Re: In kernel virtual HID devices (was Future handling of complex RGB devices on Linux v3)

Pavel Machek
2024-07-24T17:36:52Z

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Hi!

> > IMO working with the HID LampArray is the way forward. So I would
> > suggest to convert any non-HID RGB "LED display" that we are talking
> > about as a HID LampArray device through `hid_allocate_device()` in the
> > kernel. Basically what you are suggesting Hans. It's just that you don't
> > need a formal transport layer, just a child device that happens to be
> > HID.
> >
> > The next question IMO is: do we want the kernel to handle such
> > machinery? Wouldn't it be simpler to just export the HID device and let
> > userspace talk to it through hidraw, like what OpenRGB does?
>
> That's already part of my plan: The kernels main goal is to give devices a
> LampArray interface that don't have one already (e.g. because they are no
> HID devices to begin with).
>
> The actual handling of LampArray will happen in userspace.
>
> Exception is that maybe it could be useful to implement a small subset of
> LampArray in a generic leds-subsystem driver for backwards compatibility to
> userspace applications that only implement that (e.g. UPower). It would
> treat the whole keyboard as a single led.

Are you sure LampArray is good-enough interface? OpenRGB exposes
keycode-to-LED interface, how will that work with LampArray?

Best regards,
Pavel
--
People of Russia, stop Putin before his war on Ukraine escalates.

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