Re: [PATCH v2 2/5] dt-bindings: panel: add binding for Xingbangda XBD599 panel

From: Linus Walleij
Date: Fri Mar 20 2020 - 05:11:41 EST


On Fri, Mar 20, 2020 at 9:07 AM Icenowy Zheng <icenowy@xxxxxxx> wrote:
> ä 2020å3æ19æ GMT+08:00 äå10:14:27, Linus Walleij <linus.walleij@xxxxxxxxxx> åå:
> >On Mon, Mar 16, 2020 at 2:37 PM Icenowy Zheng <icenowy@xxxxxxx> wrote:

> >As noticed in the review of the driver, this display is very close to
> >himax,hx8363.
> >
> >I think the best is to determin what actual display controller it is,
> >I think it is some kind of Ilitek controller since Ilitek ili9342 is
> >clearly very similar.
>
> It's Sitronix ST7703, same as the Librem 5 panel.

Heh, I wonder how it comes that it is so similar to Ilitek.
I guess I will never understand how the silicon ecosystem works
in asia (I did read a lot of Bunnie Huang's articles and hardware
hacking book to try to understand...)

This file should be named sitronix,st7703.yaml then.

According to the code in the Librem 5:
https://source.puri.sm/Librem5/linux-next/blob/imx8-current-librem5/drivers/gpu/drm/panel/panel-sitronix-st7701.c
The actual name of the display is Techstar ts8550b.
And the display controller is st7701, so maybe we should
actually name it sitronix,st770x.yaml if there are some
sub-variants of st770x?

> >properties:
> > compatible:
> > items:
> > - const: xingbangda,xbd599
> > - const: ilitek,ili9342
> >
> >Possibly use oneOf and add support for the himax,hx8363
> >already while you're at it.

This should at least be:

compatible:
items:
- enum:
- xingbangda,xbd599
- himax,hx8363
- techstar,ts8550b
- enum:
- sitronix,st7701
- sitronix,st7703

So panel nodes using this panel become
compatible = "xingbangda,sbd599", "sitronix,st7703"
etc.

This way it is straight-forward for drivers to identify the panel
vendor and display controller.

Yours,
Linus Walleij