Thinkpad-specific ACPI driver
This is a Linux ACPI driver for the IBM ThinkPad laptops written by Borislav Deianov and Henrique de Moraes Holschuh. The driver replaces ibm-acpi in Linux mainline as of 2.6.22 (March 2007). To confuse matters further, it appears that there was also an older (now abandoned) driver of the same name written by Erik Rigtorp which never made it into the mainline kernel. The current thinkpad-acpi contains essentially the same functionality as ibm-acpi with some added features. Among which are registering of acpi events to the "thinkvantage" and volume/mute buttons which could previously only be accessed through the use of the tpb utility.
To view which hotkeys are active you can use
One important difference from ibm-acpi for those who wish to enable all possible hotkeys is that there are more possible bits to be set in the mask. Thus, to enable all possible hotkeys, do a
echo enable,0xffffffff >/proc/acpi/ibm/hotkey
To make this permanent, add the following line to /etc/modprobe.d/thinkpad_acpi:
options thinkpad_acpi hotkey=enable,0xffffffff experimental=1
More comprehensive documentation can be found in the kernel source tree (>=2.6.22) under Documentation/thinkpad_acpi.txt.
For now, please refer to the ibm-acpi page for any other information on the new thinkpad-acpi driver.
There have been no releases of the driver under the thinkpad-acpi name yet. It is available with the new name in the acpi-test git tree, and ibm-acpi development git tree.