From aebb47d4e7a9c5a4f456aa0b2e1f7d612d1c78ba Mon Sep 17 00:00:00 2001 From: Aishwarya Pant Date: Fri, 2 Mar 2018 23:00:19 +0530 Subject: [PATCH] Input: trackpoint: document sysfs interface Descriptions have been collected from git commit logs, code commits and the TrackPoint System Version 4.0 Engineering Specification. Signed-off-by: Aishwarya Pant Signed-off-by: Jonathan Corbet --- .../testing/sysfs-devices-platform-trackpoint | 115 ++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-devices-platform-trackpoint diff --git a/Documentation/ABI/testing/sysfs-devices-platform-trackpoint b/Documentation/ABI/testing/sysfs-devices-platform-trackpoint new file mode 100644 index 000000000000..df11901a6b3d --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-platform-trackpoint @@ -0,0 +1,115 @@ +What: /sys/devices/platform/i8042/.../sensitivity +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Trackpoint sensitivity. + +What: /sys/devices/platform/i8042/.../intertia +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Negative inertia factor. High values cause the cursor to + snap backward when the trackpoint is released. + +What: /sys/devices/platform/i8042/.../reach +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Backup range for z-axis press. + +What: /sys/devices/platform/i8042/.../draghys +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) The drag hysteresis controls how hard it is to drag with + z-axis pressed. + +What: /sys/devices/platform/i8042/.../mindrag +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Minimum amount of force needed to trigger dragging. + +What: /sys/devices/platform/i8042/.../speed +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Speed of the trackpoint cursor. + +What: /sys/devices/platform/i8042/.../thresh +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Minimum value for z-axis force required to trigger a press + or release, relative to the running average. + +What: /sys/devices/platform/i8042/.../upthresh +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) The offset from the running average required to generate a + select (click) on z-axis on release. + +What: /sys/devices/platform/i8042/.../ztime +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) This attribute determines how sharp a press has to be in + order to be recognized. + +What: /sys/devices/platform/i8042/.../jenks +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Minimum curvature in degrees required to generate a double + click without a release. + +What: /sys/devices/platform/i8042/.../skipback +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) When the skipback bit is set, backup cursor movement during + releases from drags will be suppressed. The default value for + this bit is 0. + +What: /sys/devices/platform/i8042/.../ext_dev +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Disable (0) or enable (1) external pointing device. + +What: /sys/devices/platform/i8042/.../press_to_select +Date: Aug, 2005 +KernelVersion: 2.6.14 +Contact: linux-input@vger.kernel.org +Description: + (RW) Writing a value of 1 to this file will enable the Press to + Select functions like tapping the control stick to simulate a + left click, and writing 0 will disable it. + +What: /sys/devices/platform/i8042/.../drift_time +Date: Dec, 2014 +KernelVersion: 3.19 +Contact: linux-input@vger.kernel.org +Description: + (RW) This parameter controls the period of time to test for a + ‘hands off’ condition (i.e. when no force is applied) before a + drift (noise) calibration occurs. + + IBM Trackpoints have a feature to compensate for drift by + recalibrating themselves periodically. By default, if for 0.5 + seconds there is no change in position, it's used as the new + zero. This duration is too low. Often, the calibration happens + when the trackpoint is in fact being used.