diff options
Diffstat (limited to 'Documentation/laptops')
| -rw-r--r-- | Documentation/laptops/thinkpad-acpi.txt | 47 |
1 files changed, 41 insertions, 6 deletions
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt index af1f2bcb6f66..73b80a7e9b03 100644 --- a/Documentation/laptops/thinkpad-acpi.txt +++ b/Documentation/laptops/thinkpad-acpi.txt @@ -876,28 +876,63 @@ The cmos command interface is prone to firmware split-brain problems, as in newer ThinkPads it is just a compatibility layer. Do not use it, it is exported just as a debug tool. -LED control -- /proc/acpi/ibm/led ---------------------------------- +LED control +----------- -Some of the LED indicators can be controlled through this feature. The -available commands are: +procfs: /proc/acpi/ibm/led +sysfs attributes: as per led class, see below for names + +Some of the LED indicators can be controlled through this feature. On +some older ThinkPad models, it is possible to query the status of the +LED indicators as well. Newer ThinkPads cannot query the real status +of the LED indicators. + +procfs notes: + +The available commands are: echo '<led number> on' >/proc/acpi/ibm/led echo '<led number> off' >/proc/acpi/ibm/led echo '<led number> blink' >/proc/acpi/ibm/led The <led number> range is 0 to 7. The set of LEDs that can be -controlled varies from model to model. Here is the mapping on the X40: +controlled varies from model to model. Here is the common ThinkPad +mapping: 0 - power 1 - battery (orange) 2 - battery (green) - 3 - UltraBase + 3 - UltraBase/dock 4 - UltraBay + 5 - UltraBase battery slot + 6 - (unknown) 7 - standby All of the above can be turned on and off and can be made to blink. +sysfs notes: + +The ThinkPad LED sysfs interface is described in detail by the led class +documentation, in Documentation/leds-class.txt. + +The leds are named (in LED ID order, from 0 to 7): +"tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", +"tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", +"tpacpi::unknown_led", "tpacpi::standby". + +Due to limitations in the sysfs led class, if the status of the LED +indicators cannot be read due to an error, thinkpad-acpi will report it as +a brightness of zero (same as LED off). + +If the thinkpad firmware doesn't support reading the current status, +trying to read the current LED brightness will just return whatever +brightness was last written to that attribute. + +These LEDs can blink using hardware acceleration. To request that a +ThinkPad indicator LED should blink in hardware accelerated mode, use the +"timer" trigger, and leave the delay_on and delay_off parameters set to +zero (to request hardware acceleration autodetection). + ACPI sounds -- /proc/acpi/ibm/beep ---------------------------------- |