[U-Boot] unified keyboard queuing?

[Michal Suchanek]

Hello,

I was looking at adding another keyboard driver.

So far there is USB keyboard and AT keyboard both with its own queuing
code and different incomplete translation table.

For one, USB keyboard has some fake arrow key hack which is *not*
included in the AT keyboard code afaict.

I managed to read a button state on my tablet and send KEY_ENTER which
produces some weird character because I was supposed to send '\r' to
stdin instead.

With 3 ~ 7 buttons it is obviously desirable that users can configure
what the buttons  send. Both because the number of buttons is limited
and because the logical button to physical button mapping may be
different on some devices. So far I only saw Vol+ and Vol- swapped,
though.

I see a few options here

1) hard code the 3 keys commonly used on tablets to do something
useful so that people can use Vol+/Vol-/power to browse a menu and
select an item. Tablets that have Vol+ and Vol- swapped will just be
slightly annoying

2) make this configurable with some sort of options in Kconfig (7
options total for all supported keys). This should result in compiled
code the size of (1)

3) make some central keyboard translation so that USB keyboard, AT
keyboard and any other keyboard can send same keycodes which are
translated to characters sent to stdin the same way. Use keycodes in
Kconfig options or possibly read a dtb which specifies the key layout
for Linux. Will result in much larger code for small 7-key keyboard
but will possibly make keyboards more predictable overall.

Thanks

Michal