> -----Original Message----- > From: linux-samsung-soc-owner@xxxxxxxxxxxxxxx [mailto:linux-samsung-soc- > owner@xxxxxxxxxxxxxxx] On Behalf Of Tomasz Figa > Sent: Tuesday, July 23, 2013 4:29 AM > To: Sylwester Nawrocki > Cc: Inki Dae; 'Chanho Park'; 'Lucas Stach'; 'Mark Rutland'; linux-samsung- > soc@xxxxxxxxxxxxxxx; devicetree-discuss@xxxxxxxxxxxxxxxx; > sw0312.kim@xxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; > kyungmin.park@xxxxxxxxxxx; kgene.kim@xxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH 2/3] drm/exynos: add dt-binding documentation for > rotator > > On Monday 22 of July 2013 16:00:22 Sylwester Nawrocki wrote: > > On 07/22/2013 03:31 PM, Inki Dae wrote: > > >> ---Original Message----- > > >> > > >> > From: linux-samsung-soc-owner@xxxxxxxxxxxxxxx > > >> > [mailto:linux-samsung-soc- owner@xxxxxxxxxxxxxxx] On Behalf Of > > >> > Lucas Stach > > >> > Sent: Monday, July 22, 2013 9:47 PM > > >> > To: Inki Dae > > >> > Cc: 'Mark Rutland'; 'Chanho Park'; > > >> > linux-samsung-soc@xxxxxxxxxxxxxxx; > > >> > devicetree-discuss@xxxxxxxxxxxxxxxx; sw0312.kim@xxxxxxxxxxx; dri- > > >> > devel@xxxxxxxxxxxxxxxxxxxxx; kyungmin.park@xxxxxxxxxxx; > > >> > kgene.kim@xxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > > >> > 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@xxxxxxx] > > >>>> > > > Sent: Monday, July 22, 2013 5:48 PM > > >>>> > > > To: Chanho Park > > >>>> > > > Cc: inki.dae@xxxxxxxxxxx; kgene.kim@xxxxxxxxxxx; > > >>>> > > > linux-samsung- > > >>>> > > > soc@xxxxxxxxxxxxxxx; jy0922.shim@xxxxxxxxxxx; devicetree- > > >>>> > > > discuss@xxxxxxxxxxxxxxxx; sw0312.kim@xxxxxxxxxxx; dri- > > >>>> > > > devel@xxxxxxxxxxxxxxxxxxxxx; kyungmin.park@xxxxxxxxxxx; > > >>>> > > > linux-arm- > > >>>> > > > kernel@xxxxxxxxxxxxxxxxxxx > > >>>> > > > 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@xxxxxxxxxxx> > > >>>>> > > > > Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > > >>>>> > > > > --- > > >>>>> > > > > > > >>>>> > > > > .../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@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? > > My gut feeling is that those constraints could be well defined > > in the driver as static data and selected by the compatible property. > > Defining this in Device Tree may easily get out of control, when the > > limits become dependant on more parameters. > > > > Whether devices should be described in much detail in DT rather than > > using multiple compatible strings had been discussed multiple times, > > for instance please see thread [1]. > > +1 > > The binding should not describe hardware functionality and how it works, > but rather what hardware it is, unless it is really necessary. Good comments. Agree. Thanks, Inki Dae > In this > case this information can be placed in per-compatible static driver data, > so there is no such need. > > Best regards, > Tomasz > > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung- > soc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
