From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: dri-devel@lists.freedesktop.org
Cc: "Hean Loong, Ong" <hean.loong.ong@intel.com>,
        Rob Herring <robh+dt@kernel.org>, Dinh Nguyen <dinguyen@kernel.org>,
        Daniel Vetter <daniel.vetter@intel.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Ong@freedesktop.org
Subject: Re: [PATCHv4 1/3] ARM:dt-bindings Intel FPGA Video and Image Processing Suite
Date: Tue, 01 Aug 2017 17:32:54 +0300
Message-ID: <13319407.idzLhy4OWn@avalon>
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Hi Hean Loong,

Thank you for the patch.

On Tuesday 01 Aug 2017 10:31:32 Hean Loong, Ong wrote:
> From: Ong Hean Loong <hean.loong.ong@intel.com>
> 
> Device tree binding for Intel FPGA Video and Image
> Processing Suite. The binding involved would be generated
> from the Altera (Intel) Qsys system. The bindings would
> set the max width, max height, buts per pixel and memory
> port width. The device tree binding only supports the Intel
> Arria10 devkit and its variants. Vendor name retained as
> altr.
> 
> Signed-off-by: Ong, Hean Loong <hean.loong.ong@intel.com>
> ---
>  .../devicetree/bindings/display/altr,vip-fb2.txt   | 39 ++++++++++++++++++
>  1 file changed, 39 insertions(+
>  create mode 100644
>  Documentation/devicetree/bindings/display/altr,vip-fb2.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/altr,vip-fb2.txt
> b/Documentation/devicetree/bindings/display/altr,vip-fb2.txt new file mode
> 100644
> index 0000000..c4338d9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/altr,vip-fb2.txt
> @@ -0,0 +1,39 @@
> +Intel Video and Image Processing(VIP) Frame Buffer II bindings
> +
> +Supported hardware: Arria 10 and above with display port IP
> +
> +The hardware associated with this device tree is a SoC FPGA. Where there is
> an ARM controller +and a FPGA device. The ARM controller would host the
> Linux OS while the FPGA device runs on its +individual IP firmware.

DT bindings should not be OS-specific, you shouldn't mention Linux here.

> In the
> Intel VIP Frame Buffer II the ARM controller would be +driving data from
> the Linux OS to the FPGA device programmed with the Frame Buffer II IP +to
> render pixels to be streamed to the Display Port connector.
> +
> +The Frame Buffer II device is a simple frame buffer device. The device
> contains the display +properties and the bridge or connector register. The
> output for this device currently +is a dedicated to a single Display Port.
> Currently the max resolution supported is 1280 x 720 at +60Hz.
> +
> +More information the FPGA video IP component can be acquired from
> +https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/literature/
> ug/ug_vip.pdf +
> +
> +New bindings:
> +=============
> +Required properties:
> +----------------------------
> +- compatible: "altr,vip-frame-buffer-2.0"
> +- reg: Physical base address and length of the framebuffer controller's
> +  registers.
> +- altr,max-width: The width of the framebuffer in pixels.
> +- altr,max-height: The height of the framebuffer in pixels.

The properties hint that those are the maximum values, but the descriptions 
don't match. One of the two needs to be fixed.

> +- altr,mem-port-width = the bus width of the avalon master port on the
> frame reader
> +
> +Example:
> +----------------------------
> +       dp_0_frame_buf: display-controller@100000280 {
> +                       compatible = "altr,vip-frame-buffer-2.0";
> +                       reg = <0x00000001 0x00000280 0x00000040>;
> +                       altr,max-width = <1280>;
> +                       altr,max-height = <720>;
> +                       altr,mem-port-width = <128>;
> +       };

-- 
Regards,

Laurent Pinchart