 100644 index b9ce910781dc..000000000000 --- a/Documentation/acpi/dsd/graph.txt +++ /dev/null @@ -1,174 +0,0 @@ -Graphs - - -_DSD ----- - -_DSD (Device Specific Data) [7] is a predefined ACPI device -configuration object that can be used to convey information on -hardware features which are not specifically covered by the ACPI -specification [1][6]. There are two _DSD extensions that are relevant -for graphs: property [4] and hierarchical data extensions [5]. The -property extension provides generic key-value pairs whereas the -hierarchical data extension supports nodes with references to other -nodes, forming a tree. The nodes in the tree may contain properties as -defined by the property extension. The two extensions together provide -a tree-like structure with zero or more properties (key-value pairs) -in each node of the tree. - -The data structure may be accessed at runtime by using the device_* -and fwnode_* functions defined in include/linux/fwnode.h . - -Fwnode represents a generic firmware node object. It is independent on -the firmware type. In ACPI, fwnodes are _DSD hierarchical data -extensions objects. A device's _DSD object is represented by an -fwnode. - -The data structure may be referenced to elsewhere in the ACPI tables -by using a hard reference to the device itself and an index to the -hierarchical data extension array on each depth. - - -Ports and endpoints -------------------- - -The port and endpoint concepts are very similar to those in Devicetree -[3]. A port represents an interface in a device, and an endpoint -represents a connection to that interface. - -All port nodes are located under the device's "_DSD" node in the hierarchical -data extension tree. The data extension related to each port node must begin -with "port" and must be followed by the "@" character and the number of the port -as its key. The target object it refers to should be called "PRTX", where "X" is -the number of the port. An example of such a package would be: - - Package() { "port@4", PRT4 } - -Further on, endpoints are located under the port nodes. The hierarchical -data extension key of the endpoint nodes must begin with -"endpoint" and must be followed by the "@" character and the number of the -endpoint. The object it refers to should be called "EPXY", where "X" is the -number of the port and "Y" is the number of the endpoint. An example of such a -package would be: - - Package() { "endpoint@0", EP40 } - -Each port node contains a property extension key "port", the value of which is -the number of the port. Each endpoint is similarly numbered with a property -extension key "reg", the value of which is the number of the endpoint. Port -numbers must be unique within a device and endpoint numbers must be unique -within a port. If a device object may only has a single port, then the number -of that port shall be zero. Similarly, if a port may only have a single -endpoint, the number of that endpoint shall be zero. - -The endpoint reference uses property extension with "remote-endpoint" property -name followed by a reference in the same package. Such references consist of the -the remote device reference, the first package entry of the port data extension -reference under the device and finally the first package entry of the endpoint -data extension reference under the port. Individual references thus appear as: - - Package() { device, "port@X", "endpoint@Y" } - -In the above example, "X" is the number of the port and "Y" is the number of the -endpoint. - -The references to endpoints must be always done both ways, to the -remote endpoint and back from the referred remote endpoint node. - -A simple example of this is show below: - - Scope (\_SB.PCI0.I2C2) - { - Device (CAM0) - { - Name (_DSD, Package () { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "compatible", Package () { "nokia,smia" } }, - }, - ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), - Package () { - Package () { "port@0", PRT0 }, - } - }) - Name (PRT0, Package() { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "reg", 0 }, - }, - ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), - Package () { - Package () { "endpoint@0", EP00 }, - } - }) - Name (EP00, Package() { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "reg", 0 }, - Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, "port@4", "endpoint@0" } }, - } - }) - } - } - - Scope (\_SB.PCI0) - { - Device (ISP) - { - Name (_DSD, Package () { - ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), - Package () { - Package () { "port@4", PRT4 }, - } - }) - - Name (PRT4, Package() { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "reg", 4 }, /* CSI-2 port number */ - }, - ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), - Package () { - Package () { "endpoint@0", EP40 }, - } - }) - - Name (EP40, Package() { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "reg", 0 }, - Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, "port@0", "endpoint@0" } }, - } - }) - } - } - -Here, the port 0 of the "CAM0" device is connected to the port 4 of -the "ISP" device and vice versa. - - -References ----------- - -[1] _DSD (Device Specific Data) Implementation Guide. - <URL:http://www.uefi.org/sites/default/files/resources/_DSD-implementation-guide-toplevel-1_1.htm>, - referenced 2016-10-03. - -[2] Devicetree. <URL:http://www.devicetree.org>, referenced 2016-10-03. - -[3] Documentation/devicetree/bindings/graph.txt - -[4] Device Properties UUID For _DSD. - <URL:http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf>, - referenced 2016-10-04. - -[5] Hierarchical Data Extension UUID For _DSD. - <URL:http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf>, - referenced 2016-10-04. - -[6] Advanced Configuration and Power Interface Specification. - <URL:http://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdf>, - referenced 2016-10-04. - -[7] _DSD Device Properties Usage Rules. - Documentation/acpi/DSD-properties-rules.txt |