diff options
author | Jean Delvare <khali@linux-fr.org> | 2011-03-21 12:59:36 -0400 |
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committer | Jean Delvare <khali@endymion.delvare> | 2011-03-21 12:59:36 -0400 |
commit | ff606677f6a47c63329cf8e6c7cf978c29f2d736 (patch) | |
tree | 565bcdaa1f5058af0a6fd2260b3c45029c955d08 /Documentation/hwmon | |
parent | efcfed9bad88be8193ee6a1b8e72d7381e7b0e0e (diff) |
Move lis3lv02d drivers to drivers/misc
The lis3lv02d drivers aren't hardware monitoring drivers, so the don't
belong to drivers/hwmon. Move them to drivers/misc, short of a better
home.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Tested-by: Eric Piel <eric.piel@tremplin-utc.net>
Tested-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation/hwmon')
-rw-r--r-- | Documentation/hwmon/lis3lv02d | 92 |
1 files changed, 0 insertions, 92 deletions
diff --git a/Documentation/hwmon/lis3lv02d b/Documentation/hwmon/lis3lv02d deleted file mode 100644 index f1a4ec840f8..00000000000 --- a/Documentation/hwmon/lis3lv02d +++ /dev/null | |||
@@ -1,92 +0,0 @@ | |||
1 | Kernel driver lis3lv02d | ||
2 | ======================= | ||
3 | |||
4 | Supported chips: | ||
5 | |||
6 | * STMicroelectronics LIS3LV02DL, LIS3LV02DQ (12 bits precision) | ||
7 | * STMicroelectronics LIS302DL, LIS3L02DQ, LIS331DL (8 bits) | ||
8 | |||
9 | Authors: | ||
10 | Yan Burman <burman.yan@gmail.com> | ||
11 | Eric Piel <eric.piel@tremplin-utc.net> | ||
12 | |||
13 | |||
14 | Description | ||
15 | ----------- | ||
16 | |||
17 | This driver provides support for the accelerometer found in various HP laptops | ||
18 | sporting the feature officially called "HP Mobile Data Protection System 3D" or | ||
19 | "HP 3D DriveGuard". It detects automatically laptops with this sensor. Known | ||
20 | models (full list can be found in drivers/platform/x86/hp_accel.c) will have | ||
21 | their axis automatically oriented on standard way (eg: you can directly play | ||
22 | neverball). The accelerometer data is readable via | ||
23 | /sys/devices/platform/lis3lv02d. Reported values are scaled | ||
24 | to mg values (1/1000th of earth gravity). | ||
25 | |||
26 | Sysfs attributes under /sys/devices/platform/lis3lv02d/: | ||
27 | position - 3D position that the accelerometer reports. Format: "(x,y,z)" | ||
28 | rate - read reports the sampling rate of the accelerometer device in HZ. | ||
29 | write changes sampling rate of the accelerometer device. | ||
30 | Only values which are supported by HW are accepted. | ||
31 | selftest - performs selftest for the chip as specified by chip manufacturer. | ||
32 | |||
33 | This driver also provides an absolute input class device, allowing | ||
34 | the laptop to act as a pinball machine-esque joystick. Joystick device can be | ||
35 | calibrated. Joystick device can be in two different modes. | ||
36 | By default output values are scaled between -32768 .. 32767. In joystick raw | ||
37 | mode, joystick and sysfs position entry have the same scale. There can be | ||
38 | small difference due to input system fuzziness feature. | ||
39 | Events are also available as input event device. | ||
40 | |||
41 | Selftest is meant only for hardware diagnostic purposes. It is not meant to be | ||
42 | used during normal operations. Position data is not corrupted during selftest | ||
43 | but interrupt behaviour is not guaranteed to work reliably. In test mode, the | ||
44 | sensing element is internally moved little bit. Selftest measures difference | ||
45 | between normal mode and test mode. Chip specifications tell the acceptance | ||
46 | limit for each type of the chip. Limits are provided via platform data | ||
47 | to allow adjustment of the limits without a change to the actual driver. | ||
48 | Seltest returns either "OK x y z" or "FAIL x y z" where x, y and z are | ||
49 | measured difference between modes. Axes are not remapped in selftest mode. | ||
50 | Measurement values are provided to help HW diagnostic applications to make | ||
51 | final decision. | ||
52 | |||
53 | On HP laptops, if the led infrastructure is activated, support for a led | ||
54 | indicating disk protection will be provided as /sys/class/leds/hp::hddprotect. | ||
55 | |||
56 | Another feature of the driver is misc device called "freefall" that | ||
57 | acts similar to /dev/rtc and reacts on free-fall interrupts received | ||
58 | from the device. It supports blocking operations, poll/select and | ||
59 | fasync operation modes. You must read 1 bytes from the device. The | ||
60 | result is number of free-fall interrupts since the last successful | ||
61 | read (or 255 if number of interrupts would not fit). See the hpfall.c | ||
62 | file for an example on using the device. | ||
63 | |||
64 | |||
65 | Axes orientation | ||
66 | ---------------- | ||
67 | |||
68 | For better compatibility between the various laptops. The values reported by | ||
69 | the accelerometer are converted into a "standard" organisation of the axes | ||
70 | (aka "can play neverball out of the box"): | ||
71 | * When the laptop is horizontal the position reported is about 0 for X and Y | ||
72 | and a positive value for Z | ||
73 | * If the left side is elevated, X increases (becomes positive) | ||
74 | * If the front side (where the touchpad is) is elevated, Y decreases | ||
75 | (becomes negative) | ||
76 | * If the laptop is put upside-down, Z becomes negative | ||
77 | |||
78 | If your laptop model is not recognized (cf "dmesg"), you can send an | ||
79 | email to the maintainer to add it to the database. When reporting a new | ||
80 | laptop, please include the output of "dmidecode" plus the value of | ||
81 | /sys/devices/platform/lis3lv02d/position in these four cases. | ||
82 | |||
83 | Q&A | ||
84 | --- | ||
85 | |||
86 | Q: How do I safely simulate freefall? I have an HP "portable | ||
87 | workstation" which has about 3.5kg and a plastic case, so letting it | ||
88 | fall to the ground is out of question... | ||
89 | |||
90 | A: The sensor is pretty sensitive, so your hands can do it. Lift it | ||
91 | into free space, follow the fall with your hands for like 10 | ||
92 | centimeters. That should be enough to trigger the detection. | ||