Re: [PATCH 3/3] backlight: lp8864: Convert from LED to backlight class driver

[Sverdlin, Alexander]

Hi Daniel,

On Tue, 2026-06-23 at 12:41 +0100, Daniel Thompson wrote:
> > The mechanism we have regarding hot plugging currently is just I2C bridge,
> > which de-registers and registers the bridged bus. So no additional drivers
> > are required, as long as I2C devices are self-contained and not glued with
> > platform devices.
> > 
> > So bottom line is, I'd prefer to just add the backlight interface to the
> > existing driver, no matter where it would live in the future.
> 
> Is there any reasion that LP8864/LP8866 is unique in appearing on a 
> hotplugged I2C bus? In other words if support for dynamism is added
> specifically to leds-lp8864.c rather than in led_bl.c then what will stop
> the same dynamic tricks from being adde to other LED drivers?

LP8864 is not special in this regard, not different from adp8860_bl.c,
adp8870_bl.c or lm3639_bl.c, which would work in my application.

So I just wanted to add currently missing backlight_device_register() to
LP8864, but there were no such dual-API drivers under drivers/leds/ that's
wht I started with moving LP8864 driver into drivers/video/backlight/.

led_bl.c however could only be hot-pluggable either if one actively
creates/destroys platform device somewhere in the code programmatically
or uses DT overlays.

Just adding backlight API to LP8864 would be much more idiomatic, I'd
say.

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com