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Pavel Machek455fbdd2008-11-12 13:27:02 -08001Kernel driver lis3lv02d
2==================
3
4Supported chips:
5
6 * STMicroelectronics LIS3LV02DL and LIS3LV02DQ
7
8Author:
9 Yan Burman <burman.yan@gmail.com>
10 Eric Piel <eric.piel@tremplin-utc.net>
11
12
13Description
14-----------
15
16This driver provides support for the accelerometer found in various HP laptops
17sporting the feature officially called "HP Mobile Data Protection System 3D" or
18"HP 3D DriveGuard". It detect automatically laptops with this sensor. Known models
19(for now the HP 2133, nc6420, nc2510, nc8510, nc84x0, nw9440 and nx9420) will
20have their axis automatically oriented on standard way (eg: you can directly
21play neverball). The accelerometer data is readable via
22/sys/devices/platform/lis3lv02d.
23
24Sysfs attributes under /sys/devices/platform/lis3lv02d/:
25position - 3D position that the accelerometer reports. Format: "(x,y,z)"
26calibrate - read: values (x, y, z) that are used as the base for input class device operation.
27 write: forces the base to be recalibrated with the current position.
28rate - reports the sampling rate of the accelerometer device in HZ
29
30This driver also provides an absolute input class device, allowing
31the laptop to act as a pinball machine-esque joystick.
32
33Axes orientation
34----------------
35
36For better compatibility between the various laptops. The values reported by
37the accelerometer are converted into a "standard" organisation of the axes
38(aka "can play neverball out of the box"):
39 * When the laptop is horizontal the position reported is about 0 for X and Y
40and a positive value for Z
41 * If the left side is elevated, X increases (becomes positive)
42 * If the front side (where the touchpad is) is elevated, Y decreases (becomes negative)
43 * If the laptop is put upside-down, Z becomes negative
44
45If your laptop model is not recognized (cf "dmesg"), you can send an email to the
46authors to add it to the database. When reporting a new laptop, please include
47the output of "dmidecode" plus the value of /sys/devices/platform/lis3lv02d/position
48in these four cases.
49