Re: [PATCH v2] video: s3c-fb: Add device tree support

On Fri, Mar 30, 2012 at 09:25:14PM +0530, Rabin Vincent wrote:

On Fri, Mar 30, 2012 at 11:23, Thomas Abraham [off-list ref] wrote:

quoted

+    - samsung,fimd-display: The fimd controller is interfaced with the a
+      display device such as a lcd panel. This property should specify the
+      phandle of the display device node. For a display device node that
+      represents a RGB type display interface, it is expected to specify the
+      video interface timing using the following properties.
+
+      - lcd-htiming: Specifies the horizontal timing for the overlay. The
+        horizontal timing includes four parameters in the following order.
+
+        - horizontal back porch (in number of lcd clocks)
+        - horizontal front porch (in number of lcd clocks)
+        - hsync pulse width (in number of lcd clocks)
+        - Display panels X resolution.
+
+      - lcd-vtiming: Specifies the vertical timing for the overlay. The
+        vertical timing includes four parameters in the following order.
+
+        - vertical back porch (in number of lcd lines)
+        - vertical front porch (in number of lcd lines)
+        - vsync pulse width (in number of lcd clocks)
+        - Y resolution.

In this old thread, it was suggested to use a raw EDID block to supply
timings, and since then a couple of drivers in mainline (sm501fb and
fsl-diu) are doing it that way:

http://lists.ozlabs.org/pipermail/linuxppc-dev/2010-February/080683.html

Shouldn't this driver be doing the same thing?  If not, shouldn't
whatever interface this is adding be provided in a common helper (like
that old patch was trying to add) so it's standardized between drivers?

+1

We need a generic binding for the data defined in "struct fb_videomode"
and a generic helper function to retrieve the data from device tree,
so that individual display driver does not have to invent their owns.

-- 
Regards,
Shawn