[maemo-developers] N810 & FN key & X

[From: Joni Valtanen]

I only readed xomap code. So I'm not 100% sure about this.

But anyway - How it works with xomap:

1. read fn:s code from evdev (0x1d0)

2. put fn:s code (__u16) to KdEnqueeueKeyboardEvent-functions scan_code
    (unsigned char). This looks dangerous and (propably) drops msbyte
    away. only 0xd0 stays. How about "and" and "typecast"?

3. key_code = scan_code + KD_MIN_KEYCODE - ki->minScanCode

    scan_code=0xd0, KD_MIN_KEYCODE=8, ki->minScanCode is propably 0
    result: 0xd8 = 216 which can be found from
    /usr/share/X11/xkb/keycodes/evdev as <FN>


...and same with sources

----------------------------
linux-kernel-headers/input.h
----------------------------
....
struct input_event {
         struct timeval time;
         __u16 type;
         __u16 code;
         __s32 value;
};
.....

-----------------------
hw/kdrive/linux/evdev.c
-----------------------
....
evdev_device_read(int evdevPort, void *closure)
{
...
struct input_event events[NUM_EVENTS];
...
        case EV_KEY:
             if (info->type == Keyboard)
                 KdEnqueueKeyboardEvent(info->device, events[i].code,
                                        !events[i].value);
...

----------------------
hw/kdrive/src/kinput.c
----------------------
KdEnqueueKeyboardEvent(KdKeyboardInfo   *ki,
                        unsigned char scan_code,
                        unsigned char is_up)
{
     unsigned char key_code;
     KeyClassPtr keyc = NULL;
     KeybdCtrl *ctrl = NULL;
     int type, nEvents, i;
...
   key_code = scan_code + KD_MIN_KEYCODE - ki->minScanCode;
...


----------------------
hw/kdrive/src/kdrive.h
----------------------
...
#define KD_MIN_KEYCODE  8
...


- Joni


On Tue, 11 Mar 2008, Tuomas Kulve wrote:

>
> Hi
>
> The FN key on N810 keyboard seems to send (the standard FN) keycode 464
> which is a bit tricky as X doesn't support keycodes over 255 (afaik).
>
> HAL should be able to remap the keycodes using the EVIOCSKEYCODE with
> the ioctl but I get EINVAL on n810 and n800 when I try to use it. On my
> PC it works without errors.
>
> I wonder how's this done in Maemo's Xomap?
>
> -- 
> Tuomas
>
>
>