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

On Tue, 28 Feb 2023, Pavel Machek [off-list ref] wrote:

Hi!

quoted

quoted

+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 [off-list ref]
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