| Pavel Machek | 455fbdd | 2008-11-12 13:27:02 -0800 | [diff] [blame] | 1 | Kernel driver lis3lv02d |
| 2 | ================== |
| 3 | |
| 4 | Supported chips: |
| 5 | |
| 6 | * STMicroelectronics LIS3LV02DL and LIS3LV02DQ |
| 7 | |
| 8 | Author: |
| 9 | Yan Burman <burman.yan@gmail.com> |
| 10 | Eric Piel <eric.piel@tremplin-utc.net> |
| 11 | |
| 12 | |
| 13 | Description |
| 14 | ----------- |
| 15 | |
| 16 | This driver provides support for the accelerometer found in various HP laptops |
| 17 | sporting 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 |
| 20 | have their axis automatically oriented on standard way (eg: you can directly |
| 21 | play neverball). The accelerometer data is readable via |
| 22 | /sys/devices/platform/lis3lv02d. |
| 23 | |
| 24 | Sysfs attributes under /sys/devices/platform/lis3lv02d/: |
| 25 | position - 3D position that the accelerometer reports. Format: "(x,y,z)" |
| 26 | calibrate - 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. |
| 28 | rate - reports the sampling rate of the accelerometer device in HZ |
| 29 | |
| 30 | This driver also provides an absolute input class device, allowing |
| 31 | the laptop to act as a pinball machine-esque joystick. |
| 32 | |
| 33 | Axes orientation |
| 34 | ---------------- |
| 35 | |
| 36 | For better compatibility between the various laptops. The values reported by |
| 37 | the 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 |
| 40 | and 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 | |
| 45 | If your laptop model is not recognized (cf "dmesg"), you can send an email to the |
| 46 | authors to add it to the database. When reporting a new laptop, please include |
| 47 | the output of "dmidecode" plus the value of /sys/devices/platform/lis3lv02d/position |
| 48 | in these four cases. |
| 49 | |