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

Hi Olof,


On 10 May 2013 11:08, Olof Johansson [off-list ref] wrote:

On Thu, May 9, 2013 at 7:55 PM, Vikas Sajjan [off-list ref]
wrote:

quoted

Hi Tomasz,


On 10 May 2013 05:35, Tomasz Figa [off-list ref] wrote:

quoted

Hi Vikas,

On Wednesday 08 of May 2013 11:31:34 Vikas Sajjan wrote:

quoted

Adds display timing node for a DP panel to Arndale Board DTS file

Signed-off-by: Vikas Sajjan <redacted>
---
 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@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

quoted

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.

quoted

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

quoted

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