Hi,
I am trying to bring up LVDS on Apalis evaluation board V1.1C, which has an
Apalis-imx8 SoM. To do that, I am modifying the device tree file to enable
LVDS and to include the display timing characteristics. The display is a
7" one from Riverdi (RVT35HHTNWN00 - Riverdi
display-rvt70hslfwca0-7-inch-projected-capacitive-touch-panel-air-bonding-
atouch-lvds-frame/).
According to Toradex (High performance, low power Embedded Computing Systems | Toradex Developer Center
output-resolution-and-timings-linux), LVDS interface has Device-Tree Node
Reference “ldb2”, so my current device tree file looks like this:
// SPDX-License-Identifier: GPL-2.0+ OR X11
/*
- Copyright 2020 Toradex
*/
/dts-v1/;
#include “fsl-imx8qm-apalis-v1.1.dtsi”
#include “fsl-imx8qm-apalis-eval.dtsi”
/ {
model = “Toradex Apalis iMX8QM/QP V1.1 on TracPilot Board”;
compatible = “toradex,apalis-imx8qm-v1.1-eval”, “toradex
,apalis-imx8qm-eval”,
“toradex,apalis-imx8qm”, “fsl,imx8qm”;
riverdi_panel {
compatible = “riverdi_panel”;
backlight = <&backlight;>;
display-timings {
lvds {
clock-frequency = <51200000>;
hactive = <1024>;
vactive = <600>;
hfront-porch = <160>;
hsync-len = <140>;
hback-porch = <160>;
vfront-porch = <12>;
vsync-len = <20>;
vback-porch = <23>;
hsync-active = <0>;
vsync-active = <0>;
pixelclk-active = <0>;
};
};
port {
riverdi_panel_in: endpoint {
remote-endpoint = <&lvds1;_out>;
};
};
};
};
&ldb1; {
status = “disabled”;
};
&ldb2; {
status = “okay”;
lvds-channel@0 {
fsl,data-mapping = “spwg”;
fsl,data-width = <24>;
status = “okay”;
port@1 {
reg = <1>;
lvds1_out: endpoint {
remote-endpoint = <&riverdi;_panel_in>;
};
};
};
};
However, there is not clock signal and there are no LVDS signals on the LVDS
interface (X13). I can only see DC offset values on some of the LVDS signal
pins, so I am assuming its because there is no clock signal. What am I doing
wrong here? I would really appreciate your feedback.
Thank you very much for your help and I look forward to you reply.
Best regards,
Adam Barghati
