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Re: XFree4.0x and Pismo touchpad

> Maybe that's a good opportunity to suggest to add the fnkeys tool, as well.
> Unfortunately, that app doesn't exist yet :o(.
> A while ago, I was asking for a way to switch the setting of the F[1-12] 
> keys combined with the Fn-key on the powerbook in Linux 
> (default F-keys <-> default backlight control etc.)
> BenH brought up some information on the register settings involved, and
> I tried to modify trackpad.c following his suggestions, but I'm afraid I 
> don't really understand which registers trackpad is reading/writing.

Trackpad locates the trackpad device first by reading register 1 from each
device present, and looks for some specific signature (0x74 0x70 0x61 0x64).
The device mode is then set by writing the proper magic bytes to register
2 of the device found (my extension lets you also read back the current
device state, by reading register 2).
> > If you write 0xc6 0x01 to register 1 of the keyboard, the Fx keys will be
> > real function keys by default and Fn will trigger the control buttons.
> > Write 0xc6 00 to revert the behaviour to default.

Sounds easy enough. You just need to figure out what the usual response to
a read register 1 command is for a keyboard. It seems the kernel
recognizes keyboards by means of the handler ID (byte 2 in register 3)
rather than by using the register 1 contents. 

See technote HW01 'space aliens ate my mouse' for details.


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