[PATCH 3/3] ARM: dts: Add display timing node to exynos5250-arndale.dts

[Vikas Sajjan]

Hi Olof,


On 10 May 2013 11:51, Vikas Sajjan <vikas.sajjan at linaro.org> wrote:

> Hi Olof,
>
>
> On 10 May 2013 11:08, Olof Johansson <olof at lixom.net> wrote:
>
>> On Thu, May 9, 2013 at 7:55 PM, Vikas Sajjan <vikas.sajjan at linaro.org>
>> wrote:
>> > Hi Tomasz,
>> >
>> >
>> > On 10 May 2013 05:35, Tomasz Figa <tomasz.figa at gmail.com> wrote:
>> >>
>> >> Hi Vikas,
>> >>
>> >> On Wednesday 08 of May 2013 11:31:34 Vikas Sajjan wrote:
>> >> > Adds display timing node for a DP panel to Arndale Board DTS file
>> >> >
>> >> > Signed-off-by: Vikas Sajjan <vikas.sajjan at linaro.org>
>> >> > ---
>> >> >  arch/arm/boot/dts/exynos5250-arndale.dts |   16 ++++++++++++++++
>> >> >  1 file changed, 16 insertions(+)
>> >> >
>> >> > diff --git a/arch/arm/boot/dts/exynos5250-arndale.dts
>> >> > b/arch/arm/boot/dts/exynos5250-arndale.dts index f68b820..c831a5c
>> >> > 100644
>> >> > --- a/arch/arm/boot/dts/exynos5250-arndale.dts
>> >> > +++ b/arch/arm/boot/dts/exynos5250-arndale.dts
>> >> > @@ -459,4 +459,20 @@
>> >> >               samsung,lane-count = <4>;
>> >> >       };
>> >> >
>> >> > +     display-timings {
>> >> > +             native-mode = <&timing0>;
>> >> > +             timing0: timing at 0 {
>> >> > +                     /* 2560x1600 DP panel */
>> >> > +                     clock-frequency = <50000>;
>> >> > +                     hactive = <2560>;
>> >> > +                     vactive = <1600>;
>> >> > +                     hfront-porch = <48>;
>> >> > +                     hback-porch = <80>;
>> >> > +                     hsync-len = <32>;
>> >> > +                     vback-porch = <16>;
>> >> > +                     vfront-porch = <8>;
>> >> > +                     vsync-len = <6>;
>> >> > +             };
>> >> > +     };
>> >>
>> >> What display are those timings used for? Shouldn't they be placed
>> inside
>> >> node of that display?
>> >>
>> >
>> > This timing information will be used parsed by the FIMD probe with the
>> help
>> > of "Video Helper function"  as done in this link
>> >
>> >
>> https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm-exynos.git/commit/?h=exynos-drm-next&id=7f4596f4aebcc9fcf2d50d3fe398508d710c4dd0
>>
>> That function passes in a device node pointer to the FIMD device node,
>> and only looks for a display-timings node under there. Tomasz is
>> right, as far as I can tell.
>>
>> Placing display timings at the root of the device tree seems completely
>> wrong.
>>
>>         I referred this "
Documentation/devicetree/bindings/video/display-timing.txt" for example

            here it dosen't mention about whether display timings node can
be placed at the root of the device tree or NOT.
 Not sure how we should be placing the node then.


>
>
>> > Please refer to this patch which is used for exynos4412-origen and
>> > exynos5250-smdk5250 respectively in similar way
>> >
>> >
>> https://git.kernel.org/cgit/linux/kernel/git/kgene/linux-samsung.git/commit/?h=for-next&id=0207775d6ff7e6a6eddb9931f9328f0f0173a338
>> >
>> >
>> https://git.kernel.org/cgit/linux/kernel/git/kgene/linux-samsung.git/commit/?h=for-next&id=06c460b73f75894cabfb1f5277f27cddbc92745c
>>
>> That needs to be fixed up as well, thanks for pointing it out.
>>
>>
>> -Olof
>>
>
>
>
> --
> Thanks and Regards
>  Vikas Sajjan
>



-- 
Thanks and Regards
 Vikas Sajjan
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