[PATCH 2/3] drm/exynos: add dt-binding documentation for rotator
Inki Dae
inki.dae at samsung.com
Mon Jul 22 06:31:42 PDT 2013
> -----Original Message-----
> From: linux-samsung-soc-owner at vger.kernel.org [mailto:linux-samsung-soc-
> owner at vger.kernel.org] On Behalf Of Lucas Stach
> Sent: Monday, July 22, 2013 9:47 PM
> To: Inki Dae
> Cc: 'Mark Rutland'; 'Chanho Park'; linux-samsung-soc at vger.kernel.org;
> devicetree-discuss at lists.ozlabs.org; sw0312.kim at samsung.com; dri-
> devel at lists.freedesktop.org; kyungmin.park at samsung.com;
> kgene.kim at samsung.com; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH 2/3] drm/exynos: add dt-binding documentation for
> rotator
>
> Am Montag, den 22.07.2013, 21:37 +0900 schrieb Inki Dae:
> >
> > > -----Original Message-----
> > > From: Mark Rutland [mailto:mark.rutland at arm.com]
> > > Sent: Monday, July 22, 2013 5:48 PM
> > > To: Chanho Park
> > > Cc: inki.dae at samsung.com; kgene.kim at samsung.com; linux-samsung-
> > > soc at vger.kernel.org; jy0922.shim at samsung.com; devicetree-
> > > discuss at lists.ozlabs.org; sw0312.kim at samsung.com; dri-
> > > devel at lists.freedesktop.org; kyungmin.park at samsung.com; linux-arm-
> > > kernel at lists.infradead.org
> > > Subject: Re: [PATCH 2/3] drm/exynos: add dt-binding documentation for
> > > rotator
> > >
> > > On Mon, Jul 22, 2013 at 07:49:26AM +0100, Chanho Park wrote:
> > > > This patch adds a dt-binding document for exynos rotator. It
> describes
> > > which
> > > > nodes should be defined to use the rotator.
> > > >
> > > > Signed-off-by: Chanho Park <chanho61.park at samsung.com>
> > > > Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> > > > ---
> > > > .../bindings/drm/exynos/samsung-rotator.txt | 35
> > > ++++++++++++++++++++
> > > > 1 file changed, 35 insertions(+)
> > > > create mode 100644
> > > Documentation/devicetree/bindings/drm/exynos/samsung-rotator.txt
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/drm/exynos/samsung-
> > > rotator.txt b/Documentation/devicetree/bindings/drm/exynos/samsung-
> > > rotator.txt
> > > > new file mode 100644
> > > > index 0000000..6b1d704
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/drm/exynos/samsung-
> rotator.txt
> > > > @@ -0,0 +1,35 @@
> > > > +* Samsung Image Rotator
> > > > +
> > > > +Required properties:
> > > > + - compatible : value should be the "samsung,exynos4210".
> >
> > Please, add more compatible strings for other SoC.
> >
> > > > + - reg : Physical base address of the IP registers and length of
> > > memory
> > > > + mapped region.
> > > > + - interrupts : interrupt number to the CPU.
> > > > + - clocks : clock number of exynos4 rotator clock.
> > > > + - clocks : clock name of rotator
> > >
> > > clock-names?
> > >
> > > > + - status : "okay" or "disabled"
> > > > + - limit table for image formats : min_w/min_h/max_w/max_h for
> min/max
> > > of image
> > >
> > > Limit table? This doesn't seem to be a well-defined binding, and it
> > > seems like a relatively generic thing to describe.
> > >
> > > > +
> > > > +Example:
> > > > + rotator: rotator at 12810000 {
> > > > + compatible = "samsung,exynos4210-rotator";
> > > > + reg = <0x12810000 0x1000>;
> > > > + interrupts = <0 83 0>;
> > > > + clocks = <&clock 278>;
> > > > + clock-names = "rotator";
> > > > + status = "disabled";
> > > > + ycbcr420_2p {
> > >
> > > Which names are allowed for these subnodes?
> > >
> > > > + min_w = <32>;
> > > > + min_h = <32>;
> > > > + max_w = <32768>;
> > > > + max_h = <32768>;
> > > > + align = <3>;
> > >
> > > min-width, min-height, max-width, max-height? What units are they in?
> > >
> > > What does alignment specify exactly?
> > >
> > > Are these a configurable part of the rotator hardware, or are these
> > > values always the same?
> >
> > Right, that seems like configurable part. At least, min_w/h and max_w/h
> can
> > be different values according to SoC and pixel formats so they should be
> > described enough in this dt-binding document file.
> >
> Is there really this much configurability? Could each of those values be
> a different on different SoCs
Not much but Yes. Rotator devices of Exynos SoC support various pixel formats; RGB888, RGB565, YUV422, YUV420-2Plane, and YUV420-3Plane, and each of these pixel formats could be different limitation to minimum and maximum sizes.
For example, the below shows the limitation to Rotator device of Exynos4412 SoC according to pixel formats,
Image format Minimum size Maximum size
RGB888 8x8 8kx8k
RGB565 16x16 16kx16k
YUV422 16x16 16kx16k
YUV420 2-Plane 32x32 32kx32k(in case of Y components)
YUV420 3-Plane 64x32 32kx32k(in case of Y components)
And, I guess those limitations are slightly different according to Exynos SoC versions as long as I know.
Thanks,
Inki Dae
> , or could you just extract those values
> from the SoC/rotator hardware version and thus the DT compatible string?
>
> >
> > > If thery're always the same, there's no need to
> > > describe in in the devicetree.
> > >
> > > Thanks,
> > > Mark.
> > >
> > > > + };
> > > > + rgb888 {
> > > > + min_w = <8>;
> > > > + min_h = <8>;
> > > > + max_w = <8192>;
> > > > + max_h = <8192>;
> > > > + align = <2>;
> > > > + };
> > > > + };
> > > > --
> > > > 1.7.9.5
> > > >
> > > >
> > > > _______________________________________________
> > > > linux-arm-kernel mailing list
> > > > linux-arm-kernel at lists.infradead.org
> > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> > > >
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Pengutronix e.K. | Lucas Stach |
> Industrial Linux Solutions | http://www.pengutronix.de/ |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-
> soc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
More information about the dri-devel
mailing list