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authorStephen Warren <swarren@wwwdotorg.org>2013-05-24 15:55:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-24 16:22:51 -0700
commit26549c8d36a64d9130e4c0f32412be7ba6180923 (patch)
treea2b08793316a95ded04ea90fd6aabaa2d5dc9236 /Documentation
parentafe1bb73f8ed588ab6268c27c5a447fe0484e48f (diff)
downloadlinux-linaro-stable-26549c8d36a64d9130e4c0f32412be7ba6180923.tar.gz
drivers/video: implement a simple framebuffer driver
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. Examples use-cases include: * The built-in LCD panels on the Samsung ARM chromebook, and Tegra devices, and likely many other ARM or embedded systems. These cannot yet be supported using a full graphics driver, since the panel control should be provided by the CDF (Common Display Framework), which has been stuck in design/review for quite some time. One could support these panels using custom SoC-specific code, but there is a desire to use common infra-structure rather than having each SoC vendor invent their own code, hence the desire to wait for CDF. * Hardware for which a full graphics driver is not yet available, and the path to obtain one upstream isn't yet clear. For example, the Raspberry Pi. * Any hardware in early stages of upstreaming, before a full graphics driver has been tackled. This driver can provide a graphical boot console (even full X support) much earlier in the upstreaming process, thus making new SoC or board support more generally useful earlier. [akpm@linux-foundation.org: make simplefb_formats[] static] Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Olof Johansson <olof@lixom.net> Cc: Rob Clark <robclark@gmail.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Tomasz Figa <tomasz.figa@gmail.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/video/simple-framebuffer.txt25
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+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";
+ };