Re: [PATCH] dt-bindings: display: renesas,du: Make resets optional on R-Car H1

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>, David Airlie <airlied@linux.ie>,
	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
	DRI Development <dri-devel@lists.freedesktop.org>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH] dt-bindings: display: renesas,du: Make resets optional on R-Car H1
Date: Thu, 17 Jun 2021 09:22:40 +0200	[thread overview]
Message-ID: <CAMuHMdWe-84ga-f4GC7h+jZnAPu5ayvV=xnB7mNgQs3XqRVW=w@mail.gmail.com> (raw)
In-Reply-To: <YMqsAkFfAU02t4oD@pendragon.ideasonboard.com>

Hi Laurent,

On Thu, Jun 17, 2021 at 3:57 AM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> On Thu, Apr 29, 2021 at 06:47:06PM +0300, Laurent Pinchart wrote:
> > On Thu, Apr 29, 2021 at 02:47:31PM +0200, Geert Uytterhoeven wrote:
> > > The "resets" property is not present on R-Car Gen1 SoCs.
> > > Supporting it would require migrating from renesas,cpg-clocks to
> > > renesas,cpg-mssr.
> > >
> > > Reflect this in the DT bindings by removing the global "required:
> > > resets".  All SoCs that do have "resets" properties already have
> > > SoC-specific rules making it required.
> >
> > Should we drop the
> >
> >         resets:
> >         maxItems: 1
> >
> > from renesas,du-r8a7779 then ? And maybe the
> >
> >   resets: true
> >
> > in the general case ?
>
> Any opinion on this ?

Oops, I did reply to this on April 29, but accidentally dropped
all CCs, which made it disappear from your radar, too?

| R-Car H1 does have a reset controller, we just don't have support for
| it in the DT bindings and Linux driver yet.  So from that point of view
| it makes sense to keep it.
|
| Of course we can remove it, and re-add it later if we ever add support,
| as at that time we probably will want to change the bindings anyway
| to make it required again.

And you replied on April 30, also in private:

|> R-Car H1 does have a reset controller, we just don't have support for
| > it in the DT bindings and Linux driver yet.  So from that point of view
| > it makes sense to keep it.
|
| Not sure what we would "keep", given that there's no reset controller
| available :-)
|
| > Of course we can remove it, and re-add it later if we ever add support,
| > as at that time we probably will want to change the bindings anyway
| > to make it required again.
|
| Let's not bother. I doubt H1 will get support for a reset controller as
| that's an old platform, and the DT bindings thus don't matter too much.
| I'll take this patch as-is.
|
| Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> > > Fixes: 99d66127fad25ebb ("dt-bindings: display: renesas,du: Convert binding to YAML")
> > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > > ---
> > >  Documentation/devicetree/bindings/display/renesas,du.yaml | 1 -
> > >  1 file changed, 1 deletion(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/display/renesas,du.yaml b/Documentation/devicetree/bindings/display/renesas,du.yaml
> > > index 552a99ce4f1280d7..e955034da53b86e2 100644
> > > --- a/Documentation/devicetree/bindings/display/renesas,du.yaml
> > > +++ b/Documentation/devicetree/bindings/display/renesas,du.yaml
> > > @@ -89,7 +89,6 @@ required:
> > >    - reg
> > >    - clocks
> > >    - interrupts
> > > -  - resets
> > >    - ports
> > >
> > >  allOf:

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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