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author | Sakari Ailus <sakari.ailus@linux.intel.com> | 2019-08-14 15:58:58 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-08-20 23:53:46 +0200 |
commit | 2b2d4247e445b97113c5e61df8fbc0d756482ef8 (patch) | |
tree | e0950a41d699fb2fcf95b0526d2dc889851be816 /Documentation/acpi | |
parent | d1abaeb3be7b5fa6d7a1fbbd2e14e3310005c4c1 (diff) | |
download | linux-2b2d4247e445b97113c5e61df8fbc0d756482ef8.tar.gz linux-2b2d4247e445b97113c5e61df8fbc0d756482ef8.tar.bz2 linux-2b2d4247e445b97113c5e61df8fbc0d756482ef8.zip |
Documentation: ACPI: DSD: Convert LED documentation to ReST
Convert the LED documentation in text format into ReST.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/acpi')
-rw-r--r-- | Documentation/acpi/dsd/leds.txt | 99 |
1 files changed, 0 insertions, 99 deletions
diff --git a/Documentation/acpi/dsd/leds.txt b/Documentation/acpi/dsd/leds.txt deleted file mode 100644 index cc58b1a574c5..000000000000 --- a/Documentation/acpi/dsd/leds.txt +++ /dev/null @@ -1,99 +0,0 @@ -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/firmware-guide/acpi/dsd/data-node-references.rst |