Commit a4138e7c authored by Sakari Ailus's avatar Sakari Ailus Committed by Rafael J. Wysocki
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ACPI: property: graph: Update graph documentation to use generic references 



Instead of port and endpoint properties for representing ports and
endpoints, use the keys of the hierarchical data extension references
when referring to the port and endpoint nodes. Additionally, use "reg"
properties as in Device Tree to specify the number of the port or the
endpoint.

The keys of the port nodes begin with "port" and the keys of the endpoint
nodes begin with "endpoint", both followed by "@" character and the number
of the port or the endpoint.

These changes have the advantage that no ACPI specific properties need to
be added to refer to non-device nodes. Additionally, using the name of the
node instead of an integer property inside the node is easier to parse in
code and easier for humans to understand.

Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent e49363e9

Documentation/acpi/dsd/data-node-references.txt

+1 −0
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ Example 
	    })

	}



Please also see a graph example in graph.txt .



References

----------

Documentation/acpi/dsd/graph.txt

+35 −30
Original line number Diff line number Diff line
@@ -38,34 +38,39 @@ 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 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:

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() { "port4", PRT4 }

    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 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:

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() { "endpoint0", EP40 }

    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 "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.

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.
@@ -83,24 +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" } },

		}

	    })

	}
@@ -113,26 +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" } },

		}

	    })

	}

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