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-rw-r--r--Documentation/acpi/dsd/graph.txt72
1 files changed, 42 insertions, 30 deletions
diff --git a/Documentation/acpi/dsd/graph.txt b/Documentation/acpi/dsd/graph.txt
index ac09e3138b79..b9ce910781dc 100644
--- a/Documentation/acpi/dsd/graph.txt
+++ b/Documentation/acpi/dsd/graph.txt
@@ -36,29 +36,41 @@ 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 property extension related to
-each port node must contain the key "port" and an integer value which
-is the number of the port. The object it refers to should be called "PRTX",
-where "X" is the number of the port.
-
-Further on, endpoints are located under the individual port nodes. The
-first hierarchical data extension package list entry of the endpoint
-nodes must begin with "endpoint" and must be followed by 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.
-
-Each port node contains a property extension key "port", the value of
-which is the number of the port node. The each endpoint is similarly numbered
-with a property extension key "endpoint". Port numbers must be unique within a
-device and endpoint numbers must be unique within a port.
+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, number of the port in the device and finally the
-number of the endpoint in that port. Individual references thus appear as:
+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_number, endpoint_number }
+ 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.
@@ -76,24 +88,24 @@ A simple example of this is show below:
},
ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
Package () {
- Package () { "port0", "PRT0" },
+ Package () { "port@0", PRT0 },
}
})
Name (PRT0, Package() {
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package () {
- Package () { "port", 0 },
+ Package () { "reg", 0 },
},
ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
Package () {
- Package () { "endpoint0", "EP00" },
+ Package () { "endpoint@0", EP00 },
}
})
Name (EP00, Package() {
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package () {
- Package () { "endpoint", 0 },
- Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, 4, 0 } },
+ Package () { "reg", 0 },
+ Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, "port@4", "endpoint@0" } },
}
})
}
@@ -106,26 +118,26 @@ A simple example of this is show below:
Name (_DSD, Package () {
ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
Package () {
- Package () { "port4", "PRT4" },
+ Package () { "port@4", PRT4 },
}
})
Name (PRT4, Package() {
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package () {
- Package () { "port", 4 }, /* CSI-2 port number */
+ Package () { "reg", 4 }, /* CSI-2 port number */
},
ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
Package () {
- Package () { "endpoint0", "EP40" },
+ Package () { "endpoint@0", EP40 },
}
})
Name (EP40, Package() {
ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
Package () {
- Package () { "endpoint", 0 },
- Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, 0, 0 } },
+ Package () { "reg", 0 },
+ Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, "port@0", "endpoint@0" } },
}
})
}
@@ -151,7 +163,7 @@ References
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.pdf>,
+ <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.