Re: Fn + [KEYS] question

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Wed, Sep 16, 2009 at 03:24:13PM +0800, Xiangfu Liu wrote:
> Hi
> 
> I know in the IBM laptop, you use Fn + F1 to do something.
> I want [Fn + U = 7] in my device. 
> when you press Fn + U in the terminal it will display '7'.
> 
> 
> I look into the keyboard.c file.
> but don't know which function is handle the Fn key?
> 
> there is [1] in the keyboard.h file. I don't know 
> which Fn key belong. is it KT_SHIFT???
> 

Fn in laptops usually handled by firmware (OS does not see the scancode
for Fn at all). In your driver you will probably have to handle it
manually and adjust which keycode you emit (KEY_Y or KEY_7) depending on
whether Fn is active or not. I'd recommend not hardcoding KEY_* but
actually "shift" to different part of driver keymap so userspace could
change the keycodes if it wishes to do so.

-- 
Dmitry