From ef2cfc790bf5f0ff189b01eabc0f4feb5e8524df Mon Sep 17 00:00:00 2001 From: Pavel Machek Date: Wed, 18 Feb 2009 14:48:23 -0800 Subject: hp accelerometer: add freefall detection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This adds freefall handling to hp_accel driver. According to HP, it should just work, without us having to set the chip up by hand. hpfall.c is example .c program that parks the disk when accelerometer detects free fall. It should work; for now, it uses fixed 20seconds protection period. Signed-off-by: Pavel Machek Cc: Thomas Renninger Cc: Éric Piel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/hwmon/lis3lv02d | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation/hwmon/lis3lv02d') diff --git a/Documentation/hwmon/lis3lv02d b/Documentation/hwmon/lis3lv02d index 0fcfc4a..287f8c9 100644 --- a/Documentation/hwmon/lis3lv02d +++ b/Documentation/hwmon/lis3lv02d @@ -33,6 +33,14 @@ rate - reports the sampling rate of the accelerometer device in HZ This driver also provides an absolute input class device, allowing the laptop to act as a pinball machine-esque joystick. +Another feature of the driver is misc device called "freefall" that +acts similar to /dev/rtc and reacts on free-fall interrupts received +from the device. It supports blocking operations, poll/select and +fasync operation modes. You must read 1 bytes from the device. The +result is number of free-fall interrupts since the last successful +read (or 255 if number of interrupts would not fit). + + Axes orientation ---------------- -- cgit v1.1