i.MX ProcessorsのトピックRe: IMX8MP EVK native LVDS panel example device tree source

IMX8MP EVK native LVDS panel example device tree source

ufnguru — Tue, 20 Jun 2023 18:47:28 GMT

Can anyone provide an example of a device tree file that supports a single native LVDS panel on either LVDS0 or LVDS1 connector? I am trying to use a single native LVDS panel on either LVDS0 or LVDS1 connector. When I try this DTB I lose the HDMI and the LVDS panel does not work.

Re: IMX8MP EVK native LVDS panel example device tree source

Bio_TICFSL — Wed, 21 Jun 2023 15:29:17 GMT

Hello,

In you bsp come with different dtb that you can use as example imx8mp-evk-jdi-wuxga-lvds-panel.dts. Also please take a look at:

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/Add-i-MX8MP-LVDS-driver-in-uboot/ta-p/1434826

Regards

Re: IMX8MP EVK native LVDS panel example device tree source

ufnguru — Wed, 21 Jun 2023 17:57:18 GMT

I'm convinced you did not even look at my file. Also, the imx8mp-evk-jdi-wuxga-lvds-panel.dts would never work unless the panel was one of those. My file works for all generic native panels on LVDS0 connector. It does not work on LVDS1 and I want it to work on LVDS1 what do I change?

Re: IMX8MP EVK native LVDS panel example device tree source

ufnguru — Thu, 22 Jun 2023 17:07:48 GMT

Here is my solution for a generic native LVDS panel on LVDS1, it works great:

#include "imx8mp-evk.dts"

/ {

lvds1_panel {

compatible = "panel-lvds";

status = "okay";

backlight = <&lvds_backlight>;

data-mapping = "vesa-24";

width-mm = <216>;

height-mm = <135>;

panel-timing {

clock-frequency = <72400000>;

hactive = <1280>;

vactive = <800>;

hback-porch = <80>;

hfront-porch = <48>;

vback-porch = <3>;

vfront-porch = <29>;

hsync-len = <1>;

vsync-len = <6>;

};

port {

panel1_lvds_in: endpoint {

remote-endpoint = <&lvds1_out>;

};

&ldb {

status = "okay";

lvds-channel@1 {

fsl,data-mapping = "spwg";

fsl,data-width = <24>;

status = "okay";

port@1 {

reg = <1>;

lvds1_out: endpoint {

remote-endpoint = <&panel1_lvds_in>;

};

Re: IMX8MP EVK native LVDS panel example device tree source

Wobaffet — Sun, 08 Oct 2023 15:26:57 GMT

Hello, I am trying to also intilize my LVDS display for my custom board also. I've used similar DT config like below, but I get:

root@imx8mp-lpddr4-evk:~# /usr/bin/weston --backend=drm-backend.so --shell=fullscreen-shell.so --no-clients-resize Date: 2022-11-08 UTC [14:04:39.947] weston 11.0.1 https://wayland.freedesktop.org Bug reports to: https://gitlab.freedesktop.org/wayland/weston/issues/ Build: lf-6.1.1-1.0.0+ [14:04:39.947] Command line: /usr/bin/weston --backend=drm-backend.so --shell=fullscreen-shell.so --no-clients-resize [14:04:39.947] OS: Linux, 6.1.1+gcc0d1d210bdd, #1 SMP PREEMPT Thu Mar 2 14:54:17 UTC 2023, aarch64 [14:04:39.947] Flight recorder: enabled [14:04:39.947] Using config file '/etc/xdg/weston/weston.ini' [14:04:39.947] Output repaint window is 16 ms maximum. [14:04:39.948] Loading module '/usr/lib/libweston-11/drm-backend.so' [14:04:39.953] initializing drm backend [14:04:39.953] Trying logind launcher... [14:04:39.953] logind: failed to get session seat [14:04:39.953] logind: cannot setup systemd-logind helper error: (No data available), using legacy fallback [14:04:39.953] fatal: your system should either provide the logind D-Bus API, or use seatd. [14:04:39.953] fatal: failed to create compositor backend Internal warning: debug scope 'drm-backend' has not been destroyed.

/ { lvds0_panel { compatible = "panel-lvds"; fsl,data-mapping="spwg"; width-mm=<216>; height-mm=<135>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_lvds>; gpio = <&gpio1 10 GPIO_ACTIVE_HIGH &gpio1 11 GPIO_ACTIVE_HIGH>; panel-timing{ clock-frequency=<74250000>; hactive=<1280>; vactive=<800>; hfront-porch=<53>; hback-porch=<53>; hsync-len=<54>; vfront-porch=<8>; vback-porch=<8>; vsync-len=<7>; de-active=<1>; }; port { panel_lvds_in: endpoint { remote-endpoint = <&lvds_out>; }; }; }; }; /delete-node/ &lvds_bridge; /delete-node/ &pwm2; /delete-node/ &lvds_backlight; &ldb { status = "okay"; lvds-channel@0 { status="okay"; fsl,data-mapping = "spwg"; /delete-node/ port@1; port@1 { reg = <1>; lvds_out: endpoint { remote-endpoint = <&panel_lvds_in>; }; }; }; }; &iomuxc{ pinctrl_lvds:lvdsgrp { fsl,pins=< MX8MP_IOMUXC_GPIO1_IO10__GPIO1_IO10 0x1c0 MX8MP_IOMUXC_GPIO1_IO11__GPIO1_IO11 0x1c0 >; }; };

What am I missing? Thank you in advance!

Re: IMX8MP EVK native LVDS panel example device tree source

gigli_korg — Fri, 19 Apr 2024 14:53:31 GMT

Hi ufnguru,

since I have some troubles on LVDS of iMX8MP board, I am navigating on several source of information, this thread included.

As suggestion, I recommend to you read the following documentation on kernel sources (repo is https://github.com/nxp-real-time-edge-sw/real-time-edge-linux, branch is linux_6.1.22):

[1] - $ROOT/Documentation/devicetree/bindings/display/imx/ldb.txt
[2] - $ROOT/Documentation/devicetree/bindings/display/bridge/fsl,ldb.yaml

They refers to two different kernel configuration options, hence two different source files, but with the same "compatible" property ""

In a short sentences dotted list list I understood the followings:
a- ldb component has 3 ports:
port@0 is the input port, linked with lcdif2 module
port@1 is an output port, linked with lvds0 phy and external module
port@2 is an other output port, linked with lvds1 phy and external module
b- ldb component has two channel
c- each ldb channel, imx8mp, has an output port linked to panlel/displayexternal-bridge

Hence, I suppose
- for LVDS0 output, the node "lvds-channel@0" shall have defined two subnodes: port@0 and port@1
- for LVDS1 output, the node "lvds-channel@1" shall have defined two subnodes: port@0 and port@2

I hope some NXP people can confirm (or not) my assertions.

Hoping to be useful.