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authorMaxime Ripard <maxime.ripard@free-electrons.com>2016-09-30 16:37:06 +0200
committerArchit Taneja <architt@codeaurora.org>2016-10-10 10:58:44 +0530
commit56fe8b6f499167e3f9e0aafc0909efe9fb673323 (patch)
tree1cde29555ecc1adc74dc8454e8d949f551410dd6 /Documentation
parenta4fce9cb782ad340ee5576a38e934e5e75832dc6 (diff)
drm/bridge: Add RGB to VGA bridge support
Some boards have an entirely passive RGB to VGA bridge, based on DACs implemented by resistor ladders. Those might or might not have an i2c bus routed to the VGA connector in order to access the screen EDIDs. Add a bridge that doesn't do anything but expose the modes available on the screen, either based on the EDIDs if available, or based on the XGA standards. Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Archit Taneja <architt@codeaurora.org> Link: http://patchwork.freedesktop.org/patch/msgid/20160930143709.1388-3-maxime.ripard@free-electrons.com
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt48
1 files changed, 48 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
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+Dumb RGB to VGA DAC bridge
+---------------------------
+
+This binding is aimed for dumb RGB to VGA DAC based bridges that do not require
+any configuration.
+
+Required properties:
+
+- compatible: Must be "dumb-vga-dac"
+
+Required nodes:
+
+This device has two video ports. Their connections are modelled using the OF
+graph bindings specified in Documentation/devicetree/bindings/graph.txt.
+
+- Video port 0 for RGB input
+- Video port 1 for VGA output
+
+
+Example
+-------
+
+bridge {
+ compatible = "dumb-vga-dac";
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ vga_bridge_in: endpoint {
+ remote-endpoint = <&tcon0_out_vga>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ vga_bridge_out: endpoint {
+ remote-endpoint = <&vga_con_in>;
+ };
+ };
+ };
+};