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From: tomi.valkeinen@ti•com (Tomi Valkeinen)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH V2] video: implement a simple framebuffer driver
Date: Tue, 30 Apr 2013 10:39:43 +0300	[thread overview]
Message-ID: <517F753F.5090909@ti.com> (raw)
In-Reply-To: <1365043183-28905-1-git-send-email-swarren@wwwdotorg.org>

On 04/04/2013 05:39 AM, Stephen Warren wrote:
> A simple frame-buffer describes a raw memory region that may be rendered
> to, with the assumption that the display hardware has already been set
> up to scan out from that buffer.
> 
> This is useful in cases where a bootloader exists and has set up the
> display hardware, but a Linux driver doesn't yet exist for the display
> hardware.
> 
> Signed-off-by: Stephen Warren <swarren@wwwdotorg•org>
> ---
> v2: s/dumb/simple/ throughout. Provide more details on pixel format.
> 
> I ended up going with a separate FB driver:
> * DRM/KMS look much more complex, and don't provide any benefit that I can
>   tell for this simple driver.
> * Creating a separate driver rather than adjusting offb.c to work allows a
>   new clean binding to be defined, and doesn't require removing or ifdefing
>   PPC-isms in offb.c.
> ---
>  .../bindings/video/simple-framebuffer.txt          |   25 +++
>  drivers/video/Kconfig                              |   17 ++
>  drivers/video/Makefile                             |    1 +
>  drivers/video/simplefb.c                           |  234 ++++++++++++++++++++
>  4 files changed, 277 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/video/simple-framebuffer.txt
>  create mode 100644 drivers/video/simplefb.c
> 
> diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
> new file mode 100644
> index 0000000..3ea4605
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
> @@ -0,0 +1,25 @@
> +Simple Framebuffer
> +
> +A simple frame-buffer describes a raw memory region that may be rendered to,
> +with the assumption that the display hardware has already been set up to scan
> +out from that buffer.
> +
> +Required properties:
> +- compatible: "simple-framebuffer"
> +- reg: Should contain the location and size of the framebuffer memory.
> +- width: The width of the framebuffer in pixels.
> +- height: The height of the framebuffer in pixels.
> +- stride: The number of bytes in each line of the framebuffer.
> +- format: The format of the framebuffer surface. Valid values are:
> +  - r5g6b5 (16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b).
> +
> +Example:
> +
> +	framebuffer {
> +		compatible = "simple-framebuffer";
> +		reg = <0x1d385000 (1600 * 1200 * 2)>;
> +		width = <1600>;
> +		height = <1200>;
> +		stride = <(1600 * 2)>;
> +		format = "r5g6b5";
> +	};

I'm not an expert on DT, but I think the point of DT is to describe the
hardware. This doesn't describe the hardware at all.

 Tomi


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  parent reply	other threads:[~2013-04-30  7:39 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-04  2:39 [PATCH V2] video: implement a simple framebuffer driver Stephen Warren
2013-04-09  0:16 ` Andrew Morton
2013-04-09  3:16   ` Stephen Warren
2013-04-09  8:08   ` Geert Uytterhoeven
2013-04-11  9:56   ` Laurent Pinchart
2013-04-11 16:06     ` Stephen Warren
2013-04-11 20:06       ` Laurent Pinchart
2013-04-11 20:38         ` Stephen Warren
2013-04-29 20:56           ` Laurent Pinchart
2013-04-29 21:15     ` Tomasz Figa
2013-04-29 21:20       ` Laurent Pinchart
2013-04-29 21:31         ` Tomasz Figa
2013-04-29 21:40           ` Laurent Pinchart
2013-04-29 22:04             ` Arnd Bergmann
2013-04-29 22:23               ` Laurent Pinchart
2013-04-29 22:40                 ` Olof Johansson
2013-04-30  9:50                   ` Laurent Pinchart
2013-05-02 18:25               ` Stephen Warren
2013-05-02 18:35                 ` Geert Uytterhoeven
2013-05-03 10:06                 ` Laurent Pinchart
2013-05-07 21:33                   ` Andrew Morton
2013-05-08  2:36                     ` Stephen Warren
2013-05-08 19:28                       ` Olof Johansson
2013-05-08 20:58                       ` Rob Landley
2013-04-30  7:28       ` Tomi Valkeinen
2013-04-11 10:42 ` Geert Uytterhoeven
2013-04-11 16:10   ` Stephen Warren
2013-04-30  7:27 ` Tomi Valkeinen
2013-04-30 10:28   ` Arnd Bergmann
2013-04-30 11:42     ` Laurent Pinchart
2013-04-30 11:48       ` Tomi Valkeinen
2013-04-30 11:49         ` Laurent Pinchart
2013-04-30 11:46     ` Tomi Valkeinen
2013-05-03  5:40       ` Dave Airlie
2013-04-30  7:39 ` Tomi Valkeinen [this message]
2013-04-30 10:34   ` Arnd Bergmann
2013-04-30 14:38   ` Re[2]: " Alexander Shiyan
2013-04-30 15:07     ` Arnd Bergmann
2013-05-18 10:29 ` Alexandre Courbot
2013-05-20 15:25   ` Stephen Warren

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