On Sunday 18 Sep 2016 13:01:16 Laurent Pinchart wrote:
On Thursday 08 Sep 2016 14:17:48 Maxime Ripard wrote:
Some boards have an entirely passive RGB to VGA bridge, based on either DACs or 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 Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com
.../bindings/display/bridge/rgb-to-vga-bridge.txt | 52 +++++ drivers/gpu/drm/bridge/Kconfig | 6 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/rgb-to-vga.c | 232 ++++++++++++++++ 4 files changed, 291 insertions(+) create mode 100644
Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt create mode 100644 drivers/gpu/drm/bridge/rgb-to-vga.c
diff --git a/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt new file mode 100644 index 000000000000..83a053fb51a0 --- /dev/null +++ b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt @@ -0,0 +1,52 @@ +Passive RGB to VGA bridge +-------------------------
+This binding is aimed for entirely passive RGB to VGA bridges that do not +require any configuration.
Couldn't it also support active RGB to VGA bridges that don't require any configuration ? It would seem a bit pointless to define a separate DT binding for them.
I'm thinking in particular about the ADV7123 (http://www.analog.com/media/en/technical-documentation/data-sheets/ADV7123.p...) that already has a DT binding. Would it be feasible to combine the two, and support both devices with a single driver ?
+Required properties:
+- compatible: Must be "rgb-to-vga-bridge"
+Required nodes:
+This device has two video ports. Their connections are modeled 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 = "rgb-to-vga-bridge";
- #address-cells = <1>;
- #size-cells = <0>;
- ports {
#address-cells = <1>;#size-cells = <0>;port@0 {#address-cells = <1>;#size-cells = <0>;reg = <0>;vga_bridge_in: endpoint {remote-endpoint = <&tcon0_out_vga>;};};port@1 {#address-cells = <1>;#size-cells = <0>;reg = <1>;vga_bridge_out: endpoint {remote-endpoint = <&vga_con_in>;};};- };
+};