Re: [PATCH 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays

From: Geert Uytterhoeven
Date: Tue Feb 01 2022 - 09:20:33 EST


Hi Javier,

On Tue, Feb 1, 2022 at 2:09 PM Javier Martinez Canillas
<javierm@xxxxxxxxxx> wrote:
> On 2/1/22 12:38, Geert Uytterhoeven wrote:
> >> Since the current binding has a compatible "ssd1305fb-i2c", we could make the
> >> new one "ssd1305drm-i2c" or better, just "ssd1305-i2c".
> >
> > DT describes hardware, not software policy.
> > If the hardware is the same, the DT bindings should stay the same.
> >
>
> Yes I know that but the thing is that the current binding don't describe
> the hardware correctly. For instance, don't use a backlight DT node as a
> property of the panel and have this "fb" suffix in the compatible strings.
>
> Having said that, my opinion is that we should just keep with the existing
> bindings and make compatible to that even if isn't completely correct.
>
> Since that will ease adoption of the new DRM driver and allow users to use
> it without the need to update their DTBs.

To me it looks like the pwms property is not related to the backlight
at all, and only needed for some variants?

And the actual backlight code seems to be about internal contrast
adjustment?

So if the pwms usage is OK, what other reasons are there to break
DT compatibility? IMHO just the "fb" suffix is not a good reason.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds