diff options
Diffstat (limited to 'Documentation/firmware-guide/acpi/dsd/graph.rst')
| -rw-r--r-- | Documentation/firmware-guide/acpi/dsd/graph.rst | 51 |
1 files changed, 22 insertions, 29 deletions
diff --git a/Documentation/firmware-guide/acpi/dsd/graph.rst b/Documentation/firmware-guide/acpi/dsd/graph.rst index 7072db801aeb..d6ae5ffa748c 100644 --- a/Documentation/firmware-guide/acpi/dsd/graph.rst +++ b/Documentation/firmware-guide/acpi/dsd/graph.rst @@ -7,11 +7,11 @@ Graphs _DSD ==== -_DSD (Device Specific Data) [7] is a predefined ACPI device +_DSD (Device Specific Data) [dsd-guide] 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 +specification [acpi]. There are two _DSD extensions that are relevant +for graphs: property [dsd-guide] and hierarchical data extensions. 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 @@ -36,8 +36,9 @@ 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. +[devicetree, graph-bindings]. A port represents an interface in a device, and +an endpoint represents a connection to that interface. Also see [data-node-ref] +for generic data node references. 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 @@ -65,12 +66,9 @@ 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 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:: +name followed by a string reference in the same package. [data-node-ref]:: - Package() { device, "port@X", "endpoint@Y" } + "device.datanode" In the above example, "X" is the number of the port and "Y" is the number of the endpoint. @@ -108,7 +106,7 @@ A simple example of this is show below:: ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), Package () { Package () { "reg", 0 }, - Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, "port@4", "endpoint@0" } }, + Package () { "remote-endpoint", "\\_SB.PCI0.ISP.EP40" }, } }) } @@ -140,7 +138,7 @@ A simple example of this is show below:: ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), Package () { Package () { "reg", 0 }, - Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, "port@0", "endpoint@0" } }, + Package () { "remote-endpoint", "\\_SB.PCI0.I2C2.CAM0.EP00" }, } }) } @@ -153,25 +151,20 @@ the "ISP" device and vice versa. References ========== -[1] _DSD (Device Specific Data) Implementation Guide. - https://www.uefi.org/sites/default/files/resources/_DSD-implementation-guide-toplevel-1_1.htm, - referenced 2016-10-03. +[acpi] Advanced Configuration and Power Interface Specification. + https://uefi.org/specifications/ACPI/6.4/, referenced 2021-11-30. -[2] Devicetree. https://www.devicetree.org, referenced 2016-10-03. +[data-node-ref] Documentation/firmware-guide/acpi/dsd/data-node-references.rst -[3] Documentation/devicetree/bindings/graph.txt +[devicetree] Devicetree. https://www.devicetree.org, referenced 2016-10-03. -[4] Device Properties UUID For _DSD. - https://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf, - referenced 2016-10-04. +[dsd-guide] DSD Guide. + https://github.com/UEFI/DSD-Guide/blob/main/dsd-guide.adoc, referenced + 2021-11-30. -[5] Hierarchical Data Extension UUID For _DSD. - https://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf, - referenced 2016-10-04. +[dsd-rules] _DSD Device Properties Usage Rules. + Documentation/firmware-guide/acpi/DSD-properties-rules.rst -[6] Advanced Configuration and Power Interface Specification. - https://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdf, - referenced 2016-10-04. - -[7] _DSD Device Properties Usage Rules. - :doc:`../DSD-properties-rules` +[graph-bindings] Common bindings for device graphs (Devicetree). + https://github.com/devicetree-org/dt-schema/blob/main/schemas/graph.yaml, + referenced 2021-11-30. |