Re: [PATCH v3 5/7] dt-bindings: display: Add common rotation property

From	Thierry Reding <thierry.reding@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 5/7] dt-bindings: display: Add common rotation property
Date	2017-02-06 08:20 +0100
Message-ID	<t7LKG-1Lj-11@gated-at.bofh.it> (permalink)
References	<t5Jai-2Mv-23@gated-at.bofh.it> <t5Jai-2Mv-21@gated-at.bofh.it> <t67cC-tm-31@gated-at.bofh.it> <t6L0l-1tH-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On Fri, Feb 03, 2017 at 01:16:45PM +0100, Noralf Trønnes wrote:
> Thierry, please have a look at this.
> In which direction should we rotate to match how drm rotation works?
> 
> 
> Den 01.02.2017 18.41, skrev Rob Herring:
> > On Tue, Jan 31, 2017 at 05:03:17PM +0100, Noralf Trønnes wrote:
> > > Display panels can be oriented many ways, especially in the embedded
> > > world. The rotation property is a way to describe this orientation.
> > > The counter clockwise direction is chosen because that's what fbdev
> > > and drm use.
> > The h/w mounting is rotated counter clockwise, so the framebuffers'
> > contents are rotated clockwise, right?

Given that this describes the rotation of the panel, I think it should
be described in terms of how the panel is rotated, not how the
framebuffer needs to be rotated. Using counter-clockwise, as described
in this binding seems fine to me.

It would have to be up to fbdev and DRM/KMS to transform that into a
clockwise rotation for the framebuffer, CRTC, plane, ...

Ideally with some sort of helper.

Thierry

> > 
> > > Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
> > > ---
> > >   Documentation/devicetree/bindings/display/display.txt | 4 ++++
> > This is panel property, so bindings/display/panel/panel.txt.
> > 
> > >   1 file changed, 4 insertions(+)
> > >   create mode 100644 Documentation/devicetree/bindings/display/display.txt
> > > 
> > > diff --git a/Documentation/devicetree/bindings/display/display.txt b/Documentation/devicetree/bindings/display/display.txt
> > > new file mode 100644
> > > index 0000000..e2e6867
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/display/display.txt
> > > @@ -0,0 +1,4 @@
> > > +Common display properties
> > > +-------------------------
> > > +
> > > +- rotation:	Display rotation in degrees counter clockwise (0,90,180,270)
> > > -- 
> > > 2.10.2
> > > 
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe devicetree" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH v3 5/7] dt-bindings: display: Add common rotation property Noralf Trønnes <noralf@tronnes.org> - 2017-01-31 17:10 +0100
  Re: [PATCH v3 5/7] dt-bindings: display: Add common rotation property Rob Herring <robh@kernel.org> - 2017-02-01 18:50 +0100
    Re: [PATCH v3 5/7] dt-bindings: display: Add common rotation property Noralf Trønnes <noralf@tronnes.org> - 2017-02-03 13:20 +0100
      Re: [PATCH v3 5/7] dt-bindings: display: Add common rotation property Thierry Reding <thierry.reding@gmail.com> - 2017-02-06 08:20 +0100

csiph-web