[PATCH 2/3] drm/exynos: add dt-binding documentation for rotator

[Chanho Park]

> -----Original Message-----
> From: Inki Dae [mailto:inki.dae at samsung.com]
> Sent: Tuesday, July 23, 2013 10:36 AM
> To: 'Chanho Park'; 'Mark Rutland'; 'Chanho Park'
> Cc: kgene.kim at samsung.com; linux-samsung-soc at vger.kernel.org;
> jy0922.shim at samsung.com; 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
> 
> 
> 
> > -----Original Message-----
> > From: Chanho Park [mailto:chanho61.park at samsusng.com]
> > Sent: Tuesday, July 23, 2013 10:22 AM
> > To: 'Mark Rutland'; '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; 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
> >
> > Hi Mark,
> > Thank you for your review.
> >
> > > -----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".
> > > > +  - 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?
> >
> > Yes. It seems to have ​​a mistake during copy and paste.
> > I'll modify it next patch.
> >
> > >
> > > > +  - 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? If thery're always the same, there's no need
> > > to describe in in the devicetree.
> >
> > I've checked the rotator limitation for all of exynos4 chipsets and
> > exynos5250.
> > As a result, these have same value.
> 
> Not true. See the Exynos4210 user manual again. At least, the manual
> says maximum size is 64k x 64k in case of Y components.

Yes. The exynos4210 has different maximum limits of RGB888/YCbCr420 2p
compared with any other  SoCs(exynos4x12/exynos5250).
I'll make a next patch with considering it.

Thanks

Best Regards,
Chanho Park.

> 
> > I think it seems to be better leave on static value.
> > I'll prepare next patches including your suggestion.
> >
> 
> So, you should consider such a little bit difference.
> 
> > Thanks
> >
> > Best Regards,
> > Chanho Park
> >
> > >
> > > Thanks,
> > > Mark.
> > >
> > > > +		};
> > > > +		rgb888 {
> > > > +			min_w = <8>;
> > > > +			min_h = <8>;
> > > > +			max_w = <8192>;
> > > > +			max_h = <8192>;
> > > > +			align = <2>;
> > > > +		};
> > > > +	};
> > > > --
> > > > 1.7.9.5
> > > >
> > > >
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> > > >