Re: AUXdisplay for LED arrays, keyboards with per-key LEDs -- was Re: [PATCH v2 2/2] leds: add aw20xx driver

From: Jani Nikula
Date: Wed Mar 01 2023 - 04:39:08 EST


On Tue, 28 Feb 2023, Pavel Machek <pavel@xxxxxx> wrote:
> Hi!
>
>> > +config LEDS_AW200XX
>> > + tristate "LED support for Awinic AW20036/AW20054/AW20072"
>> > + depends on LEDS_CLASS
>> > + depends on I2C
>> > + help
>> > + This option enables support for the AW20036/AW20054/AW20072 LED driver.
>> > + It is a 3x12/6x9/6x12 matrix LED driver programmed via
>> > + an I2C interface, up to 36/54/72 LEDs or 12/18/24 RGBs,
>> > + 3 pattern controllers for auto breathing or group dimming control.
>>
>> I'm afraid this should be handled as a display, not as an array of
>> individual LEDs.
>
> You probably want to see
>
> AUXILIARY DISPLAY DRIVERS
> M: Miguel Ojeda <ojeda@xxxxxxxxxx>
> S: Maintained
> F: Documentation/devicetree/bindings/auxdisplay/
> F: drivers/auxdisplay/
> F: include/linux/cfag12864b.h
>
> And this brings another question...
>
> ...sooner or later we'll see LED displays with around 100 pixels in
> almost rectangular grid. Minority of the pixels will have funny
> shapes. How will we handle those? Pretend it is regular display with
> some pixels missing? How do we handle cellphone displays with rounded
> corners and holes for front camera?
>
> And yes, such crazy displays are being manufactured -- it is called
> keyboard with per-key backlight...
>
> https://www.reddit.com/r/MechanicalKeyboards/comments/8dtvgo/keyboard_with_individually_programmable_leds/

But... is that a display or a HID?

Only half-joking, really. This somewhat reminds me of using input system
force feedback stuff for touch screen vibrations.

Cc: Dmitry & linux-input.


BR,
Jani.

--
Jani Nikula, Intel Open Source Graphics Center