imx8MP LVDS Display settings

Technical Support
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2

Hi eoin_oc1,

I have worked with IMX8QM before and had some problems with LVDS. I guess you should change your clock signal from dtb files. I will share my currently using dtb files as an example with you. Which OS do you use? is it Torizon? Or custom build like yocto, buildroot? Kindly, I generally suggest building buildroot and kernel separately because they can be controllable easily. In another case, Torizon has very good abilities if you may think to use it.

apalis-imx8_lvds_overlay.dts

// Enable a generic LVDS display.

/dts-v1/;
/plugin/;
/ {
compatible = “toradex,apalis-imx8”;
};

&ldb2 {
status = “okay”;
};

&ldb2_phy {
status = “okay”;
};

&panel_lvds {
status = “okay”;
};

imx8-apalis-v1.1.dtsi : you should change “clock frequency” in the “panel-timing” section according to your clock frequency. In addition to this other parameters should be changed according to your display specifications. For instance: width and height…

&ldb2_phy {
status = “okay”;
};

&ldb2 {
status = “okay”;
fsl;

lvds-channel@0 {
fsl,data-mapping = “spwg”;
fsl,data-width = <24>;
status = “okay”;

  port@1 {
  	reg = <1>;

  	lvds1_out: endpoint {
  		remote-endpoint = <&panel_lvds_in>;
  	};
  };

};
};

&panel_lvds {
status = “okay”;
data-mapping = “jeida-24”;
compatible = “panel-lvds”;
backlight = <&backlight>;

    width-mm = <211>;
    height-mm = <158>;

    panel-timing {
            clock-frequency = <65000000>;
  hactive = <1024>;
  vactive = <768>;
  hback-porch = <114>;
  hsync-len = <30>;
  hfront-porch = <16>;
  vback-porch = <32>;
  vsync-len = <3>;
  vfront-porch = <10>;
  hsync-active = <0>;
  vsync-active = <0>;
  de-active = <1>;
  pixelclk-active = <0>;

    };

    port {
                    panel_lvds_in: endpoint {
                            remote-endpoint = <&lvds1_out>;
                    };
            };

};

In addition to this, torizon comes with an HDMI overlay.dtb file as a default. So you should definitely change from overlay.dtb file in the /dev/mmcblk0p1 partition. If you have any other questions I would like to help please don’t hesitate about that but first, you should have a display unit.