1What: /sys/devices/platform/i8042/.../sensitivity 2Date: Aug, 2005 3KernelVersion: 2.6.14 4Contact: linux-input@vger.kernel.org 5Description: 6 (RW) Trackpoint sensitivity. 7 8What: /sys/devices/platform/i8042/.../intertia 9Date: Aug, 2005 10KernelVersion: 2.6.14 11Contact: linux-input@vger.kernel.org 12Description: 13 (RW) Negative inertia factor. High values cause the cursor to 14 snap backward when the trackpoint is released. 15 16What: /sys/devices/platform/i8042/.../reach 17Date: Aug, 2005 18KernelVersion: 2.6.14 19Contact: linux-input@vger.kernel.org 20Description: 21 (RW) Backup range for z-axis press. 22 23What: /sys/devices/platform/i8042/.../draghys 24Date: Aug, 2005 25KernelVersion: 2.6.14 26Contact: linux-input@vger.kernel.org 27Description: 28 (RW) The drag hysteresis controls how hard it is to drag with 29 z-axis pressed. 30 31What: /sys/devices/platform/i8042/.../mindrag 32Date: Aug, 2005 33KernelVersion: 2.6.14 34Contact: linux-input@vger.kernel.org 35Description: 36 (RW) Minimum amount of force needed to trigger dragging. 37 38What: /sys/devices/platform/i8042/.../speed 39Date: Aug, 2005 40KernelVersion: 2.6.14 41Contact: linux-input@vger.kernel.org 42Description: 43 (RW) Speed of the trackpoint cursor. 44 45What: /sys/devices/platform/i8042/.../thresh 46Date: Aug, 2005 47KernelVersion: 2.6.14 48Contact: linux-input@vger.kernel.org 49Description: 50 (RW) Minimum value for z-axis force required to trigger a press 51 or release, relative to the running average. 52 53What: /sys/devices/platform/i8042/.../upthresh 54Date: Aug, 2005 55KernelVersion: 2.6.14 56Contact: linux-input@vger.kernel.org 57Description: 58 (RW) The offset from the running average required to generate a 59 select (click) on z-axis on release. 60 61What: /sys/devices/platform/i8042/.../ztime 62Date: Aug, 2005 63KernelVersion: 2.6.14 64Contact: linux-input@vger.kernel.org 65Description: 66 (RW) This attribute determines how sharp a press has to be in 67 order to be recognized. 68 69What: /sys/devices/platform/i8042/.../jenks 70Date: Aug, 2005 71KernelVersion: 2.6.14 72Contact: linux-input@vger.kernel.org 73Description: 74 (RW) Minimum curvature in degrees required to generate a double 75 click without a release. 76 77What: /sys/devices/platform/i8042/.../skipback 78Date: Aug, 2005 79KernelVersion: 2.6.14 80Contact: linux-input@vger.kernel.org 81Description: 82 (RW) When the skipback bit is set, backup cursor movement during 83 releases from drags will be suppressed. The default value for 84 this bit is 0. 85 86What: /sys/devices/platform/i8042/.../ext_dev 87Date: Aug, 2005 88KernelVersion: 2.6.14 89Contact: linux-input@vger.kernel.org 90Description: 91 (RW) Disable (0) or enable (1) external pointing device. 92 93What: /sys/devices/platform/i8042/.../press_to_select 94Date: Aug, 2005 95KernelVersion: 2.6.14 96Contact: linux-input@vger.kernel.org 97Description: 98 (RW) Writing a value of 1 to this file will enable the Press to 99 Select functions like tapping the control stick to simulate a 100 left click, and writing 0 will disable it. 101 102What: /sys/devices/platform/i8042/.../drift_time 103Date: Dec, 2014 104KernelVersion: 3.19 105Contact: linux-input@vger.kernel.org 106Description: 107 (RW) This parameter controls the period of time to test for a 108 ���hands off��� condition (i.e. when no force is applied) before a 109 drift (noise) calibration occurs. 110 111 IBM Trackpoints have a feature to compensate for drift by 112 recalibrating themselves periodically. By default, if for 0.5 113 seconds there is no change in position, it's used as the new 114 zero. This duration is too low. Often, the calibration happens 115 when the trackpoint is in fact being used. 116