diff options
Diffstat (limited to 'Documentation/acpi/dsd')
| -rw-r--r-- | Documentation/acpi/dsd/data-node-references.txt | 89 | ||||
| -rw-r--r-- | Documentation/acpi/dsd/graph.txt | 174 | ||||
| -rw-r--r-- | Documentation/acpi/dsd/leds.txt | 99 |
3 files changed, 99 insertions, 263 deletions
diff --git a/Documentation/acpi/dsd/data-node-references.txt b/Documentation/acpi/dsd/data-node-references.txt deleted file mode 100644 index c3871565c8cf..000000000000 --- a/Documentation/acpi/dsd/data-node-references.txt +++ /dev/null @@ -1,89 +0,0 @@ -Copyright (C) 2018 Intel Corporation -Author: Sakari Ailus <sakari.ailus@linux.intel.com> - - -Referencing hierarchical data nodes ------------------------------------ - -ACPI in general allows referring to device objects in the tree only. -Hierarchical data extension nodes may not be referred to directly, hence this -document defines a scheme to implement such references. - -A reference consist of the device object name followed by one or more -hierarchical data extension [1] keys. Specifically, the hierarchical data -extension node which is referred to by the key shall lie directly under the -parent object i.e. either the device object or another hierarchical data -extension node. - -The keys in the hierarchical data nodes shall consist of the name of the node, -"@" character and the number of the node in hexadecimal notation (without pre- -or postfixes). The same ACPI object shall include the _DSD property extension -with a property "reg" that shall have the same numerical value as the number of -the node. - -In case a hierarchical data extensions node has no numerical value, then the -"reg" property shall be omitted from the ACPI object's _DSD properties and the -"@" character and the number shall be omitted from the hierarchical data -extension key. - - -Example -------- - - In the ASL snippet below, the "reference" _DSD property [2] contains a - device object reference to DEV0 and under that device object, a - hierarchical data extension key "node@1" referring to the NOD1 object - and lastly, a hierarchical data extension key "anothernode" referring to - the ANOD object which is also the final target node of the reference. - - Device (DEV0) - { - Name (_DSD, Package () { - ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), - Package () { - Package () { "node@0", NOD0 }, - Package () { "node@1", NOD1 }, - } - }) - Name (NOD0, Package() { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "random-property", 3 }, - } - }) - Name (NOD1, Package() { - ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), - Package () { - Package () { "anothernode", ANOD }, - } - }) - Name (ANOD, Package() { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "random-property", 0 }, - } - }) - } - - Device (DEV1) - { - Name (_DSD, Package () { - ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), - Package () { - Package () { "reference", ^DEV0, "node@1", "anothernode" }, - } - }) - } - -Please also see a graph example in graph.txt . - -References ----------- - -[1] Hierarchical Data Extension UUID For _DSD. - <URL:http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf>, - referenced 2018-07-17. - -[2] Device Properties UUID For _DSD. - <URL:http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf>, - referenced 2016-10-04. 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 diff --git a/Documentation/acpi/dsd/leds.txt b/Documentation/acpi/dsd/leds.txt new file mode 100644 index 000000000000..81a63af42ed2 --- /dev/null +++ b/Documentation/acpi/dsd/leds.txt @@ -0,0 +1,99 @@ +Describing and referring to LEDs in ACPI + +Individual LEDs are described by hierarchical data extension [6] nodes under the +device node, the LED driver chip. The "reg" property in the LED specific nodes +tells the numerical ID of each individual LED output to which the LEDs are +connected. [3] The hierarchical data nodes are named "led@X", where X is the +number of the LED output. + +Referring to LEDs in Device tree is documented in [4], in "flash-leds" property +documentation. In short, LEDs are directly referred to by using phandles. + +While Device tree allows referring to any node in the tree[1], in ACPI +references are limited to device nodes only [2]. For this reason using the same +mechanism on ACPI is not possible. A mechanism to refer to non-device ACPI nodes +is documented in [7]. + +ACPI allows (as does DT) using integer arguments after the reference. A +combination of the LED driver device reference and an integer argument, +referring to the "reg" property of the relevant LED, is used to identify +individual LEDs. The value of the "reg" property is a contract between the +firmware and software, it uniquely identifies the LED driver outputs. + +Under the LED driver device, The first hierarchical data extension package list +entry shall contain the string "led@" followed by the number of the LED, +followed by the referred object name. That object shall be named "LED" followed +by the number of the LED. + +An ASL example of a camera sensor device and a LED driver device for two LEDs. +Objects not relevant for LEDs or the references to them have been omitted. + + Device (LED) + { + Name (_DSD, Package () { + ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), + Package () { + Package () { "led@0", LED0 }, + Package () { "led@1", LED1 }, + } + }) + Name (LED0, Package () { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () { + Package () { "reg", 0 }, + Package () { "flash-max-microamp", 1000000 }, + Package () { "flash-timeout-us", 200000 }, + Package () { "led-max-microamp", 100000 }, + Package () { "label", "white:flash" }, + } + }) + Name (LED1, Package () { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () { + Package () { "reg", 1 }, + Package () { "led-max-microamp", 10000 }, + Package () { "label", "red:indicator" }, + } + }) + } + + Device (SEN) + { + Name (_DSD, Package () { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () { + Package () { + "flash-leds", + Package () { ^LED, "led@0", ^LED, "led@1" }, + } + } + }) + } + +where + + LED LED driver device + LED0 First LED + LED1 Second LED + SEN Camera sensor device (or another device the LED is + related to) + +[1] Device tree. <URL:http://www.devicetree.org>, referenced 2019-02-21. + +[2] Advanced Configuration and Power Interface Specification. + <URL:https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf>, + referenced 2019-02-21. + +[3] Documentation/devicetree/bindings/leds/common.txt + +[4] Documentation/devicetree/bindings/media/video-interfaces.txt + +[5] Device Properties UUID For _DSD. + <URL:http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf>, + referenced 2019-02-21. + +[6] Hierarchical Data Extension UUID For _DSD. + <URL:http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf>, + referenced 2019-02-21. + +[7] Documentation/acpi/dsd/data-node-reference.txt |