Hello James,
LVDS is configured from the device tree and the overlays. While it is possible to override the mode (timing and resolution) from the command line we recommend configuring everything in the device tree and/or the overlay file.
The ldb node and its lvds-channel child nodes represent the bridge that creates the LVDS signals.
Set fsl,data-mapping and fsl,data-width in the lvds-channel node according to the color mapping and color depth of your panel.
Valid combinations are:
| fsl,data-mapping |
fsl,data-width |
data-mapping (panel-lvds node) |
| spwg |
18 |
jeida-18 |
| spwg |
24 |
vesa-24 |
| jeida |
24 |
jeida-24 |
(If your display is jeida 18, use the identical spwg 18 combinations)
Specify the property 'fsl,dual-channel;' in the ldb node if you want the ldb in dual channel mode, don't specify it for single-channel mode.
The connected panel is represented in the device tree in its own node. That node references the used LDB/LVDS channel through its node 'port'.
One can either use the panel-simple or the panel-lvds driver, both options are outlined below.
Specify detailed timings in the panel node:
With the "panel-lvds" you can specify detailed timings in the device tree. This driver additionally requires you to specify the property 'data-mapping'. See the required value in the color mapping table above.
panel_lvds: panel-lvds {
compatible = "panel-lvds";
backlight = <&backlight>;
data-mapping = "jeida-18";
width-mm = <345>;
height-mm = <194>;
panel-timing {
clock-frequency = <138500000>;
hactive = <1920>;
vactive = <1080>;
hfront-porch = <48>;
hsync-len = <32>;
hback-porch = <80>;
vfront-porch = <3>;
vsync-len = <5>;
vback-porch = <23>;
hsync-active = <0>;
vsync-active = <0>;
pixelclk-active = <0>;
};
port {
panel_lvds_in: endpoint {
remote-endpoint = <&lvds1_out>;
};
};
};
The LVDS can not Display always ON since it is not plugged it have to send the color bar.
Regards
