can i.mx93 evkcm support dual display via hdmi and lvds

[Nobita]

Hello Sir,

    I have an i.mx 93 evkcm board, it works well when use only single display output by change the dtb in uboot:

via hdmi: default dtb imx93-11x11-evk.dtb is ok;

via lvds: in uboot, type following commands to change dtb

setenv fdtfile imx93-11x11-evk-boe-wxga-lvds-panel.dtb
saveenv

 both works well，but it only output by one display port，when lvds work，the hdmi output nothing，
I found that you disabled hdmi related node in imx93-11x11-evk-boe-wxga-lvds-panel.dts， so I write a new dts to check if it support dual display， here is the content：

#include "imx93-11x11-evk-boe-wxga-lvds-panel.dts"



&adv7535 {
    status = "okay";
};

&dphy {
    status = "okay";
};

&dsi {
    status = "okay";
};

 when I use my dts to boot the i.mx imx-yocto-bsp-6.1.36-2.1.0, it shows pictures on my lvds panel while nothing shows on my hdmi，but when the boot process runs to the point at weston starting，the log shows weston started failed， and my lvds panel display lost at the same time. the dmesg is in the attachment ng.txt.
Can you help me figure out my issue, can i.mx93 evkcm support dual display? if it should support dual display, how to configure it?

Sincerely.

[Nobita]

Hi, I see above message in the i.mx93 reference manaul, so how to drive the same output to multiple displays?

[Zhiming_Liu]

For clone mode, modify dts and make sure these three/two display interfaces are using same resolution.

From the internal test, the max resolution is decided LVDS limitation while using MIPI DSI and LVDS panel.

[Nobita]

Would you please show me the dts sample since my modification does not work.

[Zhiming_Liu]

Hi @Nobita 

I will reply you if i finish the patch.

[Nobita]

Okay, looking forward to your good news.

[Zhiming_Liu]

Hi @Nobita 

I got more information about the clone mode, the clone mode need two/three panels have same timing paramters. This is very hard for customer to find such panels. 

For evk hardware, it's very difficult to match different output device, adv7535+lvds panel, they have different clocks and timing.

The internal test can only run modetest, can't support weston.

If you can find two panels have same timing paramters, you can test it.

The root cause still be one lcdif interface in i.MX93.

BR

Zhiming

[Nobita]

Thank you for your response, appreciate your recent hard work.

BR

[Zhiming_Liu]

Asked the internal team, they lost the demo code, need finetune lvds clock and adv7535 clock. Let me try to reproduce this demo on MIPI and LVDS panel.

[shuyang_guan]

Hi, Zhiming,

I just saw this community post by accident. We have verify this feature using a i.MX93 14X14 board recently, you could refer this link:

https://community.nxp.com/t5/iMX-and-Vybrid-Support/Dual-display-on-i-MX93/ta-p/1788513?emcs_t=S2h8Z...

[Eddy1]

Hi：

The link is inaccessible.can i.mx93 can support dual display via hdmi and lvds?Could you provide the corresponding patch, please?

 

[shuyang_guan]

Hi @Eddy1 ,

i.MX93 doesn't support HDMI output directly (you can use a convert board to convert MIPI DSI or LVDS to HDMI). It can only support MIPI DSI, LVDS, or parallel screen directly. 

We have tried dual display using MIPI DSI and LVDS. The link is in private space. You can tell me email address then we can share you patches for reference offline.

BR

Shuyang

[Zhiming_Liu · Accepted solution]

Hi @Nobita 

There is only one lcdif in i.MX93, so the chip can’t support dual display interface (MIPI/LVDS/DPI-LCDIF)

One lcdif port

	display-subsystem {
		compatible = "fsl,imx-display-subsystem";
		ports = <&lcdif_disp>;
	};

Three display interfaces from display mux unit :