i.MX ProcessorsのトピックRe: IMX6Solo Dual LVDS Screen

IMX6Solo Dual LVDS Screen

guillaume_costa — Mon, 09 Aug 2021 10:05:36 GMT

Hello,

I have an IMX6Solo with 2 screens connected on Linux OS :

- LVDS multitouch screen (1024x600)

- RGB Screen (400x272)

I would like to have two separate screen, send different images to the two screens.

My problem is that only one screen is working correctly. The small one (RGB screen) and the large screen displays the same content as the RGB.

I wonder if the problem is not linked to the framebuffer or virtual console ? I have only one framebuffer, in /dev/fb0 (and /dev/fbcon). I can't declare two framebuffer, I tried in the device tree without success.

Thank you for the help,

Best Regards,

Re: IMX6Solo Dual LVDS Screen

igorpadykov — Mon, 09 Aug 2021 23:46:26 GMT

Hi Guillaume

one can look at digi "fb" tutorial and dts examples with different "mxcfb" configurations :

https://www.digi.com/resources/documentation/digidocs/90001945-13/reference/yocto/r_an_adding_custom_display.htm
https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm/boot/dts/imx6q-sabreauto.dts?h=lf-5.10.y

https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi?h=lf-5.10.y

Best regards
igor

Re: IMX6Solo Dual LVDS Screen

guillaume_costa — Tue, 10 Aug 2021 13:21:00 GMT

Hi,

The changes made by following your links changed nothing to my configuration. I always have one /dev/fb0 and the screens tried to display the same content. I already checked theses website my configuration seems to be okay.

I work on the kernel version 5.4.70, and after looking for the "mxc_sdb" driver wich is used in your exemples (by digi). I can't find this driver in my kernel. But, Kernel options in menuconfig seems correctly set...

- > Can you send me, your .config (configuration for your kernel), or/and a device tree exemple of two screens working on an imx6solo under 5.4.70 Kernel version ?

My goal is just to have two framebuffer and display each screen on each framebuffer.

Thank you for the help !

Guillaume

Re: IMX6Solo Dual LVDS Screen

guillaume_costa — Fri, 13 Aug 2021 08:27:16 GMT

The same clock is probed on the two screens, whereas (display 1 (9Mhz) and the lvds screen 2 should be at 52 Mhz)). I have set the display-timing correctly.

If someone has an idea.

Guillaume

Re: IMX6Solo Dual LVDS Screen

igorpadykov — Fri, 13 Aug 2021 12:27:12 GMT

may be useful to look on

https://variwiki.com/index.php?title=Dual_Display

https://variwiki.com/index.php?title=VAR-SOM-MX6_Dual_Displays

Best regards
igor