diff options
Diffstat (limited to 'Documentation/firmware-guide/acpi/dsd/leds.rst')
| -rw-r--r-- | Documentation/firmware-guide/acpi/dsd/leds.rst | 40 |
1 files changed, 18 insertions, 22 deletions
diff --git a/Documentation/firmware-guide/acpi/dsd/leds.rst b/Documentation/firmware-guide/acpi/dsd/leds.rst index b99fff8e06f2..93db592c93c7 100644 --- a/Documentation/firmware-guide/acpi/dsd/leds.rst +++ b/Documentation/firmware-guide/acpi/dsd/leds.rst @@ -5,19 +5,20 @@ Describing and referring to LEDs in ACPI ======================================== -Individual LEDs are described by hierarchical data extension [6] nodes under the +Individual LEDs are described by hierarchical data extension [5] 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 +connected. [leds] 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. +Referring to LEDs in Device tree is documented in [video-interfaces], 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]. +While Device tree allows referring to any node in the tree [devicetree], in +ACPI references are limited to device nodes only [acpi]. For this reason using +the same mechanism on ACPI is not possible. A mechanism to refer to non-device +ACPI nodes is documented in [data-node-ref]. ACPI allows (as does DT) using integer arguments after the reference. A combination of the LED driver device reference and an integer argument, @@ -90,22 +91,17 @@ where References ========== -[1] Device tree. https://www.devicetree.org, referenced 2019-02-21. +[acpi] Advanced Configuration and Power Interface Specification. + https://uefi.org/specifications/ACPI/6.4/, referenced 2021-11-30. -[2] Advanced Configuration and Power Interface Specification. - https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf, - referenced 2019-02-21. +[data-node-ref] Documentation/firmware-guide/acpi/dsd/data-node-references.rst -[3] Documentation/devicetree/bindings/leds/common.txt +[devicetree] Devicetree. https://www.devicetree.org, referenced 2019-02-21. -[4] Documentation/devicetree/bindings/media/video-interfaces.txt +[dsd-guide] DSD Guide. + https://github.com/UEFI/DSD-Guide/blob/main/dsd-guide.adoc, referenced + 2021-11-30. -[5] Device Properties UUID For _DSD. - https://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf, - referenced 2019-02-21. +[leds] Documentation/devicetree/bindings/leds/common.yaml -[6] Hierarchical Data Extension UUID For _DSD. - https://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf, - referenced 2019-02-21. - -[7] Documentation/firmware-guide/acpi/dsd/data-node-references.rst +[video-interfaces] Documentation/devicetree/bindings/media/video-interfaces.yaml |