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-rw-r--r--Documentation/hwmon/lis3lv02d31
1 files changed, 24 insertions, 7 deletions
diff --git a/Documentation/hwmon/lis3lv02d b/Documentation/hwmon/lis3lv02d
index 21f090252209..06534f25e643 100644
--- a/Documentation/hwmon/lis3lv02d
+++ b/Documentation/hwmon/lis3lv02d
@@ -20,18 +20,35 @@ sporting the feature officially called "HP Mobile Data Protection System 3D" or
models (full list can be found in drivers/hwmon/hp_accel.c) will have their
axis automatically oriented on standard way (eg: you can directly play
neverball). The accelerometer data is readable via
-/sys/devices/platform/lis3lv02d.
+/sys/devices/platform/lis3lv02d. Reported values are scaled
+to mg values (1/1000th of earth gravity).
Sysfs attributes under /sys/devices/platform/lis3lv02d/:
position - 3D position that the accelerometer reports. Format: "(x,y,z)"
-calibrate - read: values (x, y, z) that are used as the base for input
- class device operation.
- write: forces the base to be recalibrated with the current
- position.
-rate - reports the sampling rate of the accelerometer device in HZ
+rate - read reports the sampling rate of the accelerometer device in HZ.
+ write changes sampling rate of the accelerometer device.
+ Only values which are supported by HW are accepted.
+selftest - performs selftest for the chip as specified by chip manufacturer.
This driver also provides an absolute input class device, allowing
-the laptop to act as a pinball machine-esque joystick.
+the laptop to act as a pinball machine-esque joystick. Joystick device can be
+calibrated. Joystick device can be in two different modes.
+By default output values are scaled between -32768 .. 32767. In joystick raw
+mode, joystick and sysfs position entry have the same scale. There can be
+small difference due to input system fuzziness feature.
+Events are also available as input event device.
+
+Selftest is meant only for hardware diagnostic purposes. It is not meant to be
+used during normal operations. Position data is not corrupted during selftest
+but interrupt behaviour is not guaranteed to work reliably. In test mode, the
+sensing element is internally moved little bit. Selftest measures difference
+between normal mode and test mode. Chip specifications tell the acceptance
+limit for each type of the chip. Limits are provided via platform data
+to allow adjustment of the limits without a change to the actual driver.
+Seltest returns either "OK x y z" or "FAIL x y z" where x, y and z are
+measured difference between modes. Axes are not remapped in selftest mode.
+Measurement values are provided to help HW diagnostic applications to make
+final decision.
On HP laptops, if the led infrastructure is activated, support for a led
indicating disk protection will be provided as /sys/class/leds/hp::hddprotect.