[PATCH v2 2/2] Input: tegra-kbc - add default chromeos map

[Stephen Warren]

Olof Johansson wrote at Wednesday, December 28, 2011 12:33 AM:
> On Tue, Dec 27, 2011 at 10:50 PM, Dmitry Torokhov
> <dmitry.torokhov at gmail.com> wrote:
> > On Tue, Dec 27, 2011 at 10:19:30PM -0800, Olof Johansson wrote:
> >> This adds a simple way to specify the ChromeOS-specific keyboard map
> >> instead of the "standard" map that is used on other Tegra devices such
> >> as Harmony-with-keyboard and Seaboard.
> >>
> >> I expect the number of different keyboard layouts to be quite limited,
> >> and not many should be added over time. So instead of encoding the layout
> >> in the device tree, with all the can of worms that entails w.r.t. agreeing
> >> on a suitable binding, just add a property to specify that this is the
> >> map to be used, and include it in the driver.
> >>
> >> If, over time, the number of mappings increase, the binding can be
> >> updated to include a custom map as a new property, without having to
> >> worry about backwards compatibility on existing devices.
> >>
> >
> > I'd rather we did not make shortcuts and did the proper DT binding.
> > Samsung folks want the similar thing so making a generic DT keymap
> > parser and using it in the driver would be the best way.
> 
> Ok, fair point. I found the last posted version of the samsung driver
> in my archives so I'll continue the discussion there (see separate
> followup there).

I agree here. Simon Glass has posted some patches to U-Boot to add the
Tegra KBC driver including DT bindings. Can you please co-ordinate with
him to ensure the bindings you're proposing for the kernel match those
he's proposing for U-Boot; from memory, I don't think they are so far.
Also, we need to work out the issue of the kernel needing just the base
and function-modified keymap, but U-Boot needing a shift- and ctrl-
modified keymap since there's no input layer handling shift/ctrl in
U-Boot. I'd prefer that the DT binding be encoded as:

matrix -> keycode for base
matrix -> keycode for function-modified

With the binding for those two defined by either the Tegra KBC binding or
a generic matrix KBC binding.

keycode -> keycode for shift-modified
keycode -> keycode for ctrl-modified

With the binding for those two defined by some kind of generic modifier
mapping binding, so it could feed into the input layer on Linux, although
in U-Boot, the Tegra KBC driver would have to handle it itself, since
there's nowhere else to handle it.

-- 
nvpublic