Messages in this thread | | | Date | Sat, 25 Aug 2007 13:36:00 +0200 | From | Yan Burman <> | Subject | Re: [PATCH 2.6.23-rc2] hwmon: HP Mobile Data Protection System 3D ACPI driver (resend) |
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Pavel Machek wrote: > On Sat 2007-08-11 14:26:02, Yan Burman wrote: > >> HP Mobile Data Protection System 3D ACPI driver. Similar to hdaps in functionality. >> This driver provides 4 kinds of functionality: >> 1) Creates a misc device /dev/accel that acts similar to /dev/rtc and unblocks >> the process reading from it when the device detects free-fall interrupt >> 2) Functions as an input class device to provide similar functionality to >> hdaps, in order to be able to use the laptop as a joystick >> 3) Provides an interface similar to hdaps, so that hdapsd could work with it >> 4) Makes it possible to power the device off. >> > > I assume this means 'power the sensor down'? What is interface for > that? > > Aha, /sys. Could we simply power off the device when its input device > is not opened? > > No, we can't since the sys interface provides the position info and some applications (hdaps apps for example) use this interface. It will be very CPU intensive if I power off the device and power it back on every time /sys/ is read - this stuff goes through ACPI for each read/write. >> +Description >> +----------- >> + >> +This driver provides support for the HP Mobile Data Protection >> +System 3D (mdps), which is an accelerometer. HP nc6420, nw9440 and nx9420 >> +are supported right now, but it may work on other models as well. The >> +accelerometer data is readable via /sys/devices/platform/mdps. >> + >> +Sysfs attributes under /sys/devices/platform/mdps/: >> +position - 2D position that the accelerometer reports. Format: "(x,y)" >> +position3d - 3D position that the accelerometer reports. Format: "(x,y,z)" >> +calibrate - read: values (x, y) that are used as the base for input class device operation. >> + write: forces the base to be recalibrated. >> +rate - reports the sampling rate of the accelerometer device in HZ >> +state - read: the current power state of the accelerometer device >> + write: "0" or "1" to power on/off the device >> +joystick - read: whether the input class device is active or not >> + write: "0" or "1" to enable/disable the input device >> + >> +Load time parameters: >> +bool joystick - whether to enable the input class device or not (default 1) >> +bool power_off - whether to power off the device on module load (default 0) >> +bool hdaps_compat - Make the driver export same interfaces as hdaps, >> + so that apps like hdaps-gl will work the same as with hdaps (default 0) >> + The effect of this is: >> + 1) Instead of /sys/devices/platform/mdps/, /sys/devices/platform/hdaps/ is created >> + 2) Sensitivity is adjusted to match that of hdaps >> +bool input_3d - Whether to operate as a 3D input device. (default 0) >> + BIG FAT WARNING: Do not enable this mode unless you are sure >> + that you want it, since it eats more CPU >> + >> +This driver also provides an absolute input class device, allowing >> +the laptop to act as a pinball machine-esque joystick. >> + >> > > Pavel >
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