Re: [PATCH V3 2/2] video: drm: exynos: Add device tree support

[Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

On Thu, Aug 16, 2012 at 03:38:09PM +0530, Leela Krishna Amudala wrote:
> Add device tree based discovery support for DRM-FIMD driver.
> 
> Signed-off-by: Leela Krishna Amudala <l.krishna-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> ---
>  Documentation/devicetree/bindings/fb/drm-fimd.txt |   80 +++++++++++++++++
>  drivers/gpu/drm/exynos/exynos_drm_fimd.c          |   95 ++++++++++++++++++++-
>  2 files changed, 173 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/fb/drm-fimd.txt
> 
> diff --git a/Documentation/devicetree/bindings/fb/drm-fimd.txt b/Documentation/devicetree/bindings/fb/drm-fimd.txt
> new file mode 100644
> index 0000000..8ad8814
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/fb/drm-fimd.txt
> @@ -0,0 +1,80 @@
> +* Samsung Display Controller using DRM frame work
> +
> +The display controller is used to transfer image data from memory to an
> +external LCD driver interface. It supports various color formats such as
> +rgb and yuv.
> +
> +Required properties:
> + - compatible: Should be "samsung,exynos5-drm" for fimd using DRM frame work.
> + - reg: physical base address of the controller and length of memory
> +   mapped region.
> + - interrupts: Three interrupts should be specified. The interrupts should be
> +   specified in the following order.
> +   - VSYNC interrupt
> +   - FIFO level interrupt
> +   - FIMD System Interrupt
> +
> + - samsung,fimd-display: This property should specify the phandle of the
> +   display device node which holds the video interface timing with the
> +   below mentioned 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)
> +     - Display panels Y resolution.

I started an approach to add a common description for displays:

https://patchwork.kernel.org/patch/1154751/https://patchwork.kernel.org/patch/1154751/

There are still comments to this approach, but I think rather than
inventing SoC specific bindings we should use a common binding.

Sascha

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